Platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury

The effect of platelet-rich plasma on nerve regeneration remains controversial.In this study,we established a rabbit model of sciatic nerve small-gap defects with preserved epineurium and then filled the gaps with platelet-rich plasma.Twenty-eight rabbits were divided into the following groups(7 rabbits/group):model,low-concentrati on PRP(2.5-3.5-fold concentration of whole blood platelets),medium-concentration PRP(4.5-6.5-fold concentration of whole blood platelets),and high-concentration PRP(7.5-8.5-fold concentration of whole blood platelets).Electrophysiological and histomorphometrical assessments and proteomics analysis we re used to evaluate regeneration of the sciatic nerve.Our results showed that platelet-rich plasma containing 4.5-6.5-and 7.5-8.5-fold concentrations of whole blood platelets promoted repair of sciatic nerve injury.Proteomics analysis was performed to investigate the possible mechanism by which platelet-rich plasma promoted nerve regeneration.Proteomics analysis showed that after sciatic nerve injury,platelet-rich plasma increased the expression of integrin subunitβ-8(ITGB8),which participates in angiogenesis,and differentially expressed proteins were mainly enriched in focal adhesion pathways.Additionally,two key proteins,ribosomal protein S27 a(RSP27 a)and ubiquilin 1(UBQLN1),which were selected after protein-protein interaction analysis,are involved in the regulation of ubiquitin levels in vivo.These data suggest that platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury by affecting angiogenesis and intracellular ubiquitin levels.

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.

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.

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.

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.

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.

An inside-out vein graft filled with platelet-rich plasma for repair of a short sciatic nerve defect in rats

Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.

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.

Platelet-rich plasma,an adjuvant biological therapy to assist peripheral nerve repair

Therapies such as direct tension-free microsurgical repair or transplantation of a nerve autograft,are nowadays used to treat traumatic peripheral nerve injuries（PNI）,focused on the enhancement of the intrinsic regenerative potential of injured axons.However,these therapies fail to recreate the suitable cellular and molecular microenvironment of peripheral nerve repair and in some cases,the functional recovery of nerve injuries is incomplete.Thus,new biomedical engineering strategies based on tissue engineering approaches through molecular intervention and scaffolding offer promising outcomes on the field.In this sense,evidence is accumulating in both,preclinical and clinical settings,indicating that platelet-rich plasma products,and fibrin scaffold obtained from this technology,hold an important therapeutic potential as a neuroprotective,neurogenic and neuroinflammatory therapeutic modulator system,as well as enhancing the sensory and motor functional nerve muscle unit recovery.

Single injection of platelet-rich plasma as a novel treatment of carpal tunnel syndrome

Both in vitro and in vivo experiments have confirmed that platelet-rich plasma has therapeutic effects on many neuropathies, but its effects on carpal tunnel syndrome remain poorly understood. We aimed to investigate whether single injection of platelet-rich plasma can improve the clinical symptoms of carpal tunnel syndrome. Fourteen patients presenting with median nerve injury who had suffered from mild carpal tunnel syndrome for over 3 months were included in this study. Under ultrasound guidance, 1-2 m L of platelet-rich plasma was injected into the region around the median nerve at the proximal edge of the carpal tunnel. At 1 month after single injection of platelet-rich plasma, Visual Analogue Scale results showed that pain almost disappeared in eight patients and it was obviously alleviated in three patients. Simultaneously, the disabilities of the arm, shoulder and hand questionnaire showed that upper limb function was obviously improved. In addition, no ultrasonographic manifestation of the carpal tunnel syndrome was found in five patients during ultrasonographic measurement of the width of the median nerve. During 3-month follow-up, the pain was not greatly alleviated in three patients. These findings show very encouraging mid-term outcomes regarding use of platelet-rich plasma for the treatment of carpal tunnel syndrome.

Platelet-rich plasma enhances adipose-derived stem cell-mediated angiogenesis in a mouse ischemic hindlimb model

AIM To evaluate the angiogenic effect of platelet-rich plasma(PRP)-preconditioned adipose-derived stem cells(ADSCs) both in vitro and in a mouse ischemic hindlimb model.METHODS ADSCs were divided based on culture medium: 2.5% PRP, 5% PRP, 7.5% PRP, and 10% PRP. Cell proliferation rate was analyzed using the MTS assay. The gene expression of CD31, vascular endothelial growth factor, hypoxia-inducible factors, and endothelial cell nitric oxide synthase was analyzed using reverse transcription polymerase chain reaction. Cell markers and structural changes were assessed through immunofluorescence staining and the tube formation assay. Subsequently, we studied the in vivo angiogenic capabilities of ADSCs by a mouse ischemic hindlimb model.RESULTS The proliferation rate of ADSCs was higher in the 2.5%, 5%, and 7.5% PRP groups. The expression of hypoxia-inducible factor, CD31, vascular endothelial growth factor, and endothelial cell nitric oxide synthase in the 5% and 7.5% PRP groups increased. The 5%, 7.5%, and 10% PRP groups showed higher abilities to promote both CD31 and vascular endothelial growth factor production and tubular structure formation in ADSCs. According to laser Doppler perfusion scan, the perfusion ratios of ischemic limb to normal limb were significantly higher in 5% PRP, 7.5% PRP, and human umbilical vein endothelial cells groups compared with the negative control and fetal bovine serum(FBS) groups(0.88 ± 0.08, 0.85 ± 0.07 and 0.81 ± 0.06 for 5%, 7.5% PRP and human umbilical vein endothelial cells compared with 0.42 ± 0.17 and 0.54 ± 0.14 for the negative control and FBS, P < 0.01).CONCLUSION PRP-preconditioned ADSCs presented endothelial cell characteristics in vitro and significantly improved neovascularization in ischemic hindlimbs. The optimal angiogenic effect occurred in 5% PRP-and 7.5% PRPpreconditioned ADSCs.

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.

Platelet-rich plasma-induced bone marrow mesenchymal stem cells versus autologous nerve grafting for sciatic nerve repair

Autologous nerve grafting is the gold standard of peripheral nerve repair.We previously showed that autologous platelet-rich plasma（PRP）contains high concentrations of growth factors and can induce in vitro cultured bone marrow mesenchymal stem cells（BMSCs）to differentiate into Schwann cells.Here we used PRP-induced BMSCs combined with chemically extracted acellular nerves to repair sciatic nerve defects and compared the effect with autologous nerve grafting.The BMSCs and chemically extracted acellular nerve promoted target muscle wet weight restoration,motor nerve conduction velocity,and axonal and myelin sheath regeneration,with similar effectiveness to autologous nerve grafting.This finding suggests that PRP induced BMSCs can be used to repair peripheral nerve defects.

Role of platelet-rich plasma in ischemic heart disease: An update on the latest evidence

Myocardial infarction is the most common cause of congestive heart failure. Novel strategies such as directly reprogramming cardiac fibroblasts into cardiomyocytes are an exciting area of investigation for repair of injured myocardial tissue. The ultimate goal is to rebuild functional myocardium by transplanting exogenous stem cells or by activating native stem cells to induce endogenous repair. Cell-based myocardial restoration, however, has not penetrated broad clinical practice yet. Plateletrich plasma, an autologous fractionation of whole blood containing high concentrations of growth factors, has been shown to safely and effectively enhance healing and angiogenesis primarily by reparative cell signaling. In this review, we collected all recent advances in novel therapies as well as experimental evidence demonstrating the role of platelet-rich plasma in ischemic heart disease, focusing on aspects that might be important for future successful clinical application.

Submucosal injection of platelet-rich plasma in endoscopic resection of large sessile lesions

AIM To prospectively evaluate the efficacy of submucosal injection of platelet-rich plasma(PRP) on endoscopic resection of large sessile lesions.METHODS Eleven patients were submitted to endoscopic mucosal resection(EMR) with prior injection of PRP, obtained at the time of endoscopy. Patients were followed during 1 mo. The incidence of adverse events(delayed bleeding or perforation) and the percentage of mucosal healing(MHR) after 4 wk were registered. RESULTS EMR was performed in 11 lesions(46.4 mm ± 4 mm, range 40-70 mm). Delayed bleeding or perforation was not observed in any patient. Mean ulcerated area atbaseline was 22.7 cm^2 ± 11.7 cm^2 whereas at week 4 were 2.9 cm^2 ± 1.5 cm^2. Patients treated with PRP showed a very high MHR after 4 wk(87.5%). CONCLUSION PRP is an easy-to-obtain solution with proven and favourable biological activities that could be used in advanced endoscopic resection.

Subtenon Injection of Autologous Platelet-Rich Plasma in Retinitis Pigmentosa: Is It a New Therapeutic Option?

Purpose: Growth factors (GFs) and neurotrophins can decelerate retinal degeneration. This study aimed to investigate the safety, efficacy and durability of subtenon injections of autologous platelet-rich plasma (aPRP) which is a rich source of GFs in retinitis pigmentosa (RP) patients. Methods: 154 eyes of 77 RP patients with various degrees of narrowed visual field were investigated in this study. Each patient received three injections with 4-week intervals and followed for at least 12 months. The examinations and the tests were obtained before the injection, 1 month after the third injection and every 3 months during the study. The primary aim was to evaluate the effects of aPRP on visual acuity (VA) and visual functions, the second aim was to estimate the duration of the therapy effect and the need for additional aPRP injection. Results: Median age of the 77 RP patients was 35.2 ± 13.9 years. All of the eyes received 3 monthly bilateral subtenon aPRP injections. Of these patients 26 received an additional one, 12 received additional two and 1 patient received additional 3 injections with 3-month interval. There were no significant ocular or systemic side effects. The mean baseline VA was 0.22 ± 0.18 Snellen lines. It improved to 0.31 ± 0.19 following three aPRP injections, which was statistically significant. At the end of the study period, the mean VA was 0.27 ± 0.22 Snellen lines. Conclusion: The subtenon injection of aPRP might be an effective therapy and might have a positive influence in the preservation of visual functions and visual acuity of RP patients.

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.

Effect of Autologus Platelet-Rich Plasma on IL-6, MMP-3 and MCP-1 Expression in Synoviocytes from Osteoarthritic Patients Knees

Nowadays, some studies reported promising results of platelet-rich plasma (PRP) for the treatment of osteoarthritis (OA). However, the effects of PRP on prevention of osteoarthritis in knee joints have been debated. The present study investigated the effects of PRP on osteoarthritis related inflammatory cytokines expressed in fibroblast-like synoviocytes (FLS) from osteoarthritic knees. The synovial tissues were harvested from eight osteoarthritic patients who had undertaken total knee arthroplasties (TKAs) and cultured in DMEM containing 10% FBS. Platelet-rich plasma releasate (PRPr) was made by clotting or activation of PRP by citrate. The levels of PDGF-AA and VEGF in PRPr and whole blood were measured with ELISA method. The FLS were isolated and cultured from osteoarthritic knees. The IL-1β stimulated FLS were cultivated with three different conditions (none, 1% and 10% of PRP). To determine the expression of IL-6, MMP-3, and MCP-1, we used reverse transcriptase polymerase chain reaction (RT-PCR). The concentrations of platelet count in PRP were about 7 to 9 times higher than those of whole blood. The levels of PDGF-AA in PRPr were approximately 3 to 4 times higher than those of whole blood. The levels of VEGF in PRPr were also significantly 7 to 18 times higher than those of whole blood. Without induction of the FLS with IL-1β, 1% or 10% PRPr did not reduce expressions of inflammatory proteins (MMP-3, MCP-1), except for IL-6. However, with induction of the FLS with IL-1β, both concentrations (1% and 10%) of PRPr reduced significantly all inflammatory protein expressions (IL-6, MMP-3, MCP-1). PRPr diminished inflammatory IL-1β-mediated effects on human osteoarthritic fibroblast-like synoviocytes. These results suggest that platelet-rich plasma can be a good therapeutic option for the treatment of osteoarthritis.