Platelet rich fibrin is not a barrier membrane!Or is it?

Platelet-rich fibrin(PRF)is widely used in dentistry and other fields of medicine,and its use has become popular in dental implantology.In several published studies,PRF has been used as a barrier membrane.A barrier membrane is a sheet of a certain material that acts as a biological and mechanical barrier against the invasion of cells that are not involved in bone formation,such as epithelial cells.Among the basic requirements of a'barrier membrane,occlusivity,stiffness,and space maintenance are the criteria that PRF primarily lacks;therefore,it does not fall under the category of barrier membranes.However,there is evidence that PRF membranes are useful in significantly improving wound healing.Does the PRF membrane act as a barrier?Should we think of adding or subtracting some points from the ideal requirements of a barrier membrane,or should we coin a new term or concept for PRF that will incorporate some features of a barrier membrane and be a combination of tissue engineering and biotechnology?This review is aimed at answering the basic question of whether the PRF membrane should be considered a barrier membrane or whether it is something more beyond the boundaries of a barrier membrane.

Effect of Bismuth Subgallate/Borneol Combined with Autologous Platelet-Rich Gel in the Treatment of Patients with Diabetic Foot Ulcers

Objective: To explore the effect of Bismuth Subgallate/Borneol (SuileTM BSB) healing dressing combined with autologous platelet-rich gel (APG) in the treatment of diabetic foot ulcer (DFU). Methods: A total of 120 patients with DFU hospitalized in the Changsha Central Hospital from August 2020 to September 2021 were selected and randomly divided into an experimental group (BSB + APG, n = 60) and a control group (BSB, n = 60) according to random number table method. The total therapeutic effect, healing time, hospital stay, level indexes of various inflammatory factors before and after treatment and ulcer area were observed in the two groups. Results: The total effect of the control group was worse than that of the experimental group, and the data between the two groups were significant (P 0.05);after treatment, the levels of inflammatory factors including WBC, CRP, IL-6 and TNF-α in the control group were higher than those in the experimental group, and there was significant difference between the two groups (P 0.05);after 14 days of treatment, the ulcer area in the control group was larger than that in the experimental group, and the data between the two groups were significant (P Conclusion: BSB combined with APG can achieve better therapeutic effect, reduce the inflammatory reaction of patients, and promote wound healing in the treatment of patients with diabetic foot ulcer.

Clinical Evaluation of Platelet Rich Growth Factors (PRGFS) in Treatment of Temporomandibular Joint Disc Displacement—Study Report

Objective: The aim of the study was to evaluate the effect of platelet rich growth factors (PRGFs) in treatment of temporomandibular joint disc displacement. Materials and Methods: The study subjects included 8 females having bilateral anterior disc displacement with reduction and 1 female having bilateral anterior disc displacement without reduction with the age range between 20 - 35 years. The process of obtaining PRGFs was carried out following the Anitua Technique. Results: Clinical parameters of Interincisal distance, Lateral excursion of mandible using digital caliper in millimeters and Visual Analogue Scale (VAS 0/10) for pain intensity score were used. All of these parameters were running through the intervals of two, four, and eight weeks till the end of the follow-up period at twenty-six weeks (six months). The participated patients showed the clinical improvement in the different clinical statuses such as interincisal distance;lateral excursion of mandible and Pain Score. Conclusion: the study reported early efficacy of PRGFs after the arthrocentesis of the joint in treatment of TMJ disc displacement, and according to our results, the injection of PRGFs could be a possible alternative treatment for patients who did not respond to standard treatment.

The Role of Leukocyte and Platelet-Rich Fibrin in Enhancing the Healing of Extraction Sockets: An Overview of the Literature

Introduction: Leukocyte and platelet-rich fibrin (L-PRF) is an emerging material in dentistry, however, there are controversies surrounding its effectiveness. Despite the amount of literature available, debates regarding its effect continue. This review aims to summarize and clarify the data surrounding the use of L-PRF in promoting the healing of extraction sockets, which may offer a better outcome for future treatments. Purpose: The purpose of this review is to evaluate the current literature on the use of L-PRF in promoting the healing of extraction sockets, and to provide a comprehensive overview of the available evidence. Methods: A comprehensive computer-based search of databases such as PubMed, Medline, and Cochrane Library was conducted. Results: The results of this review suggest that L-PRF has shown promise in promoting early healing of extraction sockets, but the evidence for its effectiveness over a longer period is limited. Conclusion: Although L-PRF has shown promising results in the early healing periods, its effectiveness over a longer healing period cannot be confirmed based on the available data. More clinical trials with standardized protocols and consistent measurement methods are needed to establish the role of L-PRF in enhancing the healing of extraction sockets.

Evaluating the Benefits of Platelet Rich-Fibrin in Periodontal Regeneration: A Literature Review

Introduction: Platelet Rich-Fibrin (PRF) is a biological matrix derived from a patient’s own blood, rich in growth factors and platelets. Its use in various periodontal and non-periodontal procedures is gaining recognition due to its potential in promoting tissue regeneration. The purpose of this review was to evaluate the benefits of using PRF in intra-bony defect regeneration, guided-bone regeneration, and sinus floor elevation. Methods: The study searched PubMed for manuscripts published between 2017 and 2022 to better understand the clinical and radiological effects of PRF. The manuscripts were divided into the following sections: intra-bony defect regeneration, guided-bone regeneration, and sinus floor elevation. Results: In intra-bony defects, PRF improved clinical and radiological parameters when compared with OFD alone, with a significant difference in wound healing at 7 days. In GBR, a CBCT evaluation shows no statistical difference between the PRF-autogenous bone complex group and the bovine bone-collagen membrane complex regarding volume change of the augmented bone with a 16% rate of bone loss following a 6-month healing period. Also, a slight increase in bone thickness has been seen when liquid PRF is used. In sinus floor elevation, results revealed no differences in graft volume between PRF group and control group at any of the evaluated time points. Although higher implant stability immediately postoperatively, higher new bone formation, the lesser amount of residual graft and earlier implant placement. Conclusion: Platelet Rich-Fibrin is widely accepted for use in periodontal surgery and dentistry due to its minimally invasive nature and low risk of adverse effects, with positive results in tissue regeneration. There is evidence that PRF leads to improved and faster healing, as well as cost-effective regenerative procedures compared to other treatments.

Evaluating the Effects on Ultrasound and on Magnetic Resonance for Knee Osteoarthritis Treatment by Platelet Rich Plasma Therapy in Combination with Mesenchymal Stem Cells from Autologous Adipose Tissue

Aim: To evaluate the effects based the changes on ultrasound and on magnetic resonance for knee osteoarthritis treatment by platelet-rich plasma therapy in combination with mesenchymal stem cell from autologous adipose tissue. Objects and Methods: 30 patients, 26 females, 4 males, mean age 58.63 ± 11.11, mean disease duration 5.3 ± 4.6 years, respectively 60 knee joints were diagnosed with osteoarthritis at stage II - III according to the Kellgren and Lawrence classifications. After ultrasound and magnetic resonance imaging in the first time, all patients were injected with platelet-rich plasma combined with mesenchymal stem cells from autologous adipose tissue into both knee joints. Results: After treatment 12 months by platelet-rich plasma injection combined with mesenchymal stem cells from autologous adipose tissue: The thickness of articular cartilage on ultrasound increased significantly from 2.08 ± 0.36 mm to 2.48 ± 0.36 mm with p Conclusion: The treatment of knee osteoarthritis by platelet-rich plasma combined with mesenchymal stem cells from autologous adipose tissue was effective in improving cartilage thickness on ultrasound and magnetic resonance, thereby improving the motor function of the knee joint.

Clinical and Magnetic Resonance Image Changes of Platelet-Rich Plasma Therapy in Combination with Human Mesenchymal Stem Cells from Autologous Adipose Tissue for Knee Osteoarthritis Treatment

Objective: To evaluate the efficacy based on clinical symptom and on magnetic resonance image of platelet-rich plasma therapy in combination with mesenchymal stem cells from autologous adipose tissue for knee osteoarthritis treatment. Patients and Method: 30 patients including 26 females and 4 males;correspondingly, 60 knee joints were diagnosed with osteoarthritis with stages II - III of Kellgren and Lawrence, their mean age was 58.63 ± 11.11. All were injected with autologous platelet-rich plasma that was extracted by PRP set, APC 30 PRP PRCEDURE PRAK and autologously extracted mesenchymal stem cells from abdominal adipose tissue using the ADI-25-01 ADIPOSEPRCEDURE PRAK of USA. Results: After 12 months: the pain level according to VAS score at the right knee joint was decreased from 6.0 ± 1.28 before treatment to 1.9 ± 0.3;VAS score at the left knee joint was decreased from 6.43 ± 1.19 to 2.25 ± 0.43. Total Lequene score at right knee joint was decreased from 16.04 ± 1.57 before treatment to 4.31 ± 1.04, at left knee joint was decreased from 17.52 ± 1.74 before treatment to 5.15 ± 1.48. Total WOMAC score at right knee joint was decreased from 55.93 ± 5.56 to 10.37 ± 1.56;at left knee joint was decreased from 53.97 ± 5.57 to 10.07 ± 1.59. There were 86.77% joints with cartilage thickness change and the patellar cartilage thickness was increased from 1.56 ± 0.09 mm before treatment to 1.65 ± 0.09 mm. Conclusion: The treatment of knee osteoarthritis by platelet-rich plasma therapyin combination with mesenchymal stem cells from autologous adipose tissue is effective in reducing pain, improving patient's mobility and walking function, reforming articular cartilage thickness on magnetic resonance image.

Platelets in hemostasis and thrombosis:Novel mechanisms of fibrinogen-independent platelet aggregation and fibronectin-mediated protein wave of hemostasis

Platelets are small anucleate cells generated from megakaryocytes in the bone marrow. Although platelet genera- tion, maturation, and clearance are still not fully understood, significant progress has been made in the last 1-2 dec- ades. In blood circulation, platelets can quickly adhere and aggregate at sites of vascular injury, forming the platelet plug （i.e. the first wave of hemostasis）. Activated platelets can also provide negatively charged phosphatidylserine- rich membrane surface that enhances cell-based thrombin generation, which facilitates blood coagulation （i.e. the second wave of hemostasis）. Platelets therefore play central roles in hemostasis. However, the same process of hemostasis may also cause thrombosis and vessel occlusion, which are the most common mechanisms leading to heart attack and stroke following ruptured atherosclerotic lesions. In this review, we will introduce the classical mechanisms and newly discovered pathways of platelets in hemostasis and thrombosis, including fibrinogen-inde- pendent platelet aggregation and thrombosis, and the plasma fibronectin-mediated ＂protein wave＂ of hemostasis that precedes the classical first wave of hemostasis. Furthermore, we briefly discuss the roles of platelets in inflam- marion and atherosclerosis and the potential strategies to control atherothrombosis.

Intraarticular injections(corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis

Osteoarthritis(OA)is a complex"whole joint"disease pursued by inflammatory mediators,rather than purely a process of"wear and tear".Besides cartilage degradation,synovitis,subchondral bone remodeling,degeneration of ligaments and menisci,and hypertrophy of the joint capsule take parts in the pathogenesis.Pain is the hallmark symptom of OA,but the extent to which structural pathology in OA contributes to the pain experience is still not well known.For the knee OA,intraarticular(IA)injection(corticosteroids,viscosupplements,blood-derived products)is preferred as the last nonoperative modality,if the other conservative treatment modalities are ineffective.IA corticosteroid injections provide short term reduction in OA pain and can be considered as an adjunct to core treatment for the relief of moderate to severe pain in people with OA.IA hyaluronic acid(HA)injections might have efficacy and might provide pain reduction in mild OA of knee up to 24 wk.But for HA injections,the costeffectiveness is an important concern that patients must be informed about the efficacy of these preparations.Although more high-quality evidence is needed,recent studies indicate that IA platelet rich plasma injections are promising for relieving pain,improving knee function and quality of life,especially in younger patients,and in mild OA cases.The current literature and our experience indicate that IA injections are safe and have positive effects for patient satisfaction.But,there is no data that any of the IA injections will cause osteophytes to regress or cartilage and meniscus to regenerate in patients with substantial and irreversible bone and cartilage damage.

Topical application of platelet-rich plasma for diabetic foot ulcers: a systematic review

AIM To determine if topical application of platelet-rich plasma(PRP) to diabetic foot ulcers(DFUs) results in superior healing rates. METHODS A systematic review was registered with PROSPERO and performed using PRISMA guidelines. Level Ⅰ-Ⅳ investigations of topical PRP application in DFUs were sought in multiple databases including: MEDLINE, Web of Science, and Cochrane Central Register of Controlled Trials. The search terms used were "platelet rich plasma", "diabetes", "ulcers", and "wound". The Modified Coleman Methodology Score(MCMS) was used to analyze study methodological quality. Study heterogeneity and a mostly non-comparative nature of evidence precluded meta-analysis. Only the outcome measurements used by more than 50% of the studies were included in the data synthesis to increase power of the measurement over that of individual studies. A weighted mean of healing rate per week between PRP group vs controls were compared using two-sample z-tests using P-value of less than 0.05 for significance.RESULTS One thousand two hundred and seventeen articles were screened. Eleven articles(322 PRP subjects, 126 controls, PRP subject mean age 58.4 ± 7.2 years, control mean age 58.7 ± 5.9 years) were analyzed. Six articles were level Ⅱ evidence, four were level Ⅲ, and one article was level Ⅳ. The mean MCMS was 61.8 ± 7.3. Healing rate was significantly faster with PRP application compared to controls(0.68 ± 0.56 cm2/wk vs 0.39 ± 0.09 cm2/wk; P < 0.001). Mean heal time to > 90% of the original ulcer area was 7.8 ± 2.7 wk and 8.3 ± 3.7 wk for patients in the PRP group and control groups, respectively(P = 0.115). There were significantly lower adverse effects reported with PRP application compared to controls(7 wound infections, 1 contact dermatitis vs 14 wound infections, 1 maceration; P < 0.001).CONCLUSION The topical application of PRP for DFUs results in statistically superior healing rates and lower complication rates compared to controls.

Platelet-rich plasma for muscle injuries: A systematic review of the basic science literature

BACKGROUND Platelet-rich plasma(PRP) is an increasingly used biologic adjunct for muscle injuries, as it is thought to expedite healing. Despite its widespread use, little is known regarding the mechanisms by which PRP produces its efficacious effects in some patients.AIM To clarify the effects of PRP on muscular pathologies at the cellular and tissue levels by evaluating the basic science literature.METHODS A systematic review of PubMed/MEDLINE and EMBASE databases was performed using the Preferred Reporting Items for Systematic Reviews and MetaAnalyses(PRISMA) guidelines and checklist. Level III in vivo and in vitro studies examining PRP effects on muscles, myocytes and/or myoblasts were eligible for inclusion. Extracted data included PRP preparation methods and study results.RESULTS Twenty-three studies were included(15 in vivo, 6 in vitro, 2 in vitro/in vivo). Only one reported a complete PRP cytology(platelets, and red and white blood cell counts). Five in vitro studies reported increased cellular proliferation, four reported increased gene expression, and three reported increased cellular differentiation. Five in vivo studies reported increased gene expression, three reported superior muscle regeneration, and seven reported improved histological quality of muscular tissue.CONCLUSION The basic science literature on the use of PRP in muscle pathology demonstrates that PRP treatment confers several potentially beneficial effects on healing in comparison to controls. Future research is needed to determine optimal cytology,dosing, timing, and delivery methods of PRP for muscle pathologies.

Platelet-rich plasma increases transforming growth factor-beta1 expression at graft-host interface following autologous osteochondral transplantation in a rabbit model

AIM: To explore the effect of platelet-rich plasma on protein expression patterns of transforming growth factor-beta1(TGF-β1) in cartilage following autologous osteochondral transplantation(AOT) in a rabbit knee cartilage defect model.METHODS: Twelve New Zealand white rabbits received bilateral AOT. In each rabbit, one knee was randomized to receive an autologous platelet rich plasma(PRP) injection and the contralateral knee received saline injection. Rabbits were euthanized at 3, 6 and 12 wk post-operatively. Articular cartilage sections were stained with TGF-β1 antibody. Histological regions of interest(ROI)(left, right and center of the autologous grafts interfaces) were evaluated using Meta Morph. Percentage of chondrocytes positive for TGF-β1 was then assessed.RESULTS: Percentage of chondrocytes positive for TGF-β1 was higher in PRP treated knees for selected ROIs(left; P = 0.03, center; P = 0.05) compared to control and was also higher in the PRP group at each post-operative time point(P = 6.6 × 10^(-4), 3.1 × 10^(-4) and 7.3 × 10^(-3) for 3, 6 and 12 wk, respectively). TGF-β1 expression was higher in chondrocytes of PRP-treated knees(36% ± 29% vs 15% ± 18%)(P = 1.8 × 10^(-6)) overall for each post-operative time point and ROI. CONCLUSION: Articular cartilage of rabbits treated with AOT and PRP exhibit increased TGF-β1 expression compared to those treated with AOT and saline. Our findings suggest that adjunctive PRP may increase TGF-β1 expression, which may play a role in the chondrogenic effect of PRP in vivo.

The effect of platelet-rich plasma on cavernous nerve regeneration in a rat model

The aim of this study was to investigate the effect of platelet-rich plasma(PRP)on cavernous nerve(CN)regeneration and functional status in a nerve-crush rat model.Twenty-four Sprague-Dawley male rats were randomly divided into three equal groups:eight had a sham operation,eight underwent bilateral nerve crushing with no further intervention and eight underwent bilateral nerve crushing with an immediate application of PRP on the site of injury.Erectile function was assessed by CN electrostimulation at 3 months and nerve regeneration was assessed by toluidine blue staining of CN and nicotinamide adenine dinucleotide phosphate(NADPH)-diaphorase staining of penile tissue.Three months after surgery,in the group that underwent bilateral nerve crushing with no further intervention,the functional evaluation showed a lower mean maximal intracavernous pressure(ICP)and maximal ICP per mean arterial pressure(MAP)with CN stimulation than those in the sham group.In the group with an immediate application of PRP,the mean maximal ICP and maximal ICP/MAP were significantly higher than those in the injured control group.Histologically,the group with the application of PRP had more myelinated axons of CNs and more NADPH-diaphorase-positive nerve fibres than the injured control group but fewer than the sham group.These results show that the application of PRP to the site of CN-crush injury facilitates nerve regeneration and recovery of erectile function.Our research indicates that clinical application of PRP has potential repairing effect on CN and peripheral nerves.

Combined administration of platelet rich plasma and autologous bone marrow aspirate concentrate for spinal cord injury: a descriptive case series

Administration of platelet rich plasma(PRP) and bone marrow aspirate concentrate(BMAC) has shown some promise in the treatment of neurological conditions;however, there is limited information on combined administration. As such, the purpose of this study was to assess safety and functional outcomes for patients administered combined autologous PRP and BMAC for spinal cord injury(SCI). This retrospective case series included seven patients who received combined treatment of autologous PRP and BMAC via intravenous and intrathecal administration as salvage therapy for SCI. Patients were reviewed for adverse reactions and clinical outcomes using the Oswestry Disability Index(ODI) for up to 1 year, as permitted by availability of follow-up data. Injury levels ranged from C3 through T11, and elapsed time between injury and salvage therapy ranged from 2.4 months to 6.2 years. Post-procedure complications were mild and rare, consisting only of self-limited headache and subjective memory impairment in one patient. Four patients experienced severe disability prior to PRP combined with BMAC injection, as evidenced by high(> 48/100) Oswestry Disability Index scores. Longitudinal Oswestry Disability Index scores for two patients with incomplete SCI at C6 and C7, both of whom had cervical spine injuries, demonstrated a decrease of 28–40% following salvage therapy, representing an improvement from severe to minimal disability. In conclusion, intrathecal/intravenous co-administration of PRP and BMAC resulted in no significant complications and may have had some clinical benefits. Larger clinical studies are needed to further test this method of treatment for patients with SCI who otherwise have limited meaningful treatment options. This study was reviewed and approved by the Ohio Health Institutional Review Board(IRB No. 1204946) on May 16, 2018.

High plasma fibrinogen concentration and platelet count unfavorably impact survival in non–small cell lung cancer patients with brain metastases

High expression of fibrinogen and platelets are often observed in non–small cell lung cancer(NSCLC) patients with local regional or distant metastasis. However, the role of these factors remains unclear. The aims of this study were to evaluate the prognostic significance of plasma fibrinogen concentration and platelet count, as well as to determine the overall survival of NSCLC patients with brain metastases. A total of 275 NSCLC patients with brain metastasis were enrolled into this study. Univariate analysis showed that high plasma fibrinogen concentration was associated with age ≥ 65 years(P = 0.011), smoking status(P = 0.009), intracranial symptoms(P = 0.022), clinical T category(P = 0.010), clinical N category(P = 0.003), increased partial thromboplastin time(P < 0.001), and platelet count(P < 0.001). Patients with low plasma fibrinogen concentration demonstrated longer overall survival compared with those with high plasma fibrinogen concentration(median, 17.3 months versus 11.1 months; P ≤ 0.001). A similar result was observed for platelet counts(median, 16.3 months versus 11.4 months; P = 0.004). Multivariate analysis showed that both plasma fibrinogen concentration and platelet count were independent prognostic factors for NSCLC with brain metastases(R2 = 1.698, P < 0.001 and R2 = 1.699, P < 0.001, respectively). Our results suggest that high plasma fibrinogen concentration and platelet count indicate poor prognosis for NSCLC patients with brain metastases. Thus, these two biomarkers might be independent prognostic predictors for this subgroup of NSCLC patients.

Platelet-rich plasma for regeneration of neural feedback pathways around dental implants: a concise review and outlook on future possibilities

Along with the development of new materials, advanced medical imaging and surgical techniques, osseointegrated dental implants are considered a successful and constantly evolving treatment modality for the replacement of missing teeth in patients with complete or partial edentulism. The importance of restoring the peripheral neural feedback pathway and thus repairing the lack of periodontal rnechanoreceptors after tooth extraction has been highlighted in the literature. Nevertheless, regenerating the nerve fibers and reconstructing the neural feedback pathways around osseointegrated implants remain a challenge. Recent studies have provided evidence that platelet-rich plasma （PRP） therapy is a promising treatment for musculoskeletal injuries. Because of its high biological safety, convenience and usability, PRP therapy has gradually gained popularity in the clinical field Although much remains to be learned, the growth factors from PRP might play key roles in peripheral nerve repair mechanisms. This review presents known growth factors contributing to the biological efficacy of PRP and illustrates basic and （pre-）clinical evidence regarding the use of PRP and its relevant products in peripheral nerve regeneration. In addition, the potential of local application of PRP for structural and functional recovery of iniured peripheral nerves around dental implants is discussed.

Single-and double-dose of platelet-rich plasma versus hyaluronic acid for treatment of knee osteoarthritis: A randomized controlled trial

BACKGROUND Platelet-rich plasma(PRP)and hyaluronic acid have been shown to be useful in the treatment of knee osteoarthritis.However,investigations comparing the efficacy of these two drugs together are insufficient.AIM To compare the outcomes of PRP vs hyaluronic acid injections in three groups of patients with bilateral knee osteoarthritis.METHODS This randomized controlled trial study involved 95 patients.Thirty-one subjects received a single injection of PRP(group PRP-1),33 subjects received two injections of PRP at an interval of 3 wk(group PRP-2)and 31 subjects received three injections of hyaluronic acid at 1-wk intervals(group hyaluronic acid).The patients were investigated prospectively at the enrollment and at 4-,8-and 12-wk follow-up with the Western Ontario and McMaster Universities Arthritis Index(WOMAC)and Visual Analogue Scale questionnaires.RESULTS Percentages of patients experiencing at least a 30%decrease in the total score for the WOMAC pain subscale from baseline to wk 12 of the intervention were 86%,100%and 0%in the groups PRP-1,PRP-2 and hyaluronic acid,respectively(P<0.001).The mean total WOMAC scores for groups PRP-1,PRP-2 and hyaluronic acid at baseline were 63.71,61.57 and 63.11,respectively.The WOMAC scores were significantly improved at final follow-up to 42.5,35.32 and 57.26,respectively.The highest efficacy of PRP was observed in both groups at wk 4 with about 50%decrease in the symptoms compared with about 25%decrease for hyaluronic acid.Group PRP-2 had higher efficacy than group PRP-1.No major adverse effects were found during the study.CONCLUSION PRP is a safe and efficient therapeutic option for treatment of knee osteoarthritis.It was demonstrated to be significantly better than hyaluronic acid.We also found that the efficacy of PRP increases after multiple injections.

Establishing proof of concept:Platelet-rich plasma and bone marrow aspirate concentrate may improve cartilage repair following surgical treatment for osteochondral lesions of the talus

Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative(microfracture) or replacement(autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration,with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma(PRP) and bone marrow aspirate concentrate(BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.

The use of autologous platelet-rich plasma in the treatment of intractable skin ulcer: A case series

Platelet rich plasma (PRP) contains a high concentration of thrombocytes and the a granules of platelets contain platelet released growth factors. The usefulness of PRP for regeneration of bone and soft tissues has been reported previously. We firstly reported the efficacy of PRP prepared using the Magellan Autologous Platelet Separator System for intractable skin ulcers such as diabetic and venous ulcers. The system consists of a microprocessor controlled centrifuge, syringe pumps, and necessary single use processing components. No complications occurred in any patients and the wounds achieved complete epithelialization. Our results have shown the efficiency of platelet rich plasma for the treatment of intractable skin ulcers.

Platelet-rich plasma gel in combination with Schwann cells for repair of sciatic nerve injury

Bone marrow mesenchymal stem cells were isolated from New Zealand white rabbits, culture-expanded and differentiated into Schwann cell-like cells. Autologous platelet-dch plasma and Schwann cell-like cells were mixed in suspension at a density of 1 x 106 cells/mL, prior to introduction into a poly （lactic-co-glycolic acid） conduit. Fabricated tissue-engineered nerves were implanted into rabbits to bridge 10 mm sciatic nerve defects （platelet-rich plasma group）. Controls were established using fibrin as the seeding matrix for Schwann cell-like cells at identical density to construct tissue-engineered nerves （fibrin group）. Twelve weeks after implantation, toluidine blue staining and scanning electron microscopy were used to demonstrate an increase in the number of regenerating nerve fibers and thickness of the myelin sheath in the platelet-rich plasma group compared with the fibrin group. Fluoro-gold retrograde labeling revealed that the number of Fluoro-gold-positive neurons in the dorsal root ganglion and the spinal cord anterior horn was greater in the platelet-rich plasma group than in the fibrin group. Electrophysiological examination confirmed that compound muscle action potential and nerve conduction velocity were superior in the platelet-rich plasma group compared with the fibrin group. These results indicate that autologous platelet-rich plasma gel can effectively serve as a seeding matrix for Schwann cell-like cells to construct tissue-engineered nerves to promote perJpheral nerve regeneration.