Do the fibrin architecture and leukocyte content influence the growth factor release of platelet concentrates? An evidence-based answer comparing a pure platelet-rich plasma (P-PRP) gel and a leukocyte- and platelet-rich fibrin (L-PRF)

Guided bone regeneration using beta-tricalcium phosphate and leucocyte platelet-rich fibrin versus a novel biodegradable urethane composite in critical-size osseous defects in rabbit tibia: Histologic results of a pilot study

BACKGROUND

Insufficient bone volume is a major problem in implant dentistry, which can be counteracted by using guided bone regeneration technique. Among the materials recently tested, synthetic polymers have been recommended as showing excellent biocompatibility and biodegradability.

OBJECTIVE

The aim of this pilot study was to analyze and compare through means of histology the healing of the bone tissue in critical size osseous defects in New-Zealand rabbit tibiae after application of beta-tricalcium phosphate (β-TCP) alone, β-TCP combined with leucocyte platelet-rich fibrin (L-PRF) and an injectable experimental bone cement (EBC) represented by a dual-curable degradable synthetic polymer.

METHODS

Two New-Zealand rabbits were used. Three standardized osseous defects of 5 mm diameter were created in each tibia. Each defect was filled with either β-TCP alone (control), β-TCP combined with L-PRF (test) or with EBC (test). The animals were sacrificed at 25 and 70 days; the tibia samples were removed, fixed in 10 % formaldehyde and stained with AZAN.

RESULTS

While at 25 days β-TCP produced sparse bone formation, at 70 days mature bone formation was visible in all areas of the defect with minimum remaining graft particles; at 25 days, β-TCP combined with L-PRF produced broad areas of bone lamellae, while at 70 days bone tissue formation was limited; at both 25 and 70 days, the EBC was stable and not penetrated by bone cells, while a narrow band of connective tissue could be seen superjacent and inferior to it.

CONCLUSIONS

Among the tested biomaterials, β-TCP was capable of generating bone formation at both healing time-points, while the addition of L-PRF seemed to provide a synergistic effect only in the early phase of bone healing.

Tensile Strength, Cellular Content and Degradation properties in three generations of concentrated growth factors

BACKGROUND

Concentrated growth factors (CGF) is a biomaterial with regenerative potential, enriched with platelets, leukocytes, growth factors, and fibrin, but it degrades within 2-3 weeks. Albumin extends CGF stability, while silver nanoparticles (SNP) improve its mechanical and antibacterial properties. This in vitro and ex vivo study investigates the impact of albumin (Alb-CGF) and albumin with SNP (Alb-CGF-SNP) on CGF's mechanical properties, degradation rate, and cellular bioactivity.

METHODS

Blood samples were collected from 15 healthy volunteers who met specific inclusion criteria, with the sample size determined using G*Power software for power calculation. Three groups were prepared: control CGF, experimental Alb-CGF, and Alb-CGF-SNP. Membranes were produced using a Medifuge MF200 centrifuge and activated plasma albumin gel (APAG) device following standard settings. In experimental groups, the superficial 2.5 ml of plasma layer was heated at 75 °C for 10 min before combining with the buffy coat layer of CGF. Mechanical properties were tested using a texture analyzer, degradation rates were measured by weight loss percentage, and cellular bioactivity was evaluated with a Sysmex hematology analyzer. Data analysis was conducted using GraphPad Prism 8.0. Group differences were assessed via one-way ANOVA and Welch ANOVA, with Tukey's HSD test for post hoc paired group comparisons.

RESULTS

The control (CGF) showed the highest mechanical properties, with Ultimate Tensile Strength (UTS) (95.6 kPa), Modulus of Toughness (55.55 kJ/m3), and Young's Modulus (75.73 kPa; (P < 0.01). No significant differences were observed in the strain at break across groups (P > 0.90). Alb-CGF-SNP displayed superior degradation resistance, with 45.2% weight loss at day 60 versus 84.2% in CGF (P < 0.01). CGF had the highest WBC and platelet levels, with amounts of 2.25 and 3.11-fold, respectively (P < 0.01).

CONCLUSION

The modification of CGF with albumin and silver nanoparticles enhanced degradation resistance, although it did not reach the tensile strength and cellular content of unmodified CGF. Clinically, Alb-CGF and Alb-CGF-SNP serve as effective barrier membranes due to their prolonged stability, while CGF remains advantageous where high mechanical strength is required. Despite lower elasticity limiting suturing, their plasticity supports use as fillers or for tissue phenotype modification in regenerative applications.

Enhanced Palatal Wound Healing with Leucocyte- and Platelet-Rich Fibrin After Free Gingival Graft Harvesting: A Prospective Randomized Controlled Clinical Trial

Background/Objectives: Autogenous palatal free gingival graft (FGG) harvesting presents challenges for patients due to the increased risk of postoperative morbidity related to a second intraoral surgical wound that heals with secondary intention. This parallel-group, randomized, controlled, open-label trial aimed to evaluate the efficacy of the application of leukocyte- and platelet-rich fibrin (L-PRF) membrane to the palatal donor site on wound healing, hemostasis, and pain control after FGG harvesting. Methods: Twenty-eight adult patients with insufficient attached gingiva underwent soft tissue augmentation using FGG harvested from the palate at the Department of Oral and Maxillofacial Surgery, Baskent University, Turkey. Patients were randomized to either an L-PRF group or a control group. In the L-PRF group, the L-PRF membrane was sutured to the donor sites, whereas in the control group, donor sites healed by secondary intention. Postoperative evaluations were conducted on days 1, 3, 5, and 7 and at weeks 2, 3, 4, 5, and 6. Donor sites were evaluated clinically for pain, burning sensation, bleeding, wound healing, and color match to adjacent tissues. Donor site wound areas were analyzed using digital images. Results: Two patients were excluded from the analysis due to loss of contact, leaving 26 (n = 13, n = 13) patients for analysis. Donor site pain and burning sensation were significantly lower in the L-PRF group compared to the control group during the first two postoperative weeks (p < 0.001). Bleeding was significantly lower in the L-PRF group on postoperative days 1 and 3 (p < 0.001). Clinical healing index scores were significantly higher in the L-PRF group at weeks 3 and 4 (p < 0.001). Additionally, palatal wound area reductions from baseline were significantly greater in the L-PRF group at all follow-up intervals (p < 0.001). Conclusions: The application of an L-PRF membrane to palatal donor wounds after FGG harvesting significantly reduces postoperative pain, decreases bleeding, and accelerates healing, providing a valuable autologous biomaterial for enhanced wound healing and improved patient comfort.

L-PRF in extra-oral wound care

Leukocyte- and platelet-rich fibrin (L-PRF), a by-product of centrifuged autologous whole blood, contains high concentrations of platelets, leukocytes, and fibrin (the latter spontaneously creating a strong 3-D network (a membrane)). L-PRF membranes possess several characteristics essential in wound healing, including a barrier function, an antibacterial and analgesic activity, and the release of growth factors enhancing tissue regeneration and neo-vasculogenesis. This review investigated the role of L-PRF in treating non-responding chronic wounds such as diabetic foot, venous leg ulcers, pressure ulcers, complex wounds, leprosy ulcers (Hansen's Disease), and other demanding wounds. Chronic wounds affect millions worldwide, negatively impacting their quality of life, productivity, and life expectancy while incurring high treatment costs for themselves and private and public health systems. L-PRF has demonstrated clear adjunctive advantages in treating chronic skin wounds, shortening the time to complete wound closure, and improving patient-reported outcome measures (including reducing pain and minimizing the need for analgesics). Also, in other demanding wounds, L-PRF facilitates healing. To help clinicians, this article also proposes recommendations for the use of L-PRF in the treatment of extra-oral wounds.

Differences between first- and second-generation autologous platelet concentrates

Autologous platelet concentrates (APCs) applied alone or combined with other biomaterials are popular bioactive factors employed in regenerative medicine. The main biological rationale of using such products is to concentrate blood-derived growth factors and cells into the wound microenvironment to enhance the body's natural healing capacity. First-generation APC is represented by platelet-rich plasma (PRP). While different protocols have been documented for PRP preparation, they overall consist of two cycles of centrifugation and have important limitations related to the use of an anticoagulant first and an activator afterward, which may interfere with the natural healing process and the release of bioactive molecules. The second generation of platelet concentrates is represented by leukocyte and platelet-rich fibrin (L-PRF). L-PRF protocols involve a single centrifugation cycle and do not require the use of anticoagulants and activators, which makes the preparation more straight forward, less expensive, and eliminates potential risks associated with the use of activators. However, since no anticoagulant is employed, blood undergoes rapid clotting within the blood collection tube; hence, a timely management of L-PRF is crucial. This review provides an overview on the most documented protocols for APC preparations and critically discusses the main differences between first- and second-generation APCs in terms of cell content, protein release, and the formation of a 3D fibrin network. It appears evident that the inconsistency in reporting protocol parameters by most studies has contributed to conflicting conclusions regarding the efficacy of different APC formulations and has significantly limited the ability to interpret the results of individual clinical studies. In the future, the use of a standardized classification system, together with a detailed reporting on APC protocol parameters is warranted to make study outcomes comparable. This will also allow to clarify important aspects on the mechanism of action of APCs (like the role of leukocytes and centrifugation parameters) and to optimize the use of APCs in regenerative medicine.

The Role of Platelet Concentrates and Growth Factors in Facial Rejuvenation: A Systematic Review with Case Series

Background and objectives: Due to the regeneration potential of growth factors (GFs) and platelet concentrates (PCs), facial rejuvenation has been a major area of attention in esthetic medicine. The effectiveness and safety of PCs and GFs in promoting face rejuvenation are examined in this systematic review, which is complemented by a case series. GFs are essential for collagen production and dermal matrix remodeling, while PCs, like Platelet-Rich Plasma (PRP), are abundant in bioactive chemicals that promote tissue healing and cellular regeneration. Materials and Methods: A comprehensive literature search was performed on PubMed, Web of Science, and Scopus, focusing on human clinical trials published between February 2019 and February 2024 related to PRP and facial esthetics. Results: Thirteen studies met the inclusion criteria and were analyzed. Conclusions: The review summarizes the most recent data on patient outcomes, treatment regimens, and possible hazards. The case series that goes with it shows real-world examples of how to improve skin elasticity, texture, and general facial appearance with little negative side effects. These results highlight the potential use of PCs and GFs as minimally invasive procedures.

Guided Bone Regeneration: CGF and PRF Combined With Various Types of Scaffolds-A Systematic Review

Objective: Bone regeneration plays a pivotal role in modern oral surgery, particularly in facilitating successful implant-prosthetic rehabilitation. This systematic review explores the regenerative potential of growth factors, such as platelet-rich fibrin (PRF) and concentrated growth factors (CGFs), when combined with various types of scaffolds in bone augmentation procedures, including guided bone regeneration, split crest, sinus lift (SL), and alveolar ridge preservation. Method: A comprehensive search strategy yielded 18 relevant studies, which were analyzed for bone formation and stabilization outcomes. Results: Results indicate that PRF enhances bone regeneration and stabilization in SL and ridge augmentation procedures, while CGFs facilitate surgical techniques and augment bone. However, some studies did not report significant differences. Growth factors also demonstrate benefits in wound healing, reducing bone resorption, and enhancing socket preservation. Conclusion: Despite valuable insights, further research is needed to comprehensively understand the characteristics of growth factors in various surgical interventions, ensuring informed decision-making in bone regeneration surgery.

Use of Autologous Leukocyte-Platelet Rich Fibrin (L-PRF) in Endoscopic Anterior Skull Base Defect Repair-A Newer Graft Material: Name of Authors

CSF rhinorrhea secondary to anterior skull base defect may be spontaneous or traumatic (accidental or iatrogenic), spontaneous being common in middle aged, obese females. Nowadays endoscopic technique is gold standard for anterior skull base defect repair. The graft materials available may be autologous (fat, temporalis fascia, fascia lata, septal mucosa, cartilage, middle turbinate), homologous e.g., cadaveric pericardium or allograft e.g. dural substitute. Leukocyte-platelet rich fibrin (L-PRF) is a newer graft material that contain concentrated platelets and doesn't require any exogenous material or chemical in blood. A prospective study including 31 patients was carried out at tertiary care centre in eastern India, over the period of 2 years. All the surgeries targeted for closure of the anterior skull base defect were performed endoscopically under general anaesthesia. 30 out of 31 (96.77%) patients successfully improved after repair and one patient required revision surgery due to recurrence of disease and was cured after revision surgery. Autologous Leokocyte-plasma rich fibrin (L-PRF) is a newer and cost-effective graft material for the CSF leak repair with good healing property and with a success rate of more than 95%.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of select 2023 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertize in their subject areas that include (in order of appearance here): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine, oral and maxillofacial surgery, and oral radiology; and dental caries and cariology. The authors have focused their efforts on presenting information likely to influence the daily dental treatment decisions of the reader with an emphasis on current innovations, new materials and processes, emerging technology, and future trends in dentistry. With the overwhelming volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to inform and update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope readers find this work helpful in providing evidence-based care to patients seeking healthier and happier lives.

First- vs. Second-Generation Autologous Platelet Concentrates and Their Implications for Wound Healing: Differences in Proteome and Secretome

Differences in cell count and growth factor expression between first- and second-generation autologous platelet concentrates (APCs) have been well described. The debate over which formula best supports wound healing in various surgical procedures is still ongoing. This study aims to assess the whole proteome assembly, cell content, immunological potential and pro-angiogenic potential of second-generation APC, Platelet-Rich Fibrin (PRF) vs. first-generation APC, Platelet-Rich Plasma (PRP). The global proteome of the APCs was analyzed using nano-liquid chromatography mass spectrometry. Blood cell concentrations were determined by an automated cell counter. The effect of APCs on macrophage polarization was analyzed by flow cytometry. A yolk sac membrane (YSM) assay was used to monitor the neo-vessel formation and capillary branching in vivo. Cell count analysis revealed a higher number/concentration of leukocytes in PRF vs. PRP. Incubation of macrophages with PRP or platelet-free plasma (PFP) did not induce a significant pro-inflammatory state but led to a shift to the M0/M2 phenotype as seen in wound healing for all tested formulas. Label-free proteomics analysis identified a total of 387 proteins from three biological replicates of the respective designated groups. PRF induced increased formation of neo-vessels and branching points in vivo in comparison to PRP and PFP (each p < 0.001), indicating the enhanced pro-angiogenic potential of PRF. Overall, PRF seems superior to PRP, an important representative of first-generation formulas. Inclusion of leucocytes in PRF compared to PRP suggested rather an anti-inflammatory effect on macrophages. These results are important to support the versatile clinical applications in regenerative medicine for second-generation autologous platelet concentrates to optimize wound healing.

The Effect of Advanced Platelet-Rich Fibrin Plus (A-PRF+) on Graft Stability in Dental Implants and Alveolar Ridge Augmentation Procedures: A New Low-Speed Standardized Centrifugation Protocol

Background: Platelet-rich fibrin (PRF) is a concentrate derived from autologous blood, containing platelets, fibrin, and growth factors (GF) obtained through centrifugation. PRF can be mixed with bone replacement material to form sticky bone, which is then introduced into the desired area for stabilizing and graft-covering. Depending on the centrifugation protocol, the effectiveness of the end products can vary. This controlled clinical study examines the impact of our established PRF protocol in alveolar augmentation and dental implant placement on vertical bone loss. Materials and Methods: A total of 362 implants were performed in 170 patients at the Department of Oral and Maxillofacial Surgery at the University Hospital Innsbruck between 2018 and 2021. After accounting for lost implants, we retrospectively evaluated a radiological vertical bone loss exceeding 1 mm in the first year as the primary endpoint. Results: The use of PRF was significantly associated with vertical bone loss > 1 mm (OR = 0.32, 95% CI (0.13-0.81), p = 0.016). There were no significant associations between PRF and the number of implants lost, the type of augmentation, or bone loss. Discussion: A-PRF+ sticky bone grafts, when combined with bone graft materials, show reduced resorption rates, indicating their potential to enhance graft stability in oral implantology. Our data indicate that the Medifuge MF 100 (Silfradent srl, Forlì, Italy) is effective in producing A-PRF+.

Effectiveness of concentrated growth factors with or without grafting materials in maxillary sinus augmentation: a systematic review

Concentrated Growth Factor (CGF) is a highly effective biomaterial known for its ability to promote tissue regeneration. While it's been studied extensively in intraoral procedures and bone grafting, its benefits in maxillary sinus lifting lack substantial evidence. This review aimed to evaluate CGF's effectiveness in maxillary sinus augmentation, focusing on clinical, radiographic, and histological outcomes.A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Google Scholar, and Cochrane Library databases using specific mesh terms and keywords and adhered to PRISMA guidelines. Studies up to March 2024 involving transcrestal or lateral maxillary sinus floor elevation with CGF, either alone or in combination with grafting materials, were included.Out of 783 publications, 13 studies met the eligibility criteria. The review assessed CGF's role in minimizing postoperative complications, enhancing new bone formation, and improving implant survival. Despite data variability among studies, the majority reported that CGF positively influenced maxillary sinus augmentation outcomes.While more robust randomized clinical trials are required to draw definitive conclusions, initial results are promising, and the findings suggest that CGF utilization in maxillary sinus augmentation seems to enhance clinical outcomes by promoting vascularization and regeneration at the surgical sites and improving both the quality and quantity of newly formed sinus bone. Furthermore, it exhibits potential for improving postoperative sequelae and achieving high implant survival rates.

Effectiveness of autologous leukocyte-platelet-rich fibrin on the rate of maxillary canine retraction, rotation, pain, and soft tissue healing: A split-mouth randomized controlled trial

Objective

To assess the effectiveness of leukocyte-platelet-rich fibrin (L-PRF) compared with conventional treatment on canine retraction, rotation, pain, and soft tissue healing.

Methods

Sixteen adult patients aged 18-25 years (10 females, and 6 males; mean age 22.25 ± 2.26 years) with Class I bimaxillary protrusion and Class II div 1 malocclusion participated in this single-center, split-mouth randomized controlled trial at the Orthodontics Department of a single hospital in SCB Dental College and Hospital, Cuttack, India. Randomization was performed using a computer-assisted function with a 1:1 allocation ratio. The intervention included the placement of L-PRF on the experimental side and follow-up for 90 days. The primary outcome measures were canine retraction, rotation, pain, and soft tissue healing. The range of tooth movement was evaluated at 15-day intervals: 0th day (T0), 15th day (T1), 30th day (T2), 45th day (T3), 60th day (T4), 75th day (T5), and 90th day (T6). Canine rotation was assessed at T0 and T6, and pain and soft tissue healing were evaluated on the 3rd, 7th, and 15th days of the treatment.

Results

Cumulatively, the L-PRF group demonstrated a significantly greater tooth movement as compared to conventional treatment group (P < 0.001). Overall, canine retraction was 1.5 times greater on the L-PRF side than on the control side. Canine rotation showed no significant relationship, whereas pain and soft tissue healing were significantly better on the L-PRF side than on the control side.

Conclusions

Local administration of L-PRF amplifies canine retraction while improving pain and soft tissue repair.

The Use of Platelet-Rich Fibrin (PRF) in the Management of Dry Socket: A Systematic Review

Dry socket or alveolar osteitis is a common postoperative complication following tooth extraction, characterized by severe pain due to the disintegration of the blood clot within the socket. Various factors contribute to its development, such as traumatic extraction, patient age and sex, smoking, and anesthetic use. To mitigate this condition, socket preservation techniques, including the use of bone substitute materials, have been employed. Platelet-rich fibrin (PRF) has emerged as a promising biomaterial, enhancing healing and reducing the incidence of dry socket. Materials and Methods: This systematic review, adhering to the PRISMA guidelines and registered with PROSPERO (ID: CRD 578018), examines the efficacy of PRF in managing dry socket by analyzing studies from PubMed, Scopus, and Web of Science published between January 2013 and May 2024. Boolean keywords have been used in the search strategy: ("Treatment") AND ("Dry Socket") AND ("Platelet Rich Fibrin" OR "PRF"). A total of 738 publications were found using the electronic database search. After the screening phase, 13 records were chosen for qualitative analysis. The results from multiple clinical trials and comparative studies indicate that PRF significantly reduces postoperative pain, expedites healing, and lowers the incidence of Alveolar Osteitis. Despite promising results, further large-scale, randomized studies are needed to validate PRF as a standard treatment for dry socket.

The Role of Autologous Platelet Concentrates as a Local Antibiotic Delivery System: A Systematic Scoping Review

OBJECTIVES

Ongoing research has begun to develop innovative approaches to deliver local antibiotics while minimizing systemic side effects, antimicrobial resistance, and limited tissue penetration. Autologous platelet concentrates (APCs) offer promise in delivering antibiotics directly to infection sites. Despite the interest, a comprehensive evaluation of their effectiveness is lacking. Therefore, this systematic scoping review aims to collect and appraise studies regarding the efficacy of APCs in delivering antibiotics.

METHODS

A systematic electronic search of PubMed, Scopus, and Web of Science, using a combination of keywords, was conducted up to February 2024. Articles addressing the use of APCs as a local antibiotic delivery system were included.

RESULTS

A total of 13 articles, including 10 in vitro studies, 1 in vitro and clinical study, 1 ex vivo study, and 1 clinical study, were selected. Antibiotic loading capacity and release was confirmed in all studies using doxycycline, gentamicin, linezolid, vancomycin, metronidazole, and penicillin. In addition, the antibacterial effect was obtained mainly against E. coli., P. aeruginosa, S. mitis, H. influenzae, S. pneumoniae, and S. aureus.

CONCLUSIONS

The incorporation of antibiotics into APCs has been proven to facilitate the effective release of antimicrobial agents at optimal concentrations, potentially reducing the incidence of post-operative infections, substituting, or augmenting systemic antibiotic treatment while retaining APCs' inherent healing properties.

Platelet-rich fibrin as an adjunct to scaling and root planing in treatment of shallow periodontal pockets: A randomized clinical trial

OBJECTIVES

To evaluate the efficacy of platelet-rich fibrin (PRF) as an adjunct to scaling and root planing (ScRp) for healing shallow periodontal pockets.

METHODS

Twelve patients with periodontitis were enrolled in this split-mouth, randomized clinical trial. A total of 24 shallow periodontal pockets (4-6 mm) were treated by either ScRp alone (control) or PRF (test). Clinical attachment loss (CAL), probing pocket depth (PPD), bleeding on probing (BOP), and plaque index (PLI), as well as platelet-derived growth factor-BB (PDGF-BB) by enzyme-linked immunosorbent assay (ELISA) in gingival crevicular fluid (GCF) were measured at baseline and at 1- and 3-month follow-up visits.

RESULTS

At 1- and 3-month follow-up visits, greater CAL gains (2.6 ± 0.25 mm and 3.26 ± 0.31 mm, respectively) and PPD reductions (2.58 ± 0.38 and 3.31 ± 0.39 mm, respectively) were observed in the test group compared to those in controls (CAL gain of 1.01 ± 0.49 mm and 1.43 ± 0.48 mm; PPD reduction of 1.1 ± 0.55 and 1.37 ± 0.49 mm, respectively). In addition, the increase in PDGF-BB in GCF in the test group (724.5 ± 186.09 pg/μl and 1957.5 ± 472.9 pg/μl) was significantly greater than that in controls (109.3 ± 24.07 and 614.64 ± 209.3 pg/μl) at 1- and 3-month follow-up visits, respectively.

CONCLUSIONS

The noninvasive use of PRF as an adjunct to ScRp successfully improved clinical periodontal parameters and might contribute to increased PDGF-BB in GCF.

A Systematic Review of Laser Photobiomodulation Dosimetry and Treatment Protocols in the Management of Medications-Related Osteonecrosis of the Jaws: A Rationalised Consensus for Future Randomised Controlled Clinical Trials

Medication-related osteonecrosis of the jaw (MRONJ) is a debilitating adverse effect of bisphosphates, antiresorptive therapy or antiangiogenic agents that can potentially increase oxidative stress, leading to progressive osteonecrosis of the jaws. Despite the large number of published systematic reviews, there is a lack of potential MRONJ treatment protocols utilising photobiomodulation (PBM) as a single or adjunct therapy for preventive or therapeutic oncology or non-oncology cohort. Hence, this systematic review aimed to evaluate PBM laser efficacy and its dosimetry as a monotherapy or combined with the standard treatments for preventive or therapeutic approach in MRONJ management. The objectives of the review were as follows: (1) to establish PBM dosimetry and treatment protocols for preventive, therapeutic or combined approaches in MRONJ management; (2) to highlight and bridge the literature gaps in MRONJ diagnostics and management; and (3) to suggest rationalised consensus recommendations for future randomised controlled trials (RCTs) through the available evidence-based literature. This review was conducted according to the PRISMA guidelines, and the protocol was registered at PROSPERO under the ID CRD42021238175. A multi-database search was performed to identify articles of clinical studies published from their earliest records until 15 December 2023. The data were extracted from the relevant papers and analysed according to the outcomes selected in this review. In total, 12 out of 126 studies met the eligibility criteria. The striking inconsistent conclusions made by the various authors of the included studies were due to the heterogeneity in the methodology, diagnostic criteria and assessment tools, as well as in the reported outcomes, made it impossible to conduct a meta-analysis. PBM as a single or adjunct treatment modality is effective for MRONJ preventive or therapeutic management, but it was inconclusive to establish a standardised and replicable protocol due to the high risk of bias in a majority of the studies, but it was possible to extrapolate the PBM dosimetry of two studies that were close to the WALT recommended parameters. In conclusion, the authors established suggested rationalised consensus recommendations for future well-designed robust RCTs, utilising PBM as a monotherapy or an adjunct in preventive or therapeutic approach of MRONJ in an oncology and non-oncology cohort. This would pave the path for standardised PBM dosimetry and treatment protocols in MRONJ management.

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.

A randomised Trial of Autologous Blood products, leukocyte and platelet-rich fibrin (L-PRF), to promote ulcer healing in LEprosy: The TABLE trial

INTRODUCTION

Autologous blood products like Platelet Rich Plasma (PRP) and Leukocyte and Platelets Rich Fibrin (L-PRF) have been used for many years across many types of skin ulcers. However, the effectiveness of autologous blood products on wound healing is not well established.

METHODS

We evaluated the 'second generation' autologous product- Leukocyte and Platelet- Rich Fibrin (L-PRF). Our trial was undertaken on patients suffering from neuropathic leprosy ulcers at the Anandaban hospital which serves the entire country of Nepal. We conducted a 1:1 (n = 130) individually randomised trial of L-PRF (intervention) vs. normal saline dressing (control) to compare rate of healing and time to complete healing. Rate of healing was estimated using blind assessments of ulcer areas based on three different measurement methods. Time to complete healing was measured by the local unblinded clinicians and by blind assessment of ulcer images.

RESULTS

The point estimates for both outcomes were favourable to L-PRF but the effect sizes were small. Unadjusted mean differences (intervention vs control) in mean daily healing rates (cm2) were respectively 0.012 (95% confidence interval 0.001 to 0.023, p = 0.027); 0.016 (0.004 to 0.027, p = 0.008) and 0.005 (-0.005 to 0.016, p = 0.313) across the three measurement methods. Time to complete healing at 42 days yielded Hazard Ratios (unadjusted) of 1.3 (0.8 to 2.1, p = 0.300) assessed by unblinded local clinicians and 1.2 (0.7 to 2.0, p = 0.462) on blind assessment.

CONCLUSION

Any benefit from L-PRF appears insufficient to justify routine use in care of neuropathic ulcers in leprosy.

TRIAL REGISTRATION

ISRCTN14933421. Date of trial registration: 16 June 2020.

Ultrasonographic analysis of palatal donor site healing accelerated with platelet-rich fibrin following subepithelial connective tissue harvesting

OBJECTIVE

Platelet-rich fibrin (PRF) contains a variety of growth factors and bioactive molecules that play crucial roles in wound healing and angiogenesis. We aimed to evaluate the effects of PRF on tissue thickness and vascularization of the palatal donor site by ultrasound (USG) following subepithelial connective tissue harvesting.

METHODOLOGY

A subepithelial connective tissue graft was harvested from the palatal region with a single incision for root coverage in 20 systemically healthy patients. In the test group (n = 10), the PRF membrane was placed at the donor site, whereas no material was applied in the control group (n=10). Palatal tissue thickness (PTT) and pulsatility index (PI) were evaluated by USG at baseline and on the 3rd, 7th, 14th, 30th, and 90th days after surgery. The early healing index (EHI) was used to evaluate donor site healing for 30 days.

RESULTS

PTT was significantly higher in the PRF group on the 3rd and 14th days after surgery when compared to the controls. In the PRF-treated group, PI levels were significantly higher than in the controls, especially on the 14th day. PTT increased significantly 90 days after surgery compared to the test group baseline, but controls showed a significant decrease. The PRF group showed statistically significant improvements in EHI scores compared to controls on days 3, 7, and 14. This study found a negative correlation between PI values and EHI scores on postoperative days three and seven in the test group.

CONCLUSION

USG is a non-invasive, objective method to radiographically evaluate the regenerative effects of PRF on palatal wound healing after soft tissue harvesting. To overcome graft inadequacy in reharvesting procedures, PRF application may enhance clinical success and reduce possible complications by increasing tissue thickness and revascularization in the donor area.

A Novel Fibrin Matrix Derived from Platelet-Rich Plasma: Protocol and Characterization

Although fibrin matrices derived from Platelet-Rich Plasma (PRP) are widely used in regenerative medicine, they have some limitations that can hinder their application. Modifying the composition of the PRP-derived fibrin matrix may improve its properties, making it suitable for certain medical uses. Three types of fibrin matrices were obtained: a PRP-derived fibrin matrix (FM), a PRP-derived fibrin matrix with a high fibrinogen content and platelets (FM-HFP) and a PRP-derived fibrin matrix with a high fibrinogen content (FM-HF). The fibrinogen levels, biomechanical properties and cell behavior were analyzed. The presence of platelets in the FM-HFP generated an inconsistent fibrin matrix that was discarded for the rest of the analysis. The fibrinogen levels in the FM-FH were higher than those in the FM (p < 0.0001), with a concentration factor of 6.86 ± 1.81. The values of clotting and swelling achieved using the FM-HF were higher (p < 0.0001), with less clot shrinkage (p < 0.0001). The FM had a significantly higher stiffness and turned out to be the most adherent composition (p = 0.027). In terms of cell viability, the FM-HF showed less cell proliferation but higher live/dead ratio values (p < 0.01). The increased fibrinogen and platelet removal in the FM-HF improved its adhesion and other biomechanical properties without affecting cell viability.

Review of Dohan Eherenfest et al. (2009) on "Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)"

This classic discusses the original publication of Dohan Eherenfest et al. on "Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)", in which the authors propose four categories of platelet concentrates depending on their leucocyte and fibrin content (P-PRP, leucocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and L-PRF) to group a "jungle" of products in which the term platelet-rich plasma (PRP) was used indistinctly. They were able to identify common factors such as: (1) the use of anticoagulants and immediate centrifugation of the blood after its collection; (2) most preparation techniques allowed platelet concentrate preparation within an hour; (3) the centrifugation aimed to separate the blood in layers that would allow the extraction of specific fractions; and (4) the product was activated with thrombin or calcium chloride. The reviewed manuscript has been listed among the most cited PRP articles in regenerative medicine, with more than 800 citations, driving current scientific research and clinical practise by categorising L-PRP and P-PRP (now, leucocyte-poor PRP). The classification has also opened the door to understanding intrinsic biological mechanisms between platelets, leukocytes, fibrin, and growth factors, which will later be considered for studying the proliferation and differentiation of cells in different tissues affected by PRP. Since the initial classification of platelet concentrates, several other classification systems have been proposed and published in the current literature such as platelet, activation, white blood cell (PAW), Mishra, platelet, leucocyte, red blood cells, and activation (PLRA), dose of platelet, efficiency, purity, and activation (DEPA), method, activation, red blood cells, spin, platelets, image guidance, leukocytes, and light activation (MARSPILL), etc. These classifications have identified important aspects of PRP that affect the biological composition and, ultimately, the indications and outcomes. To date, there is still a lack of standardisation in sample preparation, cohort heterogeneity, and incomplete reporting of sample preparation utilised, leading to a lack of clarity and challenging researchers and clinicians.

Towards optimized tissue regeneration: a new 3D printable bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate

Introduction

Autologous platelet concentrate (APC) are pro-angiogenic and can promote wound healing and tissue repair, also in combination with other biomaterials. However, challenging defect situations remain demanding. 3D bioprinting of an APC based bioink encapsulated in a hydrogel could overcome this limitation with enhanced physio-mechanical interface, growth factor retention/secretion and defect-personalized shape to ultimately enhance regeneration.

Methods

This study used extrusion-based bioprinting to create a novel bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate. Chemico-physical testing exhibited an amorphous structure characterized by high shape fidelity. Cytotoxicity assay and incubation of human osteogenic sarcoma cells (SaOs2) exposed excellent biocompatibility. enzyme-linked immunosorbent assay analysis confirmed pro-angiogenic growth factor release of the printed constructs, and co-incubation with HUVECS displayed proper cell viability and proliferation. Chorioallantoic membrane (CAM) assay explored the pro-angiogenic potential of the prints in vivo. Detailed proteome and secretome analysis revealed a substantial amount and homologous presence of pro-angiogenic proteins in the 3D construct.

Results

This study demonstrated a 3D bioprinting approach to fabricate a novel bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate with high shape fidelity, biocompatibility, and substantial pro-angiogenic properties.

Conclusion

This approach may be suitable for challenging physiological and anatomical defect situations when translated into clinical use.

Three Milliliters of Peripheral Blood Is Sufficient for Preparing Liquid Platelet-Rich Fibrin (PRF): An In Vitro Study

Platelet-rich fibrin (PRF) has assumed an important role in supporting tissue regeneration in different fields. To date, the standard protocol for liquid PRF requires at least 10 mL of peripheral blood. The present study aimed to analyze the composition, growth factor release, and effects on the cell proliferation of PRF samples produced using 3 mL vs. 10 mL of peripheral blood in vitro. Peripheral venous blood from six healthy donors was used to prepare liquid PRF using either 3 mL or 10 mL tubes. Three different centrifugation protocols were used according to the low-speed centrifugation concept. The cellular distribution was evaluated using immunohistology and automated cell count. ELISA was used to determine the release of different growth factors (EGF, TGF-β1, and PDGF) and interleukin 8 at different time points. Primary human osteoblasts (pOBs) were cultivated for 7 days using PRF-conditioned media acquired from either 3 mL or 10 mL of peripheral blood. The results showed that 3 mL of peripheral blood is sufficient to produce a liquid PRF concentrate similar to that acquired when using 10 mL blood. The concentrations of platelets and leukocytes were comparable regardless of the initial blood volume (3 mL vs. 10 mL). Similarly, the release of growth factors (EGF, TGF-β1, and PDGF) and interleukin 8 was often comparable in both groups over 7 days. The cultivation of pOBs using PRF-conditioned media showed a similar proliferation rate regardless of the initial blood volume. This proliferation rate was also similar to that of pOBs treated with 20% FBS-conditioned media. These findings validated the use of 3 mL of peripheral blood to generate liquid PRF matrices according to the low-speed centrifugation concept, which may open new application fields for research purposes such as in vivo experiments and clinical applications such as pediatric surgery.

Fucoidan/chitosan hydrogels as carrier for sustained delivery of platelet-rich fibrin containing bioactive molecules

Platelet-rich fibrin (PRF), derived from human blood, rich in wound healing components, has drawbacks in direct injections, such as rapid matrix degradation and growth factor release. Marine polysaccharides, mimicking the human extracellular matrix, show promising potential in tissue engineering. In this study, we impregnated the self-assembled fucoidan/chitosan (FU_CS) hydrogels with PRF obtaining PRF/FU_CS hydrogels. Our objective was to analyze the properties of a hydrogel and the sustained release of growth factors from the hydrogel that incorporates PRF. The results of SEM and BET-BJH demonstrated the relatively porous nature of the FU_CS hydrogels. ELISA data showed that combining FU_CS hydrogel with PRF led to a gradual 7-day sustained release of growth factors (VEGF, EGF, IL-8, PDGF-BB, TGF-β1), compared to pure PRF. Histology confirmed ELISA data, demonstrating uniform PRF fibrin network distribution within the FU_CS hydrogel matrix. Furthermore, the FU_CS hydrogels revealed excellent cell viability. The results revealed that the PRF/FU_CS hydrogel has the potential to promote wound healing and tissue regeneration. This would be the first step in the search for improved growth factor release.

Bone Formation and Maintenance in Oral Surgery: The Decisive Role of the Immune System-A Narrative Review of Mechanisms and Solutions

Based on the evidence of a significant communication and connection pathway between the bone and immune systems, a new science has emerged: osteoimmunology. Indeed, the immune system has a considerable impact on bone health and diseases, as well as on bone formation during grafts and its stability over time. Chronic inflammation induces the excessive production of oxidants. An imbalance between the levels of oxidants and antioxidants is called oxidative stress. This physio-pathological state causes both molecular and cellular damage, which leads to DNA alterations, genetic mutations and cell apoptosis, and thus, impaired immunity followed by delayed or compromised wound healing. Oxidative stress levels experienced by the body affect bone regeneration and maintenance around teeth and dental implants. As the immune system and bone remodeling are interconnected, bone loss is a consequence of immune dysregulation. Therefore, oral tissue deficiencies such as periodontitis and peri-implantitis should be regarded as immune diseases. Bone management strategies should include both biological and surgical solutions. These protocols tend to improve immunity through antioxidant production to enhance bone formation and prevent bone loss. This narrative review aims to highlight the relationship between inflammation, oxidation, immunity and bone health in the oral cavity. It intends to help clinicians to detect high-risk situations in oral surgery and to propose biological and clinical solutions that will enhance patients' immune responses and surgical treatment outcomes.

Evaluation of the efficacy of injectable platelet-rich fibrin versus platelet-rich plasma in the regeneration of traumatized necrotic immature maxillary anterior teeth: A randomized clinical trial

BACKGROUND/AIM

This study aimed at comparing the regenerative potential of injectable platelet-rich fibrin (i-PRF) (Group 1) and platelet-rich plasma (Group 2) scaffolds.

MATERIALS AND METHODS

Twenty-three patients, aged from 9 to 24 years, having 24 immature traumatized necrotic maxillary anterior teeth, were enrolled. Teeth trauma was confirmed by patients' history. Preoperative three-dimensional scans were done. In the first visit, canals were irrigated with 1.5% sodium hypochlorite then medicated with calcium hydroxide. After 2 weeks, patients were randomly assigned into one of the treatment groups (n = 12). The platelet concentrate was applied after centrifuging 10 mL of autologous venous blood with respect to the centrifugation protocol for each platelet concentrate. Patients were recalled at 6 and 12 months posttreatment, during which clinical and radiographic examinations and assessment of pulp sensitivity were done. Three-dimensional scanning was done after 12 months. The increase in root length and decrease in root canal diameters were calculated at three canal levels. Statistical analysis was done using the paired t-test and the independent t-test. The significance level was set at p < .05.

RESULTS

There was no statistically significant difference between both groups regarding the increase in root length, decrease in coronal and middle canal diameters and the response to the electric pulp tester. Group (1) showed significantly greater decrease in apical canal diameter than Group (2) (p = .008).

CONCLUSION

I-PRF can be considered as a valid regenerative scaffold for clinical use and with regards to the easier preparation technique, it is more recommended than platelet-rich plasma.

Autologous platelet-rich plasma (APRP) in diabetes foot disease: a meta-analysis

INTRODUCTION

This study will explore the effectiveness of autologous platelet-rich plasma in the treatment of diabetic foot disease compared to conventional treatments, based on the ulcer healing rate.

METHODS

The electronic databases of PubMed, EMBASE, and WOS internet were searched. Evaluated outcome rate of complete ulcer healing. Statistical analysis was performed with RevMan 5.0 software and SPSS 25.0.

RESULTS

Eleven RCTs with 828 patients were included in this study. The meta-analysis showed a higher complete ulcer healing rate (OR = 3.69, 95 % CI 2.62 to 5.20, P < 0.01, I2 = 0 %) in growth factors based in autologous platelech-rich plasma (aPRP) group compared with control. Mixed evidence was seen for publication bias, but analyses by using the trim-and-fill method did not appreciably alter results.

CONCLUSION

Autologous platelet-rich plasma can improve the complete healing rate of the ulcer compared to current conventional treatments in diabetic foot ulcer patients.

The Potential Therapeutic Effects of Platelet-Derived Biomaterials on Osteoporosis: A Comprehensive Review of Current Evidence

Osteoporosis is a chronic multifactorial condition that affects the skeletal system, leading to the deterioration of bone microstructure and an increased risk of bone fracture. Platelet-derived biomaterials (PDBs), so-called platelet concentrates, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), have shown potential for improving bone healing by addressing microstructural impairment. While the administration of platelet concentrates has yielded positive results in bone regeneration, the optimal method for its administration in the clinical setting is still debatable. This comprehensive review aims to explore the systemic and local use of PRP/PRF for treating various bone defects and acute fractures in patients with osteoporosis. Furthermore, combining PRP/PRF with stem cells or osteoinductive and osteoconductive biomaterials has shown promise in restoring bone microstructural properties, treating bony defects, and improving implant osseointegration in osteoporotic animal models. Here, reviewing the results of in vitro and in vivo studies, this comprehensive evaluation provides a detailed mechanism for how platelet concentrates may support the healing process of osteoporotic bone fractures.

Reinforcement of colon anastomosis healing with leukocyte platelet-rich fibrin in rabbit model

AIM

This study investigated the regenerative efficacy of leukocyte platelet-rich fibrin (L-PRF) on colon anastomotic healing in rabbits.

MAIN METHODS

Thirty-six healthy male white New Zealand rabbits were subjected to complete transactions of the ascending colon. The rabbits were equally divided into two groups: the control group, where the transected colon ends were anastomosed by a simple interrupted suture pattern, and the L-PRF-treated group, in which L-PRF was wrapped entirely around the anastomotic line. The postoperative acute pain scale was assessed using the Bristol Rabbit Pain Scale before surgery and at each four-hour interval post-operatively. After euthanizing the rabbits, the adhesion degree score, anastomotic bursting pressure, and stenosis degree of the anastomotic colon were assessed, and histopathological examination at the 7th, 14th, and 28th days postoperatively.

KEY FINDINGS

Rabbits in both groups showed a significant increase in pain scores compared to baseline. Postoperatively, the L-PRF group exhibited significantly lower pain scores, adhesion scores, and stenosis degrees than the control group. However, the anastomotic bursting pressure was significantly higher in the L-PRF group. Re-epithelialization, polymorphonuclear neutrophil infiltration, granulation tissue formation, and collagen deposition scores were improved considerably in the L-PRF group compared to the control group. Immunostaining of growth factor expression was significantly lower in the control than in the L-PRF group.

SIGNIFICANCE

The L-PRF can augment collagen deposition, re-epithelialize the mucosa, promote angiogenesis, reduce adhesions, and diminish the stenosis degree scores. Therefore, it can be considered a promising aid in healing bowel anastomoses.

Does leukocyte-platelet-rich fibrin (L-PRF) cause long term acceleration in the rate of canine retraction? A split-mouth, two-arm parallel group, randomized control trial

OBJECTIVE

The present study was conducted to investigate the effects of leukocyte-platelet-rich fibrin (L-PRF) on the rate of maxillary canine retraction for a period of 5 months.

METHODS

A split-mouth study was conducted on 16 subjects (9 males and 7 females; age range 17-25 years; mean age, 21.85±2.45 years) who required therapeutic extraction of bilateral maxillary first premolars. After the initial leveling and alignment, L-PRF plugs were placed in a randomly selected extraction socket (Experimental Group), and the other side served as a control (Control Group). Canine retraction was carried out by the activation of nickel-titanium (NiTi) closed-coil springs delivering 150 g of force. The rates of canine movement, canine rotation, tipping, root resorption, and molar movement were assessed at monthly intervals for five months (T0-T5). Pain, swelling and discomfort accompanying the procedure were assessed using a Likert scale.

RESULTS

The study revealed a significant increase in the rate of canine movement on the experimental side in the first two months, and significant molar anchorage loss was observed only in the first month for control side. There were no statistically significant differences between the groups regarding canine rotation, tipping, probing depth, root resorption, and pain perception.

CONCLUSIONS

The use of L-PRF plugs in extraction sockets considerably enhanced the rate of canine movement only in the first two months, and long-term efficacy was not observed in this study.

Influence of periodontitis and diabetes on structure and cytokine content of platelet-rich fibrin

BACKGROUND

Platelet-rich fibrin (PRF) is a second-generation platelet concentrate with multiple applications in wound healing and regeneration in both periodontitis and diabetes. However, the three dimensional (3-D) structure and cytokine content of PRF might be altered in patients suffering from either/both of the chronic inflammatory conditions, ultimately influencing the efficacy of PRF as a biomaterial for regenerative medicine.

AIM

The aim of the present study was hence to evaluate the effect of both these chronic inflammatory diseases on the 3-D structure of PRF membrane. An attempt was also made to compare the growth factor content between the plasma and RBC ends of the prepared PRF gel.

MATERIALS & METHODS

L-PRF was prepared for twenty participants, healthy (5), periodontitis (5), T2DM (5) and T2DM with periodontitis (5). Porosity and fiber diameter of PRF membranes was visualized under FE-SEM and measured using ImageJ Software. PDGF-BB and TGF-β1 levels in PRF gel were assessed by ELISA.

RESULTS

The average diameter of fibrin fibers under FE-SEM was 0.15 to 0.30 micrometers. Porosity was higher at the plasma end (p = 0.042). Red blood cell (RBC) end of the membrane had thinner fibers arranged in a comparatively more dense and compact structure with smaller porosities. Healthy subjects had the least porous PRF compared to subjects with either/both of the chronic conditions. PDGF-BB levels were similar along all the four groups. TGF-β1 levels were highest in healthy subjects.

DISCUSSION

3-D structure and growth factor content of PRF are influenced by a person's periodontal and/or diabetic status. The RBC end of the PRF membrane, as compared to the plasma end, has thinner fibers arranged in a comparatively more dense and compact structure with smaller porosities, and hence should be favored during periodontal regenerative procedures.

CONCLUSION

Both periodontitis and diabetes have a significant influence on the 3-D structure and growth factor content of PRF produced.

The Effect of Leukocyte- and Platelet-Rich Fibrin on Central and Peripheral Nervous System Neurons-Implications for Biomaterial Applicability

Leukocyte- and Platelet-Rich Fibrin (L-PRF) is a second-generation platelet concentrate that is prepared directly from the patient's own blood. It is widely used in the field of regenerative medicine, and to better understand its clinical applicability we aimed to further explore the biological properties and effects of L-PRF on cells from the central and peripheral nervous system. To this end, L-PRF was prepared from healthy human donors, and confocal, transmission, and scanning electron microscopy as well as secretome analysis were performed on these clots. In addition, functional assays were completed to determine the effect of L-PRF on neural stem cells (NSCs), primary cortical neurons (pCNs), and peripheral dorsal root ganglion (DRG) neurons. We observed that L-PRF consists of a dense but porous fibrin network, containing leukocytes and aggregates of activated platelets that are distributed throughout the clot. Antibody array and ELISA confirmed that it is a reservoir for a plethora of growth factors. Key molecules that are known to have an effect on neuronal cell functions such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) were slowly released over time from the clots. Next, we found that the L-PRF secretome had no significant effect on the proliferative and metabolic activity of NSCs, but it did act as a chemoattractant and improved the migration of these CNS-derived stem cells. More importantly, L-PRF growth factors had a detrimental effect on the survival of pCNs, and consequently, also interfered with their neurite outgrowth. In contrast, we found a positive effect on peripheral DRG neurons, and L-PRF growth factors improved their survival and significantly stimulated the outgrowth and branching of their neurites. Taken together, our study demonstrates the positive effects of the L-PRF secretome on peripheral neurons and supports its use in regenerative medicine but care should be taken when using it for CNS applications.

Histological, Immunohistochemical, Biomechanical, and Wettability Evaluations of the Leukocyte- and Platelet-Rich Fibrin Membranes Derived from Canine Blood

This study aimed to perform histological, immunohistochemical, biomechanical, and wettability assessments of leukocyte- and platelet-rich fibrin (L-PRF) membranes obtained from the blood of healthy dogs. Ten client-owned Labrador Retriever dogs were enrolled. Blood samples were obtained from the external jugular vein using a vacuum tube without anticoagulant, which was immediately centrifuged at 400g for 12 min in a dedicated centrifuge. The L-PRF clot was removed from the tube, and the red clot was released from the buffy coat using a spatula. The membrane was produced using a PRF box. Histological examination identified the three portions of the L-PRF membranes. The first portion was composed mainly of red blood cells with the presence of a low number of leukocytes among them. The second portion was composed of white blood cells, mainly neutrophils. The third portion was composed of the fibrin network which was characterized by acidophilic staining. The immunohistochemical analysis showed that vascular endothelial growth factor and platelet-derived growth factor were expressed in all samples at different intensities, both in cellular components and fibrin mesh. The tensile test and wettability assessments were measured in membranes 30 min and 3 h after production. The 30 min L-PRF membranes supported twice the ultimate tensile strength compared to 3 h L-PRF membranes. The wettability of the 30 min sample membranes was statistically higher than the 3 h sample membranes. In conclusion, the centrifugation protocol allowed production of the L-PRF membrane using canine blood and this was confirmed by histological and immunohistochemical analysis. The mechanical resistance and wettability of the L-PRF membrane were significantly reduced over time.

Current Concepts in Patellar Tendinopathy: An Overview of Imaging, Pathogenesis, and Nonoperative and Operative Management

» Approximately 1 in 3 high-impact athletes develops patellar tendinopathy (PT), with the proximal insertion of the patellar tendon being the most commonly affected anatomical site.» Nonoperative treatment options are effective in reducing pain and restoring functionality in most patients with PT. However, operative intervention should be considered when conservative management fails.» A comprehensive review of the literature on surgical procedures, including both open and arthroscopic approaches, was conducted with a specific focus on clinical outcomes and return to sports.» Both open surgery and arthroscopic surgery for PT have demonstrated favorable success rates and return-to-sport outcomes, with arthroscopic treatment potentially expediting the recovery process.

Effect of the use of platelet concentrates on new bone formation in alveolar ridge preservation: a systematic review, meta-analysis, and trial sequential analysis

OBJECTIVES

To investigate the histomorphometric changes occurring in alveolar ridge preservation (ARP) based on the use of different plasma concentrates (PCs) in randomized clinical trials (RCT). There is controversy whether the placement of PCs in ARP is effective in the formation of new bone.

MATERIALS AND METHODS

A systematic review search was conducted in PubMed, Scopus, Web of Science, and Cochrane Database to answer the PICO question: In patients undergoing tooth extraction followed by ARP, do PCs alone in the post-extraction socket in comparison with spontaneous healing improve new vital bone formation percentage in histomorphometric analysis after more than 10 weeks? The risk of bias was assessed and a meta-analysis was conducted.

RESULTS

Of 3809 results, 8 studies were considered suitable for inclusion. A total of 255 teeth were extracted in 250 patients. Regarding the PCs used, ARP was performed with platelet- and leukocyte-rich fibrin (L-PRF) in 120 sockets, and with pure platelet-rich plasma (P-PRP) in 31 sockets and 104 sockets were controlled. PCs improved new bone formation in ARP with respect to the spontaneous healing group (SMD = 1.77, 95%C.I. = 1.47-2.06, p-value < 000.1). There were no differences between the different PCs (L-PRF and P-PRP).

CONCLUSION

The results of this meta-analysis support the efficacy of the use of PCs in new bone formation in ARP. With respect to the different types of PCs studied, no differences were observed.

CLINICAL RELEVANCE

When planning implant surgery after tooth extraction, treatment with PCs should be considered for ARP. Any PC increases new bone formation compared to spontaneous healing.

Evaluation of Implant Surface Modification with Nanohydroxyapatite Associated with the Use of L-PRF: In Vivo Study in Rats

Leukocyte-platelet-rich fibrin (L-PRF) contains growth factors that stimulate bone regeneration. This study evaluated the bone repair in a tibia rat model around two implant surfaces in combination or not with L-PRF by assessing microtomographic and histomorphometric parameters. A total of 48 female rats were used in the study, in which 24 received implants with two types of surface treatments (dual acid etched-DAE or nanohydroxyapatite-nanoHA), and the other 24 received the same mini implants with L-PRF, which was collected by cardiac puncture, centrifugated, and inserted in the bone bed. The animals were euthanized 7 and 30 days after implant placement, and the retrieved samples were prepared for microtomographic and histomorphometric (bone-to-implant contact-BIC; and Bone Area Fraction Occupancy-BAFO) analyses. The adhesion of the nanoHA surface onto the implant surface was investigated by insertion and removal in simulated bone medium (Sawbones). The adhesion evaluation revealed that the loss of nanoHA after this procedure (as measured with SEM) from the implant surface was less than 1%. Overall, the nanoHA surface presented more bone in contact and in proximity to the implant, a higher bone surface/tissue volume fraction, a higher number of bone trabeculae, as well as trabecular separation relative to the DAE surface. Such results were more evident when the nanoHA surface was combined with L-PRF and after 30 days in vivo. The nanoHA surface presented higher BAFO when compared to DAE, with or without association with L-PRF. Therefore, implants with a nanoHA surface potentially benefit from the association to L-PRF.

Maxillary Sinus Augmentation Using Autologous Platelet Concentrates (Platelet-Rich Plasma, Platelet-Rich Fibrin, and Concentrated Growth Factor) Combined with Bone Graft: A Systematic Review

BACKGROUND

The current review aims to provide an overview of the most recent research on the potentials of concentrated growth factors used in the maxillary sinus lift technique.

MATERIALS AND METHODS

"PRP", "PRF", "L-PRF", "CGF", "oral surgery", "sticky bone", "sinus lift" were the search terms utilized in the databases Scopus, Web of Science, and Pubmed, with the Boolean operator "AND" and "OR".

RESULTS

Of these 1534 studies, 22 publications were included for this review.

DISCUSSION

The autologous growth factors released from platelet concentrates can help to promote bone remodeling and cell proliferation, and the application of platelet concentrates appears to reduce the amount of autologous bone required during regenerative surgery. Many authors agree that growth factors considerably enhance early vascularization in bone grafts and have a significantly positive pro-angiogenic influence in vivo when combined with alloplastic and xenogeneic materials, reducing inflammation and postoperative pain and stimulating the regeneration of injured tissues and accelerating their healing.

CONCLUSIONS

Even if further studies are still needed, the use of autologous platelet concentrates can improve clinical results where a large elevation of the sinus is needed by improving bone height, thickness and vascularization of surgical sites, and post-operative healing.

Halting the Progression of Cicatricial Alopecia with Injectable Platelet-Rich Fibrin

Discoid lupus erythematosus (DLE) is a chronic variant of cutaneous lupus erythematosus characterized by well-defined erythematous plaques with adherent scales and follicular plugging. The affected scalp shows erythema, edema, atrophy, alopecia, and telangiectasia. Trichoscopy of DLE shows branching capillaries, white patches, keratin plugs, reduced follicular ostia, and white dots and blue-gray dots arranged in speckles pattern. Prompt diagnosis and aggressive, early multimodal therapy helps in preventing disfiguring hair loss and psychosocial sequelae. Hereby, we present a case of reversal of hair loss in DLE with newer modalities of treatment such as injectable platelet-rich fibrin.

Standardization of Animal Models and Techniques for Platelet-Rich Fibrin Production: A Narrative Review and Guideline

Experimental research is critical for advancing medical knowledge and enhancing patient outcomes, including in vitro and in vivo preclinical assessments. Platelet-rich fibrin (PRF) is a blood by-product that has garnered attention in the medical and dental fields due to its potential for tissue regeneration and wound healing. Animal models, such as rabbits and rats, have been used to produce PRF and examine its properties and applications. PRF has demonstrated potential in the dental and medical fields for reducing inflammation, promoting tissue repair, and accelerating wound healing. This narrative review aims to compare existing evidence and provide guidelines for PRF animal research, emphasizing the importance of standardizing animal models, following ethical considerations, and maintaining transparency and accountability. The authors highlight the necessity to use the correct relative centrifugal force (RCF), standardize centrifugal calibration, and report detailed information about blood collection and centrifuge parameters for reproducible results. Standardizing animal models and techniques is crucial for narrowing the gap between laboratory research and clinical applications, ultimately enhancing the translation of findings from bench to bedside.

Leukocyte-Rich and Platelet-Rich Fibrin for Skull Base Reconstruction After Endoscopic Endonasal Skull Base Surgery

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leak is one of the most common complications after endoscopic endonasal approach to the skull base.

OBJECTIVE

To analyze the effect of leukocyte-rich and platelet-rich fibrin (L-PRF) as part of a standardized endonasal skull base repair protocol on postoperative infection and CSF leak rate.

METHODS

One hundred three patients who underwent an endoscopic endonasal approach and were reconstructed using a standard technique (Group A) were compared with 139 patients using the same protocol with the addition of L-PRF (Group B). Postoperative intracranial infection and CSF leak at 6 months were analyzed.

RESULTS

In patients with intraoperative CSF leak, postoperative leak occurred in 10.8% in Group A and 2.6% in Group B ( P .024), and in patients with intraoperative high-flow leaks, the incidences were 11.7% and 3.1%, respectively ( P .048). L-PRF reduced postoperative CSF leak by 76% in cases with intraoperative CSF leak (relative risk 0.24, 95% CI 0.06-0.87) and by 73% of patients with high-flow leak (relative risk 0.27, 95% CI 0.07-0.99). In patients undergoing surgery for diagnoses other than adenomas, there were no cases of postoperative leak in Group B, whereas in Group A occurred in 13.4% of those with intraoperative leaks ( P .047) and 15.8% with high-flow intraoperative leaks ( P .033). No significant differences were found in patients with pituitary adenoma. Meningitis occurred in 0.97% in Group A vs 2.16% in Group B ( P .639), without differences between subgroups.

CONCLUSION

L-PRF reduced the rate of postoperative CSF leaks in patients with intraoperative leaks, without differences on postoperative meningitis.

A meta-analysis on the efficacy of vacuum sealing drainage combined with autologous platelet-rich plasma in the treatment of Grade 2 and Grade 3 diabetic foot ulcers

This meta-analysis aims to systemically evaluate the efficacy of vacuum sealing drainage (VSD) combined with autologous platelet-rich plasma (PRP) in the treatment of diabetic foot ulcers (DFU). The China HowNet, China Biomedical Literature, VIP periodical resource integration service platform, Wanfang, Embase, Cochrane Central, and PubMed databases were retrieved using the computer. The retrieval period was up to July 2021. Randomised controlled trials on VSD combined with PRP in the treatment of DFU were collected. Those trials that met the inclusion criteria were included for meta-analysis using RevMan 5.3 software. A total of 13 articles were included. In the trial group, 477 patients with DFU were treated with VSD combined with PRP, while in the control group, 482 patients with DFU were treated with conventional dressings and/or VSD. The meta-analysis showed that, compared with the control group, VSD combined with PRP has significant advantages in shortening healing time (standardised mean difference [SMD] = -0.87, 95% confidence interval [CI]: -1.07 to -0.67, P < .00001), improving ulcer healing rates (odds ratio = 4.01, 95% CI: 2.95 ~ 5.46, P < .00001), and reducing hospital stays (mean difference = -15.29, 95% CI: -16.05 to -14.54, P < .00001), but the differences in dressing change times (SMD = -1.27, 95% CI: -2.71 to 0.17, P = .08) and hospitalisation expenses (SMD = -0.16, 95% CI: -13.40 to 13.07, P = .98) were not statistically significant. VSD combined with autologous PRP has good curative efficacy in the treatment of DFU and is a better treatment option. However, this treatment is limited in patients with platelet dysfunction, thrombocytopenia, leukaemia, and poor general condition.

Skin and Bone Regeneration of Solid Bone Marrow Aspirate Concentrate Versus Platelet-Rich Fibrin

Solid bone marrow aspirate concentrate (sBMAC) is harvested from bone marrow aspirate without anticoagulants by a centrifugation protocol similar to that for platelet-rich fibrin (PRF) prepared from peripheral blood. It was hypothesized that sBMAC could accelerate not only wound healing but also bone regeneration because of the abundant growth factor (GF) releases from enriched bone marrow cells. The purpose of the present study was to investigate skin wound healing and bone regenerative potential of sBMAC compared with arterial blood-derived PRF (Ar-PRF) and venous blood-derived PRF (Ve-PRF) in a skin defect and calvarial bone defect model in rabbits. GF release assays revealed significantly higher release of transforming growth factor-β (TGF-β), alkaline phosphatase (ALP), and osteocalcin (OCN) from sBMAC compared with PRFs for 24 h. In the skin defect animal model, sBMAC and PRFs promoted wound bed angiogenesis and re-epithelization in skin defect sites with higher collagen 1 synthesis, cytokeratin AE1/AE3, vascular endothelial growth factor (VEGF) expressions on week 1. Furthermore, a calvarial defect assay revealed that sBMAC promoted new bone formation with a sufficient bone marrow structure similar to that of intact bone in the bone defects. Ar-PRF achieved the second highest bone closure and new bone volume but yielded new bone that was thinner than the intact bone. In conclusion, sBMAC treatment might be a good option instead of PRF as an adjuvant therapy for both skin and bone tissue regeneration therapies in certain clinical situations. Impact statement Solid bone marrow aspirate concentrate (sBMAC) is new type of clot material prepared from bone marrow aspirate. The present study for the first time showed that sBMAC significantly accelerated both skin wound healing and bone formation in the defects, compared with conventional platelet-rich fibrin in rabbit experiment models.

Efficacy of intrauterine infusion therapy before embryo transfer in recurrent implantation failure: A systematic review and network meta-analysis

Previous studies of intrauterine infusion therapy in recurrent implantation failure (RIF) patients have shown conflicting results, and there is a lack of head-to-head horizontal comparisons between different drugs. This study aimed to assess the effectiveness of four intrauterine infusion drugs, including human chorionic gonadotropin (HCG), granulocyte colony-stimulating factor (G-CSF), peripheral blood mononuclear cells (PBMCs) and autologous platelet-rich plasma (PRP), in improving pregnancy outcomes in RIF patients through the network meta-analysis. Randomized controlled trials (RCTs) of preimplantation intrauterine infusion for RIF were searched in the Cochrane Library, Embase, Medline and CINAHL. Meanwhile, relevant data were extracted and Stata 15.0 software was applied to statistical analysis. A total of 21 studies with a sample size of 2917 cases were included in this study. Clinical pregnancy rate network meta-analysis showed that, intrauterine infusion of all four drugs is significantly better than the blank and placebo groups, while only PRP could significantly increase live birth rate compared with the blank and placebo groups. The SUCRA plots of clinical pregnancy and live birth rates showed a higher ranking of PRP and PBMCs. Early abortion intervention analysis found that only G-CSF is significantly better than the blank and placebo groups, and the SUCRA plot of G-CSF showed the highest ranking. All these findings confirmed that all four intrauterine infusion drugs can improve pregnancy outcomes in RIF patients to varying degrees, with PRP being the most effective. Further prospective, large-scale and high-quality RCTs are still necessary to determine the exact subgroups of benefit for the different drugs.

Autologous Tooth Graft: Innovative Biomaterial for Bone Regeneration. Tooth Transformer® and the Role of Microbiota in Regenerative Dentistry. A Systematic Review

Different biomaterials, from synthetic products to autologous or heterologous grafts, have been suggested for the preservation and regeneration of bone. The aim of this study is to evaluate the effectiveness of autologous tooth as a grafting material and examine the properties of this material and its interactions with bone metabolism. PubMed, Scopus, Cochrane Library, and Web of Science were searched to find articles addressing our topic published from 1 January 2012 up to 22 November 2022, and a total of 1516 studies were identified. Eighteen papers in all were considered in this review for qualitative analysis. Demineralized dentin can be used as a graft material, since it shows high cell compatibility and promotes rapid bone regeneration by striking an ideal balance between bone resorption and production; it also has several benefits, such as quick recovery times, high-quality newly formed bone, low costs, no risk of disease transmission, the ability to be performed as an outpatient procedure, and no donor-related postoperative complications. Demineralization is a crucial step in the tooth treatment process, which includes cleaning, grinding, and demineralization. Since the presence of hydroxyapatite crystals prevents the release of growth factors, demineralization is essential for effective regenerative surgery. Even though the relationship between the bone system and dysbiosis has not yet been fully explored, this study highlights an association between bone and gut microbes. The creation of additional scientific studies to build upon and enhance the findings of this study should be a future objective of scientific research.

Peripheral nerve regeneration in rats using nerve graft in a vein conduit pre-filled with platelet-rich fibrin (PRF)

Treatment of peripheral nerve injury is not always satisfactory. To improve results, specific adjuvant methods have been used, such as platelet-rich fibrin (PRF) and vein conduits. The goal of this study was to assess whether use of PRF and vein conduits after nerve suture improves nerve regeneration as measured by a functional score and histomorphometry analysis. Ten isogenic spontaneously hypertensive rats were randomly assigned to 4 experimental procedures: 1) Sham group (n = 10); 2) Nerve graft (NG) group (n = 10); 3) Nerve graft covered with a vein conduit (NGVC) (n = 10); and 4) Nerve graft covered with a vein conduit pre-filled with PRF (NGVCP) (n = 10). Nerve repair results were evaluated on: sciatic functional index (SFI) at 0, 30, 60 and 90 days; morphometric and morphologic analysis of the distal nerve; and histological analysis of Fluoro-Gold® stained motor neurons in the anterior horn of the spinal cord. Compared to the Sham control group, the NGVC and NGVCP groups exhibited lower SFI on all measures. The NGVC group showed improvement in SFI at day 90, which was significant compared to the NG group. Fiber and axon diameters were comparable in the NGVC and NGVCP groups, which were both significantly lower than in the Sham and NG groups. Significant improvement was expected with PRF, but in fact the release of factors from this substance was not as effective as hoped.

Effect of leukocyte-platelet-rich fibrin in bone healing around dental implants placed in conventional and wide osteotomy sites: A pre-clinical study

Leukocyte-platelet-rich fibrin (L-PRF) has been suggested for gap management for immediate implant placement when the distance is greater than 2 mm. However, there remains a paucity in hierarchically designed research to support this application. The present study aimed to evaluate the effect of L-PRF on the osseointegration parameters of dental implants placed after conventional osteotomy of surgically created bone defects that simulate post extraction sockets in a canine model after 3, 6, and 12 weeks in vivo. Eighty dental implants (Intra-Lock, Boca Raton, FL) were placed in the radius of 13 beagle dogs. The experiment consisted of 4 groups (n = 20 implants/group): 1) Regular osteotomy (Reg n/L-PRF); 2) Regular osteotomy and implant placement with L-PRF membrane (Reg L-PRF); 3) Wide osteotomy with no gap management performed, where an osteotomy/bony defect (6 mm of diameter and ~5 mm deep) was created to simulate immediate implant placement in post-extraction sockets, and the gap was left for spontaneous healing (Wide nL-PRF); and 4) Wide osteotomy with L-PRF gap management (Wide L-PRF). L-PRF membranes were obtained by blood drawn from each subject and centrifuged at 2700 rpm (408 RCF-clot) for 12 min. In the experimental groups where L-PRF was utilized, the membrane was inserted into the osteotomy site prior to implant placement. Six dogs had implants placed in the radius for 3 weeks; and 7 dogs had implants placed in the left radius for 6 weeks and in the right radius for 12 weeks. At the corresponding experimental time points, samples were harvested, and subjected to histological processing for qualitative and quantitative analyses, via bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO). Qualitative analysis demonstrated increased amounts of bone formation around the implant and within the healing chambers over time for all groups. While comparable histological features were observed for both Reg groups (L-PRF and nL-PRF), the gap management performed in Wide L-PRF group resulted in effective gap filling with improved bone growth in close proximity to the implant surface. Quantitative analyses of BIC and BAFO yielded higher values for both variables at 3 weeks for Wide L-PRF (~38% and ~56% respectively) compared to Wide nL-PRF (~20% for BIC and BAFO) (p < .03). No statistical differences were detected between Wide groups at 6 and 12 weeks, neither between Reg groups, independent of the association with or without the L-PRF membrane at all healing times. L-PRF placed within wide osteotomies, prior to implant placement, resulted in increased early bone formation compared to unfilled wide osteotomies at the early healing time (3 weeks in vivo).

Autologous platelet-rich gel in the treatment of diabetic foot ulcers: A retrospective study

This study retrospectively investigated the effectiveness and safety of autologous platelet-rich gel (APRG) for the treatment of diabetic foot ulcers (DFU). In this retrospective study, we reviewed the electronic medical records (EMR) of 72 patients with DFU. The patients were allocated to a treatment group (n = 36) or a control group (n = 36). The patients in both groups received standard care (SC) and dressing change. In addition, patients in the treatment group also received APRG. Patients in both groups were treated for 12 weeks. The outcomes were DFU healing time (days), length of hospital stay (days), healing rate of DFU, DFU surface area reduction (cm2), and adverse events. We assessed and analyzed the outcomes before and after the 12-week treatment period. After treatment, there were significant differences in DFU healing time (P = .04), length of hospital stay (P = .04), DFU healing rate, and DFU surface area reduction (P < .01). Regarding safety, no EMR reported adverse events in this study. The results of this study showed that the APRG may benefit patients with DFU. However, high-quality prospective randomized controlled trials are required to verify these findings.