Antimicrobial action of autologous platelet-rich plasma on MRSA-infected skin wounds in dogs

Antibacterial Effect of Canine Leucocyte Platelet-Rich Plasma (L-PRP) and Canine Platelet-Poor Plasma (PPP) Against Methicillin-Sensitive and Methicillin-Resistant Staphylococcus pseudintermedius

Staphylococcus pseudintermedius (SP) is a commensal and opportunistic pathogen of skin and mucosal surfaces, isolated from healthy dogs and from canine pyoderma cases. It has recently gained attention due to its increasing antibiotic resistance. Platelet-rich plasma (PRP) is a biological product, obtained through a blood centrifugation process, which has antibacterial properties evidenced by in vitro and in vivo studies conducted in both the human and veterinary field. This in vitro study evaluated the antimicrobial effect of canine non-activated and activated leucocyte-rich PRP (L-PRP) and platelet-poor plasma (PPP) against two strains of SP isolated from dogs with pyoderma: one a multidrug-resistant strain (MDR) and one a non-MDR strain. Twenty healthy un-sedated adult blood donor dogs were enrolled for L-PRP and PPP production via a closed semi-automatic system for veterinary use. The evaluation of antimicrobial effect was performed using the micro-inhibition in broth method, exposing SP strains to 10 L-PRP, 10 activated L-PRP and 10 PPP samples, respectively. Bacterial growth was evaluated using CFU count at three timepoints (immediately after incubation T0, after 1 h T1 and after 2 h T2). L-PRP and PPP had a significant antimicrobial effect at all three timepoints which was similar against both non-MDR and MDR SP strains. Activation appeared to reduce the duration of the antimicrobial effect in L-PRP. More studies are necessary to confirm these preliminary results.

The synergistic effects of platelet-rich plasma and negative pressure wound therapy in cavitary infected wounds: a single-centre experience

OBJECTIVE

To evaluate the efficacy of the combined application of platelet-rich plasma (PRP) and negative pressure wound therapy (NPWT) in cavitary infected wounds, in addition to the parameter settings of NPWT.

METHODS

The outcomes of patients with cavitary wounds who received debridement with either PRP plus NPWT (PRP group) or NPWT alone (controls) as part of their treatment protocol were retrospectively compared by examining preoperative and postoperative data on high-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), white blood cell (WBC) count, neutrophil percentage, bacterial cultures, pain (measured using visual analogue scale [VAS] scores), postoperative hospitalization duration, and effective hospitalization days.

RESULTS

A total of 24 patients were included (11 who received PRP plus NPWT and 13 who received NPWT alone). Postoperative hs-CRP levels, ESR, VAS scores, and effective hospitalization days were found to be significantly reduced in the PRP group versus controls. Moreover, the PRP group exhibited a significantly elevated rate of bacterial culture conversion at postoperative day 3.

CONCLUSIONS

The integration of surgical debridement with PRP and NPWT in the management of infected cavitary wounds may expedite infection containment and bacterial eradication, stimulate granulation tissue formation, and facilitate cavity closure, offering a novel and uncomplicated approach to wound healing.

Efficacy and safety of allogeneic platelet-rich plasma in chronic wound treatment: a meta-analysis of randomized controlled trials

Allogeneic platelet-rich plasma (al-PRP) is gaining attention in clinical practice for treating chronic refractory wounds, though research results remain controversial. To assess the clinical efficacy of al-PRP for chronic refractory wounds. Databases including PubMed, Cochrane Library, Embase, CNKI, SinoMed, VIP, and WFPD were searched for randomized controlled trials comparing al-PRP with conventional treatments up to October 2023. Two researchers independently screened studies, extracted data, and assessed quality. Statistical analysis was conducted using RevMan 5.4, and potential publication bias was assessed and corrected using funnel plots and Egger's test. Twelve studies with 717 cases were included. Meta-analysis showed al-PRP significantly improved outcomes compared to non-al-PRP treatments: increased healing rate (RR 2.72, 95% CI 1.77-4.19, p < 0.00001), shortened healing time (SMD - 1.03, 95% CI -1.31 to -0.75, p < 0.00001), improved efficacy rate (RR 1.19, 95% CI 1.10-1.28, p < 0.00001), increased wound shrinkage (MD 35.65%, 95% CI 21.65-49.64, p < 0.00001), and reduced hospital stays (MD -2.62, 95% CI -4.35 to -0.90, p = 0.003). Al-PRP is a feasible, effective, and safe biological therapy for chronic refractory wounds.Trial registration: PROSPERO Identifier CRD42022374920.

Immunomodulation in Non-traditional Therapies for Methicillin-resistant Staphylococcus aureus (MRSA) Management

The rise of methicillin-resistant Staphylococcus aureus (MRSA) poses a significant challenge in clinical settings due to its ability to evade conventional antibiotic treatments. This overview explores the potential of immunomodulatory strategies as alternative therapeutic approaches to combat MRSA infections. Traditional antibiotics are becoming less effective, necessitating innovative solutions that harness the body's immune system to enhance pathogen clearance. Recent advancements in immunotherapy, including the use of antimicrobial peptides, phage therapy, and mechanisms of immune cells, demonstrate promise in enhancing the body's ability to clear MRSA infections. However, the exact interactions between these therapies and immunomodulation are not fully understood, underscoring the need for further research. Hence, this review aims to provide a broad overview of the current understanding of non-traditional therapeutics and their impact on immune responses, which could lead to more effective MRSA treatment strategies. Additionally, combining immunomodulatory agents with existing antibiotics may improve outcomes, particularly for immunocompromised patients or those with chronic infections. As the landscape of antibiotic resistance evolves, the development of effective immunotherapeutic strategies could play a vital role in managing MRSA infections and reducing reliance on traditional antibiotics. Future research must focus on optimizing these approaches and validating their efficacy in diverse clinical populations to address the urgent need for effective MRSA management strategies.

Decoding the Decade: Exploring the Efficacy of Platelet-Rich Plasma (PRP) in Complex Wound Management - A Comprehensive Study

Introduction

Autologous platelet-rich plasma (PRP) therapy has emerged as a promising regenerative treatment modality, offering potential improvements in healing outcomes through its rich content of growth factors and cytokines. We evaluated the effectiveness of PRP therapy in the management of complex wounds, using a decade-long retrospective analysis of treatments conducted at a tertiary care center from 2010 to 2020. The study introduces and assesses the efficacy of the Sandeep's Technique for Assisted Regeneration of Skin (STARS) in enhancing wound healing and quality of life for patients with complex wounds.

Materials and methods

A prospective interventional study was conducted, involving two phases: the development and initial testing of PRP therapy (2010-2015) and the application and evaluation of the STARS protocol (2015-2020). The study included patients with complex wounds, utilizing autologous PRP prepared through a double spin centrifuge technique. Outcome measures included wound-healing rates, infection management, and complication rates, compared to conventional treatment methods.

Results

The study treated 500 wounds in 432 patients with autologous PRP, noting significant improvements in wound-healing rates, 97.7% had infection control without antibiotics (even in MRSA cases), and all had a good pain control. Histopathological examinations confirmed collagen-rich healing with minimal scarring. The STARS protocol demonstrated the potential of PRP therapy in accelerating wound healing, reducing the need for additional surgical interventions, and enhancing patient outcomes.

Conclusion

PRP therapy, particularly when administered following the STARS protocol, represents a safe, effective, and patient-friendly approach for the management of complex wounds. This study supports the integration of PRP therapy into regenerative care strategies, suggesting a shift toward more innovative and efficacious treatments in wound management.

Teicoplanin-Decorated Reduced Graphene Oxide Incorporated Silk Protein Hybrid Hydrogel for Accelerating Infectious Diabetic Wound Healing and Preventing Diabetic Foot Osteomyelitis

Developing hybrid hydrogel dressings with anti-inflammatory, antioxidant, angiogenetic, and antibiofilm activities with higher bone tissue penetrability to accelerate diabetic wound healing and prevent diabetic foot osteomyelitis (DFO) is highly desirable in managing diabetic wounds. Herein, the glycopeptide teicoplanin is used for the first time as a green reductant to chemically reduce graphene oxide (GO). The resulting teicoplanin-decorated reduced graphene oxide (rGO) is incorporated into a mixture of silk proteins (SP) and crosslinked with genipin to yield a physicochemically crosslinked rGO-SP hybrid hydrogel. This hybrid hydrogel exhibits high porosity, self-healing, shear-induced thinning, increased cell proliferation and migration, and mechanical properties suitable for tissue engineering. Moreover, the hybrid hydrogel eradicates bacterial biofilms with a high penetrability index in agar and hydroxyapatite disks covered with biofilms, mimicking bone tissue. In vivo, the hybrid hydrogel accelerates the healing of noninfected wounds in a diabetic rat and infected wounds in a diabetic mouse by upregulating anti-inflammatory cytokines and downregulating matrix metalloproteinase-9, promoting M2 macrophage polarization and angiogenesis. The implantation of hybrid hydrogel into the infected site of mouse tibia improves bone regeneration. Hence, the rGO-SP hybrid hydrogel can be a promising wound dressing for treating infectious diabetic wounds, providing a further advantage in preventing DFO.

Inhibitory effects against zoonotic bacteria by Oroxylum indicum ointment and effects to dog wound

A topical antimicrobial ointment was developed from the fruit extract of Oroxylum indicum and was evaluated for its antibacterial and wound-healing effects and acute toxicity in animal models. O. indicum fruit and seed extracts exhibited antibacterial activities against clinically isolated bacteria and showed in vitro antioxidant activities. To develop a topical antimicrobial ointment from the fruit extract of O. indicum and evaluate for its antibacterial and wound-healing effects. O. indicum fruit extract ointment was prepared and qualitatively controlled. Acute toxicity of the extract was evaluated in the animal model. Antibacterial effects and healing effects of the ointment to the dog wound were investigated. The results are expressed as mean ± standard deviation. The ointment exhibited in vitro antibacterial effects. A single daily application of the ointment to a dog's wound exhibited a wound-healing effect with complete epithelialization within 7 days while the wound was completely healed with the removal of the scabs, the size was decreased to 14% of the original size within 12 days. The ointment was found no acute toxicity in the animal model. O. indicum ointment promoted in vitro antibacterial activity and wound-healing effect in dogs with no acute toxicity.

Platelet-rich plasma attenuates the UPEC-induced cystitis via inhibiting MMP-2,9 activities and downregulation of NGF and VEGF in Canis Lupus Familiaris model

One of the most prevalent disorders of the urinary system is urinary tract infection, which is mostly brought on by uropathogenic Escherichia coli (UPEC). The objective of this study was to evaluate the regenerative therapeutic and antibacterial efficacy of PRP for induced bacterial cystitis in dogs in comparison to conventional antibiotics. 25 healthy male mongrel dogs were divided into 5 groups (n = 5). Control negative group that received neither induced infection nor treatments. 20 dogs were randomized into 4 groups after two weeks of induction of UPEC cystitis into; Group 1 (control positive; G1) received weekly intravesicular instillation of sodium chloride 0.9%. Group 2 (syst/PRP; G2), treated with both systemic intramuscular antibiotic and weekly intravesicular instillation of PRP; Group 3 (PRP; G3), treated with weekly intravesicular instillation of PRP, and Group 4 (syst; G4) treated with an intramuscular systemic antibiotic. Animals were subjected to weekly clinical, ultrasonographic evaluation, urinary microbiological analysis, and redox status biomarkers estimation. Urinary matrix metalloproteinases (MMP-2, MMP-9) and urinary gene expression for platelet-derived growth factor -B (PDGF-B), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) were measured. At the end of the study, dogs were euthanized, and the bladder tissues were examined macroscopically, histologically, and immunohistochemically for NF-κB P65 and Cox-2. The PRP-treated group showed significant improvement for all the clinical, Doppler parameters, and the urinary redox status (p < 0.05). The urinary MMPs activity was significantly decreased in the PRP-treated group and the expression level of urinary NGF and VEGF were downregulated while PDGFB was significantly upregulated (p < 0.05). Meanwhile, the urinary viable cell count was significantly reduced in all treatments (P < 0.05). Gross examination of bladder tissue showed marked improvement for the PRP-treated group, expressed in the histopathological findings. Immunohistochemical analysis revealed a marked increase in Cox-2 and NF-κB P65 in the PRP-treated group (P < 0.05). autologous CaCl2-activated PRP was able to overcome the bacterial infection, generating an inflammatory environment to overcome the old one and initiate tissue healing. Hence, PRP is a promising alternative therapeutic for UPEC cystitis instead of conventional antibiotics.

Artificial Dermis and Autologous Platelet-Rich Plasma for Treatment of Refractory Wounds: A Clinical Study

Refractory wounds present a complex and serious clinical dilemma in plastic and reconstructive surgery. However, there are currently no standard guidelines for the treatment of refractory wounds. Artificial dermis (AD) has achieved some satisfactory results, but also has some limitations. Autologous platelet-rich plasma (PRP), as a cell-therapy material, was a valuable and safe treatment dressing for chronic non-healing wounds. This study aimed to evaluate the efficacies of artificial dermis (AD) with and without autologous platelet-rich plasma (PRP) in patients with refractory wounds. Sixteen patients with refractory wounds were randomly allocated to autologous PRP therapy combined with artificial dermis (PRP + AD [N = 8]) or an artificial dermis program only (AD [N = 8]). We compared the efficacies of the two methods in terms of times to wound healing, infection control, and AD vascularization, as well as hospitalization days and eventual clinical outcomes.13 patients achieved complete healing, including seven (87.5%) in the PRP + AD group and six (75.0%) in the AD group (P > .05). The times to wound healing, infection control, and AD vascularization, and hospitalization time after transfer were significantly shorter in the PRP + AD group compared with the AD group (P < .05). In conclusion, the combination of AD and PRP promoted refractory wound healing and shortened waiting times compared with simple dermal grafts.

Methicillin-resistant coagulase-positive staphylococci in new, middle-aged, and old veterinary hospitals in southern Thailand: A preliminary study

Background and Aim

Methicillin-resistant coagulase-positive staphylococci (MRCoPS) cause pyoderma, dermatitis, and nosocomial infection. Numerous factors, including indiscriminate antimicrobial use (AMU) in veterinary medicine, cleaning practices, and AMU in hospitals, contribute to MRCoPS. However, the relationship between hospital age and MRCoPS has not yet been investigated. This study aimed to estimate the prevalence of MRCoPS in the treatment and operation rooms of new, middle-aged, and old veterinary hospitals.

Materials and Methods

Samples were collected from small animal hospitals in Surat Thani, Nakhon Si Thammarat, and Songkhla in Thailand. Hospitals were defined as those that had been in operation for 5 years (new, n = 5), 5-15 years (middle-aged, n = 6), or >15 years (old, n = 3). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify 280 samples, and duplex polymerase chain reaction was used to identify resistance genes (mecA and blaZ). The VITEK2® automated system was then used to determine the minimum inhibitory concentration.

Results

A total of 57 Staphylococcus species were identified and classified as coagulase-positive staphylococci (CoPS) (22/57, 38.60%) or coagulase-negative staphylococci (35/57, 61.40%), respectively. Nine of the 22 CoPS (40.90%) harbored the mecA gene, and 21 isolates (95.45%) harbored the blaZ gene. Interestingly, more MRCoPS was found in new hospitals (six isolates) than in middle-aged (one isolate) and old hospitals (two isolates), although there was no statistically significant difference in the presence of MRCoPS across new, middle-aged, and old veterinary hospitals (p = 0.095), Kruskal-Wallis test. There is a need for further detailed studies, including an increase in the number of hospitals in various locations.

Conclusion

MRCoPS is a nosocomial pathogen that causes zoonotic and recurrent infections in veterinary hospitals. The prevalence of MRCoPS tended to be higher in new hospitals. Areas with heavy animal contact, such as hospital floors, are areas of particular concern, and cleaning/disinfection of these areas must be highlighted in hygiene regimens.

Addressing radiotherapy-induced fibrosis: the potential of platelet-rich plasma and infliximab for improved breast cancer management

Breast cancer treatment encompasses various therapeutic modalities, including surgery, radiotherapy, and chemotherapy. Breast-conserving surgery has been an integral part of breast cancer management. However, radiotherapy, an important component of breast cancer management, can lead to complications, particularly fibrosis, affecting reconstructive surgery outcomes. We conducted an in vivo study using 48 female Wistar Albino rats, employing segmental mastectomy and radiotherapy to simulate post-mastectomy conditions. The rats were divided into six groups: control, mastectomy, mastectomy + radiotherapy, mastectomy + platelet-rich plasma (PRP) + radiotherapy, mastectomy + infliximab + radiotherapy, and mastectomy + infliximab + PRP + radiotherapy. Edema, hyperemia, inflammation, and fibrosis were assessed as indicators of tissue response. Histopathological analysis revealed that mastectomy + infliximab and mastectomy + infliximab + PRP groups showed significant reductions in fibrosis compared to other groups. Edema, hyperemia, and inflammation were also less severe in these groups compared to the control group. Radiotherapy-induced fibrosis is a major concern in breast reconstruction. Our study suggests that local PRP application and systemic infliximab administration, either alone or in combination, could mitigate the adverse effects of radiotherapy. This approach has the potential to improve reconstructive outcomes in patients undergoing or having the possibility to undergo radiotherapy. This is the first study showing the effectiveness of infliximab and PRP combination on wound healing. The provided experimental rat model might offer guidance for further research. This study provides insights into optimizing outcomes in reconstructive breast surgery, paving the way for further research and clinical studies.

Antimicrobial Effects of Platelet-Rich Plasma and Platelet-Rich Fibrin: A Scoping Review

Platelet-rich plasma (PRP), derived from the centrifugation and subsequent separation of whole blood, results in an unusually high concentration of platelets. A newer form of platelet concentrate, platelet-rich fibrin (PRF), has also been developed. There has been significant research into the therapeutic effects of PRP, particularly in enhancing wound healing and preventing infections in surgical wounds. This scoping review aims to thoroughly evaluate preclinical and clinical evidence regarding the antimicrobial effects of PRP and PRF. In conducting this review, 612 records were examined, and 36 articles were selected for inclusion. The studies reviewed include preclinical research, such as in-vitro and in-vivo studies, and clinical trials involving human participants. The current clinical evidence suggests a notable trend towards the antimicrobial capabilities of PRP and PRF, underscoring their potential benefits in treating wounds. The application of PRP and PRF in wound management shows encouraging outcomes, but further investigation is needed to optimize their use as antimicrobial agents. Additional research, particularly randomized controlled trials, is essential to substantiate their antimicrobial effectiveness in specific diseases and types of wounds, considering their potential impact on clinical results.

Tissue adhesive, ROS scavenging and injectable PRP-based 'plasticine' for promoting cartilage repair

Platelet-rich plasma (PRP) that has various growth factors has been used clinically in cartilage repair. However, the short residence time and release time at the injury site limit its therapeutic effect. The present study fabricated a granular hydrogel that was assembled from gelatin microspheres and tannic acid through their abundant hydrogen bonding. Gelatin microspheres with the gelatin concentration of 10 wt% and the diameter distribution of 1-10 μm were used to assemble by tannic acid to form the granular hydrogel, which exhibited elasticity under low shear strain, but flowability under higher shear strain. The viscosity decreased with the increase in shear rate. Meanwhile, the granular hydrogel exhibited self-healing feature during rheology test. Thus, granular hydrogel carrying PRP not only exhibited well-performed injectability but also performed like a 'plasticine' that possessed good plasticity. The granular hydrogel showed tissue adhesion ability and reactive oxygen species scavenging ability. Granular hydrogel carrying PRP transplanted to full-thickness articular cartilage defects could integrate well with native cartilage, resulting in newly formed cartilage articular fully filled in defects and well-integrated with the native cartilage and subchondral bone. The unique features of the present granular hydrogel, including injectability, plasticity, porous structure, tissue adhesion and reactive oxygen species scavenging provided an ideal PRP carrier toward cartilage tissue engineering.

Application of platelet-rich-plasma in the postoperative treatment of perianal abscess pseudohealing: A case report

RATIONALE

Perianal abscess is a common disease of the anus and intestine. Surgery is an important treatment option for perianal abscess. However, some patients have a long healing time, poor healing effect after surgery, or even pseudo-healing. Platelet-rich plasma (PRP) is rich in platelets that can release a large number of factors when activated and promote wound healing. Moreover, there are few reports on the use of PRP for wounds that are difficult to heal after perianal abscess surgery.

PATIENT CONCERNS

The patient had reported a complaint of perianal swelling and discomfort associated with anal pain, which was considered a perianal abscess. Ceftriaxone, fumigation, and sitz bath were administered after mixed hemorrhoid and perianal abscess surgeries were performed; however, the wound remained unhealed for more than 3 months, and there was a fistula under the skin.

DIAGNOSIS

Perianal color ultrasonography revealed perianal abscess.

INTERVENTIONS

Autologous PRP treatment was performed 5 times for each patient.

OUTCOMES

The postoperative wound healed within 15 days after 5 times PRP treatments.

LESSONS

PRP is a novel treatment option for pseudo-healing.

Platelet-rich plasma influence on the sternal wounds healing: A meta-analysis

A meta-analysis research was executed to appraise the effect of platelet-rich plasma (PRP) on sternal wound healing (SWH). Inclusive literature research till April 2023 was done and 1098 interconnected researches were revised. The 11 picked researches, enclosed 8961 cardiac surgery (CS) persons were in the utilised researchers' starting point, 3663 of them were utilising PRP, and 5298 were control. Odds ratio (OR) and 95% confidence intervals (CIs) were utilised to appraise the effect of PRP on the SWH by the dichotomous approach and a fixed or random model. PRP had significantly lower sternal wound infection (SWI) (OR, 0.11; 95% CI, 0.03-0.34, p < 0.001), deep SWI (OR, 0.29; 95% CI, 0.16-0.51, p < 0.001), and superficial SWI (OR, 0.20; 95% CI, 0.13-0.33, p < 0.001), compared to control in CS persons. PRP had significantly lower SWI, deep SWI, and superficial SWI, compared to control in CS persons. However, caution must be taken when interacting with its values since there was a low sample size of some of the nominated research found for the comparisons in the meta-analysis.

Engineering homologous platelet-rich plasma, platelet-rich plasma-derived exosomes, and mesenchymal stem cell-derived exosomes-based dual-crosslinked hydrogels as bioactive diabetic wound dressings

The management of diabetic wounds remains a critical therapeutic challenge. Platelet-rich plasma (PRP) gel, PRP-derived exosomes (PRP-Exos), and mesenchymal stem cell-derived exosomes (MSC-Exos) have demonstrated therapeutic potential in wound treatment. Unfortunately, their poor mechanical properties, the short half-lives of growth factors (GFs), and the burst release of GFs and exosomes have limited their clinical applications. Furthermore, proteases in diabetic wounds degrade GFs, which hampers wound repair. Silk fibroin is an enzyme-immobilization biomaterial that could protect GFs from proteases. Herein, we developed novel dual-crosslinked hydrogels based on silk protein (SP) (sericin and fibroin), including SP@PRP, SP@MSC-Exos, and SP@PRP-Exos, to promote diabetic wound healing synergistically. SP@PRP was prepared from PRP and SP using calcium gluconate/thrombin as agonist, while SP@PRP-Exos and SP@MSC-Exos were derived from exosomes and SP with genipin as crosslinker. SP provided improved mechanical properties and enabled the sustained release of GFs and exosomes, thereby overcoming the limitations of PRP and exosomes in wound healing. The dual-crosslinked hydrogels displayed shear-induced thinning, self-healing, and eradication of microbial biofilms in a bone-mimicking environment. In vivo, the dual-crosslinked hydrogels contributed to faster diabetic wound healing than PRP and SP by upregulating GFs expression, down-regulating matrix metalloproteinase-9 expression, and by promoting an anti-NETotic effect, angiogenesis, and re-epithelialization. Hence, these dual-crosslinked hydrogels have the potential to be translated into a new generation of diabetic wound dressings.

The usefulness of platelet-rich plasma to manage skin wounds: A meta-analysis

A meta-analysis investigation to measure the usefulness of platelet-rich plasma (PRP) to manage skin wounds (SWs). A comprehensive literature inspection till February 2023 was applied and 1349 interrelated investigations were reviewed. The 22 chosen investigations enclosed animals' SWs were in the chosen investigations' starting point, 3348 of them were treated with PRP, and 2259 were control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to compute the value of the usefulness of PRP to manage SWs by the dichotomous and continuous approaches and a fixed or random model. PRP significantly higher percent of decreases in open wound area (OWA) (MD, 10.07; 95% CI, 6.55-13.59, P < 0.001), and lower healing time (HT) (MD, -6.31; 95% CI, -10.69 to -1.93, P = 0.005) compared to control in animals' SWs. PRP had a significantly higher percent of decreases in OWA and lower HT compared to control in animals' SWs. However, caused of the small sample sizes of several chosen investigations for this meta-analysis, care must be exercised when dealing with its values.

Combining the dual antibacterial and regenerative activities of platelet-rich plasma with β-lactams to mitigate MRSA-infected skin wounds

The emergence of multidrug-resistant bacteria contributes to the necessity of developing novel infection treatment approaches. This study was designed to evaluate the antimicrobial and wound healing activities of platelet-rich plasma (PRP) in combination with β-lactams (ampicillin and/or oxacillin) for the application on methicillin-resistant Staphylococcus aureus (MRSA)-infected skin. PRP was collected from the peripheral blood of healthy donors. The anti-MRSA activity was tested through a growth inhibition curve, colony-forming unit (CFU), and SYTO 9 assay. The PRP incorporation lowered the minimum inhibitory concentration (MIC) of ampicillin and oxacillin against MRSA. The combination of β-lactams together with PRP showed a three-log CFU reduction of MRSA. The major components of PRP for eliminating MRSA were found to be the complement system and iron sequestration proteins, according to the proteomic analysis. The adhesive bacterial colony in the microplate was decreased from 2.9 × 107 to 7.3 × 105 CFU after the treatment of cocktails containing β-lactams and PRP. The cell-based study indicated that keratinocyte proliferation was stimulated by PRP. The in vitro scratch and transwell experiments revealed that PRP improved keratinocyte migration. In the MRSA-infected mouse skin model, PRP appeared to show a synergistic effect for wound area reduction by 39% when combined with β-lactams. The MRSA burden in the infected area was lessened two-fold after topical administration of the combined β-lactams and PRP. PRP inhibited macrophage infiltration in the wound site to shorten the inflammatory phase and accelerate the initiation of the proliferative phase. No skin irritation was detected with the topical delivery of this combination. Our findings suggested that β-lactams plus PRP was applicable to alleviate the problems associated with MRSA via dual antibacterial and regenerative activities.

Hyaluronic acid-based dual network hydrogel with sustained release of platelet-rich plasma as a diabetic wound dressing

In recent years, the incidence of diabetic skin ulcers has increased. Because of its extremely high disability and fatality rate, it brings a huge burden to patients and society. Platelet-rich plasma (PRP) contains a large number of biologically active substances and is of great clinical value in the treatment of various wounds. However, its weak mechanical properties and the consequent abrupt release of active substances greatly limit its clinical application and therapeutic efficacy. Here, we chose hyaluronic acid (HA) and ε-polylysine (ε-PLL) to prepare a hydrogel with the ability to prevent wound infection and promote tissue regeneration. At the same time, using the macropore barrier effect of the lyophilized hydrogel scaffold, platelets in PRP are activated with calcium gluconate in the macropores of the scaffold carrier, and fibrinogen from PRP is converted in a fibrin-packed network forming a gel that interpenetrates the hydrogel scaffold carrier, thus creating a double network hydrogel with slow-release of growth factors from degranulated platelets. The hydrogel not only showed better performance in functional assays in vitro, but also showed more superior therapeutic effects in reducing inflammatory response, promoting collagen deposition, facilitating re-epithelialization and angiogenesis in the treatment of full skin defects in diabetic rats.

Microbial Complexity of Oral Cavity of Healthy Dogs Identified by Mass Spectrometry and Next-Generation Sequencing

The high complexity of the oral microbiota of healthy dogs and the close exposure of humans to companion animals represent a risk of the transmission of potential zoonotic microorganisms to humans, especially through dog bites, including multidrug-resistant ones. Nonetheless, a limited number of comprehensive studies have focused on the diversity of the microorganisms that inhabit the oral cavities of healthy dogs, particularly based on modern molecular techniques. We investigated bacterial and fungal organisms in the oral cavities of 100 healthy dogs based on a combination of conventional and selective microbiological culture, mass spectrometry (MALDI-TOF MS), and next-generation sequencing. In addition, in vitro antimicrobial susceptibility patterns of isolates and mecA resistance gene were assessed. A total of 213 bacteria and 20 fungi were isolated. Staphylococcus pseudintermedius (40/100 = 40%), α-hemolytic Streptococcus (37/100 = 37%), and Pasteurella stomatis (22/100 = 22%) were the most prevalent bacteria diagnosed by microbiological culture and MALDI-TOF MS, whereas Aspergillus (10/100 = 10%) was the most common fungi identified. Based on next-generation sequencing of selected 20 sampled dogs, Porphyromonas (32.5%), Moraxella (16.3%), Fusobacterium (12.8%), Conchiformibius (9.5%), Bergeyella (5%), Campylobacter (3.8%), and Capnocytophaga (3.4%) genera were prevalent. A high multidrug resistance rate was observed in Staphylococcus pseudintermedius isolates, particularly to azithromycin (19/19 = 100%), penicillin (15/19 = 78.9%), and sulfamethoxazole/trimethoprim (15/19 = 78.9%). In addition, the mecA resistance gene was detected in 6.1% (3/49) of coagulase-positive staphylococci. Here, we highlight the microbial complexity of the oral mucosa of healthy dogs, including potential zoonotic microorganisms and multidrug-resistant bacteria, contributing with the investigation of the microbiota and antimicrobial resistance patterns of the microorganisms that inhabit the oral cavity of healthy dogs.

Multifactorial assessment of leukocyte reduced platelet rich plasma injection in dogs undergoing tibial plateau leveling osteotomy: A retrospective study

This study assessed the effects of concurrent intra-articular injection and Tibial Plateau Leveling Osteotomy (TPLO) plate surface treatment with leukoreduced platelet rich plasma (lPRP) on outcomes of dogs undergoing TPLO. A retrospective study of medical records for cases presenting from January 2018 to December 2020 was performed. Client-owned dogs with naturally occurring cranial cruciate ligament rupture that underwent TPLO surgery were divided into two groups. The lPRP group included cases that underwent intra-articular injection and plate surface treatment at the time of their TPLO. The control group (C) underwent TPLO without PRP treatment. Data analyzed included: presence of surgical site infection, implant removal rate, degree of change in OA progression score, lameness score progression and radiographic bone healing. The short- and long-term complication rate, hospitalization and antibiotic therapy were also compared between the groups. Descriptive statistics, comparison analyses (Chi square test, t-test, Fisher's exact test) and multi-level logistic regression models were used for statistical analysis. A total of 110 cases met the study inclusion criteria: 54 = lPRP, 56 = C. There were no significant differences between groups with regard to gender, age, presence of meniscal tear, weight, or body condition score. Significant findings included: improved radiographic healing of the osteotomy in the lPRP group, improved global OA scores in the lPRP group, and improved lameness score at recheck examination in the lPRP group. There was no significant difference between the lPRP and C group with regard to surgical site infection and implant removal rate. Concurrent intra-articular injection and plate surface treatment with leukocyte reduced PRP at the time of TPLO, is beneficial in slowing the progression of OA, hastening the radiographic evidence of osteotomy healing, and improved lameness score on recheck examination. Leukocyte reduced PRP was not a significant factor in reducing SSI or implant removal rate.

Regenerative Medicine and Rehabilitation Therapy in the Canine

Regenerative medicine is used in the canine to optimize tissue healing and treat osteoarthritis and soft tissue injuries. Rehabilitation therapy is also often implemented in the treatment and management of musculoskeletal conditions in the canine. Initial experimental studies have shown that regenerative medicine and rehabilitation therapy may work safely and synergistically to enhance tissue healing. Although additional study is required to define optional rehabilitation therapy protocols after regenerative medicine therapy in the canine, certain fundamental principles of rehabilitation therapy still apply to patients treated with regenerative medicine.

A case series of autologous platelet-rich plasma injection in treating chronic ulcers conducted in Saudi Arabia

Objective

This is a case series study of 14 cases of chronic unhealed ulcers involving patients of 19-85 years, aimed to demonstrate the positive therapeutic outcomes of using autologous platelet rich plasma (PRP) in diabetic foot ulcer (DFU) and other chronic wound healing.

Methods

This is a formal consecutive clinical case series. Patients with chronic unhealed ulcers were enrolled from the amputation prevention clinic by an interdisciplinary team includes podiatrist, general surgeon, orthopedic, vascular surgeon, and wound care nurses at Kahel Specialized Centre, a specialized center for managing foot and ankle diseases, located in Riyadh, Saudi Arabia. Those patients who presented with chronic wounds and showed no significant wound reduction despite following the standard wound care protocol were included in the study. There were no specific predetermined exclusion criteria when considering patients for treatment with this modality.

Results

In this case series, majority (80%) of the patients were above 50 years of age, and 10 (66.7%) patients were male and 5 (33.3%) were female. Of all the cases presented to the amputation prevention clinic, majority (73.3%) reported suffering from type 2 diabetes mellitus (DM) and also, one reported type 1 DM [6.7%]). All the cases of DFU received a combination of hydrogel and autologous PRP treatment and were put of suitable offloading devices, except one case received a combination of Cadexomer iodine, hydrogel and PRP treatment. In the present case series involving 3-14 weeks of the treatment duration, only 2-3 doses of autologous PRP provided complete healing and or maximum wound closure.

Conclusion

Autologous PRP therapy is efficacious in facilitating, enhancing wound healing and aids in complete wound closure. This case series was limited in term of the sample size which is the number patients enrolled for the study, hence, the study finding remain inconclusive to some extent and hence, further study is required with greater number of sample size. The strength of this study is that it is the first study in Saudi Arabia and gulf region, to report the beneficial effect of PRP in chronic unhealed ulcers including diabetic ulcers.

Evaluation of Survival of Subdermal Plexus Skin Flaps in 8 Cats After Injection of Platelet Rich Plasma

The aim of the present study was to evaluate the effect of platelet-rich plasma injection on the survival of experimentally developed subdermal plexus skin flaps in cats. Two flaps, 2 cm wide and 6 cm long were created bilaterally in the dorsal midline in 8 cats. Each flap was randomized to 1 of 2 groups: platelet-rich plasma injection and control. After flap development, the flaps were immediately placed back on the recipient bed. Then 1.8 mL of platelet-rich plasma was equally injected into 6 different parts of the treatment flap. All flaps were evaluated macroscopically daily and on days 0, 7, 14, and 25 by planimetry, Laser Doppler flowmetry, and histology. Mean flap survival on day 14 was 80.437 % (±22.745) for the treatment group and 66.516 % (±24,12) for the control group with no statistically significant difference between the 2 groups (P = .158). Histologically, a significant difference was found between the base of the PRP and the control flap in edema score on day 25 (P = .034). In conclusion, there is no evidence to support the use of platelet-rich plasma in subdermal plexus flaps in cats. However, the use of platelet-rich plasma may aid in reducing edema of subdermal plexus flaps.

Enhanced Bioactive Potential of Functionalized Injectable Platelet-Rich Plasma

Injectable platelet-rich fibrin (iPRF) is a frequently used platelet concentrate used for various medical purposes both in veterinary and human medicine due to the regenerative potential of hard and soft tissues, and also because of its antimicrobial effectiveness. This in vitro study was carried out to assess the cumulative antimicrobial and antibiofilm effect of iPRF functionalized with a multifunctional glycoprotein, human lactoferrin (Lf). Thus, the ability to potentiate cell proliferation was tested on keratinocytes and evaluated by the CCK8 test. The combinations of iPRF and Lf induced an increase in the proliferation rate after 24 h. The average cell viability of treated cultures (all nine variants) was 102.87% ± 1.00, and the growth tendency was maintained even at 48 h. The highest proliferation rate was observed in cultures treated with 7% iPRF in combination with 50 µg/mL of Lf, with an average viability of 102.40% ± 0.80. The antibacterial and antibiofilm activity of iPRF, of human lactoferrin and their combination were tested by agar-well diffusion (Kirby-Bauer assay), broth microdilution, and crystal violet assay against five reference bacterial strains. iPRF showed antimicrobial and antibiofilm potential, but with variations depending on the tested bacterial strain. The global analysis of the results indicates an increased antimicrobial potential at the highest concentration of Lf mixed with iPRF. The study findings confirmed the hypothesized enhanced bioactive properties of functionalized iPRF against both Gram-positive and Gram-negative biofilm-producing bacteria. These findings could be further applied, but additional studies are needed to evaluate the mechanisms that are involved in these specific bioactive properties.

Effectiveness of topical administration of platelet-rich plasma on the healing of methicillin-resistant Staphylococcus aureus-infected full-thickness wound model

This study aimed to investigate the wound-healing activity of animal platelet-rich plasma (PRP) in wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) in rats. After wound induction, the rats were divided into three groups: noninfected animals treated with PRP (PRP group), MRSA-infected animals treated with mupirocin (standard control group), and MRSA-infected animals treated with PRP (MRSA+PRP group). Scratch assays, MTT test, and live/dead cells were also investigated. Total bacterial count, parameters of wound area, histopathological assessment, and expressions of IL-1β, TNF-α, iNOS, PDGF, FGF-2, and TGF-β mRNA levels and immunofluorescent staining of CD31 and collagen type 1 were assessed. The results showed that culture with PRP increased migration. PRP only showed cytotoxicity in a concentration of 100%. Topical application of PRP (50 µL) reduced the wound area and total bacterial count compared with the control group (P<0.05). The mRNA levels of IL-1β, TNF-α, and iNOS expression on days 7 and 14 (P<0.05) decreased in the treated groups compared with control rats. The mRNA levels of PDGF and TGF-β expression (P<0.05) increased in the treatment groups compared with control rats on days 3 and 7 (P<0.05). FGF-2 expression was significantly higher in the treated groups compared with the control group on days 7 and 14 (P<0.05). Moreover, positive expressions of macrophage colony-stimulating factor (M-CSF), CD31, collagen type 1 and cytokeratin proteins keratinocyte proliferation, and re-epithelization were significantly (P<0.05) increased in both PRP and MRSA+PRP-treated groups compared with the control groups on days 7 and 14. Topical administration of PRP accelerated the wound healing in MRSA-infected wound by decreasing the inflammation and improving the proliferative phase.

Locally Injected Autologous Platelet-Rich Plasma Improves Cutaneous Wound Healing in Cats

Cutaneous defects in cats are commonly encountered in clinical practice, and healing can be accomplished by first or second intention. Platelet-rich plasma (PRP) is characterized by a plasma concentration containing a large number of platelets in a small volume of plasma. The objective of the present study was to record the efficacy of PRP infiltration in open wounds in laboratory cats. Six wounds were created in the dorsal midline of eight laboratory cats, with the wounds of one side designated as the PRP group and the wounds of the other side as the control group. Wound healing was evaluated by daily clinical examination, planimetry, laser Doppler flowmetry, and histologic examination on days 0, 7, 14, and 25, and by measurement of metalloproteinases (MMPs)-2 and -9 and tissue inhibitor metalloproteinase (TIMP)-1 on days 0, 14, and 25. Based on the results of the present study, the mean time for full coverage with granulation tissue was shorter in the PRP group, the mean contraction and total wound healing percentage were increased compared to the control group, and finally, the perfusion measured with laser Doppler flowmetry was higher in the PRP group during all examination days. In conclusion, this is the first study focusing on the topical application of PRP in the treatment of open wounds in laboratory cats, and our results are encouraging—showing a more rapid healing in the PRP group.

A Platelet-Rich Plasma-Derived Biologic Clears Staphylococcus aureus Biofilms While Mitigating Cartilage Degeneration and Joint Inflammation in a Clinically Relevant Large Animal Infectious Arthritis Model

The leading cause of treatment failure in Staphylococcus aureus infections is the development of biofilms. Biofilms are highly tolerant to conventional antibiotics which were developed against planktonic cells. Consequently, there is a lack of antibiofilm agents in the antibiotic development pipeline. To address this problem, we developed a platelet-rich plasma (PRP)-derived biologic, termed BIO-PLY (for the BIOactive fraction of Platelet-rich plasma LYsate) which has potent in vitro bactericidal activity against S. aureus synovial fluid free-floating biofilm aggregates. Additional in vitro studies using equine synoviocytes and chondrocytes showed that BIO-PLY protected these cells of the joint from inflammation. The goal of this study was to test BIO-PLY for in vivo efficacy using an equine model of infectious arthritis. We found that horses experimentally infected with S. aureus and subsequently treated with BIO-PLY combined with the antibiotic amikacin (AMK) had decreased bacterial concentrations within both synovial fluid and synovial tissue and exhibited lower systemic and local inflammatory scores compared to horses treated with AMK alone. Most importantly, AMK+BIO-PLY treatment reduced the loss of infection-associated cartilage proteoglycan content in articular cartilage and decreased synovial tissue fibrosis and inflammation. Our results demonstrate the in vivo efficacy of AMK+BIO-PLY and represents a new approach to restore and potentiate antimicrobial activity against synovial fluid biofilms.

Platelet-Rich Plasma as an Orthobiologic: Clinically Relevant Considerations

Platelet-rich plasma (PRP) is an autologous blood-derived product processed to concentrate platelets and the associated growth factors. PRP has been shown to be relatively well-tolerated and safe to use for a number of conditions in humans, equines, and canines. There are multiple commercial systems that have been validated for canine use. These systems use a variety of methodologies to produce a PRP product. However, PRP products have been shown to differ greatly between systems. Further study is needed to fully elucidate optimal component concentrations for various indications.

Autologous platelet gel improves outcomes in tubularized incised plate repair of hypospadias

BACKGROUND

hypospadias is one of the most widespread male congenital anomalies, occurring in 1:250 to 1:300 live births. Several repair techniques have been developing to improve the outcomes.

PURPOSE

a randomized prospective controlled study was adopted to evaluate effectiveness of autologous platelet gel in healing promotion and improving the outcomes of hypospadias repair.

METHODS

thirty children who aged between 6 months and 12 years were recruited and subdivided into two groups; group A had tubularized incised plate (TIP) repair with autologous platelet gel application and group B had TIP repair without autologous platelet gel.

RESULTS

there was no significant difference in duration of operation between both groups. All patients in groups A and B had slit-like meatus shape in the distal glans. While all those of group A had one urine stream, yet only 11 of group B had one. There were complications that happened exclusively in group B such as spray stream (27%) and fistula (20%). Whereas other complications occurred insignificantly more in group B than in A including meatal stenosis (53 versus 27%), glans dehiscence, (20 versus 7%), bleeding (33 versus 13%), infection (33 versus 27%), edema (27% versus13), respectively. The incidence of skin necrosis was equal in both groups.

CONCLUSION

autologous platelet gel usage in TIP hypospadias repair can be a reliable technique to promote wound healing, and to limit of postoperative surgical complications.

In vitro antimicrobial activity of equine platelet lysate and mesenchymal stromal cells against common clinical pathogens

Septic arthritis is considered a medical emergency. Disease following bacterial colonization can lead to significant morbidity and mortality and requires costly treatment. Antimicrobial properties of regenerative therapies, including mesenchymal stromal cells and platelet products, have been researched extensively in human medicine. Although fewer studies have been conducted in veterinary species, they have shown promising results. The purpose of this study was to evaluate bacterial suppression by equine platelet lysate (EPL) and adipose-derived mesenchymal stromal cells (ASCs) in vitro. We hypothesized that both products would significantly inhibit the growth of Staphylococcus aureus and Escherichia coli. Pooled blood from 10 horses was used for production of EPL. Mesenchymal stromal cells were isolated from adipose tissue harvested from the gluteal region of 3 horses. The study evaluated 3 treatment groups: 10 × EPL, 1.6 million ASCs, and a control, using an incomplete unbalanced block design with repeated measurements. Optical density readings and colony-forming units/mL were calculated at 0, 3, 6, 9, 12, 18, and 24 hours. Decreased bacterial growth was seen at multiple time points for the S. aureus-ASC and S. aureus-EPL treatments, supporting our hypothesis. Increased bacterial growth was noticed in the E. coli-EPL group, with no difference in the E. coli-ASC treatment, which opposed our hypothesis. A clear conclusion of antimicrobial effects of EPL and ASCs cannot be made from this in vitro study. Although it appears that ASCs have a significant effect on decreasing the growth of S. aureus, further studies are needed to explore these effects, particularly in Gram-positive bacteria.

Healing of Chronic Wounds with Platelet-Derived Growth Factors from Single Donor Platelet-Rich Plasma following One Freeze-Thaw Cycle. A Cross-Sectional Study

Chronic non-healing wounds (CNHWs) may be associated with trauma or idiopathic in nature and are difficult to treat. Our objective was to assess the use of platelet-derived growth factor (PDGF) from single-donor platelets (al-PRP), using one freeze-thaw cycle, for treating CNHWs. We conducted a cross-sectional study. A total of 23 CNHWs being treated with al-PRP. The al-PRP treatment can be considered successful in well over half (n = 13, 56.5%) of the wounds. We found that all the wounds treated for up to 7 weeks showed partial or complete healing, while those treated for between 8 and 12 weeks did not show healing, healing again being successful in cases in which treatment was extended to more than 13 weeks (85.7%). Using chi-square tests, this relationship was found to be highly significant (p < 0.001, chi² = 19.51; p value = 0.00006). Notably, Cramer's V coefficient was very high (0.921), indicating that the effect size of PRP treatment duration on healing is very large (84.8%). We could suggest that the use of al-PRP in the healing of CNHWs is a promising approach. Further studies with larger sample sizes and long follow-ups are needed to obtain multivariate models to explain which factors favour the healing of ulcers treated with PRP.

Accelerative effect of topical Zataria multiflora essential oil against infected wound model by modulating inflammation, angiogenesis, and collagen biosynthesis

CONTEXT

Zataria multiflora Boiss (Lamiaceae) essential oil (ZME) is believed to be a bactericide herbal medicine and might alleviate negative effects of infection.

OBJECTIVE

This study evaluates the effects of an ointment prepared from ZME (ZMEO) on infected wounds.

MATERIALS AND METHODS

A full-thickness excisional skin wound was surgically created in each mouse and inoculated with 5 × 10⁷ suspension containing Pseudomonas aeruginosa and Staphylococcus aureus. The BALB/c mice (n = 72) were divided into four groups: (1) negative control that received base ointment (NCG), (2) positive control that daily received Mupirocin^® (MG), (3) therapeutic ointment containing 2% ZMEO and (4) therapeutic ointment containing 4% ZMEO, for 21 days. Wound contraction, total bacterial count, histopathological parameters, antioxidant activity, qRT-PCR analysis for expression of IL-1β, TNF-α, VEGF, IGF-1, TGF-β, IL-10, and FGF-2 mRNA levels were assessed on days 3, 7, and 14 following the wounding.

RESULTS

Topical administration of ZMEO significantly decreased the total bacterial count and wound area and also expression of IL-1β and TNF-α compared to the control groups (p < 0.05) in all days. This could also increase significantly the expression of TGF-β, IL-10 IGF-1, FGF-2, and VEGF, and also angiogenesis, fibroblasts, fibrocytes, epithelialization ratio, and collagen deposition and improve antioxidant status compared to the control group (p < 0.05).

DISCUSSION AND CONCLUSION

ZMEO accelerated the healing process of infected wounds by shortening the inflammatory factors and increasing proliferative phase. Applying ZMEO only and/or in combination with chemical agents for the treatment of wound healing could be suggested.

Antibacterial Properties of Canine Platelet-Rich Plasma and Other Non-Transfusional Hemo-Components: An in vitro Study

This in vitro study was carried out to evaluate the potential antibacterial properties of canine non-transfusional hemo-components. Therapeutic formulations commonly used for regenerative medicine purposes (platelet-rich plasma, platelet gel, platelet lysate, fibrin glue), considering both leukocyte-rich and leukocyte-poor formulations, but also platelet-poor plasma and activating substances (thrombin, calcium gluconate), were tested to detect elements with potential antimicrobial properties. The antibacterial effect was tested on different bacterial strains (Staphylococcus aureus subspecies aureus, Staphylococcus cohnii subspecies cohnii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae subspecies pneumoniae) isolated from canine wounds and classified as susceptible, multidrug-, extensively, and pandrug-resistant bacteria toward a known panel of human and veterinary antibiotics. The evaluation was carried out by agar gel diffusion method (Kirby-Bauer) and micro-inhibition in broth using microplates and spectrophotometer reading. The study findings confirmed the hypothesized antibacterial properties of canine non-transfusional hemo-components. A more effective bacteriostatic effect was found against Gram-negative bacteria, drug-resistant too. The presence of leukocytes or platelets does not appear to be essential for the antibacterial effect. Further studies should be conducted to evaluate the exact mechanism of action of the antimicrobial activity. However, non-transfusional hemo-components could be a useful natural aid in controlling bacterial infections in dogs.

Systematic literature review evaluating evidence and mechanisms of action for platelet-rich plasma as an antibacterial agent

Platelet rich plasma or PRP is a supraphysiologic concentrate of platelets derived by centrifugation and separation of whole blood components. Along with platelets and plasma, PRP contains various cell types including white blood cells (WBC)/leukocytes, both granulocytes (neutrophils, basophils, eosinophils) and agranulocytes (monocytes, lymphocytes). Researchers and clinicians have explored the application of PRP in wound healing and prevention of surgical wound infections, such as deep sternal wounds. We conducted this systematic literature review to evaluate the preclinical and clinical evidence for the antibacterial effect of PRP and its potential mechanism of action. 526 records were identified for screening. 34 unique articles were identified to be included in this literature review for data summary. Overall, the quality of the clinical trials in this review is low, and collectively qualify as Oxford level C. Based on the available clinical data, there is a clear trend towards safety of autologous PRP and potential efficacy in deep sternal wound management. The preclinical and bench data is very compelling. The application of PRP in treatment of wounds or prevention of infection with PRP is promising but there is a need for foundational bench and preclinical animal research to optimize PRP as an antibacterial agent, and to provide data to aid in the design and conduct of well-designed RCTs with adequate power to confirm antimicrobial efficacy of PRP in specific disease states and wound types.

Use of Autologous Leucocyte- and Platelet-Rich Plasma (L-PRP) in the Treatment of Aural Hematoma in Dogs

Leukocyte- and platelet-rich plasma (L-PRP) can accelerate the healing process by providing increased concentrations of platelet-derived growth factors. The objective of this study was to evaluate the clinical effect of L-PRP in the treatment of canine aural hematomas associated with otitis externa. Twenty mL of citrated whole blood was collected from each of the 17 dogs included and autologous L-PRP was produced. The aural hematoma was drained and 0.5–1 mL of L-PRP was injected. The dogs were examined weekly until 7 days after complete clinical healing. A final clinical follow-up was performed 6 weeks after the first treatment with L-PRP. If there was recurrence of the aural hematoma at the first follow-up, the treatment was repeated. In total, 2/17 cases were lost after the first follow-up. In 5/17 dogs, a short-term recurrence occurred. In 12/15 cases, complete clinical resolution was achieved with a single L-PRP application (Group A1) and in 3/15 with two treatments (Group A2). The mean time to complete clinical resolution was 16 ± 8.7 days (A1) and 23.3 ± 4 days (A2), respectively. No side effects were reported. The in situ administration of autologous L-PRP resulted in a complete resolution of the aural hematoma in all dogs that completed the clinical trial.

A Web-Based Calculator for Predicting the Occurrence of Wound Complications, Wound Infection, and Unplanned Reoperation for Wound Complications in Patients Undergoing Surgery for Spinal Metastases

BACKGROUND

In the present study, we identified the risk factors for wound complications, wound infection, and reoperation for wound complications after spine metastasis surgery and deployed the resultant model as a web-based calculator.

METHODS

Patients treated at a single comprehensive cancer center during a 7-year period were included. The demographics, pathology, comorbidities, laboratory values, and operative details were collected. Factors with P < 0.15 on univariable regression were entered into multivariable logistic regression to generate predictive models internally validated using 1000 bootstrapped samples.

RESULTS

Of the 330 patients included, 29 (7.6%) had experienced a surgical site infection. The independent predictive factors for wound-related complications were a higher Charlson comorbidity index (CCI; odds ratio [OR], 1.41 per point; P < 0.01), Karnofsky performance scale score ≤70 (OR, 2.14; P = 0.04), lower platelet count (OR, 0.49 per 10⁵/μL; P < 0.01), revision versus index surgery (OR, 3.10; P = 0.02), and increased incision length (OR, 1.21 per level; P = 0.02). Wound infection was associated with a higher CCI (OR, 1.60 per point; P < 0.01), a lower platelet count (OR, 0.35 per 10⁵/μL; P < 0.01), revision surgery (OR, 4.63; P = 0.01), and a longer incision length (OR, 1.25 per level; P = 0.03). Unplanned reoperation for wound complications was predicted by a higher CCI (OR, 1.39 per point; P = 0.003), prior irradiation (OR, 2.52; P = 0.04), a lower platelet count (OR, 0.57 per 10⁵/μL; P = 0.02), and revision surgery (OR, 3.34; P = 0.03), The optimism-corrected areas under the curve were 0.75, 0.81, and 0.72 for the wound complication, infection, and reoperation models, respectively.

CONCLUSIONS

Low platelet counts, poorer health status, more invasive surgery, and revision surgery all independently predicted the risk of wound complications, including infection and unplanned reoperation for infection. Validation of the calculators in a prospective study is merited.

Platelet-rich therapies as an emerging platform for regenerative medicine

INTRODUCTION

The combination of human plasma components with the multiple secretome from platelets has provided a new biological tool that is shaping a new future for its direct application in tissue regeneration as well as in cell culture and advanced therapy by means of its use as a clinical-grade supplement.

AREAS COVERED

Some relevant aspects related to the biology, growth factor delivery and molecular pathways driving the biological effects of platelet-rich therapies are summarized. Their use as clinical-grade cell supplements and advanced therapies is also carefully described.

EXPERT OPINION

Platelet-rich plasma therapies, and especially PRGF, contain an incredible number of biologically active agents that may exert regenerative and therapeutic potential. Here, we highlight the latest advances in this biological approach for the delivery of autologous growth factors with some of the recent new applications including the development of a clinical-grade supplement for advanced therapy.

Intrauterine Blood Plasma Platelet-Therapy Mitigates Persistent Breeding-Induced Endometritis, Reduces Uterine Infections, and Improves Embryo Recovery in Mares

Microorganisms, including pathogenic or opportunistic bacteria and fungi, may gain access to the uterus during breeding, and infectious endometritis plays a major role in equine subfertility. This study aimed to assess the post-breeding inflammatory response, endometrial culture, and embryo recovery of mares susceptible to persistent breeding-induced endometritis (PBIE) treated with plasma-rich (PRP) or -poor (PPP) plasma. Mares (n = 12) susceptible to PBIE had three cycles randomly assigned to receive intrauterine infusions of lactate ringer solution (LRS, control), or autologous PRP or PPP pre- (−48 and −24 h) and post-breeding (6 and 24 h). Mares were bred with fresh semen from one stallion. Intrauterine fluid accumulation (IUF) and endometrial neutrophils were assessed every 24 h up to 96 h post-breeding. Uterine cytokines (Ilβ, IL6, CXCL8, and IL10) were evaluated before (0 h), 6, and 24 h post-breeding, and endometrial culture three and nine days after breed. Embryo flushing was performed 8 days post-ovulation. Data were analyzed with mixed model, Tukey’s post-hoc test, and multivariate regression. PRP treatment reduced endometrial neutrophils, post-breeding IUF, and pro-inflammatory cytokines when compared to control-assigned cycles, but not significantly different than PPP. Controls had a significantly higher percentage of positive bacterial cultures (33%) in comparison to PRP-assigned cycles (0%), whereas cycles treated with PPP were not significantly different from the other groups (25%). The PRP-assigned cycles had significantly greater embryo recovery rates (83%) than the control (33%), though not significantly different than PPP (60%). Plasma infusion reduced the duration and intensity of the post-breeding inflammatory response and improved embryo recovery in mares susceptible to PBIE. Platelets incrementally downregulate PBIE and appear to have a dose-dependent antimicrobial property.

In vitro characterisation of 3D printed platelet lysate-based bioink for potential application in skin tissue engineering

Wounds impact millions of patients every year and represent a serious cause of morbidity and mortality worldwide, yet current treatment outcomes are far from ideal. Therapies based on delivery of multiple growth factors offer a promising approach for optimal wound management; however, their high production cost, low stability, and lack of effective delivery system limits their application in the clinic. Platelet lysate is a suitable, abundant and cost-effective source of growth factors that play an important role in the healing cascade. The aim of this current work is to develop an extrusion-based bioink consisting of platelet lysate (PL) and gelatin methacryloyl (GelMA) (PLGMA) for the fabrication of a multifunctional 3D printed dermal equivalent. This bioink meets the essential requirements of printability in terms of rheological properties and shape fidelity. Moreover, its mechanical properties can be readily tuned to achieve stiffness that is equivalent to native skin tissue. Biologically relevant factors were successfully released in a sustainable manner for up to two weeks of study. The bioavailability of those factors was demonstrated by high cell viability, good cell attachment and improved proliferation of printed dermal fibroblasts. Furthermore, growth factors upregulated ECM synthesis and deposition by dermal fibroblasts after two weeks of culture.

Use of platelet concentrate gel in second-intention wound healing: a case report

Background

Wound healing is a complex and dynamic process. Healing of acute and chronic wounds can be impaired by patient factors (that is, comorbidities) and/or wound factors (that is, infection). Regenerative medicine products, such as autologous/homologous platelet-rich plasma gel, may speed up the healing process. Autologous/homologous platelet-rich plasma is an advanced wound therapy used for hard-to-heal acute and chronic wounds. The cytokines and growth factors contained in platelet-rich plasma play a crucial role in the healing process.

Case presentation

A 61-year-old Caucasian male patient, suffering from mental retardation following meningitis, with a transplanted kidney due to prior renal impairment, and under immunosuppressant therapy, was submitted to aneurysmectomy of his proximal left forearm arteriovenous fistula. A few days later, the patient came to our attention with substantial blood loss from the surgical site. The wound presented no signs of healing, and after fistula reparation and considering persistent infection of the surgical site (by methicillin-resistant Staphylococcus aureus), surgeons decided for second-intention healing. To favor healing, 10 mL homologous platelet concentrate gel was sequentially applied. After each application, wound was covered with nonadherent antiseptic dressing. After only seven applications of homologous platelet concentrate gel, wound completely recovered and no amputation was necessary.

Conclusions

Topical application of homologous platelet-rich plasma gel in healing wound shows beneficial results in wound size reduction and induces granulation tissue formation. Platelet-rich plasma could be a safe and cost-effective treatment for managing the cutaneous wound healing process to shorten the recovery period and thereby improve patient quality of life.

Immune-Based Anti-Staphylococcal Therapeutic Approaches

Widespread methicillin-resistant Staphylococcus aureus (S. aureus) infections within community and healthcare settings are responsible for accelerated development of antibiotic resistance. As the antibiotic pipeline began drying up, alternative strategies were sought for future treatment of S. aureus infections. Here, we review immune-based anti-staphylococcal strategies that, unlike conventional antibiotics, target non-essential gene products elaborated by the pathogen. These strategies stimulate narrow or broad host immune mechanisms that are critical for anti-staphylococcal defenses. Alternative approaches aim to disrupt bacterial virulence mechanisms that enhance pathogen survival or induce immunopathology. Although immune-based therapeutics are unlikely to replace antibiotics in patient treatment in the near term, they have the potential to significantly improve upon the performance of antibiotics for treatment of invasive staphylococcal diseases.

Low-fluence laser-facilitated platelet-rich plasma permeation for treating MRSA-infected wound and photoaging of the skin

Platelet-rich plasma (PRP) is rich in cytokines and growth factors and is a novel approach for tissue regeneration. It can be used for skin rejuvenation but the large molecular size of the actives limits its topical application. In this study, low-fluence laser-facilitated PRP was delivered to evaluate its effect on absorption through the skin, infection-induced wound, and photoaging. The PRP permeation enhancement was compared for two ablative lasers: fractional (CO₂) laser and fully-ablative (Er:YAG) laser. In the Franz cell experiment, pig skin was treated with lasers with superficial ablation followed by the application of recombinant cytokines, growth factors, or PRP. The transport of interferon (IFN)-γ and tumor necrosis factor (TNF)-α was negligible in intact skin and stratum corneum (SC)-stripped skin. Both lasers significantly elevated skin deposition of IFN-γ and TNF-α from PRP, and fully-ablative laser showed a higher penetration enhancement. A similar tendency was found for vascular endothelial growth factor and epidermal growth factor. Er:YAG laser-exposed skin displayed 1.8- and 3.9-fold higher skin deposition of platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-β1 from PRP, respectively. According to the confocal images, both laser interventions led to an extensive and deep distribution of IFN-γ and PDGF-BB in the skin. In the in vivo methicillin-resistant Staphylococcus aureus (MRSA) infection model, CO₂ laser- and Er:YAG laser-assisted PRP delivery reduced bacterial load from 1.8 × 10⁶ to 5.9 × 10⁵ and 1.4 × 10⁴ colony-forming units, respectively. The open wound induced by MRSA was closed by the laser-assisted PRP penetration. In the mouse photoaging model, elastin and collagen deposition were fully restored by combined PRP and full-ablative laser but not by PRP alone and PRP combined with fractional laser. Laser-facilitated PRP delivery even with a low fluence setting can be considered a promising strategy for treating some dermatological disorders.

Regenerative and Antioxidant Properties of Autologous Platelet-Rich Plasma Can Reserve the Aging Process of the Cornea in the Rat Model

Aging is a natural progressive decline in the biological function of cells. Age-related changes in the cornea can affect its ability to refract light or repair itself. Platelet-rich plasma (PRP) has a promising role in regenerative medicine and evidenced its efficacy in multiple fields, but in corneal aging has not yet been elucidated. The present work was performed to estimate the regenerative antioxidant effect of PRP on corneal aging in rats. Rats were assigned into two main groups: (GI) adult group and (GII) aged group. The adult group was divided into GIa (adult rats), GIb (adult-saline treated), and GIc (adult-PRP treated). The aged group was divided into GIIa (aged rats) and GIIb (aged, PRP treated). PRP was administered by a single subconjunctival injection. After 10 days, histological, ultrastructural, immunohistochemical, and morphometrical investigations were carried out. Examination of the corneal sections of the aged group revealed corneal epithelial thinning, shedding of the surface epithelium with loss of desmosomal junction, and irregularity in Bowman's membrane. Disorganized widely spaced collagen bundles and neovascularization were detected in corneal stroma associated with thickening in Descemet's membrane. Ultrastructural examination revealed shrunken hyperchromatic nuclei, swollen mitochondria, and scanty cytoplasm with a strong nuclear reaction for caspase-3 immunostaining. Moreover, antioxidant/free radicals' imbalance was detected by the increase of malondialdehyde (MDA) level with a decrease of glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels. In contrast, GIIb (aged, PRP treated) section examination revealed a restoration of the thickness of the corneal epithelial layer and Descemet's membrane with an amendment of collagen fiber regularity that is associated with weak nuclear reaction to caspase-3 and recovery of the balance in the redox state. These findings proved the effectiveness of PRP as a promising regenerative treatment for the age-associated changes in the cornea.

Effects of platelet-rich plasma on the healing of sternal wounds: A meta-analysis

Sternal wound infection (SWI) is a devastating complication after cardiac surgery. Platelet-rich plasma (PRP) may have a positive impact on sternal wound healing. A systematic review with meta-analyses was performed to evaluate the clinical effectiveness of topical application of autologous PRP for preventing SWI and promoting sternal wound healing compared to placebo or standard treatment without PRP. Relevant studies published in English or Chinese were retrieved from the Cochrane Central Register of Controlled Trials (The Cochrane Library), PubMed, Ovid EMBASE, Web of Science, Springer Link, and the WHO International Clinical Trials Registry Platform (ICTRP) using the search terms "platelet-rich plasma" and "sternal wound" or "thoracic incision." References identified through the electronic search were screened, the data were extracted, and the methodological quality of the included studies was assessed. The meta-analysis was performed for the following outcomes: incidence of SWI, incidence of deep sternal wound infection (DSWI), postoperative blood loss (PBL), and other risk factors. In the systematic review, totally 10 comparable studies were identified, involving 7879 patients. The meta-analysis for the subgroup of retrospective cohort studies (RSCs) showed that the incidence of SWI and DSWI in patients treated with PRP was significantly lower than that in patients without PRP treatment. However, for the subgroup of randomized controlled trials (RCTs), there was no significant difference in the incidence of SWI or DSWI after intervention between the PRP and control groups. There was no significant difference in PBL in both RCTs and RSCs subgroups. Neither adverse reactions nor in-situ recurrences were reported. According to the results, PRP could be considered as a candidate treatment to prevent SWI and DSWI. However, the quality of the evidence is too weak, and high-quality RCTs are needed to assess its efficacy on preventing SWI and DSWI.

Efficacy of a Semi Automated Commercial Closed System for Autologous Leukocyte- and Platelet-Rich Plasma (l-prp) Production in Dogs: A Preliminary Study

BACKGROUND

To characterize the cellular composition (platelets, erythrocytes, and leukocytes) and determine platelet-derived growth factor isoform BB (PDGF-BB) concentration in canine leukocyte- and platelet rich plasma (L-PRP) produced using a commercial semi-automated closed system.

METHODS

Twenty milliliters of citrated whole blood were obtained from 30 healthy un-sedated canine blood donors and processed using a semi-automated completely closed commercial system (CPUNT 20, Eltek group, Casale Monferrato, Alessandria, Italy) according to the manufacturer's instructions. Erythrocyte, leukocyte, and platelet counts were determined in both whole blood (WB) and resultant L-PRP. The PDGF-BB concentration was evaluated after bovine thrombin activation of 10 L-PRP samples.

RESULTS

This commercial system produced on average 2.3 ± 0.7 mL of L-PRP containing a high concentration of platelets (767,633 ± 291,001 μL, p < 0.001), with a 4.4 fold increase in platelet count, lower concentration of erythrocytes (528,600 ± 222,773 μL, p < 0.001) and similar concentration of leukocytes (8422 ± 6346 μL, p = 0.9918) compared with WB. L-PRP had an average of 3442 ± 2061 pg/mL of PDGF-BB after thrombin activation. Neutrophils, lymphocytes and monocytes average percent content in L-PRP was 14.8 ± 13.2, 71.7 ± 18.5 and 10.7 ± 6.4, respectively.

CONCLUSION

Sterile canine L-PRP prepared using this semi-automated closed system is easy to obtain, produces a significant increase in platelet count compared to WB and contains a detectable concentration of PDGF-BB after activation. Additional in vitro and in vivo studies are needed to assess inflammatory markers concentration and the therapeutic efficacy of this L-PRP in dogs.

Prospective Evaluation of Feline Sourced Platelet-Rich Plasma Using Centrifuge-Based Systems

Objective: To evaluate the hematologic components of platelet-rich plasma (PRP) generated using feline blood with two commercially available centrifuge-based systems^1,2.

Materials and methods: Twenty healthy adult cats were enrolled in this prospective study from November 2018 to January 2019. Feline blood samples were obtained for analysis of whole blood (WB) cellular components and preparation of PRP product. PRP was prepared using two commercial systems and complete blood count (CBC) testing was performed on both WB and PRP samples. The cellular composition of the PRP product was compared to the WB sample for each patient.

Results: Both systems showed significant decrease of median RBC concentration in PRP products compared to WB samples (P = 0.002 for both systems). System 1 significantly decreased median WBC concentration (P = 0.002). System 2 decreased WBC concentration, though statistical significance was not reached (P = 0.63). Median platelet concentration was decreased by 3% using System 1, and increased by 187% using System 2. Platelet aggregation presented a challenge with 8/20 (40%) of samples demonstrating platelet aggregation.

Clinical relevance: Commercial systems available for generation of PRP may be useful for creating a feline sourced product and in this study showed promise in decreasing RBC and WBC concentration. Neither system tested achieved 2–5 times platelet concentration from baseline. Platelet aggregation presented a significant obstacle to reliable generation of PRP products using feline blood. This treatment modality may be particularly beneficial for feline patients with osteoarthritis and soft tissue injuries, though first characterizing the PRP product made using feline blood is critical to validate its use in further clinical studies.

Comparison of Allogeneic Platelet-rich Plasma With Autologous Platelet-rich Plasma for the Treatment of Diabetic Lower Extremity Ulcers

ChiCTR1900021317.