Platelet Rich Plasma: a short overview of certain bioactive components

The longevity-associated BPIFB4 gene guarantees vascular homeostasis and immune protection through platelets

Beyond their activity in hemostasis and thrombosis, recent advances attribute platelets a pro-youthful role capable to attenuate immune senescence and age-related neuroinflammation. Previous studies from our group associated a polymorphic haplotype variant in the BPIFB4 gene (LAV-BPIFB4) with exceptional longevity. Transfer of the LAV-BPIFB4 in preclinical models has proved strategic to cope with frailty conditions, aging-related events, e.g., cardiovascular ones, and immune dysfunction mainly through a favorable conditioning of the immune system. However, whether platelets participate in LAV-BPIFB4 therapeutic action is currently unknown. Herein, we discovered that platelets were instrumental in boosting the favorable health outcomes of the systemic AAV-LAV-BPIFB4 gene transfer in vivo, as the α-CD42b platelet depletion completely abolished the vascular protective action of LAV-BPIFB4 and suppressed its pro-resolutive CD206 + anti-/CD86 + pro-inflammatory Ly6C + monocyte skewing to LPS stimulation. Of note, this is associated with a huge drop in the protective levels of BPIFB4 in the plasma of AAV-LAV-BPIFB4-injected C57BL/6 mice, indicating that plasma circulating platelets may be a reservoir of the BPIFB4 protein. Indeed, we noticed that BPIFB4 was released by human platelets, a process that is amplified in LAV-allele carrier donors. Accordingly, lentivirus-mediated overexpression of human LAV-BPIFB4 isoform, but not WT-BPIFB4 isoform was able in leading differentiated megakaryocytes to release more platelet-like-particles enriched for BPIFB4. In addition, in vitro, the M2 macrophage polarization increased when releasate from platelets, and even more from LAV pre-stimulated once, was added in monocyte cell culture. Our data suggest that platelet release of BPIFB4 and of yet-to-be-determined unidentified factors mediates the therapeutic efficacy of LAV-BPIFB4 treatment.

Clinical evaluation of combined autologous Platelet-Rich Plasma and Volume-Controlled Ozone Therapy in Facial Rejuvenation: A randomized controlled Pilot Study

Platelet rich plasma and ozone therapy have been suggested in the clinical setting as promising and adjuvant therapies for managing the symptoms related to the facial aging. However, there is a lack of evidence about the effects of combining both therapies on rejuvenation. Thus, the aim of the present study was to evaluate and to compare the safety and efficacy of both therapies in facial aging. A single-center prospective pilot study was conducted. Female participants, aged 40 to 60 years, were randomized into 2 groups: participants received the platelet rich plasma treatment (PRP); participants received the therapy with platelet rich plasma associated with ozone therapy (PRPOT). Interventions were performed using the facial intradermal technique in 42 pre-established points, for 4 sessions with an interval of 15 days between them. After analyses performed using photographic records, assessment of frontal, periorbital, nasolabial and marionette wrinkles (Wrinkle Assessment Scale), self-esteem assessment (Brazilian Version of Rosenberg's Self-Esteem Scale) and assessment of patient satisfaction (FACE-Q) can be suggested that the platelet rich plasma protocol performed in the present study, as well as its association with volume-controlled ozone therapy, proved to be safe and potentially promising modalities in the treatment of facial aging.

Update on Platelet-Rich Plasma and Platelet-Rich Fibrin for Dermatologic Surgery: Addressing Knowns and Unknowns

BACKGROUND

Autologous and allogeneic platelet-rich plasma (PRP) in addition to its derivatives, such as platelet-rich fibrin (PRF), are broadly accepted therapeutic approaches in orthopedics, otolaryngology, sports medicine, plastic surgery, and oral and maxillofacial surgery. However, the absence of expert consensus, standardized protocols, and varying outcomes pose challenges to their broader acceptance in cosmetic dermatology and dermatologic surgery.

OBJECTIVE

To offer a contemporary literature overview of PRP and PRF, focusing on fundamental aspects of the technology, diversity of commercially accessible systems, and shed light on present-day controversies within the field.

METHODS

A systemic review of PRP and PRF literature was conducted, utilizing search engine databases: Cochrane Database of Systematic Reviews, Embase, Ovid MEDLINE, and PubMed. Emphasis was placed on scrutinizing higher level-of-evidence articles, specifically randomized control trials, systematic reviews, and meta-analyses (Level 1A-2A), with particular emphasis on recent data that have not been well reviewed in other publications from January 2022 to May 2024.

RESULTS

An increasing body of literature affirms advantages of PRP products in dermatology, spanning wound care, facial rejuvenation, scar revision, and hair growth.

CONCLUSION

A foundational understanding of variation in preparation protocol, outcomes, and timing of administration is needed to better comprehend market dynamics, patient demand, and strategies for integrating PRP into dermatologic practice.

Effectiveness of platelet-rich plasma in long-lasting post-viral olfactory dysfunction: a case-series

OBJECTIVE

To investigate the platelet-rich plasma (PRP) effectiveness in patients with a long-lasting postviral olfactory dysfunction (LPOD).

METHODS

Forty-three consecutive patients with a long-lasting postviral OD were prospectively recruited. The injection of 1 mL of PRP was carried out in both olfactory clefts. The pre- to 6-month post-PRP injection change in olfaction was assessed with the olfactory disorder questionnaire (ODQ) and the threshold, discrimination, and identification (TDI) tests.

RESULTS

Forty-three patients received bilateral PRP injections (24 females). The mean age of patients was 58.9 ± 16.8 years. The mean duration of LPOD was 8.7 years. The pre to 6-month post-injection mean TDI significantly improved from 10.3 ± 10.2 to 20.12 ± 12.07 (p = 0.001). The mean ODQ significantly decreased from 29.8 ± 13.0 to 23.4 ± 11.3 (p = 0.013). The average change of the TDI and the ODQ were 9.8 and 6.4, respectively. Age was inversely associated with the 6-month threshold score.

CONCLUSION

PRP appears to be a promising therapeutic strategy for long-lasting postviral OD. Our findings support the conduction of controlled randomized trial in this population of patients.

The Biological Effect of Enriching the Plasma Content in Platelet-Rich Plasma: An In Vitro Study

BACKGROUND

Platelet-rich plasma (PRP) formulations have become valuable therapeutic tools in regenerative medicine. In addition, these blood derivates have been successfully included in cell therapy as fetal bovine serum substitutes, due to the real need to avoid the risk of host immunologic reactions and the animal disease transmission associated with reagents from animal origin. However, the protocols for obtaining them should be optimized to improve their biological potential.

METHODS

PRP-derived preparations with different concentrations of the platelet and plasma components were obtained from the blood of five donors by freeze-drying. Measurements of the pH, protein, and growth factor concentration were performed. Moreover, their biological effects on cell proliferation and migration and their angiogenic potential were assessed.

RESULTS

An increased plasma component concentration resulted in an augmented quantity of the total protein content, a significative variation in the hepatocyte growth factor concentration, and an experimental but clinically irrelevant alteration of the pH value. No significant changes were induced in their potential to enhance proliferative and migratory responses in epithelial cells, with the latter being reduced for dermal fibroblasts. The endothelial cell capacity for tube formation was significatively reduced.

CONCLUSIONS

An increased blood plasma content did not improve the biological potential of the formulations. However, they have emerged as a promising approach for regenerative therapies where neovascularization must be avoided.

Pink1/Parkin deficiency alters circulating lymphocyte populations and increases platelet-T cell aggregates in rats

Parkinson's disease (PD) is the most common progressive neurodegenerative movement disorder and results from the selective loss of dopaminergic neurons in the substantia nigra pars compacta. Pink1 and Parkin are proteins that function together in mitochondrial quality control, and when they carry loss-of-function mutations lead to familial forms of PD. While much research has focused on central nervous system alterations in PD, peripheral contributions to PD pathogenesis are increasingly appreciated. We report Pink1/Parkin regulate glycolytic and mitochondrial oxidative metabolism in peripheral blood mononuclear cells (PBMCs) from rats. Pink1/Parkin deficiency induces changes in the circulating lymphocyte populations, namely increased CD4 + T cells and decreased CD8 + T cells and B cells. Loss of Pink1/Parkin leads to elevated platelet counts in the blood and increased platelet-T cell aggregation. Platelet-lymphocyte aggregates are associated with increased thrombosis risk suggesting targeting the Pink1/Parkin pathway in the periphery might have therapeutic potential.

Platelet-rich plasma as an adjuvant therapy to fractional ablative carbon dioxide lasers for cutaneous repair: a complementary treatment for atrophic acne scarring

Acne has a prevalence of over 90% among adolescents, and subsequently progresses to acne scarring in approximately 47% of cases. Due to the severe psychological and social ramifications acne scarring has on patients, there is a need for more effective treatments. Platelet-rich plasma (PRP), an autologous preparation enriched with growth factors, cytokines, and chemokines, has shown efficacy in promoting wound healing and tissue remodeling in dermatology. Recent evidence suggests that the efficacy of PRP may be enhanced when combined with laser therapy, which induces controlled tissue damage through photo-thermolysis thereby promoting tissue remodeling and epidermal regeneration. The microchannels created by laser treatments are thought to allow deeper penetration of PRP into the skin, potentially increasing its therapeutic effects. This review aims to analyze the combined use of PRP and laser therapy for treating acne scarring by examining randomized control trials from the past decade indexed on PubMed. Six studies met our inclusion criteria and were included in this review. The findings of this review support the hypothesis that combining PRP with laser therapy offers superior clinical results compared to monotherapy, providing a more effective approach to managing acne scarring.

Platelet-rich plasma for treatment of female stress urinary incontinence

INTRODUCTION AND OBJECTIVE

Stress urinary incontinence (SUI) poses a significant burden on affected individuals, impairing their quality of life and causing embarrassment due to involuntary urine leakage during activities such as sneezing or coughing. While conservative and surgical treatments exist, a subset of patients experiences persistent symptoms despite these interventions. This review provides insights into the potential role of platelet-rich plasma (PRP) as a therapeutic adjunct for patients with SUI that does not respond to conventional non-surgical or surgical treatments.

METHODS

We conducted a literature review of studies in English to evaluate PRP efficacy in managing SUI.

RESULTS

The studies conducted on PRP therapy suggest that it is an effective and safe treatment option for SUI in women. PRP injections, when used alone or in combination with other therapies, have shown significant improvements in SUI symptoms. Moreover, these studies indicate that PRP injections offer a less invasive and low-risk alternative to surgical procedures for managing SUI, which could lead to shorter recovery times.

CONCLUSION

The efficacy of PRP therapy is evidenced by significant reductions in SUI symptoms, as well as improvements in bladder function variables, without significant adverse effects reported. However, further research is necessary to establish the long-term effectiveness and safety of PRP therapy for managing SUI in diverse patient populations. Additionally, ongoing evaluations of PRP therapy in combination with other interventions will be essential for optimizing treatment outcomes and broadening the potential applications of PRP in the management of SUI.

The potential role of intracavernosal injection of platelet-rich plasma for treating patients with mild to moderate erectile dysfunction: A GRADE-Assessed systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Platelet-rich plasma (PRP) has shown positive effects on enhancing erectile function in animal studies. Human clinical trials are limited and provide contradictory results. This review aims to conduct a meta-analysis of the available Randomized controlled trials (RCT) to assess the efficacy of PRP in males with ED.

METHODS

A systematic review was carried out following the Cochrane Handbook of Intervention and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and registered in PROSPERO (CRD42023441655).

RESULTS

A total of three RCTs were included in the analysis for a total of 221 patients with mild to moderate ED. The patients receiving PRP reported significantly better improvement of IIEFEF score during 1,3- and 6-months follow-up compared to the placebo group (mean difference [MD] 2.66, 95% confidence interval [CI] 1.48 to 3.83, p < 0.01; MD 2.11, 95%CI 0.13 to 4.09, p = 0.04; MD 2.99, 95%CI 1.79 to 4.19, p < 0.01). The pooled analysis indicated that attainment of minimally clinical important difference (MCID) was significantly higher in patients receiving PRP compared to the placebo group during one and 6-month follow-up (odds ratio [OR] 5.51, 95%CI 1.2 to 254, p = 0.03; OR 5.64, 95%CI 2.05 to 15.55, p < 0.01; respectively). Encouragingly, no major AEs were reported in all three trials in the PRP and placebo groups (p = 0.99).

CONCLUSIONS

This review highlights the potential role of PRP in providing short-term improvement of erectile function parameters for up to 6 months in mild to moderate ED patients. Future RCTs with longer-duration follow-ups and more standardized treatment protocols are necessary to gain sufficient details on PRP's long-term effectiveness and safety.

Platelet-Rich Plasma Promotes the Expansion of Human Myoblasts and Favors the In Vitro Generation of Human Muscle Reserve Cells in a Deeper State of Quiescence

Stem cell therapy holds significant potential for skeletal muscle repair, with in vitro-generated human muscle reserve cells (MuRCs) emerging as a source of quiescent myogenic stem cells that can be injected to enhance muscle regeneration. However, the clinical translation of such therapies is hampered by the need for fetal bovine serum (FBS) during the in vitro generation of human MuRCs. This study aimed to determine whether fresh allogeneic human platelet-rich plasma (PRP) combined or not with hyaluronic acid (PRP-HA) could effectively replace xenogeneic FBS for the ex vivo expansion and differentiation of human primary myoblasts. Cells were cultured in media supplemented with either PRP or PRP-HA and their proliferation rate, cytotoxicity and myogenic differentiation potential were compared with those cultured in media supplemented with FBS. The results showed similar proliferation rates among human myoblasts cultured in PRP, PRP-HA or FBS supplemented media, with no cytotoxic effects. Human myoblasts cultured in PRP or PRP-HA showed reduced fusion ability upon differentiation. Nevertheless, we also observed that human MuRCs generated from PRP or PRP-HA myogenic cultures, exhibited increased Pax7 expression and delayed re-entry into the cell cycle upon reactivation, indicating a deeper quiescent state of human MuRCs. These results suggest that allogeneic human PRP effectively replaces FBS for the ex vivo expansion and differentiation of human myoblasts and favors the in vitro generation of Pax7High human MuRCs, with important implications for the advancement of stem cell-based muscle repair strategies.

Effect of rock bream iridovirus (RBIV) contained tissue intake on rock bream (Oplegnathus fasciatus) mortality and blood cell distribution

Rock bream (Oplegnathus fasciatus) is one of the highly priced cultured marine fish in Korea. Rock bream iridovirus (RBIV) outbreaks in aquaculture farms may involve environmental factors, co-infection with other pathogenic microorganisms and grounded (raw) fish feed. This study evaluated the effects of RBIV-containing tissue intake on mortality and oral transmission in rock bream. Virus-containing tissues administered to rock bream [50 mg (1.53 × 108/major capsid protein, MCP gene copies) to 2400 mg (7.34 × 109)] held at 23 °C lead to 100 % mortality by 27 days post administration. Interestingly, the mortality rates were not viral dose- or concentration dependent. Further, high MCP gene copy numbers were observed in the gill, liver, intestine, stomach, spleen, heart, kidney, brain and muscle tissues (viral load range of 3.03 × 106 to 4.01 × 107/mg, average viral load 1.70 × 107/mg) of dead rock bream. Moreover, a high viral load was detected in the intestine and stomach, where the virus was directly administered. This indicated that the intake of RBIV-containing tissue feed weakens the intestinal mucosal immunity and increases viral load in the intestine. Moreover, the levels of complete blood cell count (CBC) indicators, such as red blood cell (RBC), hemoglobin (HGB) and hematocrit (HCT) significantly decreased from 15 dpi with red blood cell distribution width (RDW), and white blood cells (lymphocyte, monocyte and granulocyte) significantly increased from the initial to later stage of infection. These results highlight the significance of blood-mediated indicators against RBIV infection in rock bream. We demonstrate the existence of an oral transmission route for RBIV in rock bream. Our findings indicate that pathogen-containing feed is an important risk factor for disease outbreaks in rock bream.

Platelet-Rich Plasma-Embedded Porous Polycaprolactone Film with a Large Surface Area for Effective Hemostasis

BACKGROUND

Uncontrollable and widespread bleeding caused by surgery or sudden accidents can lead to death if not treated with appropriate hemostasis. To prevent excessive life-threatening bleeding, various hemostatic agents based on polymeric biomaterials with various additives for accelerated blood coagulation have been adopted in clinical fields. In particular, platelet-rich plasma (PRP), which contains many blood coagulation factors that can accelerate blood clot formation, is considered as one of the most effective hemostatic additives.

METHODS

We investigated a PRP-embedded porous film using discarded (expired) PRP and a film with a leaf-stacked structure (FLSS), as a hemostatic agent to induce rapid hemostasis. The film, which contained an LSS on one side (PCL-FLSS), was fabricated by a simple heating-cooling technique using tetraglycol and polycaprolactone (PCL) film. Activated PRP was obtained by the thawing of frozen PRP at the end of its expiration date (the platelet cell membrane is disrupted during the freezing and thawing of PRP, thus releasing various coagulation factors) and embedded in the PCL-FLSS (PRP-FLSS).

RESULTS

From in vitro and in vivo experiments using a rat hepatic bleeding model, it was recognized that PRP-FLSS is not only biocompatible but also significantly accelerates blood clotting and thus prevents rapid bleeding, probably due to a synergistic effect of the sufficient supply of various blood coagulants from activated PRP embedded in the LSS layer and the large surface area of the LSS itself.

CONCLUSION

The study suggests that PRP-FLSS, a combination of a porous polymer matrix with a unique morphology and discarded biofunctional resources, can be an advanced hemostatic agent as well as an upcycling platform to avoid the waste of biofunctional resources.

Treatment of vascular leg ulcers with leukocyte- and platelet-rich fibrin (L-PRF): A systematic review

Objectives: This systematic review aimed to assess the efficacy of Leukocyte- and Platelet-Rich Fibrin (L-PRF) for the treatment of vascular leg ulcers. Method: Following PRISMA guidelines, a literature search was done for studies where L-PRF was used to treat vascular leg ulcers. Results: Among six included articles, a total of 76 venous leg ulcers were treated with L-PRF. None of the studies included ulcers of arterial or lymphatic origin. Fifty-seven (75.0%) of the venous ulcers completely healed at end of follow-up. Mean time to complete healing was 6.7 weeks (SD = 5.0). All non-healed ulcers showed an important reduction in wound area. No adverse effects related to L-PRF therapy were reported. Conclusions: The results suggest that L-PRF could be a safe, simple to use and effective therapeutic option for the treatment of venous leg ulcers, however, caution is advised as the results are based on small sample sizes.

Platelet-Rich Plasma Therapy for Rotator Cuff Injuries: A Comprehensive Review of Current Evidence and Future Directions

Rotator cuff injuries are a prevalent cause of shoulder pain and disability, significantly impacting daily activities and quality of life. Platelet-rich plasma (PRP) therapy has emerged as a potential treatment for these injuries, aiming to enhance healing by delivering concentrated platelets and growth factors. This review comprehensively evaluates the current evidence regarding PRP therapy for rotator cuff injuries. It examines clinical trial data, comparing PRP therapy with conventional treatments such as physical therapy and surgical intervention. The review also explores the biological mechanisms of PRP, including its role in promoting tendon repair and regeneration through growth factors and cytokines. In addition, it addresses variables that may affect PRP therapy outcomes, including preparation techniques, injection methods, and patient-specific factors. The review highlights the need for standardized protocols and further research to optimize PRP therapy and address existing gaps in knowledge. Future directions include exploring combined treatment approaches and assessing long-term outcomes to refine PRP therapy's role in rotator cuff injury management. This review aims to provide valuable insights into the effectiveness of PRP therapy, contributing to improved treatment strategies and enhanced patient outcomes.

Exploring the applications of platelet-rich plasma in tissue engineering and regenerative medicine: evidence from goat and sheep experimental research

Platelet-rich plasma (PRP) has emerged as a promising therapeutic approach in regenerative medicine. It contains various growth factors and bioactive molecules that play pivotal roles in tissue repair, regeneration, and inflammation modulation. This comprehensive narrative review delves into the therapeutic potential of PRP in experimental goat and sheep research, exploring recent advancements, challenges, and future prospects in the field. PRP has been explored for its application in musculoskeletal injuries, wound healing, and orthopedic conditions. Studies have demonstrated the ability of PRP to accelerate tissue healing, reduce inflammation, and improve the overall quality of healing. Recent advancements in PRP technology have led to the development of novel formulations and delivery methods to enhance its therapeutic efficacy. PRP has shown promise in tendon and ligament injuries, osteoarthritis, and bone fractures in experimental goat and sheep research. Despite these advancements, several challenges and opportunities exist to harness the full therapeutic potential of PRP in regenerative medicine. Standardizing PRP preparation protocols, including blood collection techniques, centrifugation parameters, and activation methods, is essential to ensure consistency and reproducibility of the findings. Moreover, further research is needed to elucidate the optimal dosing, frequency, and timing of PRP administration for different clinical indications. Research conducted in goat and sheep models provides evidence supporting the translational potential of PRP in tissue engineering and regenerative medicine. By harnessing the regenerative properties of PRP and leveraging insights from preclinical studies, researchers can develop innovative therapeutic strategies to address unmet clinical needs and improve patient outcomes in diverse medical specialties.

Platelet-rich plasma following endoscopic sinus surgery in patients with chronic sinusitis: A systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

To comprehensively evaluate the reported clinical effectiveness of platelet-rich plasma (PRP) in patients with chronic sinusitis undergoing endoscopic sinus surgery (ESS).

METHODS

We performed a systematic review and meta-analysis of randomised controlled trials (RCTs). Five digital online databases (PubMed, Scopus, Web of Science, Google Scholar and Cochrane CENTRAL) were searched from inception up to 1st May 2023. Our specific outcomes involved postoperative nasal endoscopy scores measured via Lund-Kennedy score or Meltzer score, olfactory sensation scores and pre-operative anosmia duration. All data were pooled as standardised mean difference (SMD) with a 95% confidence interval (CI), using the RevMan software.

RESULTS

Six RCTs were included in this systematic review and meta-analysis, with a total of 169 patients. The risk of bias in the included RCTs was low in three RCTs, some concerns in one RCT and high risk in two RCTs. The overall analysis of the postoperative nasal endoscopy scores showed that the PRP group had lower scores compared to the control group (n = 3 RCTs, SMD = -1.19; 95% CI [-1.94, -0.44], p = .002). There was no significant difference between the PRP and control groups regarding anosmia duration (n = 2 RCTs, SMD = 0.21; 95% CI [-0.17, 0.59], p = 0.28) or olfactory sensation scores, despite the PRP group having higher scores (n = 2 RCTs, SMD = 0.53; 95% CI [-0.32, 1.39], p = 0.22).

CONCLUSION

This study highlights the potential advantages of using PRP as an additional treatment for individuals with chronic sinusitis undergoing ESS. The improvements associated with PRP include facilitating wound healing, reducing inflammation and enhancing surgical outcomes. To optimise the use of PRP in clinical settings, future research should focus on conducting larger trials with standardised protocols.

Platelet-Rich Plasma (PRP) Based on Simple and Efficient Integrated Preparation Precises Quantitatively for Skin Wound Repair

Platelet-rich plasma (PRP) has become an important regenerative therapy. However, the preparation method of PRP has not been standardized, and the optimal platelet concentration for PRP used in skin wound repair is unclear, leading to inconsistent clinical efficacy of PRP. Therefore, the development of standardized preparation methods for PRP and the investigation of the dose-response relationship between PRP with different platelet concentrations and tissue regeneration plays an important role in the development and clinical application of PRP technology. This study has developed an integrated blood collection device from blood drawing to centrifugation. Response surface methodology was employed to optimize the preparation conditions, ultimately achieving a platelet recovery rate as high as 95.74% for PRP (with optimal parameters: centrifugation force 1730× g, centrifugation time 10 min, and serum separation gel dosage 1.4 g). Both in vitro and in vivo experimental results indicate that PRP with a (2×) enrichment ratio is the most effective in promoting fibroblast proliferation and skin wound healing, with a cell proliferation rate of over 150% and a wound healing rate of 78% on day 7.

Comparison of platelet-rich plasma efficacy with and without photoactivation in melasma: A randomized double-blind study

BACKGROUND

Photoactivation has been suggested to enhance the efficacy of platelet-rich plasma (PRP) in conditions other than dermatological diseases.

AIMS

To evaluate the efficacy of photoactivated PRP (P-PRP) treatment for melasma by comparing it with non-photoactivated, classical PRP (C-PRP).

METHODS

The study consisted of 38 female patients diagnosed with melasma between April 2022 and May 2023. The patients were randomized into the P-PRP and C-PRP groups. Three sessions of P-PRP or C-PRP were applied to the patients at 2-week intervals. The Melasma Area and Severity Index (MASI) and Melasma Quality of Life Index (MELASQoL) scores were compared before and 2 weeks after treatment.

RESULTS

The median age was 38 years, and the median disease duration was 60 months. Clinically, 94.7% of the cases were centrofacial and 5.3% were malar. According to Wood's lamp examination, 55.3% of the cases were epidermal, 13.2% were dermal, and 31.6% were mixed-type. The median pre- and post-treatment scores were 14.5 and 9, respectively, for MASI and 36.5 and 17, respectively, for MELASQoL. The post-treatment MASI and MELASQoL scores of both groups significantly decreased (p < 0.001 for both). However, the intergroup difference was not significant. When all patients were evaluated together a moderate, positive, and significant relationship was detected between PRP and the pre- and post-treatment MASI and MELASQoL scores (r = 0.494 and p = 0.002). No side effects associated with PRP were observed.

CONCLUSION

PRP is an effective and safe treatment method for melasma. Further studies are needed to evaluate the contribution of photoactivation to PRP treatment in melasma.

Beyond Blood Clotting: The Many Roles of Platelet-Derived Extracellular Vesicles

Platelet-derived extracellular vesicles (pEVs) are emerging as pivotal players in numerous physiological and pathological processes, extending beyond their traditional roles in hemostasis and thrombosis. As one of the most abundant vesicle types in human blood, pEVs transport a diverse array of bioactive molecules, including growth factors, cytokines, and clotting factors, facilitating crucial intercellular communication, immune regulation, and tissue healing. The unique ability of pEVs to traverse tissue barriers and their biocompatibility position them as promising candidates for targeted drug delivery and regenerative medicine applications. Recent studies have underscored their involvement in cancer progression, viral infections, wound healing, osteoarthritis, sepsis, cardiovascular diseases, rheumatoid arthritis, and atherothrombosis. For instance, pEVs promote tumor progression and metastasis, enhance tissue repair, and contribute to thrombo-inflammation in diseases such as COVID-19. Despite their potential, challenges remain, including the need for standardized isolation techniques and a comprehensive understanding of their mechanisms of action. Current research efforts are focused on leveraging pEVs for innovative anti-cancer treatments, advanced drug delivery systems, regenerative therapies, and as biomarkers for disease diagnosis and monitoring. This review highlights the necessity of overcoming technical hurdles, refining isolation methods, and establishing standardized protocols to fully unlock the therapeutic potential of pEVs. By understanding the diverse functions and applications of pEVs, we can advance their use in clinical settings, ultimately revolutionizing treatment strategies across various medical fields and improving patient outcomes.

Exploring Platelet-Rich Plasma Therapy for Knee Osteoarthritis: An In-Depth Analysis

The use of platelet-rich plasma (PRP) in all medical fields is currently gaining popularity (1). PRP is a biological product that can be defined as a segment of the plasma fraction of autologous blood with a platelet concentration level above the baseline (2). The fact that it has uses in tissue regeneration and wound healing has caught the eye of orthopedic surgeons as well, as intra-articular treatments have continued to evolve. Its benefits in the treatment of different osteoarticular pathologies are of great interest in the evolving orthopedic community, targeting mostly knee osteoarthritis, meniscus and ligament injuries (3). The purpose of this review is to update the reader on the current uses of platelet-rich plasma (PRP) in the treatment of knee osteoarthritis pathology and to provide clinical feedback on its uses in the fields of orthopedic and sports medicine practice (4). We proceeded in studying 180 titles and abstracts eligible for inclusion. Compared to alternative treatments, PRP injections greatly improve the function of the knee joint.

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.

Comparison of the therapeutic effect of platelet-rich plasma and injectable platelet-rich fibrin on testicular torsion/detorsion injury in rats

Testicular torsion is a common disorder in males and results in blockage of testicular circulation with subsequent damage of testicular germ cells. The current work aimed to compare the therapeutic effect of platelet-rich plasma (PRP) and injectable platelet-rich fibrin (i-PRF) on torsion/detorsion (T/D) injury in rats. Forty mature male Wister rats were arranged into 4 groups; (1) Control, (2) T/D, (3) T/D + PRP, and (4) T/D+ i-PRF. The right testis was twisting 1080° clockwise for 3 h in groups 2, 3 and 4, then 10 μl of PRP or i-PRF was injected intra-testicular 3 h after detorsion in groups 3 and 4, respectively. After 30 days postoperatively, the semen quality and hormonal assay were improved in PRP and i-PRF-treated groups with superiority of i-PRF (P < 0.001). High significance of Catalase, Glutathione Peroxidase (GPx), Superoxide Dismutase, Interleukin-1β (IL-1β), Caspase-3 and Tumor necrosis factor-α (TNF-α) was reported in treated rats with PRP and i-PRF (P < 0.001) with superiority to i-PRF-treated rats (P < 0.001). Testicular histoarchitectures were improved in PRP and i-PRF-treated rats with superiority of i-PRF-treated rats. It was concluded that PRP and i-PRF have regenerative efficacy on testicular damage after induced T/D injury with a superior efficacy of i-PRF.

The Use of Platelet-Rich Plasma Augmentation in Meniscus Repair Results in a Lower Failure Rate than in the Control Group: A Systematic Review From Meta-analysis

Purpose

To investigate the efficacy of platelet-rich plasma (PRP) as an augmentation in meniscus repair.

Methods

A comprehensive search of PubMed, Medline (via EBSCO), ProQuest, and ScienceDirect from January to February 2023 was conducted using the terms "meniscus repair," "PRP," and "meniscus tear." Meta-analyses that investigated the rate of failure after meniscus repair were included. Studies before 2003, not in English, associated procedures during surgery, and animal studies were excluded. The included studies underwent quality appraisal and risk of bias assessment. Data were extracted from each study's text, figures, tables, and associated supplementary files and then analyzed qualitatively.

Results

The failure rate is lower in the PRP augmentation group compared with the group without augmentation, with a mean difference of 0.42, 0.50, and 0.43. Visual analog scale score was also found to be significantly lower in the treatment group, with a mean difference of 0.40, 0.76, and 6.69. However, only mean differences in Lysholm score in one of the included studies were found significant regarding functional outcomes, which can be found in the Xie et al. study with a mean difference of 3.06.

Conclusions

In this study, we found that meniscal repairs augmented with PRP have a lower failure rate.

Level of Evidence

Level IV, systematic review of Level III-IV studies.

Platelet-Rich Therapies in Hernia Repair: A Comprehensive Review of the Impact of Platelet Concentrates on Mesh Integration in Hernia Management

Mesh-augmented hernia repair is the gold standard in abdominal wall and hiatal/diaphragmatic hernia management and ranks among the most common procedures performed by general surgeons. However, it is associated with a series of drawbacks, including recurrence, mesh infection, and adhesion formation. To address these weaknesses, numerous biomaterials have been investigated for mesh coating. Platelet-rich plasma (PRP) is an autologous agent that promotes tissue healing through numerous cytokines and growth factors. In addition, many reports highlight its contribution to better integration of different types of coated meshes, compared to conventional uncoated meshes. The use of PRP-coated meshes for hernia repair has been reported in the literature, but a review of technical aspects and outcomes is missing. The aim of this comprehensive review is to report the experimental studies investigating the synergistic use of PRP and mesh implants in hernia animal models. A comprehensive literature search was conducted across PubMed/Medline, Web of Science, and Scopus without chronological constraints. In total, fourteen experimental and three clinical studies have been included. Among experimental trials, synthetic, biologic, and composite meshes were used in four, nine, and one study, respectively. In synthetic meshes, PRP-coating leads to increased antioxidant levels and collaged deposition, reduced oxidative stress, and improved inflammatory response, while studies on biological meshes revealed increased neovascularization and tissue integration, reduced inflammation, adhesion severity, and mechanical failure rates. Finally, PRP-coating of composite meshes results in reduced adhesions and improved mechanical strength. Despite the abundance of preclinical data, there is a scarcity of clinical studies, mainly due to the absence of an established protocol regarding PRP preparation and application. To this point in time, PRP has been used as a coating agent for the repair of abdominal and diaphragmatic hernias, as well as for mesh fixation. Clinical application of conclusions drawn from experimental studies may lead to improved results in hernia repair.

Forecasting the Effects of Platelet-Rich Plasma on Follicle Development Following Premature Ovarian Insufficiency by Network Interaction Analysis

<b>Background and Objective:</b> Platelet-Rich Plasma (PRP) is proposed to have a potential regenerative effect on the ovaries following premature ovarian insufficiency (POI), however, the main impact on the process of follicle development (folliculogenesis) remains unclear. Protein-protein interaction (PPI) or network interaction analysis enables us to predict the targets of PRP's biomolecules using biological data through public databases and platforms. Therefore, this method is more efficient in time and cost than traditional laboratory procedures. The purpose of this study was to predict the targets of PRP's biomolecules on folliculogenesis following POI using PPI analysis and to clarify if those predictive targets integrate into PI3K/Akt signaling pathway which is an important pathway in folliculogenesis. <b>Materials and Methods:</b> Mining data targets of POI, PRP and folliculogenesis was done by GeneCards. Only genes with "protein-coding" category were analyzed further. Network analysis was performed using Cytoscape and STRING. Finally, STRING, Enricher and ShinyGO platforms were conducted to analyze gene ontology, including biological processes, molecular function and cellular components, as well as pathways. <b>Results:</b> Network analysis with Cytoscape and STRING discovered 107 gene hubs for POI, PRP and folliculogenesis. Analysis of KEGG pathway using STRING, Enricher and ShinyGO identified 43 genes integrated into PI3K/Akt signaling pathway. From the KEGG pathway, PI3K and Akt were revealed as two main targets following PRP treatment for POI patients. <b>Conclusion:</b> Biomolecules in PRP may recover ovarian follicle development following POI through the PI3K/Akt signaling pathway.

Efficacy of Intraoperative Platelet-Rich Plasma After Meniscal Repair: Systematic Review and Meta-analysis

Background

Meniscal injuries frequently require surgical intervention to restore knee joint function and stability. Intraoperative platelet-rich plasma (PRP) injection has emerged as a potential adjunctive therapy to enhance tissue healing post-meniscal repair. This systematic review and meta-analysis aimed to evaluate the efficacy of PRP in terms of pain relief, functional recovery, and overall success rates in patients undergoing meniscal repair procedures.

Methods

A comprehensive search strategy was employed to identify relevant studies across Scopus, PubMed, Embase, and the Cochrane Library databases. The inclusion criteria encompassed human studies, including randomized controlled trials (RCTs), cohorts, and case-control studies, focusing on intraoperative platelet-rich plasma (PRP) use post-meniscal repair and reporting outcomes related to pain, functionality, and cure rates. Exclusion criteria comprised animal studies, non-English publications, studies lacking relevant outcome measures, and those with insufficient data. Two reviewers independently screened titles and abstracts, resolving disagreements through consensus or consultation with a third reviewer, followed by a full-text assessment for potentially eligible studies. Data extraction was conducted independently by two reviewers using a standardized form. The reliability of observational studies was evaluated using the Newcastle-Ottawa Scale. Subgroup analyses and pooled effect estimates for main outcomes were computed using RevMan 5.3, a meta-analysis tool.

Results

The demographic analysis revealed that the PRP group had an average age of 41.39 years, while the control group had an average age of 42.1 years. In terms of gender distribution, the PRP group consisted of 61 men and 29 women, while the control group had 62 men and 34 women. Pain ratings showed a preference for PRP with a mean difference of 4.83 (p = 0.13). However, there was no significant difference in Lysholm scores (mean difference: - 0.44, p = 0.91) or IKDC scores (mean difference: 2.80, p = 0.14) between the PRP and control groups. Similarly, ROM measures did not show a statistically significant difference, with a mean difference of 2.80 (p = 0.18). Additionally, there was no significant distinction in failure rates between the PRP and control groups, as indicated by a weighted mean difference of 0.71 (p = 0.52). These findings suggest that while PRP may offer some benefits in pain relief, its impact on functional recovery, range of motion, and failure rates following meniscal repair procedures is inconclusive.

Conclusion

The current evidence regarding the effect of intraoperative platelet-rich plasma (PRP) injection on patients undergoing meniscal repair remains inconclusive. While some studies suggest potential benefits in terms of pain relief and functional recovery, others show no significant differences compared to control groups. The impact of PRP therapy on overall success rates, including rates of re-tear and revision surgery, is also uncertain. Further well-designed randomized controlled trials with larger sample sizes are needed to provide more robust evidence and guide clinical practice in orthopedic surgery.

Mechanisms, Efficacy, and Clinical Applications of Platelet-Rich Plasma in Tendinopathy: A Comprehensive Review

Tendinopathy poses a significant clinical challenge characterized by chronic tendon pain, swelling, and impaired function, affecting athletes and the general population. Current treatments often provide limited success, necessitating exploration into regenerative therapies such as platelet-rich plasma (PRP). PRP harnesses the regenerative potential of autologous platelets and growth factors to promote tendon healing. This review aims to comprehensively examine the mechanisms, efficacy, and clinical applications of PRP in tendinopathy. We discuss the pathophysiology of tendinopathy, highlighting collagen disorganization, increased ground substance, and inflammatory changes. PRP's action mechanism involves releasing bioactive molecules that stimulate cellular proliferation, collagen synthesis, and tissue remodeling. Clinical studies and trials evaluating PRP in various tendinopathies, including Achilles, patellar, and rotator cuff tendinopathy, are reviewed to assess its efficacy and effectiveness compared to traditional therapies. Practical aspects, such as preparation methods, injection techniques, and safety considerations, are discussed to provide insights into optimal PRP administration. Challenges, including protocol variability and evidence gaps, are addressed, and future research and clinical practice directions are proposed. By synthesizing current knowledge, this review aims to guide clinicians in enhancing treatment strategies and advancing the field of tendon regenerative medicine.

Orthobiologic Management Options for Degenerative Disc Disease

Degenerative disc disease (DDD) is a pervasive condition that limits quality of life and burdens economies worldwide. Conventional pharmacological treatments primarily aimed at slowing the progression of degeneration have demonstrated limited long-term efficacy and often do not address the underlying causes of the disease. On the other hand, orthobiologics are regenerative agents derived from the patient's own tissue and represent a promising emerging therapy for degenerative disc disease. This review comprehensively outlines the pathophysiology of DDD, highlighting the inadequacies of existing pharmacological therapies and detailing the potential of orthobiologic approaches. It explores advanced tools such as platelet-rich plasma and mesenchymal stem cells, providing a historical overview of their development within regenerative medicine, from foundational in vitro studies to preclinical animal models. Moreover, the manuscript delves into clinical trials that assess the effectiveness of these therapies in managing DDD. While the current clinical evidence is promising, it remains insufficient for routine clinical adoption due to limitations in study designs. The review emphasizes the need for further research to optimize these therapies for consistent and effective clinical outcomes, potentially revolutionizing the management of DDD and offering renewed hope for patients.

Multiomics analysis of platelet-rich plasma promoting biological performance of mesenchymal stem cells

Mesenchymal Stem Cells are ideal seed cells for tissue repair and cell therapy and have promising applications in regenerative medicine and tissue engineering. Using Platelet-Rich Plasma as an adjuvant to create and improve the microenvironment for Mesenchymal Stem Cells growth can enhance the biological properties of Mesenchymal Stem Cells and improve the efficacy of cell therapy. However, the mechanism by which Platelet-Rich Plasma improves the biological performance of Mesenchymal Stem Cells is still unknown. In this study, by examining the effects of Platelet-Rich Plasma on the biological performance of Mesenchymal Stem Cells, combined with multiomics analysis (Transcriptomics, Proteomics and Metabolomics) and related tests, we analyzed the specific pathways, related mechanisms and metabolic pathways of Platelet-Rich Plasma to improve the biological performance of Mesenchymal Stem Cells. In an in vitro cell culture system, the biological performance of Mesenchymal Stem Cells was significantly improved after replacing Foetal Bovine Serum with Platelet-Rich Plasma, and the genes (ESM1, PDGFB, CLEC7A, CCR1 and ITGA6 et al.) related to cell proliferation, adhesion, growth, migration and signal transduction were significantly upregulated. Platelet-Rich Plasma can enhance the secretion function of MSC exosomes, significantly upregulate many proteins related to tissue repair, immune regulation and anti-infection, and enhance the repair effect of exosomes on skin injury. After replacing Foetal Bovine Serum with Platelet-Rich Plasma, Mesenchymal Stem Cells underwent metabolic reprogramming, the metabolism of amino acids and fatty acids and various signaling pathways were changed, the anabolic pathways of various proteins were enhanced. These results provide a theoretical and technical reference for optimizing the Mesenchymal Stem Cells culture system, improving the biological characteristics and clinical application effects of Mesenchymal Stem Cells.

Therapeutic Potential of Platelet-Rich Plasma in Fracture Healing: A Comprehensive Review

Fracture healing is a dynamic process essential for the restoration of bone integrity and function. However, factors such as patient age, comorbidities, and the severity of the fracture can impede this process, leading to delayed healing or nonunion. Platelet-rich plasma (PRP) has emerged as a promising therapeutic option for enhancing fracture healing. PRP is an autologous blood product containing a concentrated mixture of platelets, growth factors, and cytokines known to promote tissue regeneration and repair. This comprehensive review provides an overview of the fracture healing process, emphasizing the importance of timely and efficient bone repair. We discuss the mechanisms underlying the purported efficacy of PRP in fracture healing, drawing upon both preclinical and clinical evidence. Preclinical studies in animal models have demonstrated the ability of PRP to accelerate fracture healing, stimulate osteogenesis, and enhance bone regeneration. Clinical studies have yielded mixed results, with some reporting positive outcomes in terms of accelerated healing and improved functional outcomes, while others have shown no significant benefits over standard treatments. Factors influencing the efficacy of PRP, such as timing of administration, PRP concentration, and patient-specific variables, are also examined. Furthermore, safety considerations and potential adverse effects associated with PRP therapy are discussed. Despite the promising preclinical findings, challenges remain in standardizing PRP formulations, optimizing administration protocols, and addressing unanswered questions regarding its long-term efficacy and safety. This review aims to provide insights into the therapeutic potential of PRP in fracture healing, informing future research directions and guiding clinical practice.

Pink1/Parkin deficiency alters circulating lymphocyte populations and increases platelet-T cell aggregates in rats

Parkinson's disease (PD) is the most common progressive neurodegenerative movement disorder and results from the selective loss of dopaminergic neurons in the substantia nigra pars compacta. Pink1 and Parkin are proteins that function together in mitochondrial quality control, and when they carry loss-of-function mutations lead to familial forms of PD. While much research has focused on central nervous system alterations in PD, peripheral contributions to PD pathogenesis are increasingly appreciated. We report Pink1/Parkin regulate glycolytic and mitochondrial oxidative metabolism in peripheral blood mononuclear cells (PBMCs) from rats. Pink1/Parkin deficiency induces changes in the circulating lymphocyte populations, namely increased CD4 + T cells and decreased CD8 + T cells and B cells. Loss of Pink1/Parkin leads to elevated platelet counts in the blood and increased platelet-T cell aggregation. Platelet-lymphocyte aggregates are associated with increased thrombosis risk, and venous thrombosis is a cause of sudden death in PD, suggesting targeting the Pink1/Parkin pathway in the periphery has therapeutic potential.

Platelet-rich plasma (PRP) treatment of the ovaries significantly improves fertility parameters and reproductive outcomes in diminished ovarian reserve patients: a systematic review and meta-analysis

INTRODUCTION

The incidence of infertility caused by diminished ovarian reserve has become a significant problem worldwide. The beneficial effect of PRP treatment of the ovaries has already been described, but the high-level evidence of its effectiveness has not yet been proven.

MATERIALS AND METHODS

A systematic search was performed in five databases, until March 12th, 2024. Both randomized and non-randomized studies that compared PRP treatment of the ovaries to self-control among women with diminished ovarian reserve were eligible for inclusion. Hormonal levels (Anti-Müllerian hormone (AMH), Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Estradiol (E2), In-vitro fertilization parameters (Antral follicle count, oocyte, and embryo count), biochemical and spontaneous pregnancy and livebirth were measured.

RESULTS

38 eligible studies were identified reporting on 2256 women. The level of AMH rised, the level of FSH decreased significantly after the PRP treatment. AMH 1 month MD 0.20 (n = 856, p > 0.001, 95% CI: [0.12;0.28]), 2 months MD 0.26 (n = 910, p = 0.013, 95% CI: [0.07;0.44]), 3 months MD 0.36 (n = 881, p = 0.002,95% CI: [0.20;0.52]). FSH 1 month MD -10.20 (n = 796, p > 0.039, 95% CI: [-19.80;-0.61]), 2 months MD -7.02 (n = 910, p = 0.017, 95% CI: [-12.48; -1.57]), 3 months MD -8.87 (n = 809, p = 0.010, 95% CI: [-14.19; -3.55]). The antral follicle count elevated significantly MD 1.60 (n = 1418, p =  < 0.001, 95% CI: [0.92; 2.27]). Significant improvement was observed in the number of retrieved oocytes MD 0.81 (n = 802, p = 0.002, 95% CI: [0.36; 1.26]), and embryos created MD 0.91 (n = 616, p = 0.001, 95% CI: [0.45;1.36]). The incidence of spontaneous pregnancy following PRP treatment showed a rate with a proportion of 0.07 (n = 1370, 95% CI: 0.04-0.12), the rate of biochemical pregnancy was 0.18 (n = 1800, 95% CI: 0.15-0.22), livebirth was 0.11 (n = 1482, 95% CI: 0.07-0.15).

CONCLUSIONS

Our meta-analysis showed that based on protocolized analysis of the widest scientific literature search to date, containing predominantly observational studies, PRP treatment resulted in a statistically significant improvement in the main fertility parameters of diminished ovarian reserve women. Further multicenter, randomized trials, with large patient numbers and a longer follow-up period are needed to certify our results and develop the most effective treatment protocol.

Platelet Releasate and Extracorporeal Shock Wave Therapy (ESWT) for Treatment of a Partial Supraspinatus Tear in an Adolescent Baseball Player

Supraspinatus tears are a common injury, particularly among athletes who engage in sports that include repetitive overhead motions, such as baseball players. Standard conservative therapies include rest and activity modification, physical therapy, non-steroidal anti-inflammatory drugs (NSAIDs), cold/heat therapy, and corticosteroid injections. Ongoing research and anecdotal evidence support using platelet-rich plasma (PRP) for supraspinatus/rotator cuff tears. Platelet releasate is obtained from PRP via the activation of platelets, subsequently releasing bioactive substances. Activation can be achieved through various methods, some of which include the addition of calcium chloride, thrombin, or exposure to low-level lasers. Platelet releasate has the potential to assist in the healing of tears by releasing growth factors that facilitate muscle and tendon repair. This case presentation discusses the outcomes of platelet releasate paired with extracorporeal shock wave therapy (ESWT) for the treatment of a partial-thickness supraspinatus tear in an 18-year-old male baseball athlete. After exploring conservative treatment options, the patient opted for a single platelet releasate injection along with a four-part series with ESWT. Four weeks post-procedure, the patient reported a 25% improvement. He was able to fully return to play for the entire baseball season. Although the effectiveness of platelet releasate is still a topic of debate and further investigation, this case demonstrates how platelet releasate shows promising results in accelerating the treatment recovery for a partial supraspinatus tear. Further investigation and research could support the benefit of this procedure for accelerated recovery of injuries compared to PRP.

Effect of intra-articular platelet-rich plasma or hyaluronic acid on limb function recovery in dogs with TPLO for cranial cruciate ligament rupture: a randomised controlled trial

OBJECTIVES

This study aimed to investigate the recovery of limb function following a single intra-articular injection of platelet-rich plasma or hyaluronic acid in dogs with cranial cruciate ligament rupture treated with tibial plateau levelling osteotomy compared to dogs receiving no injection intraoperatively.

MATERIALS AND METHODS

Sixty-two dogs with cranial cruciate ligament rupture, body weights of 20 to 40 kg, and no other orthopaedic conditions were enrolled in this prospective, randomised, double-blind, controlled study at the small animal clinic at LMU Munich. All dogs underwent tibial plateau levelling osteotomy. Based on random allocation, they received either a single intra-articular injection of platelet-rich plasma, hyaluronic acid or no injection intraoperatively. Gait analysis, clinical examinations, radiography of the stifle joint for osteoarthritis progression and two validated owner questionnaires were compared among groups at three timepoints postoperatively (6 weeks, 3 and 6 months). Limb function was primarily assessed by measuring the ground reaction forces.

RESULTS

At all times postoperatively, no differences were observed among groups regarding clinical examinations, osteoarthritis score values, ground reaction forces or owner questionnaires. All dogs showed significant improvement in limb function clinically, in all ground reaction forces and in the validated questionnaires. Osteoarthritis progressed minimally during rechecks in all dogs regardless of the additional injection or not.

CLINICAL SIGNIFICANCE

All dogs treated with tibial plateau levelling osteotomy for cranial cruciate ligament rupture showed improvements in limb function. No additive effect on faster recovery was demonstrated with the additional intra-articular injection of platelet-rich plasma or hyaluronic acid. Addition of platelet-rich plasma/hyaluronic acid injections during tibial plateau levelling osteotomy is unnecessary considering the lack of benefit observed up to 6 months postoperatively.

Obesity attenuates the beneficial effect of an intrauterine infusion of autologous platelet-rich plasma during in vitro fertilization

OBJECTIVE

To assess how obesity, normal weight (NW) versus overweight/obese (OW/OB), impacts platelet-rich plasma's (PRP) effectiveness during in vitro fertilization and how obesity affects platelets during the menstrual cycle.

METHODS

Endometrial mean thickness (EMT), embryo implantation, and clinical pregnancy were assessed using a self-controlled retrospective study that enrolled 59 patients with two failed cycles and treated with autologous PRP (three-dose scheme). The NHANES dataset was used to assess platelet changes during the menstrual cycle, using the mean platelet volume to platelet count ratio (MPR) index. The COSINOR packages for R were used to determine rhythmicity.

RESULTS

PRP treatments significantly improved the EMT (2.5 ± 1.4 mm, P<0.001), unaffected by obesity. After the PRP treatment, one patient spontaneously became pregnant; therefore, 58 patients underwent embryo transfer (62 cycles), of which in 39 cycles the embryos implanted (63.9%). This was a significant improvement from their previous cycle (vs. 22.6%, P<0.001). Clinical pregnancy also improved with the PRP treatment over the previous cycle (57.4% vs. 16.1%, P<0.001). When stratified by obesity, there was an appreciable decrease in embryo implantation and clinical pregnancy rates for the OW/OB group; nevertheless, the PRP treatment significantly improved embryo implantation and clinical pregnancy (P<0.05). A rhythm was observed with the MPR index (P<0.05) only for the NW group, suggesting that the platelets normally fluctuate during the menstrual cycle.

CONCLUSION

PRP improved embryo implantation and clinical pregnancy rates; however, these beneficial effects were attenuated by obesity. PRP presumptively promoted a change in the uterine environment to mimic the normal findings associated with normal-weight women.

Fucoidan/chitosan hydrogels as carrier for sustained delivery of platelet-rich fibrin containing bioactive molecules

Platelet-rich fibrin (PRF), derived from human blood, rich in wound healing components, has drawbacks in direct injections, such as rapid matrix degradation and growth factor release. Marine polysaccharides, mimicking the human extracellular matrix, show promising potential in tissue engineering. In this study, we impregnated the self-assembled fucoidan/chitosan (FU_CS) hydrogels with PRF obtaining PRF/FU_CS hydrogels. Our objective was to analyze the properties of a hydrogel and the sustained release of growth factors from the hydrogel that incorporates PRF. The results of SEM and BET-BJH demonstrated the relatively porous nature of the FU_CS hydrogels. ELISA data showed that combining FU_CS hydrogel with PRF led to a gradual 7-day sustained release of growth factors (VEGF, EGF, IL-8, PDGF-BB, TGF-β1), compared to pure PRF. Histology confirmed ELISA data, demonstrating uniform PRF fibrin network distribution within the FU_CS hydrogel matrix. Furthermore, the FU_CS hydrogels revealed excellent cell viability. The results revealed that the PRF/FU_CS hydrogel has the potential to promote wound healing and tissue regeneration. This would be the first step in the search for improved growth factor release.

Effect of platelet-rich plasma in Achilles tendon allograft in rabbits

BACKGROUND

Achilles tendon is composed of dense connective tissue and is one of the largest tendons in the body. In veterinary medicine, acute ruptures are associated with impact injury or sharp trauma. Healing of the ruptured tendon is challenging because of poor blood and nerve supply as well as the residual cell population. Platelet-rich plasma (PRP) contains numerous bioactive agents and growth factors and has been utilized to promote healing in bone, soft tissue, and tendons.

OBJECTIVE

The purpose of this study was to evaluate the healing effect of PRP injected into the surrounding fascia of the Achilles tendon after allograft in rabbits.

METHODS

Donor rabbits (n = 8) were anesthetized and 16 lateral gastrocnemius tendons were fully transected bilaterally. Transected tendons were decellularized and stored at -80°C prior to allograft. The allograft was placed on the partially transected medial gastrocnemius tendon in the left hindlimb of 16 rabbits. The allograft PRP group (n = 8) had 0.3 mL of PRP administered in the tendon and the allograft control group (n = 8) did not receive any treatment. After 8 weeks, rabbits were euthanatized and allograft tendons were transected for macroscopic, biomechanical, and histological assessment.

RESULTS

The allograft PRP group exhibited superior macroscopic assessment scores, greater tensile strength, and a histologically enhanced healing process compared to those in the allograft control group.

CONCLUSIONS

Our results suggest administration of PRP on an allograft tendon has a positive effect on the healing process in a ruptured Achilles tendon.

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.

Effect of platelet rich plasma injection on bone formation in the expanded mid-palatal suture in rabbits: a randomized controlled animal study

BACKGROUND

Mid-Palatal suture expansion needs long retention period due to delayed bone formation in the expanded suture. Platelet-rich plasma (PRP) is a concentrated source of growth factors which increase bone formation. The aim of this study was to evaluate the effect of PRP injection on bone formation in expanded mid palatal suture in rabbits.

METHODS

In this prospective randomized controlled animal study, Twenty male rabbits (8-weeks-old) were subjected to mid-palatal expansion for 5 days. Animals were afterwards randomly divided into control group A & study group B. PRP was prepared and injected in the mid-palatal suture in animals belonging to group B only. After 6 weeks of retention, all animals were euthanized, and premaxillae were prepared for histological, histomorphometric and immunohistochemical analysis. Student t-test and paired t-test were used to compare the means of the two groups and within the same group respectively. Significance level set at p ≤ 0.05.

RESULTS

Histomorphometric analysis revealed a significant increase (p < 0.001) in the mean percentage of new bone in the study group (14.4%) compared to the control (1.4%). Suture width in study group was significantly wider than the control group (278.8 ± 9μms and 120.4 ± 3.4μms, p < 0.001). There was a significant increase in vascular density in study group than control group (309 ± 65.34 and 243.86 ± 48.1, p = 0.021). Osteopontin immuno-expression revealed a significant increase in optical density in study group than control group (0.21 ± 0.02 & 0.12 ± 0.01, p < 0.001).

CONCLUSIONS

In rabbit model, PRP injection can accelerate new bone formation in the expanded mid-palatal suture when compared to the control. This could hopefully result in a more stable midpalatal expansion and a reduced retention period.

Outcome of novel pulp capping modalities after full pulpotomy in teeth diagnosed with irreversible pulpitis: A prospective randomized clinical trial

Objective

The study aimed to compare and evaluate the effect of biodentine (BD) alone, BD along with Lyophilised freeze dried platelet rich concentrate (LPC + BD), and BD along with low-level laser therapy (BD + LLLT) after pulpotomy in mature permanent molars with irreversible pulpitis.

Materials and Methods

The study was designed as a randomized, pragmatic, parallel, double-blinded clinical trial registered under the Clinical Trial Registry-India (CTRI/2020/02/023245). 120 permanent molars fulfilling the inclusion and exclusion criteria with symptoms of irreversible pulpitis were randomized after performing pulpotomy into three pulp capping groups: Group 1, BD; Group 2, lyophilized freeze-dried platelet-rich concentrate + BD (LPC + BD); and Group 3, Low level laser therapy + BD Group 3, LLLT + BD. The intergroup comparison was done using one-way analysis of variance followed by the Bonferroni test. The level of significance and confidence interval were 5% and 95%, respectively. Interobserver reliability was measured using Cohen's kappa analysis.

Results

At 1 week, there was a significant difference (P < 0.005) observed in the mean postoperative pain levels between the three groups with Group 1 (BD) exhibiting the highest postoperative pain followed by Group 2 (LPC + BD) and least pain was exhibited by Group 3 (LLLT + BD). A similar pattern was observed regarding the analgesic intake with maximum frequency in Group 1 (BD) and least with Group 3 (LLLT + BD). No significant difference in success rates was reported among the groups.

Conclusion

Pulpotomy as a treatment option for mandibular molars with irreversible pulpitis has an acceptable clinical success rate; however, long-term overall success rate remains questionable. The outcomes of incorporating adjunctive modalities with BD are remarkable and show tremendous potential for continued development and research.

Navigating the Therapeutic Landscape: A Comprehensive Review of Platelet-Rich Plasma and Bone Marrow Aspirate Concentrate in Knee Osteoarthritis

This comprehensive review provides an in-depth analysis of platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) as potential treatments for knee osteoarthritis. It explores their mechanisms of action, clinical efficacy, safety considerations, and the importance of personalised treatment approaches. The review highlights promising findings regarding the ability of PRP and BMAC to alleviate symptoms, improve joint function, and potentially slow disease progression. It emphasises the need for further research into long-term outcomes, direct comparative studies, protocol standardisation, biomarker identification, and cost-effectiveness assessments to enhance clinical practice. While the review does not directly compare PRP and BMAC, it provides valuable insights into their respective roles in knee osteoarthritis management. The review aims to contribute to evidence-based advancements in regenerative therapies for knee osteoarthritis by addressing critical research priorities and refining treatment strategies.

Molecular Biology of Meniscal Healing: A Narrative Review

This review provides insights at the molecular level into the current and old methods for treating meniscal injuries. Meniscal injuries have been found to have a substantial impact on the progression of osteoarthritis. In line with the "save the meniscus" approach, meniscectomy is considered a last-resort treatment. Nevertheless, it is important to note that mechanical repair alone may not achieve the complete restoration of the meniscus. A deep understanding of the healing pathways could lead to future improvements in meniscal healing. The inclusion of cytokines and chemokines has the potential to facilitate the process of tear repair or impede the inflammatory catabolic cascade. MicroRNA (miRNA) could serve as a potential biomarker for meniscal degeneration, and RNA injections might promote collagen and growth factor production. The critical aspect of the healing process is angiogenesis within the inner zone of the meniscus. The use of collagen scaffolds and the implantation of autologous meniscus fragments have been successfully integrated into clinical settings. These findings are encouraging and underscore the need for well-designed clinical trials to explore the most effective factors that can enhance the process of meniscal repair.

The combination treatment of methylprednisolone and growth factor-rich serum ameliorates the structural and functional changes after spinal cord injury in rat

STUDY DESIGN

Preclinical pharmacology.

OBJECTIVES

Our study aims to evaluate the combined effect of Methylprednisolone (MP) and growth factor-rich serum (GFRS) on structural and functional recovery in rats following spinal cord injury (SCI).

SETTING

Shiraz University of Medical Sciences, Shiraz, Iran METHODS: Male Sprague-Dawley rats were randomly assigned to five groups: sham group (laminectomy); SCI group (the spinal cord clip compression model); SCI-MP group (30 mg/kg MP was administrated intraperitoneally (IP) immediately after SCI); SCI-GFRS group (GFRS (200 µl, IP) was administrated for six consecutive days); and SCI-MP + GFRS group (the rats received MP (30 mg/kg, IP) immediately after SCI, and GFRS (200 µl, IP) for six consecutive days). Motor function was assessed weekly using the Basso, Beattie, and Bresnahan (BBB) scale. After 4 weeks, we conducted the rotarod test, then removed and prepared the spinal cords (including the epicenter of injury) for stereological and histological estimation, and biochemical assays.

RESULTS

The results showed that MP and GFRS combining treatment enhanced functional recovery, which was associated with a decrement in lesion volume, increased spared white and gray matter volume, reduced neuronal loss, as well as decreased necrosis and hemorrhage after SCI. Moreover, administration of MP and GFRS inhibited lipid peroxidation (malondialdehyde (MDA) content), and increased antioxidant enzymes including glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) after rat SCI.

CONCLUSIONS

We suggests that the combination treatment of MP and GFRS may ameliorate the structure and functional changes following SCI by reducing oxidative stress, and increasing the level of antioxidants enzymes.

Encapsulation of MSCs in PRP-Derived Fibrin Microbeads

Platelet-rich plasma (PRP) is a highly concentrated platelet-containing blood plasma that incorporates a significant amount of growth factors and cytokines needed to accelerate the tissue repair process. PRP has been used effectively for many years in the treatment of various wounds by direct injection into the target tissue or impregnation with scaffold or graft materials. Since autologous PRP can be obtained by simple centrifugation, it is an attractive and inexpensive product for use in repairing damaged soft tissues. Cell-based regenerative approaches, which draw attention in the treatment of tissue and organ injuries, are based on the principle of delivering stem cells to damaged sites by various means, including encapsulation. Current biopolymers used in cell encapsulation have some advantages with some limitations. By adjusting its physicochemical properties, PRP-derived fibrin can become an efficient matrix material for encapsulating stem cells. This chapter covers the fabrication protocol of PRP-derived fibrin microbeads and their use to encapsulate stem cells as a general bioengineering platform for prospective regenerative medical applications.

Optimal delivery of endothelial progenitor cells in a rat model of critical-size bone defects

Nonunion and segmental bone defects are complex issues in orthopedic trauma. The use of endothelial progenitor cells (EPCs), as part of a cell-based therapy for bone healing is a promising approach. In preclinical studies, culture medium (CM) is commonly used to deliver EPCs to the defect site, which has the potential for immunogenicity in humans. The goal of this study was to find an effective and clinically translatable delivery medium for EPCs. Accordingly, this study compared EPCs delivered in CM, phosphate-buffered saline (PBS), platelet-poor plasma (PPP), and platelet-rich plasma (PRP) in a rat model of femoral critical-size defects. Fischer 344 rats (n = 35) were divided into six groups: EPC+CM, EPC+PBS, EPC+PPP, EPC+PRP, PPP alone, and PRP alone. A 5 mm mid-diaphyseal defect was created in the right femur and stabilized with a miniplate. The defect was filled with a gelatin scaffold impregnated with the corresponding treatment. Radiographic, microcomputed tomography and biomechanical analyses were performed. Overall, regardless of the delivery medium, groups that received EPCs had higher radiographic scores and union rates, higher bone volume, and superior biomechanical properties compared to groups treated with PPP or PRP alone. There were no significant differences in any outcomes between EPC subgroups or between PPP and PRP alone. These results suggest that EPCs are effective in treating segmental defects in a rat model of critical-size defects regardless of the delivery medium used. Consequently, PBS could be the optimal medium for delivering EPCs, given its low cost, ease of preparation, accessibility, noninvasiveness, and nonimmunogenic properties.

Duo-role Platelet-rich Plasma: temperature-induced fibrin gel and growth factors' reservoir for microneedles to promote hair regrowth

INTRODUCTION

Alopecia concerns more than half our adult population. Platelet-rich plasma (PRP) has been applied in skin rejuvenation and hair loss treatment. However, the pain and bleeding during injection and the troublesome for fresh preparation of each action limit PRP's in-depth applying dedication to clinics.

OBJECTIVES

We report a temperature-sensitive PRP induced fibrin gel included in a detachable transdermal microneedle (MN) for hair growth.

RESULTS

PRP gel interpenetrated with the photocrosslinkable gelatin methacryloyl (GelMA) to realize sustained release of growth factors (GFs) and led to 14% growth in mechanical strength of a single microneedle whose strength reached 1.21 N which is sufficient to penetrate the stratum corneum. PRP-MNs' release of VEGF, PDGF, and TGF-β were characterized and quantitatively around the hair follicles (HFs) for 4-6 days consecutively. PRP-MNs promoted hair regrowth in mice models. From transcriptome sequencing, PRP-MNs induced hair regrowth through angiogenesis and proliferation. The mechanical and TGF-β sensitive gene Ankrd1 was significantly upregulated by PRP-MNs treatment.

CONCLUSION

PRP-MNs show convenient, minimally invasive, painless, inexpensive manufacture, storable and sustained effects in boosting hair regeneration.

Platelet-Rich Plasma in Dermatology: New Insights on the Cellular Mechanism of Skin Repair and Regeneration

The skin's recognised functions may undergo physiological alterations due to ageing, manifesting as varying degrees of facial wrinkles, diminished tautness, density, and volume. Additionally, these functions can be disrupted (patho)physiologically through various physical and chemical injuries, including surgical trauma, accidents, or chronic conditions like ulcers associated with diabetes mellitus, venous insufficiency, or obesity. Advancements in therapeutic interventions that boost the skin's innate regenerative abilities could significantly enhance patient care protocols. The application of Platelet-Rich Plasma (PRP) is widely recognized for its aesthetic and functional benefits to the skin. Yet, the endorsement of PRP's advantages often borders on the dogmatic, with its efficacy commonly ascribed solely to the activation of fibroblasts by the factors contained within platelet granules. PRP therapy is a cornerstone of regenerative medicine which involves the autologous delivery of conditioned plasma enriched by platelets. This is achieved by centrifugation, removing erythrocytes while retaining platelets and their granules. Despite its widespread use, the precise sequences of cellular activation, the specific cellular players, and the molecular machinery that drive PRP-facilitated healing are still enigmatic. There is still a paucity of definitive and robust studies elucidating these mechanisms. In recent years, telocytes (TCs)-a unique dermal cell population-have shown promising potential for tissue regeneration in various organs, including the dermis. TCs' participation in neo-angiogenesis, akin to that attributed to PRP, and their role in tissue remodelling and repair processes within the interstitia of several organs (including the dermis), offer intriguing insights. Their potential to contribute to, or possibly orchestrate, the skin regeneration process following PRP treatment has elicited considerable interest. Therefore, pursuing a comprehensive understanding of the cellular and molecular mechanisms at work, particularly those involving TCs, their temporal involvement in structural recovery following injury, and the interconnected biological events in skin wound healing and regeneration represents a compelling field of study.

The Synergistic Effects of Hyaluronic Acid and Platelet-Rich Plasma for Patellar Chondropathy

Musculoskeletal disorders are increasingly prevalent worldwide, causing significant socioeconomic burdens and diminished quality of life. Notably, patellar chondropathy (PC) is among the most widespread conditions affecting joint structures, resulting in profound pain and disability. Hyaluronic acid (HA) and platelet-rich plasma (PRP) have emerged as reliable, effective, and minimally invasive alternatives. Continuous research spanning from laboratory settings to clinical applications demonstrates the numerous advantages of both products. These encompass lubrication, anti-inflammation, and stimulation of cellular behaviors linked to proliferation, differentiation, migration, and the release of essential growth factors. Cumulatively, these benefits support the rejuvenation of bone and cartilaginous tissues, which are otherwise compromised due to the prevailing degenerative and inflammatory responses characteristic of tissue damage. While existing literature delves into the physical, mechanical, and biological facets of these products, as well as their commercial variants and distinct clinical uses, there is limited discussion on their interconnected roles. We explore basic science concepts, product variations, and clinical strategies. This comprehensive examination provides physicians with an alternative insight into the pathophysiology of PC as well as biological mechanisms stimulated by both HA and PRP that contribute to tissue restoration.

Platelet-Rich Plasma (PRP) in Dermatology: Cellular and Molecular Mechanisms of Action

Platelet-rich plasma (PRP) therapy has gained attention in the scientific field due to its potential regenerative effects and great benefit-risk ratio. This review extensively explores the most studied mechanisms of this therapy according to the etiopathogenesis of skin diseases: cellular proliferation, matrix formation, regulation of inflammation, angiogenesis, collagen synthesis, and the remodeling of new tissue. Moreover, it draws on newly reported and lesser-known effects of PRP: its anti-apoptotic effects, immunological suppression, decrease in melanin synthesis, anti-microbial effects, overexpression of miR-155, antioxidant effects, and their involved pathways. This work aims to provide a complete update for understanding PRP's benefits and clinical relevance in wound healing, alopecia, pigmentary disorders, scars, rejuvenation, lichen sclerosus, and other inflammatory dermatoses, based on the current evidence. Furthermore, recent reports with novel indications for PRP therapy are highlighted, and new potential pathways correlated with the pathogenesis of skin diseases are explored.

Thrombocytes and Platelet-Rich Plasma as Modulators of Reproduction and Fertility

Thrombocytes play an essential role in hemostasis and thrombosis. Moreover, the controlled activation of thrombocytes is required in reproduction and fertility. The platelet-activating factor and the controlled activation of platelets have important roles in folliculogenesis, ovulation, placental development, implantation and embryo development. Activated platelets accumulate in the follicular vessels surrounding the follicle and, due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters), locally increase oocyte maturation and hormone secretion. Furthermore, activated platelets are involved in the pathogenesis of ovarian hyperstimulation syndrome (OHSS) and preeclampsia. Low-dose aspirin can prevent OHSS during ovulation induction, while intrauterine or intraovarian administration of platelet-rich plasma (PRP) increases the endometrium thickness and receptivity as well as oocyte maturation. Activated thrombocytes rapidly release the contents of intracellular granules and have multiple adhesion molecules and receptors on their surface. Considering the numerous homeostatic endocrine functions of thrombocytes, it is reasonable to suppose a platelet-associated regulatory system (PARS) in reproduction. Although we are far from a complete understanding of the regulatory processes, the results of PARS research and the therapeutic application of aspirin and PRP during in vitro fertilization are promising.