A contemporary view of platelet-rich plasma therapies: moving toward refined clinical protocols and precise indications

Intraarticular leukocyte-poor platelet-rich plasma injection is more effective than intraarticular hyaluronic acid injection in the treatment of knee osteoarthritis: a systematic review and meta-analysis of 12 randomized controlled trials

PURPOSE

We aim to compare the clinical effects of intraarticular leukocyte-poor platelet-rich plasma (LP-PRP) injection with those of intraarticular hyaluronic acid (HA) injection in adult patients with knee osteoarthritis.

METHODS

Two authors independently reviewed databases, including PubMed, Web of Science, and the Cochrane Library. Only randomized controlled trials (RCTs) were included in our meta-analysis. Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores (WOMAC total, pain, stiffness, and physical function scores), visual analog scale (VAS) scores, EQ-VAS scores, International Knee Documentation Committee (IKDC) scores, and adverse events were used as outcome measurements to evaluate the efficacy of LP-PRP and HA treatment.

RESULTS

After screening 377 potential articles, 12 RCTs were included in this systemic review and meta-analysis. The WOMAC total scores and WOMAC physical function scores of the LP-PRP group were better than those of the HA group at 6 and 12 months. VAS scores of the LP-PRP group were better than those of the HA group at 3, 6, and 12 months. The LP-PRP group showed a better outcome of IKDC scores than the HA group at 6 months. There was no significant difference in adverse events between the LP-PRP and HA groups.

CONCLUSION

Intraarticular injections of LP-PRP showed better overall outcomes, such as WOMAC total scores, WOMAC physical function scores, VAS scores, and IKDC scores, compared with HA for adult patients with knee osteoarthritis at 6- and 12-month follow-up periods. Also, LP-PRP showed better pain relief compared with HA at 3-, 6-, and 12-month follow-up periods. Intraarticular LP-PRP improves pain relief and overall outcomes in patients with knee osteoarthritis.

Therapeutic interventions of platelet-rich plasma versus corticosteroid injections for lumbar radicular pain: a systematic review and meta-analysis

OBJECTIVE

Although epidural corticosteroid injections (ESIs) provide short-term relief for lumbar radicular pain caused by disc herniation, concerns remain regarding their long-term efficacy and complications. Platelet-rich plasma (PRP), with its dual anti-inflammatory and regenerative properties, is a promising alternative, but the comparative evidence between the two treatments remains inconclusive.

METHODS

A systematic search was conducted in PubMed, Embase, Web of Science, and the Cochrane Library, with a cutoff date of January 10, 2025. The primary outcomes were the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores. The risk of bias in the included studies was assessed using Cochrane ROB and ROBINS-I. The primary outcome measures were analyzed by evaluating standardized mean differences (SMDs).

RESULTS

A total of seven studies (four randomized controlled trials and three prospective studies) were included in the meta-analysis, comprising 416 patients. The results indicated that corticosteroids significantly reduced ODI scores at the initial follow-up (4 weeks) (SMD = 0.48, 95% CI: 0.20 to 0.75, p = 0.0008, I² = 15%), with no significant differences observed in VAS and ODI scores between the two groups at other time points. The complication rates for the PRP and corticosteroid groups were reported, with no severe adverse events reported.

CONCLUSIONS

Compared to PRP, corticosteroid injections showed significant early functional improvements in patients. Although no significant differences in pain and functional improvements were observed between the PRP and corticosteroid groups at other follow-up time points, future studies are needed to assess the efficacy and safety of PRP versus corticosteroid injections in treating lumbar radicular pain by standardizing PRP preparation, extending follow-up durations, and increasing sample sizes.

Efficacy of platelet-rich plasma use as an adjunctive treatment in autologous osteochondral transplantation for patients with osteochondral lesions of the talus accompanied by chronic lateral ankle instability

BACKGROUND

Autologous osteochondral transplantation (AOT) combined with biological agents is an advanced technique for treating osteochondral lesions. Therefore, this study aimed to explore the effect of combining platelet-rich plasma (PRP) treatment with AOT on postoperative functional and magnetic resonance imaging (MRI) outcomes in patients with osteochondral lesions of the talus (OLTs) accompanied by chronic lateral ankle instability (CLAI).

METHODS

This retrospective study had a minimum follow-up period of 1 year. Thiry-nine patients with CLAI who underwent AOT between 2019 and 2023 were included in this study. Of these, 21 and 18 received AOT combined with PRP treatment (AOT + PRP group) and AOT alone (AOT-alone group), respectively. Preoperative and postoperative follow-up assessments were performed using the visual analog scale (VAS), American Orthopedic Foot and Ankle Society (AOFAS), and foot and ankle ability measure-sport scale (FAAM-sport scale). The final follow-up MRI was evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 ankle scoring system.

RESULTS

Both groups showed a significant reduction in VAS scores and significant improvements in AOFAS and FAAM-sport scale scores at the final follow-up compared with the preoperative values. No significant differences were observed in the final follow-up VAS, AOFAS, FAAM-sport scale, and MOCART 2.0 ankle scores between the groups. However, significant between-group differences were found at postoperative months 1 (P < 0.001) and 3 (P = 0.031) for VAS scores and at postoperative month 3 for FAAM-sport scale scores (P = 0.005). The AOT + PRP group showed significantly better final follow-up scores for the "surface of the repair tissue" on the MOCART 2.0 ankle score system than the AOT-alone group (P = 0.029).

CONCLUSIONS

PRP did not result in significantly superior outcomes when used as an adjunct to AOT compared to AOT alone in the setting of concomitant OLTs and CLAI.

Effect of Patient Age on Platelet-Rich Plasma (PRP) and Fibrin Treatments for Skin Density and Thickness: A Single-Center Ultrasound Study

OBJECTIVE

This study aimed to establish a reproducible protocol for obtaining four plasma fractions (autologous platelet-rich plasma (C-PRP, PRP LCC) and platelet-rich fibrin (I-PRF, F-PRF)) from a single blood draw and to evaluate their effectiveness in enhancing skin density and thickness in facial aesthetic treatments across different age groups.

METHODOLOGY

Twenty participants aged 30-60 years received three treatments at 4-6 week intervals, with C-PRP, PRP LCC, I-PRF, and F-PRF injections in targeted facial areas. Ultrasound measurements provided an objective method to assess the outcomes, and statistical analysis evaluated the changes in skin density and thickness. A comprehensive literature review contextualized our findings within the broader scientific discourse on PRP and PRF applications in aesthetic medicine.

RESULTS

The protocol successfully yielded four distinct plasma fractions from a single blood draw. Ultrasound and statistical analyses demonstrated significant improvements in skin density and thickness, particularly in the lower eyelid area. These improvements were consistent across all the age groups, suggesting that the therapy's effectiveness is independent of age. The findings also align with previous research, underscoring PRP's and PRF's roles in stimulating fibroblast activity, promoting collagen synthesis, and enhancing skin quality.

A meta-analysis and systematic review of the clinical efficacy and safety of platelet-rich plasma combined with hyaluronic acid (PRP + HA) versus PRP monotherapy for knee osteoarthritis (KOA)

INTRODUCTION

KOA, a chronic degenerative joint disease, is commonly treated with intra-articular HA and PRP, used alone or in combination. However, the efficacy and safety of combination therapy (PRP + HA) remain unclear.

AIM

The aim of this systematic review and meta-analysis is to assess the clinical effectiveness and safety profile of PRP + HA versus PRP monotherapy for KOA.

MATERIAL AND METHODS

A systematic search was conducted using four electronic databases (PubMed, EMBASE, Scopus, and Cochrane Library) to select publications published in peer-reviewed journals. The mean difference (MD) and risk ratio (RR) was calculated, along with their 95% confidence intervals. We assessed heterogeneity using Cochrane Q and I2statistics and the appropriate p-value. The analysis used RevMan 5.4. GRADE system was used for evidence assessment for each outcome parameter.

RESULTS

This meta-analysis of 11 RCTs (n = 1023 KOA patients) revealed that PRP + HA has substantial effectiveness than PRP alone in reducing OMAC total scores [MD -1.77 (95% CI -2.20 to - 1.34); I2 = 10%, and p < 0.001], VAS scores [MD -4.27 (95% CI -4.96 to - 3.58); I2 = 13%, and p < 0.001], and Lequesne index score [MD -5.48 (95% CI -6.56 to - 4.40); I2 = 16%, and p < 0.001], while increasing IKDC scores [MD -2.10 (95% CI -3.70 to - 0.50); I2 = 9%, and p = 0.01], with low risk of adverse events [RR 0.41 (95% CI 0.35 to 0.48); I2 = 12%, and p < 0.001].

CONCLUSION

This meta-analysis reveals that, for patients with KOA, PRP + HA therapy is safe and yields better outcomes in pain relief and functional improvement compared to PRP monotherapy.

Adipose-derived mesenchymal stem cells combined with platelet-rich plasma are superior options for the treatment of osteoarthritis

BACKGROUND

There is currently no definitive treatment for osteoarthritis. We examined the therapeutic effects and underlying mechanisms of platelet-rich plasma (PRP) and adipose-derived mesenchymal stem cells (ADSCs), individually or in combination, in a rat model of anterior cruciate ligament-induced degenerative osteoarthritis (OA) of the knee. This study seeks to advance clinical approaches to OA treatment.

METHODS

Eight- to nine-week-old male Sprague-Dawley (SD) rats were randomly assigned to two groups: (1) a normal control group (Group A) and (2) a model group. The control group received no treatment. The model group underwent treatment and was further subdivided into six groups: Group B (an injury control group), Group C (high-dose ADSCs), Group D (PRP combined with high-dose ADSCs), Group E (low-dose ADSCs), Group F (PRP combined with low-dose ADSCs), and Group G (PRP alone). PRP and/or ADSCs were administered via intra-articular injection on Days 7, 37, and 67 post-surgery. Daily observations recorded activity levels and behavior, while weight changes were monitored weekly. Digital radiography (DR) was conducted on Days 30, 60, and 90 post-surgery to assess joint surface and contour alterations. Histopathological examination and inflammatory factor analysis were performed on cartilage and synovial tissue.

RESULTS

No abnormal reactions were observed in any rats, and body weights increased as expected (P > 0.05). Significant differences in knee swelling rates and Wakitani scores were observed between Groups A and B (P < 0.01). Knee swelling rates also differed significantly between Group B and Groups C-G (P < 0.01). Wakitani scores decreased on Days 60 and 90 in Groups C-G. TNF-α and IL-1β expression levels were significantly higher in Group B compared to Group A (P < 0.05). Expression levels of these genes were significantly lower in Groups C-G than in Group B (P < 0.05).

CONCLUSIONS

Repeated intra-articular injections of PRP and ADSCs alleviated inflammation and pain, promoted tissue repair, and modulated immune responses in rats with surgically induced OA. The combination of PRP and ADSCs demonstrated enhanced therapeutic efficacy, suggesting its potential as a treatment option for OA.

Exosomes derived from platelet-rich plasma present a novel potential in repairing knee articular cartilage defect combined with cyclic peptide-modified β-TCP scaffold

BACKGROUND

The aim of this study was to investigate the therapeutic effects and mechanisms of PRP-exos combined with cyclic peptide-modified β-TCP scaffold in the treatment of rabbit knee cartilage defect.

METHODS

PRP-exos were extracted and characterized by TEM, NTA and WB. The therapeutic effects were evaluated by ICRS score, HE staining, Immunohistochemistry, qRT-PCR and ELISA. The repair mechanism of PRP-exos was estimated and predicted by miRNA sequencing analysis and protein-protein interaction network analysis.

RESULTS

The results showed that PRP-exos had a reasonable size distribution and exhibited typical exosome morphology. The combination of PRP-exos and cyclic peptide-modified β-TCP scaffold improved ICRS score and the expression level of COL-2, RUNX2, and SOX9. Moreover, this combination therapy reduced the level of MMP-3, TNF-α, IL-1β, and IL-6, while increasing the level of TIMP-1. In PRP-exos miRNA sequencing analysis, the total number of known miRNAs aligned across all samples was 252, and a total of 91 differentially expressed miRNAs were detected. The results of KEGG enrichment analysis and the protein-protein interaction network analysis indicated that the PI3K/AKT signaling pathway could impact the function of chondrocytes by regulating key transcription factors to repair cartilage defect.

CONCLUSION

PRP-exos combined with cyclic peptide-modified β-TCP scaffold effectively promoted cartilage repair and improved chondrocyte function in rabbit knee cartilage defect. Based on the analysis and prediction of PRP-exos miRNAs sequencing, PI3K/AKT signaling pathway may contribute to the therapeutic effect. These findings provide experimental evidence for the application of PRP-exos in the treatment of cartilage defect.

Efficacy and safety of high tibial osteotomy combined with platelet-rich plasma for treating knee osteoarthritis: a systematic review and meta-analysis of the Chinese population

OBJECTIVE

To systematically review the clinical efficacy and safety of high tibial osteotomy (HTO) combined with platelet-rich plasma (PRP) for treating knee osteoarthritis (KOA) and to provide evidence of the effectiveness of evidence-based medicine for treating this disease.

METHODS

Clinical studies on the use of HTO combined with PRP for the treatment of KOA before September 2024 were identified. The literature that met the inclusion criteria was strictly screened out, the literature information was extracted, and the data were input into RevMan5.4 for analysis.

RESULTS

Ten studies (12 controls) with 625 patients were included. Overall, the visual analog scale (VAS) score (mean difference (MD) = -0.53, 95% confidence interval (CI) (-0.76, -0.31), P < 0.00001), range of motion (ROM) (MD = 7.24, 95% CI (2.79, 11.69), P = 0.001), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (MD = -6.91, 95% CI (-9.47, -4.34), P < 0.00001), cartilage recovery (cartilage thickness: MD = 0.43, 95% CI (0.35, 0.51), P < 0.00001; cartilage regeneration: relative risk (RR) = 1.81, 95% CI (1.40, 2.33), P < 0.00001; and the International Cartilage Repair Society (ICRS) grade: RR = 1.96, 95% CI (1.44, 2.66), P < 0.0001), and the Lysholm score (MD = 6.51, 95% CI (4.97, 8.04), P < 0.00001) after HTO-PRP treatment had certain advantages compared to the control group. After treatment, there was no statistically significant difference in the knee joint mechanical axis angle between the HTO-PRP group and the control group (femoral tibial angle (FTA): MD = -0.29, 95% CI (-1.07, 0.49), P = 0.47; medial proximal tibial angle (MPTA): MD = 0.19, 95% CI (-0.49, 0.88), P = 0.58; posterior tibial slope (PTS): MD = -0.12, 95% CI (-0.49, 0.25), P = 0.53; knee varus angle (KVA): MD = -0.30, 95% CI (-1.77, 1.17), P = 0.69; weight-bearing line (WBL): MD = 1.10, 95% CI (-0.89, 3.09), P = 0.28).

CONCLUSION

The results showed that in the treatment of KOA, the HTO-PRP group had better efficacy than the control groups did and had certain safety reliability.

A study on the effect of platelet-rich plasma (PRP) to promote bone fusion in lateral interbody fusion of the lumbar spine using artificial bone

BACKGROUND

Lateral lumbar interbody fusion (LLIF) via a retroperitoneum approach has gained popularity due to minimal invasiveness, which avoids resection of the spinous process and laminae. However, as challenges in grafting autogenous bone persist, artificial bone has been tested in Japan to fill the spinal cage. Platelet-rich plasma (PRP) contains growth factors and anti-inflammatory cytokines to promote cellular proliferation and repair damaged tissues. While the effects of PRP on tendon and ligament repair are widely known, any effects on bone healing are scarcely reported. However, PRP-loaded artificial bone carries potential to improve intervertebral bone fusion.

OBJECTIVE

This study assessed whether PRP enhances intervertebral bone fusion in LLIF surgery using β-tricalcium phosphate artificial bone.

METHODS

The current study was a prospective, randomized, controlled trial. We evaluated 13 consecutive patients undergoing LLIF surgery in our hospital. Patients received artificial bone impregnated with PRP or without PRP within the same fusion cage. The primary outcome was the intervertebral bone fusion rate at 6 and 12 months postoperatively, evaluated using CT imaging. The intervertebral bone fusion rates with and without PRP loading and with and without contact part between the endplate and the artificial bone were compared. Secondary outcomes included clinical evaluations using visual analog scale scores for low back pain, buttock-leg pain, and leg numbness from the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOA-BPEQ) and the Oswestry Disability Index (ODI), plus adverse events information.

RESULTS

Of the 13 patients (29 vertebral segments) included, bone fusion was observed in 43.4% of the PRP group and 26.1% of the non-PRP group at 6 months (p = 0.216). At 12 months, fusion rates were 60.9% with PRP and 34.8% without PRP (p = 0.074). The fusion rate was significantly higher in cases with good contact between the vertebral endplate and the artificial bone (p = 0.0004). Clinical scores improved postoperatively. Adverse events were in accordance with expectations from LLIF surgery and no PRP-specific events occurred.

CONCLUSION

PRP did not significantly improve intervertebral bone fusion rates in LLIF surgeries, particularly in cases with poor contact between the vertebral endplate and artificial bone. While PRP may have a limited role in enhancing bone fusion, maintaining good contact between the vertebral endplate and artificial bone is crucial for successful outcomes. Further research is needed to explore optimal uses of PRP in spinal fusion surgeries.

Informed consent form for platelet rich plasma injections: evidence-based and legally guide for orthopaedic surgeons

Regarding medico-legal malpractice suits, lawyers and insurers focus on informed consent documentation. Unfortunately, there is no standard protocol for obtaining informed consent for platelet-rich plasma (PRP) injections. The objective of the present study was to create a pre-designed, evidence-based informed consent form specifically for PRP injections. The current evidence on the medico-legal implications of PRP injections was accessed, as well as informed consent in general and specifically informed consent in PRP injections. Additionally, we interviewed orthopaedic surgeons and patients who had undergone PRP injections in the past year using a semi-structured approach. A legally valid and evidence-based informed consent form for PRP injections ensures rights, encouraging open communication and transparency between the patient and surgeon. Moreover, if a lawsuit arose, informed consent would be a critical document in surgeons' defence and would withstand scrutiny from lawyers and the judiciary. An evidence-based informed consent form for PRP injections was elaborated and reviewed by a legal expert to ensure adherence to legal proprieties. The final form of the informed consent for PRP injection was administered for one year and validated at our institution.

Profound Properties of Protein-Rich, Platelet-Rich Plasma Matrices as Novel, Multi-Purpose Biological Platforms in Tissue Repair, Regeneration, and Wound Healing

Autologous platelet-rich plasma (PRP) preparations are prepared at the point of care. Centrifugation cellular density separation sequesters a fresh unit of blood into three main fractions: a platelet-poor plasma (PPP) fraction, a stratum rich in platelets (platelet concentrate), and variable leukocyte bioformulation and erythrocyte fractions. The employment of autologous platelet concentrates facilitates the biological potential to accelerate and support numerous cellular activities that can lead to tissue repair, tissue regeneration, wound healing, and, ultimately, functional and structural repair. Normally, after PRP preparation, the PPP fraction is discarded. One of the less well-known but equally important features of PPP is that particular growth factors (GFs) are not abundantly present in PRP, as they reside outside of the platelet alpha granules. Precisely, insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) are mainly present in the PPP fraction. In addition to their roles as angiogenesis activators, these plasma-based GFs are also known to inhibit inflammation and fibrosis, and they promote keratinocyte migration and support tissue repair and wound healing. Additionally, PPP is known for the presence of exosomes and other macrovesicles, exerting cell-cell communication and cell signaling. Newly developed ultrafiltration technologies incorporate PPP processing methods by eliminating, in a fast and efficient manner, plasma water, cytokines, molecules, and plasma proteins with a molecular mass (weight) less than the pore size of the fibers. Consequently, a viable and viscous protein concentrate of functional total proteins, like fibrinogen, albumin, and alpha-2-macroglobulin is created. Consolidating a small volume of high platelet concentrate with a small volume of highly concentrated protein-rich PPP creates a protein-rich, platelet-rich plasma (PR-PRP) biological preparation. After the activation of proteins, mainly fibrinogen, the PR-PRP matrix retains and facilitates interactions between invading resident cells, like macrophages, fibroblast, and mesenchymal stem cells (MSCs), as well as the embedded concentrated PRP cells and molecules. The administered PR-PRP biologic will ultimately undergo fibrinolysis, leading to a sustained release of concentrated cells and molecules that have been retained in the PR-PRP matrix until the matrix is dissolved. We will discuss the unique biological and tissue reparative and regenerative properties of the PR-PRP matrix.

Platelet-rich plasma intra-articular knee injections from open preparation techniques do not pose a higher risk of joint infection: A systematic review of 91 randomized controlled trials and 5914 injections

Purpose

To compare the infection rate of intraarticular platelet-rich plasma (PRP) knee injections between open and closed techniques in randomized controlled trials (RCTs) published in the last decade.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, PubMed, Scopus and Virtual Health Library were accessed in October 2022 using the terms 'platelet-rich plasma', 'PRP', 'knee' and 'tibiofemoral' alone and in combination with Boolean operators AND/OR. RCTs published during the last 10 years evaluating PRP intra-articular knee injections were considered eligible. Studies were excluded if the kit/preparation technique was not described. Data were presented using individual studies' absolute values, totals, and pooled percentages. Publication bias was assessed using the ROBIS tool.

Results

Ninety-one studies met the predetermined eligibility criteria. Forty-one implemented a closed technique, while 50 were open. All studies implementing a closed technique disclosed their commercial kits. Only 16 studies (17.58%) failed to report joint infections. Among the studies reporting joint infections as outcomes, 30 implemented a closed technique with 1195 patients, 1921 intra-articular knee injections and 95.44% of patient follow-up. On the other hand, 45 of them implemented an open technique with 2290 patients, 3993 intra-articular knee injections and 97.07% of patient follow-up. No patient had a joint infection among the included studies. Thirty-three studies prepared their PRP in controlled environments (36.26%). Most studies did not report where the preparation occurred (48.35%). Only twelve studies disclosed using laminar flow during preparation (13.19%). The infection rate for both techniques was 0 per 1000 knee injections.

Conclusion

Open PRP preparation techniques do not pose a higher risk of joint infection and can lower manufacturing costs when appropriate facilities are available. However, PRP preparation setting and laminar flow implementation data are deficient, and minimal requirements for good manufacturing practices demand further studies while adhering to local and regional regulations.

Level of Evidence

Level I, systematic review of RCTs.

The varying clinical effectiveness of single, three and five intraarticular injections of platelet-rich plasma in knee osteoarthritis

OBJECTIVE

To investigate the variations in clinical effectiveness among patients diagnosed with knee osteoarthritis who underwent intra-articular administration of platelet-rich plasma using single, triple, or quintuple injections.

METHODS

One hundred twenty patients with grade I-III knee osteoarthritis were randomly assigned to three groups: PRP1 group, who received a single injection of platelet-rich plasma; PRP3 group, who received three PRP injections one week apart; PRP5 group, who received five PRP injections one week apart. The patients' conditions were evaluated using the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Arthritis Index-VA3.1 version (WOMAC-VA3.1) at baseline and 6, 12, 24, and 52 weeks 52 weeks follow up.

RESULTS

Out of the total participants, 106 patients (30 males and 76 females) completed the study. The primary outcome measure, WOMAC pain score, registered significant improvements across all groups when compared to pre-treatment levels. However, the application of 3 and 5 injections of platelet-rich plasma was substantially more effective than that of a single injection in reducing knee pain and stiffness, as well as enhancing physical function in patients with knee osteoarthritis. No statistically discernable difference was observed between PRP3 and PRP5 at all follow-up intervals, and there was no discernable difference between 3 and 5 PRP injections either. Mild side effects occurred in all three groups.

CONCLUSIONS

The administration of three or five injections of platelet-rich plasma is safe, substantially more effective than single injections, and leads to remarkable clinical improvement by significantly reducing knee pain, improving joint stiffness, and enhancing physical function in patients with grade I-III knee osteoarthritis. Furthermore, no significant difference was observed in the efficacy of three or five injections. Therefore, we recommend using three injections of PRP in the treatment of patients with knee osteoarthritis of grade I-III.

Platelet-Rich Plasma in Young and Elderly Humans Exhibits a Different Proteomic Profile

As people age, their ability to resist injury and repair damage decreases significantly. Platelet-rich plasma (PRP) has demonstrated diverse therapeutic effects on tissue repair. However, the inconsistency of patient outcomes poses a challenge to the practical application of PRP in clinical practice. Furthermore, a comprehensive understanding of the specific impact of aging on PRP requires a systematic investigation. We derived PRP from 6 young volunteers and 6 elderly volunteers, respectively. Subsequently, 95% of high-abundance proteins were removed, followed by mass spectrometry analysis. Data are available via ProteomeXchange with the identifier PXD050061. We detected a total of 739 proteins and selected 311 proteins that showed significant differences, including 76 upregulated proteins in the young group and 235 upregulated proteins in the elderly group. Functional annotation and enrichment analysis unveiled upregulation of proteins associated with cell apoptosis, angiogenesis, and complement and coagulation cascades in the elderly. Conversely, IGF1 was found to be upregulated in the young group, potentially serving as the central source of enhanced cell proliferation ability. Our investigation not only provides insights into standardizing PRP preparation but also offers novel strategies for augmenting the functionality of aging cells or tissues.

Standardized Informed Consent Form for Clinicians Administering Platelet-Rich Plasma

Introduction When it comes to medico-legal malpractice suits, lawyers and insurers tend to focus on informed consent documentation. Unfortunately, there is no standard protocol for obtaining informed consent for the use of platelet-rich plasma (PRP) injections, which might cause problems. This study aimed to mitigate this concern through the development of a standardized informed consent document for PRP injections, grounded in evidence-based practices. Materials and methods An examination of databases was conducted to explore the medico-legal ramifications associated with PRP injections, as well as the broader topic of informed consent, with a particular focus on the context of PRP injections. Moreover, interviews were carried out with healthcare providers and individuals who had received PRP injections within the preceding year, utilizing a semi-structured methodology. Results We developed an evidence-based informed consent document tailored for PRP injections. To guarantee its legal validity, the document underwent review by a legal specialist. Subsequently, our institutions implemented the finalized form for PRP injection procedures over one year. Conclusion A legally valid and evidence-based informed consent form for PRP injections would ensure patient's rights, and encourage open communication and transparency between them and the doctor. Moreover, if a lawsuit were to arise, it would serve as a critical document in the doctor's defense and withstand scrutiny from lawyers and the judiciary.

Assessing the Efficacy of Laser Therapy and Autologous Platelet-Rich Plasma (PRP) Treatment for Chronic Wounds

(1) Background: The management of persistent wounds is a topic of significant concern, particularly when they become chronic. Clinicians are focused on reducing the healing duration of chronic wounds and employing the most efficient treatments. Successful wound management requires an understanding of standard healing processes, the elements that can impede healing progress, and strategies to manage these impediments. (2) Methods: We participated in a study involving a cohort of 115 patients. Data were collected through subjective assessments via questionnaires, examining the comparative effects of laser therapy and platelet-rich plasma (PRP) on patients' conditions and monitored the progression of chronic wounds. For the study, we utilized a branded laser equipped with a 12-watt probe to stimulate chronic wounds in 65 patients, while the PRP procedure was administered to 50 patients. (3) Results: We observed a greater improvement in local symptoms among the patients who received laser therapy compared to those in the PRP group. (4) Conclusions: We consider both therapies to be of significant importance due to their positive and beneficial effects, particularly on the symptomatology and progression of chronic wounds. Nevertheless, superior results were documented in patients who underwent laser therapy.

An Update on Orthobiologics: Cautious Optimism

Orthobiologics are rapidly growing in use given their potential to augment healing for multiple musculoskeletal conditions. Orthobiologics consist of a variety of treatments including platelet-rich plasma and stem cells that provide conceptual appeal in providing local delivery of growth factors and inflammation modulation. The lack of standardization in nomenclature and applications within the literature has led to a paucity of high-quality evidence to support their frequent use. The purpose of this review was to describe the current landscape of orthobiologics and the most recent evidence regarding their use.

Efficacy and safety of platelet-rich plasma combined with Tai Chi for knee osteoarthritis: study protocol for a placebo-controlled randomized trial

BACKGROUND

No definitive treatment methods of curative for knee osteoarthritis (KOA). The combined therapies that into account both the biochemical and biomechanical may provide potential opportunities for treat KOA, and previous studies have demonstrated that the platelet-rich plasma of intra-articular injection (IAI-PRP) and exercise treatments afford more benefits than do their corresponding monotherapies. The absence of a specific exercise plan and detailed explanation renders the aforementioned study results questionable. Furthermore, Tai Chi (TC) with moderate-intensity, whole body movements and good adherence may prove to be more effective for treating KOA. However, few studies examined the effectiveness and safety of combined IAI-PRP and TC for KOA.

METHODS

This study protocol will be a placebo-controlled, assessor-blinded randomized trial involving 12-week intervention and 1-year follow-up. The stratified randomization will be used to randomly assign the 212 participants to four groups: group A (placebo IAI); group B (PRP IAI); group C (TC and placebo IAI); group D (TC and PRP IAI). Injection will be performed once a week, three consecutive times as a course, after a week of rest to continue the next course, a total of 3 courses (12 week). Additionally, the TC interventions will be carried out 3 days per week for a total of 12 weeks. The primary outcome measures will include the efficacy (Western Ontario and McMaster Universities Osteoarthritis Index), acceptability and safety of these interventions. The secondary outcome measures will include physical function (Timed Up and Go test), walking function (Gait Analysis), inflammatory factor levels (e.g., Interleukin-1 β, interleukin-6, vascular endothelial growth factor), quality of life (36-Item Short Form Health Survey), volume of patellofemoral cartilage and effusion-synovitis (MRI). Two-way of variance with repeated measures will be applied to examine the main effects of the group and the time factor and group-time interaction effects for all outcome measures.

DISCUSSION

This trial will be first one to propose an integrated scheme combing IAI-PRP and TC for treatment of KOA, based on the consideration of the biochemical and biomechanical pathogenesis of KOA. These results of the study will provide evidence with high quality for integrated IAI-PRP and TC to treatment KOA. Trial Registration Chinese Clinical Trial Registry ChiCTR2300067559. Registered on 11 January 2023.

Pure platelet-rich plasma promotes semaphorin-3A expression: a novel insight to ameliorate intervertebral disk degeneration in vitro

INTRODUCTION

Intervertebral disk degeneration (IVDD) can be effectively treated using platelet-rich plasma (PRP). While the exact process is fully understood, it is believed that using pure PRP (P-PRP) without leukocytes is a better option for preventing IVDD. Semaphorin-3A (Sema3A), an inhibitor of angiogenesis and innervation, is essential for preserving IVDD's homeostasis. Whether PRP prevents IVDD by modifying Sema3A has yet to receive much research. This work aims to clarify how P-PRP affects Sema3A when IVDD develops in vitro.

METHODS

Nucleus pulposus cells (NPCs) isolated from 8-week-old male Sprague-Dawley rats were exposed to 10 ng/ml IL-1β and then treated with P-PRP or leukocyte platelet-rich plasma (L-PRP) in vitro, followed by measuring cell proliferation, apoptosis and microstructures, inflammatory gene and Sema3A expression, as well as anabolic and catabolic protein expression by immunostaining, quantitative real-time polymerase chain reaction (qPCR), western blot, and enzyme-linked immunosorbent assay (ELISA).

RESULTS

In comparison with L-PRP, P-PRP had a higher concentration of growth factors but a lower concentration of inflammatory substances. P-PRP increased the proliferation of NPCs, while IL-1 relieved the amount of apoptosis due to its intervention. Anabolic genes, aggrecan, and collagen II had higher expression levels. MMP-3 and ADAMTS-4, two catabolic or inflammatory genes, showed lower expression levels. Sema3A activity was enhanced after P-PRP injection, whereas CD31 and NF200 expression levels were suppressed.

CONCLUSIONS

P-PRP enhanced the performance of NPCs in IVDD by modifying the NF-κB signaling pathway and encouraging Sema3A expression, which may offer new therapy options for IVDD.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

The findings provide a new therapeutic target for the treatment of IVDD and show a novel light on the probable mechanism of PRP and the function of Sema3A in the progression of IVDD.

Effects and action mechanisms of individual cytokines contained in PRP on osteoarthritis

Osteoarthritis (OA) is defined as a degenerative joint disease that can affect all tissues of the joint, including the articular cartilage, subchondral bone, ligaments capsule, and synovial membrane. The conventional nonoperative treatments are ineffective for cartilage repair and induce only symptomatic relief. Platelet-rich plasma (PRP) is a platelet concentrate derived from autologous whole blood with a high concentration of platelets, which can exert anti-inflammatory and regenerative effects by releasing multiple growth factors and cytokines. Recent studies have shown that PRP exhibits clinical benefits in patients with OA. However, high operational and equipment requirements greatly limit the application of PRP to OA treatment. Past studies have indicated that high-concentration PRP growth factors and cytokines may be applied as a commercial replacement for PRP. We reviewed the relevant articles to summarize the feasibility and mechanisms of PRP-based growth factors in OA. The available evidence suggests that transforming growth factor-α and β, platelet-derived growth factors, epidermal growth factor, insulin-like growth factor-1, and connective tissue growth factors might benefit OA, while vascular endothelial growth factor, tumor necrosis factor-α, angiopoietin-1, and stromal cell derived factor-1α might induce negative effects on OA. The effects of fibroblast growth factor, hepatocyte growth factor, platelet factor 4, and keratinocyte growth factor on OA remain uncertain. Thus, it can be concluded that not all cytokines released by PRP are beneficial, although the therapeutic action of PRP has a valuable potential to improve.

Safety and efficacy of intra-articular injection of platelet-rich plasma for the treatment of ankle osteoarthritis: a systematic review and meta-analysis

PURPOSE

To evaluate the safety and efficacy of platelet-rich plasma (PRP) intra-articular injective treatments for ankle osteoarthritis (OA).

METHODS

A systematic literature search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in PubMed, Scopus, Embase, Google Scholar, and the Cochrane library until May 2022. Both randomized and non-randomized studies were included with the assessment of the risk of bias. We recorded the participant's age, gender, type of PRP, injection volume, the kit used, and activating agent. We subsequently assessed the short-term and long-term efficacy of PRP using the functional scores and visual analog scale (VAS).

RESULTS

We included four studies with a total of 127 patients, with a mean age of 56.1 years. 47.2% were male (60/127), according to eligibility criteria. There were three cohort studies and one randomized controlled trial (RCT) study, and no study reported severe adverse events. All included studies used the Leukocyte-poor PRP. Short-term follow-up results suggested significant improvement of the American Orthopaedic Foot and Ankle Society (AOFAS) score in the PRP injection group compared to the control group (n = 87 patients; MD: 6.94 [95% CI: 3.59, 10.29]; P < 0.01). Consistently, there was a statistical difference in AOFAS score between PRP injection and control groups in the final follow-up (≥ 6 months) (n = 87 patients; MD: 9.63 [95% CI: 6.31, 12.94]; P < 0.01). Furthermore, we found a significant reduction in VAS scores in the PRP groups at both the short-term follow-up (n = 59 patients; MD, - 1.90 [95% CI, - 2.54, - 1.26]; P < 0.01) and the ≥ six months follow-up (n = 79 patients; MD, - 3.07 [95% CI, - 5.08, - 1.05]; P < 0.01). The improvement of AOFAS and VAS scores at ≥ six months follow-up reached the minimal clinically important difference (MCID). Nevertheless, the treatment effect of AOFAS and VAS scores offered by PRP at short-term follow-up did not exceed the MCID. Substantial heterogeneity was reported at the ≥ six months follow-up in VAS scores (I2: 93%, P < 0.01).

CONCLUSION

This meta-analysis supports the safety of PRP intra-articular injection for ankle OA. The improvements of AOFAS and VAS scores in the PRP group at short-term follow-up do not exceed the MCID to be clinically significant. PRP injection provides significant improvement of AOFAS score and reduced pain at ≥ six months follow-up. The efficacy of PRP should be interpreted with caution regarding the high heterogeneity and the scarcity of available literature, which urges large-scale RCTs with longer follow-up to confirm the potential efficacy of PRP injection for ankle OA.

Angiogenesis and Tissue Repair Depend on Platelet Dosing and Bioformulation Strategies Following Orthobiological Platelet-Rich Plasma Procedures: A Narrative Review

Angiogenesis is the formation of new blood vessel from existing vessels and is a critical first step in tissue repair following chronic disturbances in healing and degenerative tissues. Chronic pathoanatomic tissues are characterized by a high number of inflammatory cells; an overexpression of inflammatory mediators; such as tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1); the presence of mast cells, T cells, reactive oxygen species, and matrix metalloproteinases; and a decreased angiogenic capacity. Multiple studies have demonstrated that autologous orthobiological cellular preparations (e.g., platelet-rich plasma (PRP)) improve tissue repair and regenerate tissues. There are many PRP devices on the market. Unfortunately, they differ greatly in platelet numbers, cellular composition, and bioformulation. PRP is a platelet concentrate consisting of a high concentration of platelets, with or without certain leukocytes, platelet-derived growth factors (PGFs), cytokines, molecules, and signaling cells. Several PRP products have immunomodulatory capacities that can influence resident cells in a diseased microenvironment, inducing tissue repair or regeneration. Generally, PRP is a blood-derived product, regardless of its platelet number and bioformulation, and the literature indicates both positive and negative patient treatment outcomes. Strangely, the literature does not designate specific PRP preparation qualifications that can potentially contribute to tissue repair. Moreover, the literature scarcely addresses the impact of platelets and leukocytes in PRP on (neo)angiogenesis, other than a general one-size-fits-all statement that "PRP has angiogenic capabilities". Here, we review the cellular composition of all PRP constituents, including leukocytes, and describe the importance of platelet dosing and bioformulation strategies in orthobiological applications to initiate angiogenic pathways that re-establish microvasculature networks, facilitating the supply of oxygen and nutrients to impaired tissues.

Platelets Rich Plasma (PRP) Procedure in the Healing of Atonic Wounds

(1) Background: Patients suffering from chronic wounds report physical, mental, and social consequences due to their existence and care. There is a global need for tissue repair strategies and, in our case, for chronic wound healing. PRP therapy is based on the fact that platelet-derived growth factors (PGF) support the three phases of the wound healing and repair cascade (inflammation, proliferation, and remodeling); (2) Methods: A comparative study was carried out on two groups of patients with atonic wounds totaling a total of 80 cases as follows: a study group in which the PRP procedure was applied and a control group in which the biological product was not injected. The study was carried out in the surgery clinic of the Clinical Hospital C.F. Oradea City; (3) Results: A much faster healing was achieved in the case of patients who benefited from the platelet-rich plasma injection therapy compared to the group of patients in whom this therapy was not used. Three weeks after the plasma injection, a considerable reduction of the wound was evident, with some of the patients presenting with a closed wound; (4) Conclusions: The effect of PRP on the healing of chronic wounds is promising in most cases. A positive effect was also highlighted in terms of reducing treatment costs by considerably reducing the materials used as well as the number of hospitalizations for the same pathology.

Platelet-rich plasma injection for the treatment of ankle osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Platelet-rich plasma (PRP) injection for ankle osteoarthritis (OA) treatment showed contradictory results. This review was aimed to pool individual studies which assessed the efficacy of PRP for ankle OA treatment.

METHODS

This study was conducted following the preferred report items of systematic review and meta-analysis guideline. PubMed and Scopus were searched up to January 2023. Meta-analysis, or individual randomised controlled trial (RCT), or observational studies were included if they involved ankle OA with aged ≥ 18 years, compared before-after receiving PRP, or PRP with other treatments, and reported visual analog scale (VAS) or functional outcomes. Selection of eligible studies and data extraction were independently performed by two authors. Heterogeneity test using Cochrane Q test and the I²-statistic were assessed. Standardised (SMD) or unstandardised mean difference (USMD) and 95% confidence interval (CI) were estimated and pooled across studies.

RESULTS

Three studies from meta-analysis and two individual studies were included, which consisted of one RCT and four before-after studies with 184 ankle OAs and 132 PRP. The average age was 50.8-59.3 years, and 25-60% of PRP injected cases were male. The number of primary ankle OA was accounted to 0-100%. When compared to before treatment, PRP significantly reduced VAS and functional score at 12 weeks with pooled USMD of - 2.80, 95% CI - 3.91, - 2.68; p < 0.001 (Q = 82.91, p < 0.001; I² 96.38%), and pooled SMD of 1.73, 95% CI 1.37, 2.09; p < 0.001 (Q = 4.87, p = 0.18; I² 38.44%), respectively.

CONCLUSION

PRP may beneficially improve pain and functional scores for ankle OA in a short-term period. Its magnitude of improvement seems to be similar to placebo effects from the previous RCT. A large-scale RCT with proper whole blood and PRP preparation processes is required to prove treatment effects. Trial registration PROSPERO number CRD42022297503.

Submucosal Injection of Activated Platelet-Rich Plasma for Treatment of Periodontal Disease in Dogs

Periodontal disease is the most common oral disease seen in dogs, and its routine treatment usually involves dental scaling. Platelet-rich plasma (PRP) therapy may enhance the effectiveness of treatment of periodontal disease, delay the progression of the disease and decrease the time under anesthesia. However, its application in dogs is rarely discussed. The objective of this study was to evaluate the benefits of activated PRP for treatment of periodontal disease in dogs. 43 mL of whole blood was collected from six adult dogs and PRP extracted using the double centrifugation tube method. Subsequently, the PRP was activated using calcium chloride (A-PRP). Significantly elevated concentrations of PDGF-BB (7000.28 pg/mL), TGF-β (378.98 pg/mL), and VEGF (7.14 pg/mL) were detected in the A-PRP. Additionally, three of the dogs with stage 2-3 periodontal disease were enrolled in the clinical trial. Periodontal pocket depth, stage of periodontal disease, gingival index, horizontal bone loss, and alveolar bone density involving the maxillary third and fourth premolar and first molar teeth (107, 108, 109, 207, 208, and 209) were evaluated. Teeth were treated by dental scaling alone (control group) or by dental scaling followed by submucosal injection of 0.1 mL A-PRP per site. After 56 days, significant improvement in periodontal pocket depth, stage of periodontal disease, gingival index, and horizontal bone loss was observed in dogs injected with A-PRP. The high concentrations of growth factors in A-PRP likely contributed to this effect. The use of submucosal injections of A-PRP to treat canine stage 2-3 periodontal disease appears safe and effective for clinical practice.

Autologous Platelet and Extracellular Vesicle-Rich Plasma as Therapeutic Fluid: A Review

The preparation of autologous platelet and extracellular vesicle-rich plasma (PVRP) has been explored in many medical fields with the aim to benefit from its healing potential. In parallel, efforts are being invested to understand the function and dynamics of PVRP that is complex in its composition and interactions. Some clinical evidence reveals beneficial effects of PVRP, while some report that there were no effects. To optimize the preparation methods, functions and mechanisms of PVRP, its constituents should be better understood. With the intention to promote further studies of autologous therapeutic PVRP, we performed a review on some topics regarding PVRP composition, harvesting, assessment and preservation, and also on clinical experience following PVRP application in humans and animals. Besides the acknowledged actions of platelets, leukocytes and different molecules, we focus on extracellular vesicles that were found abundant in PVRP.

The Influence of Body Mass Index on Growth Factor Composition in the Platelet-Rich Plasma in Patients with Knee Osteoarthritis

BACKGROUND

An abnormally high body mass index is strongly associated with knee osteoarthritis. Usually, obese patients are excluded from clinical trials involving PRP intra-articular injections. Growth factors have been demonstrated to have a disease-modifying effect on KOA treatment, even though data on their influence on treatment effectiveness in obese patients are lacking.

PURPOSE

To prospectively compare the level of selected growth factors including transforming growth factor-b (TGF-β), epidermal growth factor (EGF), fibroblast growth factor, insulin-like growth factor-1 (IGF-1), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and fibroblast growth factor-2 (FGF-2) in platelet-rich plasma (PRP) in obese patients and patients with normal BMI.

METHODS

A total of 49 patients were included in the study according to inclusion and exclusion criteria. The groups strongly differed in body mass index (median values 21.6 vs. 32.15). Concentrations of growth factors were measured with an enzyme-linked immunosorbent assay. Statistical significance was determined with the Mann-Whitney U test. The compliance of the distribution of the results with the normal distribution was checked using the Shapiro-Wilk test separately for both groups.

RESULTS

There were no statistically significant differences in median marker levels between groups. Statistically significant Pearson correlations were observed between IGF-1 serum level and age (weak negative, r = -0.294, p = 0.041) and gender (moderate positive, r = 0.392, 0.005).

CONCLUSIONS

BMI does not influence the level of selected growth factors in patients with knee osteoarthritis. Obese and non-obese patients had similar compositions of PDGF, TGF-β, EGF, FGF-2, IGF-1, and VEGF. PRP can be used in both groups with similar effects associated with growth factors' influence on articular cartilage.

Assessment of the effectiveness and satisfaction of platelet-rich plasma compared with hyaluronic acid in knee osteoarthritis at minimum 7-year follow-up: A post hoc analysis of a randomized controlled trial

Background: Knee osteoarthritis (KOA) can be effectively treated conservatively using platelet-rich plasma (PRP) injections into the affected joints. While the short-term therapeutic clinical benefits were well documented, the mid-term results remain undetermined. To clarify its efficacy, the mid-term clinical outcomes of intra-articular injections of either PRP or hyaluronic acid (HA) in KOA were compared. Methods: One hundred patients who complied with the inclusion criteria were randomized to undergo once a week 3 weeks, intra-articular injections of either PRP or HA. Patients were evaluated before the injection, at 3, 6, and a mean of 78.9 months of follow-up. Eighty-five patients reached the final evaluation. Data on survival, re-intervention, pain, function, imaging, and satisfaction were collected and analyzed. Results: With surgery for any reason as the endpoint, the cumulative survival rate of the PRP group was 90%, while that of the HA group was 74%. There was a significant difference between the two groups in the total re-intervention rate (56.7% vs 16.2%, p < 0.05). The comparative analyses showed significant intergroup differences in the visual analog scale (VAS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) (p < 0.01, p < 0.05, respectively) at the final follow-up. And base on the regression analyses, the type of treatment, age, and Kellgren-Lawrence (K-L) grade served as statistically an independent determinants of VAS (p < 0.001, p = 0.034, p < 0.001, respectively). Likewise, those variables independently determined WOMAC in our study. However, no difference was observed in the imaging evaluation, containing the K-L grade and Cartilage Lesion Score, between the two groups (p > 0.05). Besides, the satisfaction treated by the PRP was 78.6%, with a superiority compared with HA (55.8%, p < 0.05), and no complications were noted in the whole treatment process among patients who participated. Conclusion: PRP was more effective than HA in survival and re-intervention rates, VAS, and WOMAC, although there were no significant differences in the imaging evaluation between the two groups. Furthermore, patients treated with PRP were associated with higher satisfaction compared with HA.

The efficacy and safety of platelet-rich plasma in the tendon-exposed wounds: a preliminary study

Objective

Currently, among wounds with large skin tissue defects caused by various reasons, the treatment of refractory wounds is still a major clinical problem. This study is aimed to preliminarily assess the therapeutic potentials of platelet-rich plasma (PRP) in refractory wounds with exposed tendons, as well as corresponding efficacy and safety.

Methods

A total of 12 patients (5 males and 7 females) with refractory wounds and exposed tendons who were admitted to our hospital from June 2018 to December 2020 were included in this study. After the preparation of PRP, the included patients underwent the PRP injection after the debridement of wounds, and the efficacy and prognosis were assessed by the same group of senior surgeons.

Results

The average age of included patients was 42.7 ± 12.9 years, and the causes of injury included traffic accidents (3 cases), contusion (2 cases), burns (2 cases), diabetes complications (4 cases), and melanoma complications (1 cases). The average healing time was 23.0 ± 5.0 days, and the mean size of the wound was 3.1 × 5.1 cm². During the whole treatment process, Vancouver Scar Scale (VSS) decreased from 7.4 ± 1.6 before PRP treatment to 3.6 ± 0.9 after treatment (P < 0.001), Manchester Scar Scale (MSS) decreased from 12.3 ± 4.5 before PRP treatment to 5.4 ± 1.2 after treatment (P < 0.001), and no redness and swelling were observed around wounds, the size and degree of wounds gradually reduced, the coverage rate of granulation tissue was acceptable, overall quality of scar was relatively good, skin sensitivity around wounds was normal, there was no local wounds secretion, and postoperative patient's satisfaction was relatively good during follow-up.

Conclusions

Our study has preliminarily indicated that PRP can promote the wounds healing, reduce the inflammation around wounds, and improve the granulation tissue and angiogenesis, thereby effectively polishing up the safety and efficacy.

Modifying Orthobiological PRP Therapies Are Imperative for the Advancement of Treatment Outcomes in Musculoskeletal Pathologies

Autologous biological cellular preparations have materialized as a growing area of medical advancement in interventional (orthopedic) practices and surgical interventions to provide an optimal tissue healing environment, particularly in tissues where standard healing is disrupted and repair and ultimately restoration of function is at risk. These cellular therapies are often referred to as orthobiologics and are derived from patient's own tissues to prepare point of care platelet-rich plasma (PRP), bone marrow concentrate (BMC), and adipose tissue concentrate (ATC). Orthobiological preparations are biological materials comprised of a wide variety of cell populations, cytokines, growth factors, molecules, and signaling cells. They can modulate and influence many other resident cells after they have been administered in specific diseased microenvironments. Jointly, the various orthobiological cell preparations are proficient to counteract persistent inflammation, respond to catabolic reactions, and reinstate tissue homeostasis. Ultimately, precisely delivered orthobiologics with a proper dose and bioformulation will contribute to tissue repair. Progress has been made in understanding orthobiological technologies where the safety and relatively easy manipulation of orthobiological treatment tools has been demonstrated in clinical applications. Although more positive than negative patient outcome results have been registered in the literature, definitive and accepted standards to prepare specific cellular orthobiologics are still lacking. To promote significant and consistent clinical outcomes, we will present a review of methods for implementing dosing strategies, using bioformulations tailored to the pathoanatomic process of the tissue, and adopting variable preparation and injection volume policies. By optimizing the dose and specificity of orthobiologics, local cellular synergistic behavior will increase, potentially leading to better pain killing effects, effective immunomodulation, control of inflammation, and (neo) angiogenesis, ultimately contributing to functionally restored body movement patterns.

Platelet Rich Plasma in the Repair of Articular Cartilage Injury: A Narrative Review

OBJECTIVE

This paper reviews the research of platelet-rich plasma (PRP) in articular cartilage injury repair, to assess the mechanism, utilization, and efficacy of PRP in the treatment of articular cartilage injury, hoping to provide a theoretical basis for the clinical application of PRP in the future.

MATERIALS AND METHODS

A comprehensive database search on PRP applications in cartilage repair was performed. Among them, the retrieval time range of PRP in clinical trials of repairing knee cartilage injury was from January 1, 2021 to January 1, 2022. Non-clinical trials and studies unrelated to cartilage injury were excluded.

RESULT

PRP can affect inflammation, angiogenesis, cartilage protection, and cellular proliferation and differentiation after articular cartilage injury through different pathways. In all, 13 clinical trials were included in the analysis.

CONCLUSION

PRP is an emergent therapeutic approach in tissue engineering. Most studies reported that PRP has a positive effect on cartilage injury, improving the joint function, meanwhile there is a lack of standardized standards. The technology of PRP in the repair and treatment of articular cartilage injury is worthy of further research.

An Autologous Topical Serum Derived from Platelet-Rich Plasma Therapy for the Management of Sensitive Skin Alterations: A Case Series Report

Background

Although the underlying pathophysiology of sensitive skin remains unknown, it presents clinical symptoms like erythema, burning and dryness associated with other inflammatory dermatoses such as dermatitis or rosacea.

Objective

The aim of the present report was to provide preliminary data about the efficacy of Endoret-Serum (ES) as an autologous therapy for the topical management of sensitive skin alterations.

Materials and Methods

Five patients underwent a daily topical ES treatment that was maintained for three months. Clinical assessment was carried out using validated dermatological surveys (DLQI, IGA, Likert, PGI-I). Additionally, skin hydration measurement and high-resolution topographic and reflectance confocal imaging analysis were carried out.

Results

No adverse events were observed during the treatment. At the end of the follow-up period, surveys highlighted a significant therapeutic effect compared to baseline. Skin hydration was also improved, and topographic images showed a decrease in patient’s underlying inflammatory and vascular condition.

Conclusion

This preliminary report suggests that Endoret-Serum may be useful in the management of clinical symptoms derived from sensitive skin alterations.

The effects of orthobiologics in the treatment of tendon pathologies: a systematic review of preclinical evidence

Purpose

The aim of this systematic review is to explore the current available knowledge about tendon disorders and orthobiologics derived by preclinical experiments to evaluate their role and efficacy in the different stages and conditions related to the tendon healing processes.

Methods

The systematic review was performed according to the PRISMA guidelines. Different electronic databases (MEDLINE, Web of Science, EMBASE) were searched for studies investigating orthobiologics (PRP and cell-based products from adipose tissue or bone marrow) in animal models or veterinary clinical trials for tendon pathologies (complete/partial tendon ruptures, rotator cuff tears, tendinopathy, enthesis-related injuries). Data regarding the specific product used, the treatment site/pathology, the host and the model were collected. The results were classified into the following categories: histological, biomechanical, molecular and imaging.

Results

A large pool of preclinical studies on tendon disorders have been found on platelet-rich plasma (PRP), while data about stromal vascular fraction (SVF) and bone marrow concentrate (BMAC) are still limited and frequently focused on expanded cells, rather than orthobiologics prepared at the point of care.

The effect of PRP is related to an acceleration of the healing process, without improvements in the final structure and properties of repaired tendon. Cell-based products have been reported to produce more durable results, but the level of evidence is currently insufficient to draw clear indications.

Conclusions

The preclinical results about orthobiologics applications to tendon pathologies would support the rationale of their clinical use and encourage the performance of clinical trials aimed to confirm these data in human subjects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00468-w.

In vitro effect of triamcinolone and platelet-rich plasma on cytokine levels of elbow lateral epicondylitis-derived cells

Background

The pathogenesis and treatment of lateral elbow epicondylitis (LEE) are still controversial. The purpose of the current study was to evaluate the production of inflammatory cytokines by LEE-derived cells and to compare the anti-inflammatory effect of triamcinolone acetonide with platelet-rich plasma (PRP) on cytokines production in primary culture of these cells.

Methods

Third passage cells from primary cultures of LEE were assessed for the production of the cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α by immune-enzymatic assay (ELISA), after the treatment with 1, 10 and 100 μM triamcinolone compared to no treated controls at the time points 6, 12, 18, 24, 48, 72 and 96 h, and to PRP at 48, 72 and 96 h.

Results

The cytokines IL-6 and IL-8 were produced in high concentrations by LEE cells. One, 10 and 100 μM triamcinolone induced significant decrease in the production of IL-6 and IL-8 at 48, 72 and 96 h, adding the time point 12 h for IL-8. Compared to controls, PRP caused a significant increase in the production of IL-6 and IL-8 and there was a significant increase in IL-10 production with the use of 100 μM triamcinolone at 48 h. The production of IL1-β and TNF-α was very low and did not change when the cultures were treated with triamcinolone or PRP.

Conclusion

LEE-derived cells produce IL-6 and IL-8, confirming the inflammatory nature of this condition. While triamcinolone inhibited the production of IL-6 and IL-8 by LEE cells, PRP induced an increase in these cytokines compared with controls.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02990-0.

Clinical outcome and risk factor predictive for failure of autologous PRP injections for low-to-moderate knee osteoarthritis

PURPOSE

To report the 5-year clinical efficacy of PRP intra articular injections in knee osteoarthritis (OA) and to investigate the risk factors predictive for treatment failure and poor clinical outcome.

METHODS

We retrospectively evaluated 118 patients treated for low to moderate knee OA demonstrated by X-Ray and magnetic resonance imaging (MRI) with autologous PRP injection from 2014 to 2018 with a mean 51.1 ± 14.8 (range 29 to 89) months follow-up. All the patients were evaluated with Lysholm and WOMAC score. The role of Kellgren Lawrence (KL) grade, patello-femoral (PF) degeneration, age, body mass index (BMI), relevant comorbilities, smoking status, gender, previous surgery or conservative measures were analyzed with univariate and multivariate analysis.

RESULTS

There was a significant improvement of all outcome measures at final follow-up and high satisfaction rate (79.7%). The overall failure rate was of 15.3% after a mean of 57.7 ± 15.1 (range 33 to 85) months. The BMI and the KL grade were identified as significant independent risk factor related to failure of autologous PRP injection. Patients under 60 reported significantly higher Tegner activity scale (p = 0.032) at final follow-up. Patients with KL grade 3 and patients with PF MRI-KL grade 3 had significantly lower Lysholm scores (p = 0.026 and p = 0.042 respectively) at final assessment. Younger patients with lower BMI and lower grade of radiographic OA had significantly longer therapeutic benefit (p < 0.05).

CONCLUSION

Intra articular PRP injections led to a significant clinical improvement in middle-aged adults with a low to moderate knee OA. BMI and high KL grade have been identified as significant risk factors predictive for failure at mid-term follow-up.

Characterization and Therapeutic Use of Extracellular Vesicles Derived from Platelets

Autologous blood products, such as platelet-rich plasma (PRP), are gaining increasing interest in different fields of regenerative medicine. Although growth factors, the main components of PRP, are thought to stimulate reparation processes, the exact mechanism of action and main effectors of PRP are not fully understood. Plasma contains a high amount of extracellular vesicles (EVs) produced by different cells, including anucleated platelets. Platelet-derived EVs (PL-EVs) are the most abundant type of EVs in circulation. Numerous advantages of PL-EVs, including their ability to be released locally, their ease of travel through the body, their low immunogenicity and tumourigenicity, the modulation of signal transduction as well as the ease with which they can be obtained, has attracted increased attention n. This review focuses briefly on the biological characteristics and isolation methods of PL-EVs, including exosomes derived from platelets (PL-EXOs), and their involvement in the pathology of diseases. Evidence that shows how PL-EVs can be used as a novel tool in medicine, particularly in therapeutic and regenerative medicine, is also discussed in this review.

Classification and coding of platelet-rich plasma derived from New Zealand white rabbits for tissue engineering and regenerative medicine applications

BACKGROUND AND OBJECTIVE

Platelet-rich plasma (PRP) is a category of platelet concentrate that has been widely used as a therapeutic modality in musculoskeletal medicine. The present study was conducted to classify and code the non-activated platelet-rich plasma (nPRP) derived from New Zealand white rabbits for tissue engineering and other regenerative medicine applications.

METHODS

PRP was prepared from the whole blood by double centrifugation protocol using a laboratory centrifuge. The prepared nPRP was characterized using the parameters such as platelet dose, the relative composition of platelets, WBC, and RBC. The production protocol was described using the parameters such as platelet enrichment factor, factor increase in WBC concentration, platelet capture efficiency, WBC-reducing efficiency, and RBC-reducing efficiency. The nPRP was also classified and coded using the most recent and universally accepted classification and coding systems.

RESULTS

The non-activated leukocyte-poor red cell-rich PRP had an average platelet count of 1875.75 × 10⁹/L, which is higher than the basal platelet concentration in the whole blood. Furthermore, the protocol used in this study has a mean platelet capture efficiency of 47.43 ± 6.42%.

CONCLUSION

The protocol described in this study can be used to prepare non-activated leukocyte-poor red cell-rich PRP (Red-PRP IC1) from rabbits that can be coded as 318-00-00.

The Effect of Platelet-Rich Plasma on the Intra-Articular Microenvironment in Knee Osteoarthritis

Knee osteoarthritis (KOA) represents a clinical challenge due to poor potential for spontaneous healing of cartilage lesions. Several treatment options are available for KOA, including oral nonsteroidal anti-inflammatory drugs, physical therapy, braces, activity modification, and finally operative treatment. Intra-articular (IA) injections are usually used when the non-operative treatment is not effective, and when the surgery is not yet indicated. More and more studies suggesting that IA injections are as or even more efficient and safe than NSAIDs. Recently, research to improve intra-articular homeostasis has focused on biologic adjuncts, such as platelet-rich plasma (PRP). The catabolic and inflammatory intra-articular processes that exists in knee osteoarthritis (KOA) may be influenced by the administration of PRP and its derivatives. PRP can induce a regenerative response and lead to the improvement of metabolic functions of damaged structures. However, the positive effect on chondrogenesis and proliferation of mesenchymal stem cells (MSC) is still highly controversial. Recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, significant progress has been made in understanding the mechanism of PRP action. In this review, we will discuss mechanisms related to inflammation and chondrogenesis in cartilage repair and regenerative processes after PRP administration in in vitro and animal studies. Furthermore, we review clinical trials of PRP efficiency in changing the OA biomarkers in knee joint.

Efficacy of Autologous Platelet-Rich Plasma Injections for Grade 3 Symptomatic Degenerative Meniscal Lesions: A 1-Year Follow-up Prospective Study

BACKGROUND

Platelet-rich plasma (PRP) injections have been proposed as a biologic option to provide symptomatic relief and delay surgery in patients with degenerative joint disease of osteoarthritis (OA). The efficacy of autologous PRP on symptomatic degenerative meniscal lesions (DMLs) has never been investigated.

HYPOTHESIS

We hypothesized that patients with symptomatic DMLs without OA undergoing autologous PRP injections experience a significant clinical improvement at 12 months.

STUDY DESIGN

Prospective case series.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 69 patients with symptomatic DMLs without radiographic evidence of knee OA (Kellgren-Lawrence radiographic grading scale 0-1) received 4 autologous PRP injections once a week. Patients were prospectively evaluated before the injection and then at 1, 3, 6, and 12 months. Evaluation was based on Lysholm knee scoring scale (primary outcome), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Tegner activity scale, and visual analogue scale scores.

RESULTS

Patients treated with PRP injections demonstrated an improving knee function and symptoms over the duration of the study. A significant improvement from baseline to 12 months was observed in all the outcome measures, and no patients experienced failure or required surgery during the follow-up. Patients younger than 50 years reported lower subjective level of pain and higher Tegner activity scale at baseline and had significantly better Lysholm knee scoring scale (P = 0.03) and WOMAC (P = 0.03) scores at 6 months, as well as better range of motion at 3, 6, and 12 months (P < 0.001). Thirty-three (47.8%) patients were very satisfied, 26 (37.7%) satisfied, 8 (11.6%) partially satisfied, and 2 (2.9 %) not satisfied, with 62 (89.8%) patients willing to repeat the same treatment. No patient was lost to follow-up and no patient experienced adverse reaction, infection, failure, recurrence or underwent further surgery.

CONCLUSION

PRP injections provide short-term benefits in symptomatic DMLs. Although promising results were evident at 12 months, this is a preliminary study and no definitive recommendation can be made based, for example, on longer follow-up.

CLINICAL RELEVANCE

This research supports the use of autologous PRP injections for symptomatic DMLs.

Moving toward targeting the right phenotype with the right platelet-rich plasma (PRP) formulation for knee osteoarthritis

Intra-articular injections of platelet-rich plasma (PRP) and other novel blood-derived products developed specifically for osteoarthritis (OA) can provide pain relief and potential benefits in disease progression. Meta-analyses show the clinical superiority of PRP compared with other intra-articular injections, but results are modest and the effect sizes are small. PRP injections in knee OA are performed indiscriminately, but the clinical response varies enormously between patients because of an array of mixed OA phenotypes. Subgroup analyses are scarce; some studies stratify patients according to radiographic severity and found better results in early OA, without consensus for more advanced stages of the condition. Parallel identification of soluble and imaging biomarkers is essential to personalise and leverage PRP therapies. The inflammatory phenotype is most interesting from the PRP perspective because PRPs modulate inflammation by releasing a large pool of chemokines and cytokines, which interact with synovial fibroblasts and macrophages; in addition, they can modulate the innate immune response. No soluble biomarkers have been discovered that have implications for OA research and PRP interventions. Clinical examination of patients based on their inflammatory phenotype and imaging identification of pain sources and structural alterations could help discern who will respond to PRP. Synovial inflammation and bone marrow lesions are sources of pain, and intra-articular injections of PRP combined with subchondral bone injection can enhance clinical outcomes. Further refining ultrasound phenotypes may aid in personalising PRP therapies. Intra-articular delivery combined with injections in altered ligamentous structures, medial and coronal ligaments or premeniscal pes anserinus showed positive clinical outcomes. Although the evidence supporting these approaches are weak, they merit further consideration to refine PRP protocols and target the right OA phenotypes.

PRP in wound healing applications

Platelets play a crucial role in hemostasis, tissue regeneration and host defense. Based on these settings, platelet-rich plasma (PRP) and its derivatives are therapeutically used to promote wound healing in several scenarios. This review summarizes the biological mechanisms underlying the most traditional as well as innovative applications of PRP in wound healing. These mechanisms involve the combined action of platelet-derived growth factors and cytokines, together with the role of plasma-derived fibrillar, antioxidant and homeostatic factors. In addition, regenerative treatments with PRP consist of personalized and non-standardized methods. Thus, the quality of PRP varies depending on endogenous factors (e.g., age; gender; concomitant medication; disease-associated systemic factors; nutrition) and exogenous factors (anticoagulants and cellular composition). This review also analyses whether these factors affect the biological mechanisms of PRP in wound healing applications.

Preparation Methods and Clinical Outcomes of Platelet-Rich Plasma for Intra-articular Hip Disorders: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Background:

Despite its increasing use in the management of musculoskeletal conditions, questions remain regarding the preparation methods of platelet-rich plasma (PRP) and its clinical applications for intra-articular hip disorders, including femoroacetabular impingement syndrome (FAIS), labral pathology, and osteoarthritis (OA).

Purpose:

To systematically review and assess the preparation methods and clinical outcomes from randomized clinical trials (RCTs) on the use of PRP for intra-articular hip disorders.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

A systematic review in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed in September 2019. The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Ovid Medline, and Embase were queried for studies regarding the use of PRP to treat intra-articular hip disorders. Qualifying articles were English-language RCTs describing the use of PRP for intra-articular hip disorders, either as standalone treatment or surgical augmentation. Two authors independently assessed article eligibility. Data pertaining to patient characteristics, indication for treatment, PRP preparation method, follow-up period, and clinical outcomes were extracted. Study results were qualitatively reported and quantitatively compared using meta-analysis when appropriate.

Results:

Seven RCTs met inclusion criteria. Four studies described the use of PRP for hip OA and 3 utilized PRP at arthroscopy for FAIS and labral tears. Outcomes after PRP for OA demonstrated improvement in validated patient-reported outcome measures for up to 1 year; however, pooled effect sizes found no statistically significant difference between PRP and hyaluronic acid (HA) regarding pain visual analog scale scores at short-term (≤2 months; P = .27), midterm (4-6 months; P = .85), or long-term (1 year; P = .42) follow-up. When injected at arthroscopy, 1 study reported improved outcomes, 1 reported no difference in outcomes, and 1 reported worse outcomes compared with controls. The meta-analysis demonstrated no statistically significant difference on the modified Harris Hip Score (mHHS) between PRP and control cohorts at a minimum 1-year follow-up. There were considerable deficiencies and heterogeneity in the reporting of PRP preparation methods for both indications.

Conclusion:

Treatment of OA with PRP demonstrated reductions in pain and improved patient-reported outcomes for up to 1 year. However, there was no statistically significant difference between PRP and HA in pain reduction. Likewise, for FAIS and labral surgery there was no statistically significant difference in mHHS outcomes between patients treated with PRP and controls. Given the limited number of studies and variability in PRP preparations, additional high-quality randomized trials are warranted.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.