Platelet-rich Plasma Preparation Research Articles

Relationship of Body Adiposity with Platelet Function in Obese and Non-obese Individuals.

BackgroundAdiposity is firmly linked to a higher incidence of various cardiovascular and metabolic morbidities, including diabetes, hypertension, and thromboembolism. This research study was aimed to verify the association of increased adiposity and hyperreactivity of platelets in obese and non-obese individuals.MethodsThis cross-sectional study was conducted on 42 subjects aged 18 years and above. Subjects were divided into obese and non-obese groups based on their body mass index (BMI). The data was collected through self-administered questionnaires. All participants underwent body composition analysis. Blood samples were collected from all subjects and taken to the Pharmacology Department for the preparation of platelet-rich plasma (PRP) and poor platelet plasma (PPP). Platelet aggregation was induced by arachidonic acid and was monitored with a Bio/Data multichannel aggregation profiler (Bio/Data Corp., Horsham, PA, USA).ResultsSignificant differences were observed in most parameters, such as fat mass, body fat percentage, free fat mass (FFM), the percentage of trunk fat, total body water, waist-hip ratio (WHR), and basal metabolic rate (BMR) of obese and non-obese subjects. The average percent of platelet aggregation in obese and non-obese subjects was 56.33 ± 15.62 and 59.38 ± 12.62, respectively. The average area under the curve (AUC) for platelet aggregation for both groups was 339.33 ± 191.55 and 342 ± 146.68, respectively. Platelet function was not significantly different and didn’t positively correlate with most parameters of the body composition, except WHR, which positively correlated with AUC for platelet function. ConclusionThere was no significant direct correlation between adiposity and platelet activation in obese subjects. However, a significant positive correlation of AUC for platelet aggregation with WHR was observed (resistance (r)-value: 0.307, p < 0.05). These findings suggest that WHR could be an effective determinant to assess the risk of thromboembolism in obese individuals.

Ultrasound-guided Platelet-rich Plasma Application Versus Corticosteroid Injections for the Treatment of Greater Trochanteric Pain Syndrome: A Prospective Controlled Randomized Comparative Clinical Study.

PurposeThe purpose of this clinical study was to evaluate and compare the effectiveness of ultrasound (US)-guided platelet-rich plasma (PRP) injections versus US-guided corticosteroid injections (CSI) in the treatment of greater trochanteric pain syndrome (GTPS).MethodsBetween January 2015 and December 2016, 24 patients with GTPS were enrolled and randomized in two groups (A and B). Group A (study group) patients received US-guided PRP injection treatment, while group B (control group) patients received US-guided CSI treatment. Clinical outcomes in both groups were evaluated and compared using the Visual Analogue Scale (VAS) of pain, the Harris Hip Score (HHS) and the presence or absence of complications at 4, 12, and 24 weeks post-injection. The level of significance was set at p<0.05.ResultsBoth groups showed improved scores (VAS and HHS) compared to the pre-injection period, but patients in group A had a statistically significant (p <0.05) decrease in VAS score and a significantly increased HHS at the last follow-up (24 weeks post-injection). No complications were reported.ConclusionsIn conclusion, patients with GTPS present better and longer-lasting clinical results when treated with US-guided PRP injections compared to those with CSI. Further studies are needed to optimize the technical preparation of PRP, the sample concentration, the number of injections and the time intervals between them, in order to achieve the maximum desired results.

Comparison of Platelet-Rich Plasma Prepared Using Two Methods: Manual Double Spin Method versus a Commercially Available Automated Device.

Background:In the absence of a standard protocol, several methods and devices have been used for preparing platelet-rich plasma (PRP) with varying platelet concentrations.Methods:Venous blood sample from 20 patients was used for preparing PRP using two methods: a manual double-spin method (1st spin at 160 g × 10 min, 2nd spin at 400 g × 10 min), and using a commercially available automated device (DrPRP-Kit®, REMI Laboratory Instruments). Platelet, erythrocyte, and total leukocyte counts were calculated for each PRP sample and compared.Results:Platelet count in the PRP prepared with the manual double-spin method (PRPm, 12.51 ± 5.89 × 105/μL) as well as with the automated device (PRPa, 7.25 ± 4.74 × 105/μL) had significantly higher mean platelet count than whole blood (2.58 ± 0.81 × 105/μL, P < 0.001). The mean platelet count in PRPm was statistically significantly higher than PRPa (P < 0.001). The platelet capture efficiency of the manual method (mean 47.11%, median 41.75%) was statistically significantly higher than that of the automated device (mean 31.89%, 29.51%, P = 0.012). Platelet counts in both PRPs were variable, but the counts were more dispersed in PRPa(coefficient of variation 65%) as compared to PRPm(coefficient of variation 47%).Conclusion:The manual double-spin method had a higher platelet capture efficiency resulting in a higher platelet concentration as compared to the automated device. Though there was a significant interindividual variation in the platelet yield in the PRPs produced by both methods, results were more consistent with the manual method.

Time course of platelet activation following platelet-rich plasma preparation on automated platelet light transmission aggregometry using CS-2000i

Time course of platelet activation following platelet-rich plasma preparation on automated platelet light transmission aggregometry using CS-2000i

Platelet-rich plasma preparation using three different centrifugation methods: A comparative study

<br><b>Background</b><br>Platelet-rich plasma (PRP) is a platelet concentrate contained in a small volume of plasma, it has been a promising option in the last decade to treat different dermatology diseases, such as alopecia, skin ulcers, melisma, and burns due to the high concentration of growth factors that stimulate tissue repair and regeneration. The current study aims to compare the yield of platelets comparing different centrifugation methods, which are double-spin high-centrifugation force, double-spin low-centrifugation force, and single-spin system correlating each with the growth-factor concentration.<br><b>Patients and methods</b><br>This study was performed on 30 healthy individuals (12 males and 18 females), their age ranged from 17 to 49 years old. From each individual, 20 ml of venous blood was collected for both basal blood-cell count and for PRP preparation. The PRP samples were prepared by differential centrifugation methods through one of three different procedures using the laboratory centrifuge (Eppendorf 5810 R). Growth factors, including vascular endothelial growth factor, platelet-derived growth factor, and matrix metalloprotein-9, were measured in PRP samples using enzyme-linked immunosorbent assay technique.<br><b>Results</b><br>The current study showed that the double-spin low-centrifugation method increased the platelet count by 140% than the baseline value, with significant fold rise than in the single-spin and the double-spin high-centrifugation method, meanwhile, there is a statistically significant increase in the corresponding growth factors.<br><b>Conclusions</b><br>Double-spin low-centrifugation method and single-spin centrifugation provide better platelet yielding with efficient growth-factor concentrations.<br>

Research progress of platelet-rich plasma in the treatment of androgenetic alopecia

Platelet-rich plasma (PRP) is a high-concentration platelet plasma derived from autologous blood, rich in a variety of growth factors. It can promote cell proliferation and differentiation. PRP has been widely used in oral cavity, plastic surgery, orthopedics, neurosurgery and other fields this year. This article reviews the preparation of platelet-rich plasma, the principle of treatment of androgenetic alopecia, and its clinical treatment progress, current problems and future application prospects.

A Study of the Effect of Platelet-Rich Plasma on Outcomes After Aspirated Human Fat Grafting With Experimental Design.

Over the past decade, some studies have focused on whether platelet-rich plasma (PRP) can promote the survival of fat grafts after transplantation. However, the results of these studies have been controversial because of the variations in research methods and assessment methodologies. In this study, the authors aspirated fat particles from the abdomen of a healthy woman, mixed them with PRP, and injected them into the backs of nude mice subcutaneously, which simulates the clinical model. The control group was designed to mix aspired fat with normal saline. The fat grafts were removed 10 weeks after transplantation, stained with hematoxylin and eosin, and sliced into pathological sections, which were subsequently scanned and analyzed using the Digital Slide Scanning System (PRECICE, Beijing, China). The total area of the graft section and the necrotic adipose tissue area in the control group were significantly larger than that in the PRP group. The fibrosis tissue area in the PRP group was significantly larger than that in the control group. There were no statistically significant differences in the viable adipocyte area, the cyst area, and the mature blood vessel number between the PRP and control groups. In this study, PRP did not cause an increase in the number of viable adipocytes; however, it did increase the amount of inflammation, which promoted necrotic tissue absorption and the proliferation of granulation tissue. Further research, including research on normalization of fat preparation and grafting, unification of the PRP preparation and application scheme, and optimization of histological measurement and analysis methods, is needed to assess the effect of PRP on fat grafting.

Role of Platelet-rich Plasma in the Healing of Impacted Third Molar Socket: A Comparative Study on Central India Population

The aim of the study was to compare the healing and osseous regeneration of mandibular third molar extraction sockets with and without platelet-rich plasma (PRP) with the evaluation of clinical objectives such as pain, swelling, trismus, soft tissue healing, pocket depth distal to second molar and radiological evaluation of the bony density in the postextracted third molar socket. In this prospective study, 100 patients were selected by the random sampling method from the outpatient department of oral and maxillofacial surgery in the year 2016-2017. Patients were equally allocated into intervention (transalveolar extraction followed by PRP placement) and nonintervention (transalveolar extraction without PRP placement) group as group I and group II, respectively, and evaluation parameters were considered accordingly. The statistical analysis was done using SPSS (Statistical Package for Social Sciences) Version 15.0 (IBM, USA) statistical analysis software. The pain score of patients of group I (non-PRP) was found to be higher as compared to group II (with PRP). Mean trismus of patients of group II was found to be higher than that of group I at postoperative day 7, but this difference was not found to be statistically significant. Swelling at T-Sn (Tragus-Subnasale) and T-Pog (Tragus-Pogonion) was higher among patients of group I as compared to group II. Healing in group II was two to three times faster than group I. Healing among patients of group I and group II was found to be statistically significant. The mean pocket depth of patients of group I was found to be significantly higher than that of group II at follow-up of 1 and 2 months. The bone density of patients of group II was found to be significantly higher than that of group I at 3 months and 6 months follow-up. The procedure of PRP preparation is simple and cost-effective, and can be prepared at the point of care. It had a significant impact on the postoperative healing of the third molar socket. The use of PRP application increases the bone density, healing process, and improvement in the pain and swelling, and there was a definite reduction in trismus and periodontal probing depth after the impacted mandibular wisdom teeth extraction.

The Number of Platelets in Patient's Blood Influences the Mechanical and Morphological Properties of PRP-Clot and Lysophosphatidic Acid Quantity in PRP.

The objectives of this study were to compare platelet-rich plasma (PRP) from patients with different concentrations of platelets and to assess the influence of these PRP preparations on human osteoblast (hOB) activity. In the literature, growth factors released by activated platelets have been considered responsible for the active role of PRP on bone regeneration but no specific role has been attributed to lysophosphatidic acid (LPA) as a possible effector of biological responses. In this study, patients were grouped into either group A (poor in platelets) or group B (rich in platelets). Clots from PRP fraction 2 (F2-clots), obtained with CaCl2 activation of PRP from the two groups, were compared macroscopically and microscopically and for their mechanical properties before testing their activity on the proliferation and migration of hOB. LPA was quantified before and after PRP fractioning and activation. The fibrin network of F2-clots from patients with a lower platelet concentration had an organized structure with large and distinct fibers while F2-clots from patients in group B revealed a similar structure to those in group A but with a slight increase in density. ELISA results showed a significantly higher plasma level of LPA in patients with a higher platelet concentration (group B) in comparison to those in group A (p < 0.05). This different concentration was evidenced in PRP but not in the clots. Depending on the number of platelets in patient’s blood, a PRP-clot with higher or lower mechanical properties can be obtained. The higher level of LPA in PRP from patients richer in platelets should be considered as responsible for the higher hOB activity in bone regeneration.

Treatment of Male-Pattern Alopecia with Platelet-Rich Plasma

Background: Androgenetic alopecia (AGA) affects up to 80% of men and 50% of women throughout their lifetime, causing significant discomfort. Minoxidil, finasteride, and low-level laser light therapy are the only Food and Drug Administration-approved treatments for AGA, and they have shown positive results in randomized controlled trials and meta-analyses. However, their efficacy is limited, and new therapies are needed. Injection of platelet-rich plasma (PRP), a minimally invasive technique, has been described by several authors as a promising treatment for AGA. Although many studies report beneficial effects of PRP on AGA, there is no standardized practice for PRP preparation and administration or a standard method to evaluate results. Objective: The aim of this study was to evaluate the efficacy of manually prepared PRP in the treatment of male AGA. Materials and Methods: We treated 20 male patients with AGA with 3 monthly injections of PRP and analyzed results by TrichoScan®. Results: In this study, there was no statistically significant improvement in hair count or proportion of anagen hairs. Conclusions: This lack of response could be related to any of the variables during PRP preparation described above and also to the limited number of patients in the study.

Platelet sonicates activate hair follicle stem cells and mediate enhanced hair follicle regeneration.

An increasing number of studies show that platelet‐rich plasma (PRP) is effective for androgenic alopecia (AGA). However, the underlying cellular and molecular mechanisms along with its effect on hair follicle stem cells are poorly understood. In this study, we designed to induce platelets in PRP to release factors by calcium chloride (PC) or by sonication where platelet lysates (PS) or the supernatants of platelet lysate (PSS) were used to evaluate their effect on the hair follicle activation and regeneration. We found that PSS and PS exhibited a superior effect in activating telogen hair follicles than PC. In addition, PSS injection into the skin activated quiescent hair follicles and induced K15+ hair follicle stem cell proliferation in K14‐H2B‐GFP mice. Moreover, PSS promoted skin‐derived precursor (SKP) survival in vitro and enhanced hair follicle formation in vivo. In consistence, protein array analysis of different PRP preparations revealed that PSS contained higher levels of 16 growth factors (out of 41 factors analysed) than PC, many of them have been known to promote hair follicle regeneration. Thus, our data indicate that sonicated PRP promotes hair follicle stem cell activation and de novo hair follicle regeneration.

Evaluation of platelet-rich plasma from diabetic donors shows increased platelet vascular endothelial growth factor release.

Platelet-rich plasma (PRP) contains pro-angiogenic growth factors including vascular endothelial growth factor (VEGF). Angiogenesis is a necessary component of wound healing in instances of diabetic foot ulcers (DFU). PRP composition varies depending on methods and donor health status. Our group has developed an improved PRP protocol for diabetes treatment. The aims of this study were to examine the levels of the pro-angiogenic factor VEGF in these patient populations with and without diabetes. PRP was prepared using 24 mL of whole blood from 13 diabetic and 10 non-diabetic patients registered at Klinik Hayandra. Whole blood in sodium citrate tubes were centrifuged at 1,000 rpm for 5 minutes followed by plasma separation. Plasma samples were centrifuged at 3,000 rpm for 5 minutes. Upper platelet-poor plasma layers were discarded, leaving 5 mL of concentrated platelet containing plasma (PRP). Concentrated plasma samples were mixed, aliquoted, stored at -86 °C, and pooled for platelet count, VEGF, and total protein analyses. Platelet counting was also performed using fresh whole blood and PRP to measure changes following PRP preparation. Diabetic donors had higher whole blood platelet counts than non-diabetic donors, but this difference was not statistically significant. An average increase of more than 250% in platelet number after PRP preparation using our method was noted in both groups. Freezing-thawing samples at -86 °C lysed more than 90% of PRP platelets regardless of diabetes status. Diabetic PRP had lower mean total protein and higher VEGF concentrations. Lysed platelets from diabetic donors released more VEGF than those from non-diabetic donors. PRP from diabetic donors had higher VEGF content making autologous PRP application a promising treatment for DFU. However, this should be investigated another appropriate clinical trial.

The influence of sample size and gender composition on the meta-analysis conclusion of platelet-rich plasma treatment for osteoarthritis

ObjectiveThe magnitude of the therapeutic effects of intra-articular injection of platelet-rich plasma (PRP) on osteoarthritis (OA) is still under debate. The goal of this study that was a systematic review of randomised controlled trials ​of PRP injections for the treatment of OA was to elucidate the therapeutic efficacy of PRP. MethodsElectronic databases of PubMed, CENTRAL, EMBASE, EBSCO, ClinicalTrials.gov, and International Clinical Trials Registry Platform ​were searched from inception to June 2018 for RCTs that compared PRP injections to controls in patients with OA. A random-effects approach was used to compile data and subgroups according to trial size (large trials versus small trials), patient profile (age and gender), and PRP preparation method was performed. ResultsThirty trials met the inclusion criteria and were analysed. All results had unexplained statistical heterogeneity. Patients treated with PRP compared with control showed statistically relevant pain relief and function improvement at short term (standardised mean difference [SMD] ​= ​−0.62, 95% confidence interval [CI]: −0.98 to −0.27, P ​= ​0.0006, SMD ​= ​−0.74, 95% CI: −1.11 to 0.36, P ​= ​0.0001, respectively), medium term (SMD ​= ​−0.53, 95% CI: −0.83 to −0.23, P ​= ​0.0006, SMD ​= ​−0.50, 95% CI: −0.75 to −0.25, P ​= ​0.0006), and long term (SMD ​= ​−0.69, 95% CI: −1.08 to −0.30, P ​= ​0.0006, SMD ​= ​−0.68, 95% CI: −0.1.09 to −0.27, P ​= ​0.001, respectively). A subgroup analysis of the data from large trials and from trials composed of less than 50% female patients revealed that therapeutic effects of the treatment are insignificant. ConclusionsAccording to the currently available data, PRP injections are beneficial for pain relief and function improvement in patients with OA. This meta-analysis, however, demonstrated that the efficacy of PRP is related to sample size and gender composition. Thus, more randomised controlled trials of high quality and larger patient size, also including gender aspects, are required to understand this phenomenon. The translational potential of this articleThe translation potential of this meta-analysis is that provided another perspective to analyse the treatment effect of PRP for OA. In future research, phenotypes subpopulation and gender difference of OA patient should be considered for PRP treatment.

Comparison of Two Anticoagulants for Pain Associated with Platelet-Rich Plasma Injections.

Platelet-rich plasma (PRP) has long been used in skin rejuvenation and hair loss treatment. Some patients require multiple intradermal injections into the face and scalp, and the way in which these patients process and experience pain differs, depending on the patient. Minimizing pain and discomfort during nonsurgical procedures is essential for patient satisfaction. In our experience, the use of acid citrate dextrose-A (ACD-A) as an anticoagulant caused more patient discomfort than did sodium citrate (Na-citrate) among patients who underwent facial rejuvenation with PRP. The aim of the present study was to evaluate patient-related discomfort in PRP sessions using two different anticoagulants. This clinical trial included 10 patients who received facial PRP injections for facial rejuvenation and 10 patients who received PRP injections in their scalps for hair loss. On the application area, half the surface was treated with Na-citrate PRP injections, and the other half was treated with the same amount of ACD-A PRP injections. Neither the doctors who applied the treatment nor the patients were given information about which anticoagulant was used in each area. Immediately after the procedure, the patients were asked to score their pain on each side of the application area on a scale of 1-10 using a visual analog scale (VAS). PRP injections using Na-citrate as an anticoagulant caused less discomfort on both the face and scalp as compared with that of ACD-A. The outcome was statistically significant. Anticoagulants used in PRP preparation affected patients' pain perceptions during the injections. The sensation of pain with PRP prepared with Na-citrate as an anticoagulant was lower than that of PRP prepared with ACD-A. Further studies are required to evaluate the correlation between anticoagulants used for PRP preparation and pain feelings during injections. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

A Novel Method for Flow Cytometric Quantification of Human Platelet Membrane Glycoproteins in Citrated Whole Blood

Introduction: Diagnosis of platelet receptor defects can be confirmed by flow cytometry using a panel of monoclonal antibodies. The conventional method utilizing platelet rich plasma (PRP) has many limitations such as time-consuming preparation, requirement of a large sample volume or limitations in samples from patients with thrombocytopenia or abnormally large platelets. In order to overcome these difficulties a novel method was developed using a second antibody directed against an erythrocyte protein which allows differentiation between platelets and erythrocytes in citrated whole blood (CWB). Methods: CWB or PRP from healthy blood donors and outclinic patients without platelet disorder (n= 18) as well as from two patients with Glanzmann thrombasthenia (GT) was stained with fluorescein isothiocyanate (FITC)-conjugated antibodies against CD42b (GP Ib), CD41a (GP IIb/IIIa), or CD62. CWB was stained in addition with a phycoerythrin (PE)-conjugated antibody against CD235a, a sialoglycoprotein expressed by erythroid precursors and erythrocytes. Platelet activation was induced by addition of 2 µM phorbol 12-myristate 13-acetat (PMA). The expression of CD42b, CD41a and CD62 on CD235a-negative cells was quantified by flow cytometry with and without PMA stimulation. Results: CWB and PRP samples showed no differences of mean (± standard deviation) fluorescence intensity (MFI)(GP Ib 74.78 ± 21.39 vs. 85.67 ± 26.03, GP IIb/IIIa 250.33 ± 59.08 vs. 234.50 ± 56.96, GP IIb/IIIa with PMA 349.50 ± 76.87 vs. 328.67 ± 72.92, GP IIb 26.10 ± 6.17 vs. 29.15 ± 8.29, GP IIb with PMA 35.58 ± 8.86 vs. 37.50 ± 8.98, CD62 1.91 ± 0.49 vs. 2.49 ± 1.14, CD62 with PMA 43.88 ± 10.89 vs. 37.78 ± 7.20, respectively). The increase of the fluorescence signal with PMA vs. without PMA was similar in CWB and PRP with a percentage increase of 141.17 ± 10.97 vs. 142.74 ± 15.08 % for GP IIb/IIIa, 136.76 ± 16.65 vs. 131.83 ± 16.64 % for GP IIb and 2432.14 ± 785.49 vs. 1701.37 ± 474.72 % for CD62. Patients with GT showed MFI values for GP IIb/IIIa and GPIIb expression less than 5 % in comparison to that of a healthy control. Conclusion: Flow cytometric analysis of platelet membrane proteins utilizing CWB is comparable to the conventional PRP method. Using an antibody against CD235a allows distinct differentiation between platelets and erythrocytes in CWB. This new method requires smaller amounts of blood, spares time-consuming preparation of PRP and is feasible to identify rare inherited platelet membrane disorders. Disclosures Berens: Baxter: Honoraria; Novo Nordisk: Honoraria; CSL Behring: Honoraria; Biotest: Honoraria; Shire: Honoraria; Pfizer: Honoraria. Müller:Roche: Membership on an entity's Board of Directors or advisory committees; Siemens: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; NovoNordisk: Membership on an entity's Board of Directors or advisory committees. Rühl:Sanofi Genzyme: Honoraria; SOBI: Honoraria; Shire: Honoraria; Bayer: Honoraria; CSL Behring: Honoraria; Grifols: Honoraria. Oldenburg:Swedish Orphan Biovitrum: Consultancy, Speakers Bureau; Grifols: Consultancy, Speakers Bureau; NovoNordisk: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Speakers Bureau; Takeda (Shire): Consultancy, Research Funding, Speakers Bureau; Chugai: Consultancy, Speakers Bureau; Bayer: Consultancy, Research Funding, Speakers Bureau; Biotest: Consultancy, Research Funding, Speakers Bureau; CSL Behring: Consultancy, Research Funding, Speakers Bureau; Octapharma: Consultancy, Research Funding, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau.

Platelet-rich plasma injection for adults with acute Achilles tendon rupture: the PATH-2 RCT

BackgroundAchilles tendon rupture (ATR) has a long healing period, which is challenging for patients and clinicians. Platelet-rich plasma (PRP) is an autologous concentration of platelets thought to improve tendon function recovery. Although preliminary research has indicated positive effects, there is, as yet, no evidence of clinical efficacy from adequately powered robust clinical trials.ObjectivesThe objectives were to determine the clinical efficacy of PRP in patients with acute ATR using an objective mechanical muscle–tendon function measure and patient-reported outcome measures (PROMs), and to determine which PRP components contribute to its mechanism.DesignThis was a multicentre, parallel-group, participant- and outcome assessor-blinded randomised controlled trial (RCT) comparing PRP with placebo. Two embedded substudies investigated the PRP’s quality and composition and its effects on healing tendon tissues.SettingThis trial was set in trauma and orthopaedic surgery departments in 19 NHS hospitals in England and Wales.ParticipantsAdults with acute ATR presenting within 12 days of injury to be treated non-surgically were eligible. Patients with platelet dysfunction or leg functional deficiency were excluded.InterventionsParticipants were randomised 1 : 1 to the PRP injection group or the placebo group (dry needle in the rupture gap) by central computer-based randomisation using minimisation, stratified by centre and age.Main outcome measuresThe primary outcome measure was the Limb Symmetry Index (LSI) of work during the heel-rise endurance test at 24 weeks. Secondary outcomes measures, collected at 4, 7, 13 and 24 weeks, were repetitions, maximum heel-rise height, Achilles tendon Total Rupture Score (ATRS), quality of life (as measured using the Short Form questionnaire-12 items version 2), pain and participant goal attainment. Needle biopsies of the affected tendon zone were taken under ultrasound guidance at 6 weeks from 16 participants from one centre. Whole blood was analysed for cell count. PRP was analysed for cell count, platelet activation and growth factor concentration. The primary analysis was intention to treat.ResultsA total of 230 participants were randomised: 114 to the PRP group (103 treated) and 116 to the placebo group (all treated). One participant withdrew after randomisation but before the intervention. At 24 weeks, 201 out of 230 participants (87.4%) completed the primary outcome and 216 out of 230 participants (93.9%) completed the PROMs. The treatment groups had similar participant characteristics. At 24 weeks, there was no difference in work LSI (mean difference –3.872; 95% confidence interval –10.454 to 2.710;p = 0.231), ATRS, pain or goal attainment between PRP- and placebo-injected participants. There were no differences between the groups in any PROM at any time point or in complication rates, including re-rupture and deep-vein thrombosis. There was no correlation between work LSI and platelet activation in PRP, or erythrocyte, leucocyte or platelet counts in whole blood or PRP. Biopsies showed similar cellularity and vascularity between groups.ConclusionsThis trial design and standardised PRP preparation gives the first robust RCT evidence about PRP’s role in managing ATR, which suggests that PRP offers no patient benefit. Equally robust evidence to investigate PRP application in tendon and soft tissue injuries is required. The 24-month follow-up will be completed in April 2020.Trial registrationCurrent Controlled Trials ISRCTN54992179.FundingThis project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership. The trial was supported by the NIHR Biomedical Research Centre, Oxford, and the NIHR Fellowship programme.

Reduction in post extraction waiting period for dental implant patients using plasma rich in growth factors: an in vivo study using cone-beam computed tomography.

ObjectivesThis study examined the effects of plasma-rich growth factors (PRGF) on accelerating bone regeneration/repair in fresh extraction sockets, and determined the quality and quantity of bone by assessing the bone density using cone-beam computed tomography (CBCT).Materials and MethodsTwenty patients, who had undergone bilateral extractions, were included in this study. In one extraction socket, PRGF was used and covered with an autologous fibrin plug. Nothing was used in the opposite side extraction socket. Thirteen weeks post extraction, the level of bone regeneration was evaluated on both sides with CBCT.ResultsAt the end of the study, the mean bone density according to the Hounsfield units (HU) in the control group and PRGF group was 500.05 HU (type III bone type) and 647.95 HU (type II bone type), respectively.ConclusionThis study recommends the use of PRGF in post extraction sites to accelerate the rate of bone regeneration and improve the quality of regenerated bone. The technique to process PRGF was simple compared to previously mentioned techniques used for platelet-rich plasma (PRP) preparation. PRP preparation requires a two-cycle centrifugation procedure, leading to a longer processing time.

A systematic review of the safety and effectiveness of platelet-rich plasma (PRP) for skin aging.

Injection of platelet concentrates for the treatment of aging skin has gained popularity. The objective was to systematically assess the evidence regarding the safety and effectiveness of platelet-rich plasma (PRP) for reducing the visible signs of aging. Cochrane Library, MEDLINE (PubMed), EMBASE, and Scopus were searched from inception to March 2019 for prospective trials and case series assessing PRP for skin aging in 10 or more patients. Twenty-four studies, including 8 randomized controlled trials (RCTs), representing 480 total patients receiving PRP, were included. Based on physician global assessment, injection PRP monotherapy was shown to at least temporarily induce modest improvement in facial skin appearance, texture, and lines. Periorbital fine lines and pigmentation may also benefit. Adjuvant PRP accelerated healing after fractional laser resurfacing. Although the degree of improvement was typically less than 50%, patients generally reported high satisfaction. It was limited by heterogeneity in PRP preparation and administration, and lack of standardization in outcome measures. PRP injections are safe and may be modestly beneficial for aging skin. The evidence is most convincing for improvement of facial skin texture. The persistence of these effects is not known. More high-quality trials with sufficient follow-up are needed to optimize treatment regimens.

Nonoperative Treatment of Elbow Ulnar Collateral Ligament Injuries With and Without Platelet-Rich Plasma in Professional Baseball Players: A Comparative and Matched Cohort Analysis

Background: Recent studies evaluating nonoperative treatment of elbow ulnar collateral ligament (UCL) injuries augmented with platelet-rich plasma (PRP) have shown promising results. To date, no comparative studies have been performed on professional baseball players who have undergone nonoperative treatment with or without PRP injections for UCL injuries. Hypothesis: Players who received PRP injections would have better outcomes than those who did not receive PRP. Study Design: Cohort study; Level of evidence, 3. Methods: The Major League Baseball (MLB) Health and Injury Tracking System identified 544 professional baseball players who were treated nonoperatively for elbow UCL injuries between 2011 and 2015. Of these, 133 received PRP injections (PRP group) before starting their nonoperative treatment program, and 411 did not (no-PRP group). Player outcomes and a Kaplan-Meier survival analysis were compared between groups. In addition, to reduce selection bias, a 1:1 matched comparison of the PRP group versus the no-PRP group was performed. Players were matched by age, position, throwing side, and league status: major (MLB) and minor (Minor League Baseball [MiLB]). A single radiologist with extensive experience in magnetic resonance imaging (MRI) interpretation of elbow injuries in elite athletes analyzed 243 MRI scans for which images were accessible for tear location and grade interpretation. Results: Nonoperative treatment of UCL injuries resulted in an overall 54% rate of return to play (RTP). Players who received PRP had a significantly longer delay in return to throwing (P < .001) and RTP (P = .012). The matched cohort analysis showed that MLB and MiLB pitchers in the no-PRP group had a significantly faster return to throwing (P < .05) and the MiLB pitchers in the no-PRP group had a significantly faster RTP (P = .045). The survival analysis did not reveal significant differences between groups over time. The use of PRP, MRI grade, and tear location were not statistically significant predictors for RTP or progression to surgery. Conclusion: In this retrospective matched comparison of MLB and MiLB pitchers and position players treated nonoperatively for a UCL tear, PRP did not improve RTP outcomes or ligament survivorship, although there was variability with respect to PRP preparations, injection protocols, time from injury to injection, and rehabilitation programs. MRI grade and tear location also did not significantly affect RTP outcomes or progression to surgery.

Effects of PRP and LyPRP on osteogenic differentiation of MSCs.

Platelet-rich plasma (PRP) is rich in a variety of growth factors and plays an important role in the proliferation and differentiation of mesenchymal stem cells (MSCs). It has been reported that the preparation of freeze-dried platelets (lyophilized platelets [LyPRP]) from platelets could be an effective strategy to preserve the bioactivity of platelets for a long time. In this study, the osteogenic induction effects of PRP and LyPRP on MSCs were evaluated. The rabbit arterial blood was drawing to preparation of PRP by secondary centrifugation. Whole blood was prepared by lyophilization buffer to prepare LyPRP, which were activated by chloride and their surface morphology was observed. It was observed using a scanning electron microscope that platelets were evenly distributed on the surface of PRP and LyPRP. Growth factors were slowly released from PRP and LyPRP during the first 7 days and detected by the enzyme-linked immunosorbent assay kit. Cell proliferation assays and fluoresceindiacetate/propidium iodide (FDA/PI) staining demonstrated that PRP and LyPRP could promote cell proliferation. PRP and LyPRP were also shown to promote osteogenic differentiation of MSCs in vitro by osteogenesis characteristic staining and qPCR quantitative detection of osteogenic related gene expression. Both PRP and LyPRP could promote the proliferation and osteogenic differentiation of MSCs effectively. Moreover, PRP exhibited a better osteogenic induction effect on MSC than LyPRP.