Platelet-rich plasma: growth factors and pro- and anti-inflammatory properties

Ameliorative Potential of Carvedilol Versus Platelet-Rich Plasma Against Paclitaxel-Induced Femoral Neuropathy in Wistar Rats: A Light and Electron Microscopic Study

Paclitaxel, a chemotherapeutic drug, induces sensorimotor peripheral neuropathy. Carvedilol, a nonselective β-adrenoreceptor blocker, has been shown to exert antioxidant activity. Platelet-rich plasma (PRP) has supra-physiological levels of growth factors (GFs), enhances biosynthesis of antioxidant enzymes, and suppresses oxidative stress. This study compared the ameliorative effects of carvedilol and PRP on paclitaxel-induced femoral neuropathy. Eighty-eight adult male albino rats were equally randomized into four groups: group I served as the control; group II received paclitaxel (16 mg/kg intraperitoneally, weekly); group III received carvedilol (10 mg/kg daily, orally) concomitant with paclitaxel; and group IV received PRP (0.5 mL/kg subcutaneously, twice weekly) concomitant with paclitaxel. After 5 weeks, femoral nerve conduction velocity was measured, and blood samples were collected to assess catalase and superoxide dismutase levels. All animals were sacrificed, and gene expression of miR-21 was quantified. Tissue sections were stained with hematoxylin and eosin and toluidine blue. Then, the ultrathin sections were examined by transmission electron microscopy. Both carvedilol and PRP reversed paclitaxel-induced changes in the peripheral nerve, but PRP demonstrated a stronger antioxidant effect and a more pronounced presence of GFs, as evidenced by electron microscopy. PRP may represent a promising therapeutic approach for paclitaxel-induced neuropathy.

Local delivery of platelet-derived factors mitigates ischemia and preserves ovarian function through angiogenic modulation: A personalized regenerative strategy for fertility preservation

As the most prominent and ideal modality in female fertility preservation, ovarian tissue cryopreservation, and transplantation often confront the challenge of ischemic damage and follicular loss from avascular transplantation. To surmount this impediment, we engineered a novel platelet-derived factors-encapsulated fibrin hydrogel (PFH), a paradigmatic biomaterial. PFH encapsulates autologous platelet-derived factors, utilizing the physiological blood coagulation cascade for precise local delivery of bioactive molecules. In our study, PFH markedly bolstered the success of avascular ovarian tissue transplantation. Notably, the quantity and quality of follicles were preserved with improved neovascularization, accompanied by decreased DNA damage, increased ovulation, and superior embryonic development rates under a Low-concentration Platelet-rich plasma-derived factors encapsulated fibrin hydrogel (L-PFH) regimen. At a stabilized point of tissue engraftment, gene expression analysis mirrored normal ovarian tissue profiles, underscoring the effectiveness of L-PFH in mitigating the initial ischemic insult. This autologous blood-derived biomaterial, inspired by nature, capitalizes on the blood coagulation cascade, and combines biodegradability, biocompatibility, safety, and cost-effectiveness. The adjustable properties of this biomaterial, even in injectable form, extend its potential applications into the broader realm of personalized regenerative medicine. PFH emerges as a promising strategy to counter ischemic damage in tissue transplantation, signifying a broader therapeutic prospect. (197 words).

Endodontic surgery and platelet concentrates: A comprehensive review

While autologous platelet concentrates (APCs) have gained traction as promising regenerative materials in recent years, their impact on wound healing and tissue regeneration in periapical hard tissue defects remains controversial. Endodontic microsurgery (EMS) has embraced the potential of platelet concentrates, particularly L-PRF (Leucocyte-Platelet-Rich Fibrin) and PRP (Platelet-Rich Plasma), as regenerative tools. These concentrates, rich in growth factors and other bioactive molecules, are thought to enhance healing and treatment outcomes for various endodontic conditions. However, their effectiveness remains a subject of investigation. Despite encouraging 3-D cone beam computed tomography (CBCT) based evidence for PRP's effectiveness in complex lesions and apico-marginal defects, inconsistencies in its performance across preparation and application protocols raise questions about its superiority over existing options. More research is crucial to understand its full potential as a reliable regenerative tool in endodontics. L-PRF and its derivatives are particularly effective in treating apical-marginal defects. It enhances clinical attachment levels and reduces probing pocket depths, likely due to its slow and coordinated release of various growth factors. L-PRF has been shown to also improve patients' quality of life by reducing postoperative swelling and pain. However, more research is needed to standardize its preparation methods and confirm its long-term benefits. This paper aims to provide a comprehensive review of the current knowledge and recent advances in endodontic surgery and the use of platelet concentrates, focusing on their roles in managing periapical lesions and endo-perio lesions.

A nanofibrous polycaprolactone/collagen neural guidance channel filled with sciatic allogeneic schwann cells and platelet-rich plasma for sciatic nerve repair

Sciatic nerve damage, a common condition affecting approximately 2.8% of the US population, can lead to significant disability due to impaired nerve signal transmission, resulting in loss of sensation and motor function in the lower extremities. In this study, a neural guidance channel was developed by rolling a nanofibrous scaffold produced via electrospinning. The scaffold's microstructure, biocompatibility, biodegradation rate, porosity, mechanical properties, and hemocompatibility were evaluated. Platelet-rich plasma (PRP) activated with 30,000 allogeneic Schwann cells (SCs) was injected into the lumen of the channels following implantation into a rat model of sciatic nerve injury. Recovery of motor function, sensory function, and muscle re-innervation was assessed using the sciatic function index (SFI), hot plate latency time, and gastrocnemius muscle wet weight loss. Results showed mean hot plate latency times of Autograft: 7.03, PCL/collagen scaffolds loaded with PRP and SCs (PCLCOLPRPSCs): 8.34, polymer-only scaffolds (PCLCOL): 10.66, and untreated animals (Negative Control): 12.00. The mean SFI values at week eight were Autograft: -49.30, PCLCOLPRPSCs: -64.29, PCLCOL: -75.62, and Negative Control: -77.14. The PCLCOLPRPSCs group showed a more negative SFI compared to the Autograft group but performed better than both the PCLCOL and Negative Control groups. These findings suggest that the developed strategy enhanced sensory and functional recovery compared to the negative control and polymer-only scaffold groups.

Platelet extracellular vesicles-loaded hydrogel bandages for personalized wound care

Autologous or allogeneic platelet-derived extracellular vesicles (pEVs) show potential in enhancing tissue recovery and healing chronic wounds. pEVs promote neovascularization and cell migration while reducing inflammation, oxidative stress, and scarring. However, their efficacy in clinical settings is challenged by their susceptibility to washout by wound exudate. Hydrogel-based bandages are effective carriers that stabilize pEVs for optimal personalized wound care. These bandages can be tailored for easy removal to minimize damage to regenerated tissue and can incorporate antibacterial or moisture-retaining properties. Furthermore, the possibility of integrating sensors in the wound bed will enable a theragnostic approach to healing. This review explores advancements in pEV-loaded hydrogels and their potential for personalized clinical applications.

The Effect of Long-Term Cryopreservation on the Properties and Functionality of Platelet-Rich Plasma

Platelet-Rich Plasma (PRP) is a biological treatment widely used in regenerative medicine for its restorative capacity. Although PRP is typically applied at the time of obtention, long-term storage and preservation could enhance its versatility and clinical applications. The objective of this study was to evaluate the effect of long-term freezing on PRP. For that, PRP and Platelet Lysates (PL) were collected and preserved at -20 °C and -80 °C for 6 and 12 months. The parameters analyzed included platelet count and size, fibrinogen levels, platelet activation percentage, growth factor (GF) levels, and bioactivity on cultured dermal fibroblasts. No significant changes in platelet count were found; however, variations in platelet size were observed. Platelets stored at -20 °C and -80 °C showed structural changes and increased activation over time, including membrane roughness and possible aggregation. GF analysis revealed a reduction in platelet-derived growth factors (PDGF-AB and VEGF), while extraplatelet factors like IGF-1 remained stable. Fibroblast cultures showed comparable cell viability when exposed to fresh and cryopreserved PRP and PL samples. These findings suggest that cryopreserving PRP at -20 °C or -80 °C for up to 12 months is a feasible approach for retaining its therapeutic potential, supporting its use in biobanking, and expanding clinical accessibility.

Platelet-rich plasma applications in the larynx: snake oil or stupendous?

PURPOSE OF REVIEW

To explore and summarize recent work examining the use of platelet-rich plasma (PRP) applications for vocal fold disorder.

RECENT FINDINGS

Intrachordal PRP injections have recently emerged as a treatment option for patients with damage to the lamina propria of the vocal fold (scar, atrophy, sulcus and inflammatory lesions). Studies support significant improvements in patient-reported and clinician-reported outcomes, and objective phonatory parameters. PRP demonstrates a good safety profile, absence of immune reactions, affordable cost model and improvement in mucosal wave features with resultant improved voice quality up to 12 months following treatment.

SUMMARY

PRP injection of the vocal folds is a novel repurposing of a previously validated technique, and emerging data shows consistent results across multiple centres, increasing confidence in use of this freely available material. Current published studies confirm improved voice outcomes compared with pretreatment measures and high patient satisfaction. Further research is required to properly assign the role of and ideal candidate for PRP applications, and to delineate durability of treatment.

Polynucleotide-based treatments for various facial scars including combat injuries

INTRODUCTION

This study examines the therapeutic efficacy of polynucleotide-based therapies, specifically REJURAN®, for managing scars and burns. Scars and burns present significant challenges in dermatology, often affecting patients' quality of life. Traditional treatments can be limited in effectiveness, prompting the exploration of innovative approaches like polynucleotide therapy, which utilizes salmon DNA to stimulate tissue repair, modulate inflammation, and enhance collagen production.

METHODS

A series of case studies was conducted, including diverse patient profiles with various types of scars and burns. The study evaluated the impact of REJURAN® on scar appearance, texture, and overall skin quality. Some cases also explored the combination of polynucleotide therapy with other treatments such as Platelet-Rich Plasma (PRP) and botulinum toxin.

RESULTS

Notable improvements were observed across cases, including reduced scar visibility and enhanced skin texture. The therapy proved effective in treating post-traumatic, post-operative, and burn-related scars, demonstrating its versatility and potential benefits. Combination therapies showed promising results, though further research is needed.

CONCLUSION

Polynucleotide-based therapy with REJURAN® shows promise in scar and burn management, offering a novel approach that leverages the body's regenerative processes. Further studies are recommended to confirm these findings and refine treatment protocols.

Optimizing Treatment Outcomes in Crohn's Disease: A Comprehensive Systematic Review and Meta-Analysis of Regenerative Therapies with Emphasis on Platelet-Rich Plasma

BACKGROUND/OBJECTIVES

Crohn's disease (CD) is a chronic inflammatory disorder that significantly affects patients' quality of life; conventional treatments often provide limited relief.

METHODS

This systematic review and meta-analysis explored the potential of regenerative therapies, particularly platelet-rich plasma (PRP), as an adjunctive treatment for CD. The study protocol was registered with PROSPERO (CRD42024576683), and a comprehensive search was conducted across major databases, such as PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. The search included terms related to CD and PRP. Studies assessing the efficacy of PRP in CD treatment were selected. Statistical analysis was conducted using the PICO framework with R software (version 4.3.2) and meta-package.

RESULTS

Of the 29 studies identified, 10 met the inclusion criteria, comprising pilot studies and controlled trials. Nine studies focused on Crohn's disease perianal fistulas (CDPF), and one focused on colonic CD. Among 138 patients with CDPF, 82.44% showed some fistula healing after PRP treatment, with 48.05% achieving complete resolution. In a sub-analysis, combining PRP with a stromal vascular fraction (SVF) resulted in a 58.62% complete healing rate, whereas combining PRP with adipose-derived stem cells (ASCs) showed even higher efficacy at 85.89%. PRP treatment alone resulted in a lower complete healing rate of 38.51%. PRP was well tolerated, with minor side effects such as localized pain.

CONCLUSIONS

These findings suggest that PRP, especially when combined with stem cells, offers a promising new approach for treating CD. However, larger trials are needed to confirm its long-term benefits and refine its clinical applications.

Injectable GelMA Hydrogel Microspheres with Sustained Release of Platelet-Rich Plasma for the Treatment of Thin Endometrium

Platelet-rich plasma (PRP) intrauterine infusion has been demonstrated to be effective in treating thin endometrium and achieving pregnancy. However, the rapid release of growth factors limits its effectiveness in clinical applications, and thus, multiple intrauterine infusions are often required to achieve therapeutic efficacy. In this study, a GelMA hydrogel microsphere biomaterial is developed using droplet microfluidics to modify the delivery mode of PRP and thus prolong its duration of action. Its biocompatibility is confirmed through both in vivo and in vitro studies. Cell experiments show that PRP-loaded microspheres significantly enhance cell proliferation, migration, and angiogenesis. In vivo experiments show that the effects of PRP-loaded microspheres on repairing the endometrium and restoring fertility in mice could achieve the impact of triple PRP intrauterine infusions. Further mechanistic investigations reveal that PRP could facilitate endometrial repair by regulating the expression of E2Fs, a group of transcription factors. This study demonstrates that hydrogel microspheres could modify the delivery of PRP and prolong its duration of action, enabling endometrial repair and functional reconstruction. This design avoids repeated intrauterine injections of PRP in the clinic, reduces the number of patient visits, and provides a new avenue for clinical treatment of thin endometrium.

In vitro antimicrobial activity of non-traditional therapies for infectious endometritis in mares

BACKGROUND

Endometritis is the leading cause of subfertility in horses, and it is a clinical problem where historically antibiotics have not always been used with prudent justification. Because of this, alternative therapies to treat endometritis are necessary for the rational use of antibiotics.

OBJECTIVES

To assess the in vitro antimicrobial activity of non-traditional therapies commonly used in clinical practice against microorganisms causing infectious endometritis in mares.

STUDY DESIGN

In vitro experiments.

METHODS

A microdilution technique was performed to determine the minimum inhibitory concentrations (MIC) of 50%, 90% and 100% of microorganisms and the percentage of inhibition (PI) of each therapy against each microorganism (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Candida sp.). The MIC 50% and 90% were determined using non-linear regression, while MIC 100% was assessed using the resazurin dye technique. The serial PI was evaluated for each therapy using a spectrophotometer.

RESULTS

All the therapies demonstrated a PI higher than positive controls for all microorganisms (p < 0.05); however, the only therapies that presented MIC 100 values were hydrogen peroxide and platelet-rich and -poor plasma.

MAIN LIMITATIONS

In vivo, safety and treatment efficacy were not tested.

CONCLUSION

Hydrogen peroxide and platelet-rich and -poor plasma might be alternatives to traditional therapies for endometritis to support a reduction in antibiotic use.

Current advances in the treatment of myofascial pain syndrome with trigger point injections: A review

Myofascial pain syndrome (MPS) caused by trigger points in muscles is a common cause of local or generalized pain, which is clinically common, has a high incidence, and has no specific cure. The most popular and widely used clinical method mainly targets the trigger point for treatment, i.e. trigger point injection (TPI) therapy. The injectable drugs mainly include glucose, saline, local anesthetics, botulinum toxin type A, platelet-rich plasma, platelet-poor plasma, steroid preparations, etc. This method is low cost and less invasive, and early clinical applications have shown good efficacy. In this paper, we have reviewed clinical research progress in treating MPS with TPI therapy.

The effect of platelet-rich plasma and sodium alginate hydrogel on corneal wound healing after corneal alkali burns in rats with computer-assisted anterior segment optical coherence tomography image analysis

Our objective was to determine the effect of a semi-synthetic sodium alginate hydrogel and its combination with platelet-rich plasma (PRP) on histopathological, biochemical, clinical, and anterior segment optical coherence tomography (AS-OCT) data. Alkali chemical burn of the cornea was induced. Injured rats were randomly divided into five equal groups and topically treated with phosphate-buffered saline (sham), platelet-rich plasma (PRP), 0.5% sodium citrate, a semi-synthetic sodium alginate hydrogel, or a combination of PRP and hydrogel (combined group) three times daily. The degree of corneal opacity (CO), corneal epithelial staining (CES), percentage of corneal epithelial defects (CEDP), degree of ciliary hyperemia (CH), neovascularization size (NVS), and extent of neovascularization (NVE) were evaluated. AS-OCT was performed at nine days, and then rats were sacrificed. Histological examination and enzyme-linked immunosorbent assays were performed to detect the concentrations of IL-1β and MMP-9 in the cornea. There were no significant differences between the groups regarding CEDP, CO, CES, CH, NVS, or NVE on the first day after corneal alkali burn injury (p > 0,05). At the last examination, CO was significantly lower in the PRP group than in the sham group (p = 0,044), while the CO concentrations were similar in terms of NVS (p > 0,05). Similarly, in terms of tissue MMP-9 levels, there were no significant differences between groups (p > 0,05). However, there was a significant difference in tissue IL-1β levels between the groups (p < 0,001). In the PRP and combined groups, the level of IL-1β was significantly lower than that in the sham group (p = 0,043 and p = 0,036, respectively). There was a significant difference in epithelial necrosis between the PRP, and it was the lowest in the combined group (p = 0,003). Epithelial thickness was highest in the combined group (p = 0,002). CEDP was significantly different at the last visit between the groups (p = 0.042). The fastest epithelial closing rate was observed for the combined group (p = 0,026). There was a significant negative correlation between tissue MMP-9 levels and corneal solidity and between tissue MMP-9 levels and the corneal area according to the AS-OCT measurements (p = 0,012 and p = 0,027, respectively). When used alone, topical hydrogel application did not significantly enhance the healing of corneal wounds. However, when combined with PRP, it leads to an increased rate of epithelial closure and neovascularization. This combination did not exacerbate inflammation or corneal opacity compared to PRP alone. The anticoagulant citrate solution in the PRP tube did not prove effective. The synergistic use of PRP and hydrogel could enhance epithelial thickness and reduce epithelial necrosis. The use of new parameters for corneal wound healing assessment was facilitated through AS-OCT image processing.

Use of regenerative medicine in the treatment of endometritis in mares: A systematic review and meta-analysis

Defining the optimal therapy for endometritis remains a significant challenge for clinicians. Given the public health threat posed by antibiotic resistance and the inconclusiveness of traditional therapies, regenerative medicine has been proposed as an alternative. The objective of this study was to conduct a comprehensive systematic review and meta-analysis, to investigate the efficacy of regenerative medicine products in the treatment of both post-breeding persistent and chronic degenerative endometritis (PBIE/CDE) in mares, following the PRISMA guidelines. This research could be a comprehensive scientific reference for determining appropriate treatments and clinical strategies. All studies exploring the use of regenerative medicine therapies (i.e., plasma products, autologous conditioned serum, mesenchymal stem cells MSCs, and MSC derivatives) in the treatment of PBIE/CDE were included, regardless of the specific protocol used, the evaluated outcomes, or the diagnostic method employed. Two authors independently gathered data and evaluated the risk of bias for each study. Treatment effects were assessed using risk ratios for dichotomous data, accompanied by 95 % confidence intervals. Data were aggregated utilizing the fixed-effects model. The quality of evidence for each outcome was evaluated using GRADE criteria. Eighteen studies were included in the systematic review, while fifteen trials were included in the meta-analysis. A sub-meta-analysis was conducted separately on platelet-derived products, as well as on MSCs and their derivatives. The results demonstrated an overall positive effect of regenerative therapies in treating PBIE/CDE, particularly those involving MSCs and their derivatives. The positive outcomes include an anti-inflammatory effect, characterized by reduced intrauterine fluid accumulation, neutrophils, and cytokine concentrations. Additionally, improvements in pregnancy, foaling, and embryo recovery rates have been observed in some cases. Despite the limited number of randomized controlled studies and the high variability among protocols, including the timing of treatment, type, and volume of products used, the use of regenerative products, especially MSCs and their derivatives, has promising results in terms of both efficacy and safety for treating PBIE/CDE in mares.

Release kinetics of growth factors loaded into β-TCP ceramics in an in vitro model

Introduction

β-TCP ceramics are bone replacement materials that have recently been tested as a drug delivery system that can potentially be applied to endogenous substances like growth factors found in blood platelets to facilitate positive attributes.

Methods

In this work, we used flow chamber loading to load β-TCP dowels with blood suspensions of platelet-rich plasma (PRP), platelet-poor plasma (PPP), or buffy coat (BC) character. PRP and BC platelet counts were adjusted to the same level by dilution. Concentrations of TGF-β1, PDGF-AB, and IGF-1 from dowel-surrounding culture medium were subsequently determined using ELISA over 5 days. The influence of alginate was additionally tested to modify the release.

Results

Concentrations of TGF-β1 and PDGF-AB increased and conclusively showed a release from platelets in PRP and BC compared to PPP. The alginate coating reduced the PDGF-AB release but did not reduce TGF-β1 and instead even increased TGF-β1 in the BC samples. IGF-1 concentrations were highest in PPP, suggesting circulating levels rather than platelet release as the driving factor. Alginate samples tended to have lower IGF-1 concentrations, but the difference was not shown to be significant.

Discussion

The release of growth factors from different blood suspensions was successfully demonstrated for β-TCP as a drug delivery system with release patterns that correspond to PRP activation after Ca2+-triggered activation. The release pattern was partially modified by alginate coating.

Effect of Freeze-Thawing Treatment on Platelet-Rich Plasma Purified with Different Kits

Osteoarthritis of the knee (OAK), a progressive degenerative disease affecting quality of life, is characterized by cartilage degeneration, synovial inflammation, and osteophyte formation causing pain and disability. Platelet-rich plasma (PRP) is an autologous blood product effective in reducing OAK-associated pain. PRP compositions depend on their purification. In clinical practice, PRP is typically administered immediately after purification, while cryopreserved PRP is used in research. Platelets are activated by freezing followed by release of their humoral factors. Therefore, PRP without any manipulation after purification (utPRP) and freeze-thawed PRP (fPRP) may differ in their properties. We purified leukocyte-poor PRP (LPPRP) and autologous protein solution (APS) to compare the properties of utPRPs and fPRPs and their effects on OAK target cells. We found significant differences in platelet activation and humoral factor content between utPRPs and fPRPs in both LPPRP and APS. Freeze-thawing affected the anti-inflammatory properties of LPPRP and APS in chondrocytes and synovial cells differed. Both utPRPs and fPRPs inhibited polarization toward M1 macrophages while promoting polarization toward M2 macrophages. Freeze-thawing specifically affected humoral factor production in macrophages, suggesting that evaluating the efficacy of PRPs requires considering PRP purification methods, properties, and conditions. Understanding these variations may enhance therapeutic application of PRPs in OAK.

Effectiveness of Platelet Rich Fibrin in Accelerating Canine Distal Movement: A Systematic Review of Randomized Controlled Trials

This review aimed at a systematic evaluation of the available literature on the effect of platelet-rich fibrin (PRF) in accelerating canine distal movement (CD). An elaborate search of the available literature on the effect of PRF on the acceleration of canine distal movement was conducted using appropriate search terms in PubMed, Scopus, Cochrane Central, and Google Scholar until April 2024. The risk of bias within the studies was assessed using the Cochrane risk of bias (RoB)-2 tool. Publication bias was assessed with a funnel plot, and a random effects model was used for quantitative synthesis. The certainty of the available evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Following the systematic search, a total of 11 studies were included for the qualitative analysis, and three studies were included for quantitative synthesis. Most of the studies reported an increased rate of canine distal movement following administration of PRF. The overall pooled CD at one, two, three, four, and five months showed a significantly increased mean CD in i-PRF (p<0.00001; MD = 0.23; 95% CI: 0.14 to 0.32), and a significantly increased rate of CD was noted during the first and second months. The available studies had a moderate to low risk of bias and a moderate certainty of evidence. Hence, with a moderate certainty of evidence and a risk of bias, it can be concluded that PRF accelerates orthodontic tooth movement during the first two months.

Current Challenges in the Development of Platelet-Rich Plasma-Based Therapies

Nowadays, biological therapies are booming and more of these formulations are coming to the market. Platelet-rich plasma, or PRP, is one of the most widely used biological therapies due to its ease of obtention and autologous character. Most of the techniques to obtain PRP are focusing on new processes and methods of optimization. However, not enough consideration is being given to modify the molecular components of PRP to generate more effective formulations with the aim of improving PRP treatments. Therefore, this review covers different novel PRP-obtaining methods that attempt to modify the molecular composition of the plasma.

Revitalizing female fertility: platelet-rich plasma - hype or hope?

Platelet-rich plasma (PRP) has gained popularity as an experimental tool in regenerative medicine, with potential applications in reproductive medicine. This review will assess the existing literature on the role of PRP in female fertility enhancement, focusing on ovarian rejuvenation and increased endometrial thickness. PRP is being explored as a treatment for recurrent implantation failure, primary ovarian insufficiency and poor ovarian response. While the influence of PRP on endometrial thickness and implantation success is postulated, its effectiveness remains the subject of debate due to protocol variability and unclear patient selection criteria. This narrative review includes 36 articles published before December 2022, and highlights the lack of comprehensive molecular studies examining the impact of PRP on reproductive capacity. This review underscores the importance of standardizing PRP preparation protocols in reproductive medicine. However, challenges persist, and there is a need for well-planned randomized controlled trials and a deeper understanding of the patient population that would gain the greatest benefit from PRP treatment. Clarifying these aspects is crucial to improve outcomes for low-prognosis patients undergoing assisted reproductive technology.

Activated platelet-rich plasma accelerate endometrial regeneration and improve pregnancy outcomes in murine model of disturbed endometrium

Platelet Rich Plasma (PRP) contains high concentrations of growth factors, therefore, PRP activation results in their release, stimulating the process of healing and regeneration. The study was conducted to check whether activated platelet-rich plasma (aPRP) treatment can improve regeneration of the endometrium in an experimental model of ethanol-induced disturbed endometrium. Seventy-two female Wistar rats were randomly assigned into the control group, disturbed endometrium (DE) group and aPRP treated group. Activation of PRP was performed by adding thrombin. All the animals were sacrificed on day 1, day 3, day 6 and day 9 and samples were taken from the miduterine horn. Quantification of Cytokine and chemokine profiles of activated and non-activated PRP for CCL2, TNF- α, IL-1β, CXCL8, CXCL10, IL2, IL4, IL-6 IL-10, IL-12, IL-17A, TGF- β, IFN-γ was carried out. Functional and structural recovery of the endometrium was analyzed by hematoxylin-eosin (HE) and immunohistochemical (IHC) analyses. HE confirmed proliferated epithelial lining and stromal reconstruction with decreased fibrosis in PRP treated group compared to the DE group. Epithelial thickness in aPRP treated on day 1, day 3, day 6 and day 9 revealed an significant increase (p ≤ 0.05). Significantly stronger IHC expression of alpha smooth muscle actin, Cytokeratin 18, Cytokeratin 19, Connexin-40, E-Cadherin, Claudin-1, Zona Occludin-1was found in the aPRP treated group compared to the DE group. Furthermore, aPRP treatment was associated with birth of live pups. Our results suggest that intrauterine administration of aPRP stimulated and accelerated the regeneration of endometrium in the murine model of disturbed endometrium.

Percutaneous bone marrow concentrate and platelet products versus exercise therapy for the treatment of rotator cuff tears: a randomized controlled, crossover trial with 2-year follow-up

BACKGROUND

Surgical repair is recommended for the treatment of high-grade partial and full thickness rotator cuff tears, although evidence shows surgery is not necessarily superior to non-surgical therapy. The purpose of this study was to compare percutaneous orthobiologic treatment to a home exercise therapy program for supraspinatus tears.

METHODS

In this randomized-controlled, crossover design, participants with a torn supraspinatus tendon received either 'BMC treatment', consisting of a combination of autologous bone marrow concentrate (BMC) and platelet products, or underwent a home exercise therapy program. After three months, patients randomized to exercise therapy could crossover to receive BMC treatment if not satisfied with shoulder progression. Patient-reported outcomes of Numeric Pain Scale (NPS), Disabilities of the Arm, Shoulder, and Hand, (DASH), and a modified Single Assessment Numeric Evaluation (SANE) were collected at 1, 3, 6, 12, and 24 months. Pre- and post-treatment MRI were assessed using the Snyder Classification system.

RESULTS

Fifty-one patients were enrolled and randomized to the BMC treatment group (n = 34) or the exercise therapy group (n = 17). Significantly greater improvement in median ΔDASH, ΔNPS, and SANE scores were reported by the BMC treatment group compared to the exercise therapy group (-11.7 vs -3.8, P = 0.01; -2.0 vs 0.5, P = 0.004; and 50.0 vs 0.0, P < 0.001; respectively) after three months. Patient-reported outcomes continued to progress through the study's two-year follow-up period without a serious adverse event. Of patients with both pre- and post-treatment MRIs, a majority (73%) showed evidence of healing post-BMC treatment.

CONCLUSIONS

Patients reported significantly greater changes in function, pain, and overall improvement following BMC treatment compared to exercise therapy for high grade partial and full thickness supraspinatus tears.

TRIAL REGISTRATION

This protocol was registered with www.

CLINICALTRIALS

gov (NCT01788683; 11/02/2013).

Leukocytes within Autologous Blood Concentrates Have No Impact on the Growth and Proliferation of Human Primary Osteoblasts: An In Vitro Study

Platelet-rich fibrin (PRF) is a widely used autologous blood concentrate in regenerative medicine. This study aimed to characterize the cellular composition and distribution of different PRF matrices generated by high (710 g) and low (44 g) relative centrifugal forces (RCFs) and to analyze their bioactivity on human primary osteoblasts (pOBs). PRF was separated into upper layer (UL) and buffy coat (BC) fractions, and their cellular contents were assessed using histological and immunohistochemical staining. The release of platelet-derived growth factor (PDGF) and transforming growth factor (TGF-β) was quantified using an ELISA. Indirect PRF treatment on pOBs was performed to evaluate cell viability and morphology. A histological analysis revealed higher quantities of leukocytes and platelets in the low-RCF PRF. TGF-β release was significantly higher in the low-RCF PRF compared to the high-RCF PRF. All PRF fractions promoted pOB proliferation regardless of the centrifugation protocol used. The low-RCF PRF showed higher TGF-β levels than the high-RCF PRF. These findings contribute to understanding the cellular mechanisms of PRF and provide insights into optimizing PRF protocols for bone regeneration, advancing regenerative medicine, and improving patient outcomes.

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

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

Methacrylated gelatin and platelet-rich plasma based hydrogels promote regeneration of critical-sized bone defects

Physiological repair of large-sized bone defects requires instructive scaffolds with appropriate mechanical properties, biocompatibility, biodegradability, vasculogenic ability and osteo-inductivity. The objective of this study was to fabricate in situ injectable hydrogels using platelet-rich plasma (PRP)-loaded gelatin methacrylate (GM) and employ them for the regeneration of large-sized bone defects. We performed various biological assays as well as assessed the mechanical properties of GM@PRP hydrogels alongside evaluating the release kinetics of growth factors (GFs) from hydrogels. The GM@PRP hydrogels manifested sufficient mechanical properties to support the filling of the tissue defects. For biofunction assay, the GM@PRP hydrogels significantly improved cell migration and angiogenesis. Especially, transcriptome RNA sequencing of human umbilical vein endothelial cells and bone marrow-derived stem cells were performed to delineate vascularization and biomineralization abilities of GM@PRP hydrogels. The GM@PRP hydrogels were subcutaneously implanted in rats for up to 4 weeks for preliminary biocompatibility followed by their transplantation into a tibial defect model for up to 8 weeks in rats. Tibial defects treated with GM@PRP hydrogels manifested significant bone regeneration as well as angiogenesis, biomineralization, and collagen deposition. Based on the biocompatibility and biological function of GM@PRP hydrogels, a new strategy is provided for the regenerative repair of large-size bone defects.

Regenerative potential of platelet concentrates in chronic oral mucosal lesions

Chronic oral mucosal diseases (COMDs) represent a significant challenge for clinicians and patients. They are commonly associated with chronic pain and negative effects on healing and patient's quality of life. Regenerative medicine including the use of biological autologous blood-derived substances (e.g., platelet concentrates [PCs]), has been reported to improve healing and reduce pain in orthopedic and maxillofacial surgeries as well as chronic oral mucosal diseases. In this review, we aim to describe the different types of PCs and their applications in the management of COMDs such as lichen planus, mucositis, pemphigus vulgaris, mucous membrane pemphigoid, and plasma cell mucositis, in terms of healing potential, pain control, and quality of life. Overall, PC applications seem to enhance healing and reduce pain in patients with COMDs. However, due to the small sample size and the lack of standardized clinical trials, further research is required to support these findings.

Intravesical instillation of platelet-rich plasma for treatment of interstitial cystitis/bladder pain syndrome: A pilot study

Objective

The aim of this study was to evaluate the feasibility of intravesical instillation of platelet-rich plasma (PRP) to treat interstitial cystitis/bladder pain syndrome (IC/BPS).

Materials and methods

Twenty PRP samples were tested in vitro for stability after exposure to urine samples with different pH. A pilot study involving 21 female patients with IC/BPS was conducted, and 6 weekly doses of autologous PRP (50 mL) were administered. Patients were followed up at the 2nd, 4th, 8th, and 12th weeks after terminating instillation. The primary endpoint was the visual analog scale (VAS) for pain, and the secondary endpoints included the IC symptom index, IC problem index of the O'Leary-Sant questionnaire and global response assessment, urine culture, and uroflowmetry. Success was defined as a reduction in VAS by 30% or more compared with basal level, and adverse events were recorded.

Results

The mean ± SD of VAS was significantly reduced compared with basal level (4.4 ± 2.6 vs. 8.8 ± 1.1, respectively, p = 0.001). Meanwhile, 80% of cases were considered successful, with a 50.1% reduction in the mean score compared with the basal level. The mean ± SD of IC symptom index and IC problem index significantly improved compared with the basal level. Global response assessment was markedly, moderately, and slightly improved in 2 (10%), 10 (50%), and 5 (25%) patients, respectively, and showed no change in 3 (15%). Three patients had positive urine cultures at follow-up, but 1 withdrew after 2 sessions because of a lack of efficacy.

Conclusions

Repeated intravesical instillation of PRP could be considered an effective and safe approach for treating IC/BPS.

Optimization of Platelet-Rich Plasma Preparation for Regenerative Medicine: Comparison of Different Anticoagulants and Resuspension Media

Platelet-rich plasma (PRP) has emerged as a promising therapy in regenerative medicine. However, the lack of standardization in PRP preparation protocols presents a challenge in achieving reproducible and accurate results. This study aimed to optimize the PRP preparation protocol by investigating the impact of two different anticoagulants, sodium citrate (SC) and ethylenediaminetetraacetic acid (EDTA), and resuspension media, plasma versus sodium chloride (NaCl). Platelet recovery rates were calculated and compared between groups, in addition to platelet activity and vascular endothelial growth factor (VEGF) released into plasma after PRP activation. The platelet recovery rate was higher with EDTA in comparison to SC (51.04% vs. 29.85%, p = 0.005). Platelet activity was also higher, with a higher expression of two platelet antibodies, platelet surface P-Selectin (CD62p) and PAC-1, in the EDTA group. The concentration of VEGF was higher with SC in comparison to EDTA (628.73 vs. 265.44 pg/mL, p = 0.013). Platelet recovery rates and VEGF levels were higher in PRP resuspended in plasma when compared to NaCl (61.60% vs. 48.61%, p = 0.011 and 363.32 vs. 159.83 pg/mL, p = 0.005, respectively). Our study reinforces the superiority of EDTA (as anticoagulant) and plasma (for resuspension) in obtaining a higher platelet recovery and preserving platelet functionality during PRP preparation.

Efficacy and safety of platelet-rich plasma in the treatment of venous ulcers: A systematic review and meta-analysis of randomized controlled trials

Considering the substantial impact of venous ulcers on quality of life and healthcare systems, this study evaluated the efficacy and safety of platelet-rich plasma (PRP) in comparison to conventional therapy. A systematic review of four databases identified 16 randomized clinical trials, including 20 study groups. PRP significantly enhanced complete ulcer healing, exhibiting an odds ratio (OR) of 5.06 (95% confidence interval [CI]: 2.35-10.89), and increased the percentage of healed ulcer area by a mean difference of 47% (95% CI: 32%-62%). Additionally, PRP shortened the time required for complete healing by an average of 3.25 months (95% CI: -4.06 to -2.43). Although pain reduction was similar in both groups, PRP considerably decreased ulcer recurrence rates (OR = 0.16, 95% CI: 0.05-0.50) without increasing the risks of infection or irritative dermatitis. These results suggest PRP as a viable, safe alternative for venous ulcer treatment, providing significant improvements in healing outcomes.

Enhanced Diabetic Rat Wound Healing by Platelet-Rich Plasma Adhesion Zwitterionic Hydrogel

BACKGROUND

The skin is the largest organ in the human body and serves as a barrier for protective, immune, and sensory functions. Continuous and permanent exposure to the external environment results in different levels of skin and extracellular matrix damage. During skin wound healing, the use of good dressings and addition of growth factors to the wound site can effectively modulate the rate of wound healing. A dressing containing bioactive substances can absorb wound exudates and reduce adhesion between the wound and dressing, whereas growth factors, cytokines, and signaling factors can promote cell motility and proliferation.

AIM AND OBJECTIVES

We prepared a functional wound dressing by combining platelet-rich plasma (PRP) and zwitterionic hydrogels. Functional wound dressings are rich in various naturally occurring growth factors that can effectively promote the healing process in various types of tissues and absorb wound exudates to reduce adhesion between wounds and dressings. Furthermore, PRP-incorporated zwitterionic hydrogels have been used to repair full-thickness wounds in Sprague-Dawley rats with diabetes (DM SD).

MATERIALS AND METHODS

Fibroblasts and keratinocytes were cultured with PRP, zwitterionic hydrogels, and PRP-incorporated zwitterionic hydrogels to assess cell proliferation and specific gene expression. Furthermore, PRP-incorporated zwitterionic hydrogels were used to repair full-thickness skin defects in DM SD rats.

RESULTS

The swelling ratio of hydrogel, hydrogel + PRP1000 (108 platelets/mL), and hydrogel + PRP1000 (109 platelets/mL) groups were similar (~07.71% ± 1.396%, 700.17% ± 1.901%, 687.48% ± 4.661%, respectively) at 144 hours. The tensile strength and Young modulus of the hydrogel and hydrogel + PRP10000 groups were not significantly different. High concentrations of PRP (approximately 108 and 109 platelets/mL) effectively promoted the proliferation of fibroblasts and keratinocytes. The zwitterionic hydrogels were not cytotoxic to any cell type. High PRP concentration-incorporated zwitterionic hydrogels increased the rate of cell proliferation and significantly increased the expression of characteristic genes such as collagen, fibronectin, involucrin, and keratin. Subsequently, zwitterionic hydrogels with high PRP concentrations were used to repair full-thickness skin defects in DM SD rats, and a wound healing rate of more than 90% was recorded on day 12.

CONCLUSIONS

PRP contains high concentrations of growth factors that promote cell viability, enhance specific gene expression, and have a high medical value in cell therapy. Zwitterionic hydrogels have a 3-dimensional interconnected microporous structure and can resist cell adhesion without causing cytotoxicity. Platelet-rich plasma-incorporated zwitterionic hydrogels further enhance the cellular properties and provide an effective therapeutic option for wound healing.

An Update on Orthobiologics: Cautious Optimism

Orthobiologics are rapidly growing in use given their potential to augment healing for multiple musculoskeletal conditions. Orthobiologics consist of a variety of treatments including platelet-rich plasma and stem cells that provide conceptual appeal in providing local delivery of growth factors and inflammation modulation. The lack of standardization in nomenclature and applications within the literature has led to a paucity of high-quality evidence to support their frequent use. The purpose of this review was to describe the current landscape of orthobiologics and the most recent evidence regarding their use.

Therapeutic applications of canine platelets and their derivatives: a narrative review

Platelets contain a multitude of growth factors and play a crucial role in physiological processes such as thrombogenesis, tissue repair, and angiogenesis. As a result, platelet-derived products have significant potential for efficient utilization in the realm of regenerative medicine due to their therapeutic and biological attributes. Numerous studies have already substantiated the therapeutic viability of platelets in various canine ailments. The existing literature indicates a substantial surge in the clinical application of canine platelets, positioning platelet-derived products as a viable alternative to conventional therapeutic agents. Platelet concentrates, including platelet-rich plasma and platelet-rich fibrin are commonly used as a therapeutic modality in clinical cases. These therapeutic derivatives exhibit effectiveness in tissue regeneration and can serve as complementary therapies. Notably, they offer a cost-effective and easily accessible therapeutic option, which has demonstrated its benefits in chronic inflammatory disorders such as osteoarthritis and tendinitis, ophthalmic conditions, wound healing, and mandibular injuries in canine patients. The broad spectrum of therapeutic effects displayed by platelets is providing researchers with novel perspectives for crafting therapeutic models in future investigations. This review centers on exploring the therapeutic potential of canine platelets across diverse disorders. Further exploration into platelet products, encompassing their preparation and applicability in canine medicine, is imperative. These inquiries hold the promise of unveiling fresh horizons for the domain of regenerative medicine.

Autologous concentrated growth factor mediated accelerated bone healing in root-end microsurgery: A multicenter randomized clinical trial

Introduction

Concentrated growth factor (CGF) is a new-generation autologous platelet concentrate that promotes tissue regeneration and has anti-inflammatory properties. This randomized multicenter trial aimed to evaluate the effects of CGF on bone healing in combination with root-end microsurgery.

Methods

Healthy adult patients indicated for root-end microsurgery were randomly assigned to either the CGF or control (no CGF implantation) groups. CGF was implanted into the bone cavity after root-end filling with mineral trioxide aggregate. Clinical and periapical radiographic evaluations were conducted at 1, 3, 6, and 12 months postoperatively, with follow-up cone-beam computed tomography (CBCT) at 6 months. The lesion volume reduction rate was calculated based on data from the preoperative and follow-up CBCT images.

Results

A total of 24 patients were enrolled. The treatment success rate was 91.7% and 83.3% on 12-month periapical radiography and 6-month CBCT, respectively, without a significant difference between the two groups. The lesion volume reduction rate in the CGF group (75.6%) was significantly higher than that in the control (61.0%) group.

Conclusions

Autologous CGF in conjunction with root-end microsurgery accelerated lesion reduction as observed on CBCT. Administering autologous blood products to stimulate healing in addition to removing the source of infection appears to be a promising treatment option for root-end microsurgery.

Comparison of Antimicrobial Activity of Injectable Platelet-Rich Fibrin (i-PRF) and Leukocyte and Platelet-Rich Fibrin (l-PRF) Against Oral Microbes: An In Vitro Study

Aim Injectable platelet-rich fibrin (i-PRF) and leukocyte and platelet-rich fibrin (l-PRF) are both blood-derived products used in regenerative medicine and dentistry. They contain platelets, growth factors, and leukocytes, which can have antimicrobial properties to some extent, but their primary purpose is tissue regeneration and wound healing. i-PRF and l-PRF may have some indirect antimicrobial properties due to their composition and ability to enhance tissue healing and immune responses, and they are primarily used in dentistry for their regenerative and wound healing capabilities rather than as standalone antimicrobial agents. This study aims to compare the anti-microbial activity of i-PRF and l-PRF against oral microbes. Methodology This study included 30 patients who were selected using G*Power software version 3.1 (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany) calculation with the population size. The plaque samples were collected from the subjects using area-specific Gracey curettes used for scaling and root planing to remove plaque and calculus from the teeth and root surfaces. The collected plaque samples were transferred to a tube containing 5 ml of saline (sterile saltwater). The purpose of using saline is to preserve the microbial content of the plaque sample without altering the microbial composition. To obtain a uniform solution, the samples in the saline-containing tube were vortexed for 5 minutes. After vertexing, a small amount of the suspension (0.1 ml) was taken for further analysis. The 0.1 ml suspension was used to plate blood agar using the streak method. A loop or needle is used to streak the sample back and forth across the surface of the agar, leading to the dilution and separation of the bacteria. Results Results state that i-PRF has a maximum zone of inhibition (2.19±0.47 mm) when compared with metronidazole (0.14±0.09 mm). It can be stated that platelet concentrates demonstrate better antimicrobial activity due to their higher oxygen metabolites which help in the aggregation and internalization of microorganisms, which enhances the clearance of pathogens from the bloodstream. Paired t-test has been used for the comparison between the two groups, and the p-value is >0.05 stating that the difference is statistically significant. Conclusion The present study states that i-PRF demonstrated better antimicrobial efficacy as compared to l-PRF. Hence, i-PRF helps in reducing microbial load at the periodontally infected sites when compared with l-PRF.

Systematic Review of Platelet-Rich Plasma for Low Back Pain

BACKGROUND

Low back pain (LBP) has a high economic burden and is strongly related to the degenerative process of the spine, especially in the intervertebral disc and of the facet joints. Numerous treatment modalities have been proposed for the management of LBP, and the use of platelet-rich plasma (PRP) has emerged as an innovative therapeutic option for degenerative disease of the spine. The present study aims to evaluate the efficacy of PRP injections in managing low back pain.

METHODS

We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a registered at PROSPERO Systematic Reviews Platform, under number CRD42021268491. The PubMed, Web of Science, and Scopus databases were searched to identify relevant articles, along with hand searching to identify gray literature articles, with no language restrictions. Randomized clinical trials (RCTs), nonrandomized trials (NRTs), and case series (CSs) with more than 10 patients were considered eligible. The quality assessment and the risk of bias of the randomized clinical trials were evaluated using the RoB II tool. An evaluation of the description of the preparation methods was performed using an adapted version of the MIBO checklist.

RESULTS

An electronic database search resulted in 2324 articles, and after the exclusion of noneligible articles, 13 RCTs and 27 NRTs or CSs were analyzed. Of the 13 RCTs, 11 found favorable results in comparison to the control group in pain and disability, one showed no superiority to the control group, and one was discontinued because of the lack of therapeutic effect at eight-week evaluation. Description of the PRP preparation techniques were found in almost all papers. The overall risk of bias was considered high in 2 papers and low in 11. An adapted MIBO checklist showed a 72.7% compliance rate in the selected areas.

CONCLUSIONS

In this systematic review, we analyzed articles from English, Spanish and Russian language, from large databases and grey literature. PRP was in general an effective and safe treatment for degenerative LPB. Positive results were found in almost studies, a small number of adverse events were related, the risk of bias of the RCTs was low. Based on the evaluation of the included studies, we graded as level II the quality of the evidence supporting the use of PRP in LBP. Large-scale, multicenter RCTs are still needed to confirm these findings.

Platelet-rich plasma in the pathologic processes of tendinopathy: a review of basic science studies

Tendinopathy is a medical condition that includes a spectrum of inflammatory and degenerative tendon changes caused by traumatic or overuse injuries. The pathological mechanism of tendinopathy has not been well defined, and no ideal treatment is currently available. Platelet-rich plasma (PRP) is an autologous whole blood derivative containing a variety of cytokines and other protein components. Various basic studies have found that PRP has the therapeutic potential to promote cell proliferation and differentiation, regulate angiogenesis, increase extracellular matrix synthesis, and modulate inflammation in degenerative tendons. Therefore, PRP has been widely used as a promising therapeutic agent for tendinopathy. However, controversies exist over the optimal treatment regimen and efficacy of PRP for tendinopathy. This review focuses on the specific molecular and cellular mechanisms by which PRP manipulates tendon healing to better understand how PRP affects tendinopathy and explore the reason for the differences in clinical trial outcomes. This article has also pointed out the future direction of basic research and clinical application of PRP in the treatment of tendinopathy, which will play a guiding role in the design of PRP treatment protocols for tendinopathy.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSIONS

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

Hypoxia Preconditioned Serum (HPS) Promotes Proliferation and Chondrogenic Phenotype of Chondrocytes In Vitro

Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage defects remains challenging in terms of maintaining chondrogenic phenotype during in vitro chondrocyte expansion. Growth factor supplementation has been found supportive in improving ACI outcomes by promoting chondrocyte redifferentiation. Here, we analysed the chondrogenic growth factor concentrations in the human blood-derived secretome of Hypoxia Preconditioned Serum (HPS) and assessed the effect of HPS-10% and HPS-40% on human articular chondrocytes from osteoarthritic cartilage at different time points compared to normal fresh serum (NS-10% and NS-40%) and FCS-10% culture conditions. In HPS, the concentrations of TGF-beta1, IGF-1, bFGF, PDGF-BB and G-CSF were found to be higher than in NS. Chondrocyte proliferation was promoted with higher doses of HPS (HPS-40% vs. HPS-10%) and longer stimulation (4 vs. 2 days) compared to FCS-10%. On day 4, immunostaining of the HPS-10%-treated chondrocytes showed increased levels of collagen type II compared to the other conditions. The promotion of the chondrogenic phenotype was validated with quantitative real-time PCR for the expression of collagen type II (COL2A1), collagen type I (COL1A1), SOX9 and matrix metalloproteinase 13 (MMP13). We demonstrated the highest differentiation index (COL2A1/COL1A1) in HPS-10%-treated chondrocytes on day 4. In parallel, the expression of differentiation marker SOX9 was elevated on day 4, with HPS-10% higher than NS-10/40% and FCS-10%. The expression of the cartilage remodelling marker MMP13 was comparable across all culture conditions. These findings implicate the potential of HPS-10% to improve conventional FCS-based ACI culture protocols by promoting the proliferation and chondrogenic phenotype of chondrocytes during in vitro expansion.

Platelet-rich plasma in the treatment of alopecia areata after COVID-19 vaccination

Key Clinical Message

Alopecia areata may develop in patients after COVID-19 vaccination. Platelet-rich plasma (PRP) has an outstanding anti-inflammatory effect and could be an alternative treatment for alopecia patients who are refractory or intolerant to corticosteroids.

Abstract

A 34-year-old female with no systemic illness presented with non-scarring hair loss after the second COVID-19 vaccination shot 4 weeks ago. The hair loss worsened and progressed to severe alopecia areata. We started double-spin PRP therapy. Her hair recovered completely after six courses of PRP treatment.

Platelet Rich Plasma and Adipose-Derived Mesenchymal Stem Cells Mitigate Methotrexate-Induced Nephrotoxicity in Rat via Nrf2/Pparγ/HO-1 and NF-Κb/Keap1/Caspase-3 Signaling Pathways: Oxidative Stress and Apoptosis Interplay

BACKGROUND

the nephrotoxicity of methotrexate (MTX) is observed in high-dose therapy. Moreover, low-dose MTX therapy for rheumatic diseases is debatable and claimed to cause renal impairment. This study aimed at studying the effect of methotrexate in repeated low doses on rat kidneys and assessing the efficacy of adipose-derived mesenchymal stem cells (AD-MSCs) and platelet rich plasma (PRP) for attenuating this effect.

METHODS

Forty-two male Wistar rats were used, 10 rats were donors of AD-MSCs and PRP, 8 rats served as control, and the remaining rats were subjected to induction of nephrotoxicity by MTX intraperitoneal injection once weekly for successive 8 weeks and then assigned into 3 groups of 8 animals each: Group II: received MTX only. Group III: received MTX + PRP. Group IV: received MTX + AD-MSCs. After one month, rats were anaesthetized, serum-sampled, and renal tissue removed for biochemical, histological, and ultrastructural evaluation.

RESULTS

there was significant tubular degeneration, glomerulosclerosis, fibrosis, decreased renal index, along with increased levels of urea and creatinine in the MTX group compared to the control group. Immunohistochemical expression of caspase-3 and iNOS in the renal tissue was significantly increased in group II compared to groups III and IV. Biochemical results revealed higher tissue malondialdehyde (MDA) concentration in the MTX-injected group which decreased significantly in co-treatment with either AD-MSC or PRP + MTX. MSC promoted the activation of the Nrf2/PPARγ/HO-1 and NF-κB/Keap1/caspase-3 pathways, increased antioxidant enzyme activities, reduced lipid peroxidation levels, and alleviated oxidative damage and apoptosis. PRP showed therapeutic effects and molecular mechanisms similar to MSC. Furthermore, MSC and PRP treatment significantly reduced MTX-induced upregulation of the pro-inflammatory (NF-κB, interleukin-1ß, and TNF-α), oxidative stress (Nrf-2, hemoxygenase-1, glutathione, and malondialdehyde), and nitrosative stress (iNOS) markers in the kidney.

CONCLUSION

repeated administration of low-dose MTX resulted in massive renal tissue toxicity and deterioration of renal function in rats which proved to be attenuated by PRP and AD-MSCs through their anti-inflammatory, anti-apoptotic and anti-fibrotic properties.

Use of platelet concentrates in oral surgery of patients with osteonecrosis: a scoping review

The objective of this study was to map, through a scoping review, the evidence available in the literature on the use of platelet concentrates in compromised patients undergoing oral surgeries. Searches were performed in electronic databases for clinical studies with compromised patients undergoing oral surgery who used platelet concentrates. Only studies published in English were included. Two independent researchers carried out the selection of studies. The study design and objective, surgical procedure and platelet concentrate used, systemic involvement, analyzed outcome, and main results were extracted. A descriptive analysis of the data was performed. Twenty-two studies met the eligibility criteria and were included. Case series was the most frequent study design among the included studies (41.0%). In terms of systemic disability, 19 studies reported patients with cancer and related to surgical treatment 16 studies reported patients underwent treatment for osteonecrosis related to the use of the drug. The most used platelet concentrate was pure platelet-rich fibrin (P-PRF). In general, most studies recommend the use of platelet concentrates. Thus, the results of this study suggest that the evidence related to the use of platelet concentrates in compromised patients when undergoing oral surgeries is still initial. Also, most studies assessed the use of platelet concentrates in patients with osteonecrosis.

Ovarian rescue in women with premature ovarian insufficiency: facts and fiction

The ovary has a comparatively short functional lifespan compared with other organs, and genetic and pathological injuries can further shorten its functional life. Thus, preserving ovarian function should be considered in the context of women with threats to ovarian reserve, such as ageing, premature ovarian insufficiency (POI) and diminished ovarian reserve (DOR). Indeed, one-third of women with POI retain resting follicles that can be reactivated to produce competent oocytes, as proved by the in-vitro activation of dormant follicles. This paper discusses mechanisms and clinical data relating to new therapeutic strategies using ovarian fragmentation, stem cells or platelet-rich plasma to regain ovarian function in women of older age (>38 years) or with POI or DOR. Follicle reactivation techniques show promising experimental outcomes and have been successful in some cases, when POI is established or DOR diagnosed; however, there is scarce clinical evidence to warrant their widespread clinical use. Beyond these contexts, also discussed is how new insights into the biological mechanisms governing follicular dynamics and oocyte competence may play a role in reversing ovarian damage, as no technique modifies oocyte quality. Additional studies should focus on increasing follicle number and quality. Finally, there is a small but important subgroup of women lacking residual follicles and requiring oocyte generation from stem cells.

Evaluation of the effect of local administration of PRP vs vitamin D3 on the rate of orthodontic tooth movement and the associated external apical root resorption

Background

Increased orthodontic treatment duration is associated with iatrogenic risks such as root resorption, white spot lesions etc. Recent research using pharmacological agents to accelerate tooth movement has mostly been conducted on animals and there is no reported research conducted on humans comparing the effects of Vitamin D3 and Platelet Rich Plasma (PRP) in the same subjects using a split mouth technique.

Objectives

To determine and compare effects of local injection of PRP and Vitamin D3 on the rate of tooth movement. Also, to assess association of external apical root resorption with the use of PRP, Vitamin D3 and compare it to a control group.

Materials & methods

11 subjects who diagnosed with Class I bi-maxillary malocclusion and who gave informed consent were recruited in the study. The patients were randomly divided using split mouth design and each quadrant served as either experimental or control group one. At the beginning of retraction phase, Vitamin D3 and PRP were injected to the randomly assigned quadrants while the contralateral side served as a control. The amount of space closure in 4 months was measured from distal surface of canine to mesial surface of 2nd premolar. Root resorption was assessed using CBCT taken at the beginning and at the closure of retraction phase.

Results

Mean rate of tooth movement was higher in PRP and Vitamin D3 groups compared to their controls. In the PRP group, the increased rate of tooth movement was observed throughout the study interval, but in the Vitamin D3 group it was only seen in first two months. Also, the PRP group demonstrated a higher rate of tooth movement compared to Vitamin D3 group. Root resorption was lesser in both experimental groups. Among the teeth assessed, lateral incisor showed maximum root resorption and canine the least.

Conclusions

PRP is a more efficient pharmacological agent compared to Vitamin D3 for accelerating tooth movement.

The levels of TGFβ1, VEGF, PDGF-BB, and PF4 in platelet-rich plasma of professional soccer players: a cross-sectional pilot study

Background

Regenerative therapy using platelet-rich plasma (PRP), a rich source of growth factors, has become popular in orthopedic sports medicine. Elite athletes prefer PRP therapy for their injured muscles and tendons primarily to avoid the possible risks of surgical treatment. However, the clinical effectiveness of PRP therapy in elite athletes compared to that in non-athletes remains unknown. Therefore, to investigate the effectiveness of PRP therapy in professional athletes (pro-athletes), we focused on the quality of PRP preparations and compared the levels of bioactive molecules between pro-athletes and non-athletes.

Methods

PRP was prepared from healthy, non-smoking male professional soccer players (pro-athletes) (n = 22) and non-athletes (VEGF: n = 34, others: n = 38). The levels of TGFβ1, PDGF-BB, VEGF, and PF4 were determined using ELISA kits. Polyphosphate was probed with 4’,6-diamidino-2-phenylindole and monitored using a fluorometer. The body composition of the donors was determined using a bathroom weighing scale.

Results

The levels of TGFβ1 and VEGF were significantly lower in pro-athletes than in non-athletes, whereas PF4 levels were significantly higher in pro-athletes. No significant difference was found in PDGF-BB levels between these groups. Biomolecule levels were not correlated with polyphosphate levels.

Conclusion

TGFβ1, VEGF, and PDGF-BB levels in pro-athletes were not higher than those in non-athletes. These findings suggest that growth factor levels in PRP may not be a predominant determinant of the clinical effectiveness of PRP therapy in pro-athletes. Increased PF4 levels in pro-athletes suggest an immunological function of PRP that may positively influence tissue regeneration.

Tolerance and efficacy of platelet-rich plasma injections in Peyronie's disease: Pilot study

INTRODUCTION

Platelet-rich plasma (PRP) injections are increasingly proposed for the treatment of Peyronie's disease since the discontinuation of Xiapex® despite poorly understood results.

OBJECTIVES

Evaluation of the tolerance and efficacy of intra-plate PRP injections in patients with Peyronie's disease.

METHODS

Three intra-plate injections of PRP were performed 15 days apart in 17 patients with Peyronie's disease. The Peyronie's Disease Questionnaire (PDQ) and the measurement of the angle of curvature of the erect penis were assessed before treatment and then 1, 3 and 6 months after treatment. Erectile function was assessed by different questionnaires (IIEF-EF, EHS, SEP, sexual discomfort score).

RESULTS

No side effects were noted during the study period. Three months after treatment, all three PDQ domains were significantly improved (P=0.002; P=0.015; P=0.017 respectively). The angle of curvature of the penis was significantly decreased by 11.8° with a mean angle of 40.4° before treatment and 28.6° after (P=0.007). The IIEF-EF score was significantly improved after treatment (mean preoperative value: 10.67) with a gain of 5 points at months 1 and 6 (P=0.01 and P=0.036 respectively) and 7 points at month 3 (P=0.04).

CONCLUSION

Our initial experience suggests that PRP injections for Peyronie's disease are safe. Although the limited data is suggestive of efficacy, a placebo control will be required for confirmation.

Potential therapeutic effect of platelet-rich plasma and albendazole on the muscular phase of experimental Trichinella spiralis infection

Trichinellosis is a food-borne parasitic infection causing muscle damage. This study aimed to detect the potential therapeutic effect of platelet-rich plasma (PRP) alone or in combination with albendazole (ALB) on the muscular phase of experimental Trichinella infection in rats. The study was conducted on 70 rats divided into four main groups: healthy non-infected non-treated rats, non-infected rats treated with PRP, infected untreated rats (seven rats in each group), and an infected group of 49 rats. The infected group was further subdivided based on the drug therapy received. The effects of drug therapy were evaluated using parasitological and histopathological analyses. The percent reduction in the number of Trichinella spiralis larvae per gram of muscle in the PRP-treated groups (one, two, and three doses) was 43.1%, 78.8%, and 86.1%, respectively. Groups treated with combined therapy of ALB & PRP (one, two, and three doses) showed overall reduction percentages of 87.7%, 90.9% and 95.2%, respectively. In contrast, the ALB-treated group showed a 69.4% reduction. All results of the abovementioned groups were statistically significant compared to the control-infected non-treated group. The findings of the histopathological analysis were consistent with the parasitological results. Groups receiving combined therapy showed the most significant improvement in terms of the degree of inflammation and fibrosis. It can be concluded that PRP has a modulatory effect on the pathology caused by T. spiralis larvae in the muscular phase of trichinellosis. To our knowledge, this is the first study to investigate the effect of PRP on the muscular phase of T. spiralis infection.

Autologous Platelet-Rich Growth Factor Reduces M1 Macrophages and Modulates Inflammatory Microenvironments to Promote Sciatic Nerve Regeneration

The failure of peripheral nerve regeneration is often associated with the inability to generate a permissive molecular and cellular microenvironment for nerve repair. Autologous therapies, such as platelet-rich plasma (PRP) or its derivative platelet-rich growth factors (PRGF), may improve peripheral nerve regeneration via unknown mechanistic roles and actions in macrophage polarization. In the current study, we hypothesize that excessive and prolonged inflammation might result in the failure of pro-inflammatory M1 macrophage transit to anti-inflammatory M2 macrophages in large nerve defects. PRGF was used in vitro at the time the unpolarized macrophages (M0) macrophages were induced to M1 macrophages to observe if PRGF altered the secretion of cytokines and resulted in a phenotypic change. PRGF was also employed in the nerve conduit of a rat sciatic nerve transection model to identify alterations in macrophages that might influence excessive inflammation and nerve regeneration. PRGF administration reduced the mRNA expression of tumor necrosis factor-α (TNFα), interleukin-1β (IL-1β), and IL-6 in M0 macrophages. Increased CD206 substantiated the shift of pro-inflammatory cytokines to the M2 regenerative macrophage. Administration of PRGF in the nerve conduit after rat sciatic nerve transection promoted nerve regeneration by improving nerve gross morphology and its targeted gastrocnemius muscle mass. The regenerative markers were increased for regrown axons (protein gene product, PGP9.5), Schwann cells (S100β), and myelin basic protein (MBP) after 6 weeks of injury. The decreased expression of TNFα, IL-1β, IL-6, and CD68⁺ M1 macrophages indicated that the inflammatory microenvironments were reduced in the PRGF-treated nerve tissue. The increase in RECA-positive cells suggested the PRGF also promoted angiogenesis during nerve regeneration. Taken together, these results indicate the potential role and clinical implication of autologous PRGF in regulating inflammatory microenvironments via macrophage polarization after nerve transection.

Do platelet concentrates accelerate orthodontic tooth movement?: a systematic review

PURPOSE

Surgical techniques in orthodontics have received widespread attention in recent years. Meanwhile, biomaterials with high molecular content have been introduced, such as platelet concentrates (PCs), which may accelerate orthodontic tooth movement (OTM) and reduce periodontal damage. The present systematic review aimed to answer the following PICO question: "In patients in whom orthodontic surgical techniques are performed (P), what is the effectiveness of using PCs over the surgical site (I) when compared to not placing PCs (C) to achieve faster tooth movement (O)?"

METHODS

A search was performed in 6 databases. The criteria employed were those described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses declaration. The present review included studies with a control group that provided information about the influence of PCs on the rate of OTM.

RESULTS

The electronic search identified 10 studies that met the established criteria.

CONCLUSIONS

The included studies were very diverse, making it difficult to draw convincing conclusions. However, a tendency was observed for OTM to be accelerated when PCs were used as an adjuvant for canine distalization after premolar extraction when distalization was started in the same session. Likewise, studies seem to indicate an association between PC injection and the amount of canine retraction. However, it is not possible to affirm that the use of PCs in corticotomy shortens the overall treatment time, as this question has not been studied adequately.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42021278542.

The use of platelet-rich plasma in management of musculoskeletal pain: a narrative review

Musculoskeletal pain is the most common pain reported by patients. Platelet-rich plasma (PRP) is widely used to treat musculoskeletal pain. However, the efficacy of PRP to treat this pain remains controversial. This review highlights the application of PRP in the treatment of musculoskeletal pain. PRP treatment appears to reduce pain and improve function in patients with musculoskeletal pain. However, there are limitations to the currently published studies. These limitations include the PRP preparation methods, type of activators, types of pathology to be treated, methods and times of administration, and association of PRP with other treatments.