Variability in Platelet-Rich Plasma Preparations Used in Regenerative Medicine: A Comparative Analysis

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.

Skin Telocytes Could Fundament the Cellular Mechanisms of Wound Healing in Platelet-Rich Plasma Administration

For more than 40 years, autologous platelet concentrates have been used in clinical medicine. Since the first formula used, namely platelet-rich plasma (PRP), other platelet concentrates have been experimented with, including platelet-rich fibrin and concentrated growth factor. Platelet concentrates have three standard characteristics: they act as scaffolds, they serve as a source of growth factors and cytokines, and they contain live cells. PRP has become extensively used in regenerative medicine for the successful treatment of a variety of clinical (non-)dermatological conditions like alopecies, acne scars, skin burns, skin ulcers, muscle, cartilage, and bone repair, and as an adjuvant in post-surgery wound healing, with obvious benefits in terms of functionality and aesthetic recovery of affected tissues/organs. These indications were well documented, and a large amount of evidence has already been published supporting the efficacy of this method. The primordial principle behind minimally invasive PRP treatments is the usage of the patient's own platelets. The benefits of the autologous transplantation of thrombocytes are significant, representing a fast and economic method that requires only basic equipment and training, and it is biocompatible, thus being a low risk for the patient (infection and immunological reactions can be virtually disregarded). Usually, the structural benefits of applying PRP are attributed to fibroblasts only, as they are considered the most numerous cell population within the interstitium. However, this apparent simplistic explanation is still eluding those different types of interstitial cells (distinct from fibroblasts) that are residing within stromal tissue, e.g., telocytes (TCs). Moreover, dermal TCs have an already documented potential in angiogenesis (extra-cutaneous, but also within skin), and their implication in skin recovery in a few dermatological conditions was attested and described ultrastructurally and immunophenotypically. Interestingly, PRP biochemically consists of a series of growth factors, cytokines, and other molecules, to which TCs have also proven to have a positive expression. Thus, it is attractive to hypothesize and to document any tissular collaboration between cutaneous administered PRP and local dermal TCs in skin recovery/repair/regeneration. Therefore, TCs could be perceived as the missing link necessary to provide a solid explanation of the good results achieved by administering PRP in skin-repairing processes.

Hyperdiluting Calcium Hydroxylapatite With Platelet-Rich Plasma and Hyaluronidase for Improving Neck Laxity and Wrinkle Severity

The two cases discussed in this report investigate the efficacy and safety of a novel injectable therapy for treating neck wrinkles and skin laxity, utilizing a combination of hyperdiluted calcium hydroxylapatite (CaHA), platelet-rich plasma (PRP), and hyaluronidase. Two patients presenting with moderate neck wrinkles and laxity underwent treatment and were evaluated several months later. The combined therapy demonstrated improvements in skin texture and laxity following a single treatment. The rationale behind incorporating PRP and hyaluronidase was their potential to amplify the regenerative effects of CaHA. PRP contains growth factors that stimulate collagen production and tissue regeneration while hyaluronidase facilitates the breakdown of hyaluronic acid, promoting better diffusion and more even product dispersion. The findings from these cases provide emerging preliminary evidence supporting the safety and efficacy of this innovative combination therapy for addressing neck wrinkles and laxity. This is the first documented instance of skin priming CaHA with hyaluronidase and PRP. Future investigations are warranted to explore the application of this treatment for other anatomical regions and to delineate the role of each injected component.

Does Platelet-Rich Plasma Deserve a Role in Accelerating the Recovery of Reflex Sympathetic Dystrophy Following Distal Radius Fracture?

Introduction

This study was to evaluate the efficacy of multiple platelet-rich plasma injections in reflex sympathetic dystrophy following distal radius fracture after previous various treatments have failed.

Materials and methods

This comparative prospective study was designed for 64 patients of reflex sympathetic dystrophy developed following distal radius fracture, from January 2009 to December 2020 were enrolled in this study. This cohort of patient was given either four multiple subcutaneous platelet-rich plasma injections at weekly interval (n = 32) or two injections in a month with 15 days interval (n = 32). The primary outcome measure assessed with patient rated wrist evaluation questionnaire score. The secondary outcome was a visual analogue scale pain score. The final follow up was at 2 years. p ≤ 0.05 is considered statistically.

Results

The patient rated wrist evaluation score for usual and specific activities and EQ-VAS for pain level showed statistically significant greater improvement in group A (42 ± 21%) compared to group B (19 ± 24%), (p = 0.37). Patients also had improvement in wrist movements with no statistically significant differences in both groups. The standard difference in means of all three functional scores was almost similar between both groups A and B (standard difference in means = 0.032; 95% CI 0.236-0.830; p = 0.495), considered clinically meaningful.

Conclusion

This study results suggest autologous platelet-rich plasma injections seem to be safe, cost effective, efficacious algorithm treatment for reflex sympathetic dystrophy following distal radius fracture patients where previous treatments have failed.

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.

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.

Inadequate anticoagulation and hyperuricemia cause knee pain after platelet-rich plasma injection: A retrospective study

OBJECTIVES

Platelet-rich plasma treatment delays the need for total knee replacement in patients with knee osteoarthritis. However, its use and preparation remain controversial. The aim of this study was to investigate the relationship between anticoagulant use in the preparation of platelet-rich plasma and post-treatment pain in patients with knee osteoarthritis. Additionally, we explored the efficacy of platelet-rich plasma over medium- and long-term follow-up periods and identified other factors that may affect treatment outcomes.

METHODS

In this retrospective study, 225 patients with knee osteoarthritis, who underwent knee platelet-rich plasma treatment from June 2021 to January 2022, were examined at three study centres. Patients were categorised, based on the type and amount of anticoagulant used during platelet-rich plasma preparation, into 4% sodium citrate (SC) 0.6 mL, 4% SC 1 mL, 4% SC 2 mL, heparin 0.1 mL, and heparin 0.2 mL groups. We analysed the patients' basic information, pain after treatment, and inflammatory markers (i.e., interleukin 6, tumour necrosis factor-α, and hypersensitive C-reactive protein) in the joint fluid via enzyme-linked immunosorbent assay and joint fluid crystallisation. Additionally, we assessed the patients' Western Ontario and McMaster University scores and minimal clinically significant differences after treatment.

RESULTS

Patients in the 4% SC 0.6 mL and heparin 0.1 mL groups experienced less pain after platelet-rich plasma treatment than did patients in the high-dose anticoagulant group. The joint fluid of patients with pain in these groups had lower levels of inflammatory markers. Patients treated with SC had slightly better medium- and long-term therapeutic outcomes than did patients treated with heparin. Patients with poorly controlled hyperuricemia also experienced pain after platelet-rich plasma treatment.

CONCLUSIONS

The results suggest that platelet-rich plasma prepared using high-dose anticoagulants or administered to patients with poorly controlled hyperuricaemia may lead to moderate-to-severe knee pain and joint effusion after joint puncture therapy. Platelet-rich plasma had a therapeutic effect on knee osteoarthritis; however, its efficacy gradually decreased over time. SC anticoagulant is more suitable for platelet-rich plasma preparation than is heparin. Further studies are needed to understand the safety and the various factors influencing platelet-rich plasma therapy.

Platelet-Rich Plasma (PRP) in the Treatment of Long COVID Olfactory Disorders: A Comprehensive Review

Background: Long COVID has brought numerous challenges to healthcare, with olfactory dysfunction (OD) being a particularly distressing outcome for many patients. The persistent loss of smell significantly diminishes the affected individual's quality of life. Recent attention has been drawn to the potential of platelet-rich plasma (PRP) therapy as a treatment for OD. This comprehensive review aims to evaluate the effectiveness of PRP therapy in ameliorating OD, especially when associated with long-term COVID-19. Methods: We executed a comprehensive search of the literature, encompassing clinical trials and observational studies that utilized PRP in treating OD limited to COVID-19. We retrieved and comprehensively discussed data such as design, participant demographics, and reported outcomes, focusing on the efficacy and safety of PRP therapy for OD in COVID-19 patients. Results: Our comprehensive analysis interestingly found promising perspectives for PRP in OD following COVID-19 infection. The collective data indicate that PRP therapy contributed to a significant improvement in olfactory function after COVID-19 infection. Conclusions: The evidence amassed suggests that PRP is a promising and safe therapeutic option for OD, including cases attributable to Long COVID-19. The observed uniform enhancement of olfactory function in patients receiving PRP highlights the necessity for well-designed, controlled trials. Such studies would help to refine treatment protocols and more definitively ascertain the efficacy of PRP in a broader, more varied patient cohort.

Aesthetic Rehabilitation Medicine: Enhancing Wellbeing beyond Functional Recovery

Although rehabilitation medicine emphasizes a holistic health approach, there is still a large gap of knowledge about potential interventions aimed at improving overall wellbeing through cosmetic interventions. Therefore, this narrative review investigates the role of different rehabilitative techniques in enhancing aesthetics, quality of life, and psychosocial wellbeing for patients with disabilities. The study follows the SANRA framework quality criteria for a narrative review. Literature searches across PubMed/Medline, Web of Science, and Scopus identified articles focusing on rehabilitation strategies within the aesthetic rehabilitation domain. The review identified evidence supporting injection procedures, such as Botulinum Toxin, Platelet-Rich Plasma, Hyaluronic Acid, Ozone, and Carboxytherapy, and assessing their applications in several disabling disorders. Additionally, physical therapies like Extracorporeal Shock Wave Therapy, Laser Therapy, Microcurrent Therapy, Tecar Therapy, and physical exercises were explored for their impact on cutaneous microcirculation, cellulite treatment, wound healing, and scar appearance improvement. Lastly, the manuscript underlines the role of manual therapy techniques in addressing both physical discomfort and aesthetic concerns, discussing their effectiveness in adipose tissue therapy, scar tissue mobilization, and regional fat thickness reduction. Taken together, this review emphasizes the role of a multidisciplinary approach, aiming to provide valuable insights into potential benefits for both functional and aesthetic outcomes.

Hypoxic Conditions Modulate Chondrogenesis through the Circadian Clock: The Role of Hypoxia-Inducible Factor-1α

Hypoxia-inducible factor-1 (HIF-1) is a heterodimer transcription factor composed of an alpha and a beta subunit. HIF-1α is a master regulator of cellular response to hypoxia by activating the transcription of genes that facilitate metabolic adaptation to hypoxia. Since chondrocytes in mature articular cartilage reside in a hypoxic environment, HIF-1α plays an important role in chondrogenesis and in the physiological lifecycle of articular cartilage. Accumulating evidence suggests interactions between the HIF pathways and the circadian clock. The circadian clock is an emerging regulator in both developing and mature chondrocytes. However, how circadian rhythm is established during the early steps of cartilage formation and through what signaling pathways it promotes the healthy chondrocyte phenotype is still not entirely known. This narrative review aims to deliver a concise analysis of the existing understanding of the dynamic interplay between HIF-1α and the molecular clock in chondrocytes, in states of both health and disease, while also incorporating creative interpretations. We explore diverse hypotheses regarding the intricate interactions among these pathways and propose relevant therapeutic strategies for cartilage disorders such as osteoarthritis.

A Comprehensive Review on Platelet-Rich Plasma Activation: A Key Player in Accelerating Skin Wound Healing

Platelet-rich plasma (PRP) activation is emerging as a promising and multifaceted tool for accelerating skin wound healing. This review extensively examines PRP's role in wound healing, focusing on its composition, mechanisms of action, activation methods, and clinical applications. PRP's potential to enhance both chronic and acute wound healing and its applications in cosmetic and aesthetic procedures are explored. Furthermore, this review investigates safety concerns, including adverse reactions, infection risks, and long-term safety implications. Looking to the future, emerging technologies, combination therapies, personalized medicine approaches, and regulatory developments are discussed, pointing towards an important and transformative era in wound healing and regenerative medicine. With its wide-ranging implications for healthcare, PRP activation has the potential to become a ubiquitous and essential therapeutic option, improving patient outcomes and reducing healthcare costs.

Human Platelet-Rich Plasma Regulates Canine Mesenchymal Stem Cell Migration through Aquaporins

Platelet products are commonly used in regenerative medicine due to their effects on the acceleration and promotion of wound healing, reduction of bleeding, synthesis of new connective tissue, and revascularization. Furthermore, a novel approach for the treatment of damaged tissues, following trauma or other pathological damages, is represented by the use of mesenchymal stem cells (MSCs). In dogs, both platelet-rich plasma (PRP) and MSCs have been suggested to be promising options for subacute skin wounds. However, the collection of canine PRP is not always feasible. In this study, we investigated the effect of human PRP (hPRP) on canine MSCs (cMSCs). We isolated cMSCs and observed that hPRP did not modify the expression levels of the primary class of major histocompatibility complex genes. However, hPRP was able to increase cMSC viability and migration by at least 1.5-fold. hPRP treatment enhanced both Aquaporin (AQP) 1 and AQP5 protein levels, and their inhibition by tetraethylammonium chloride led to a reduction of PRP-induced migration of cMSCs. In conclusion, we have provided evidence that hPRP supports cMSC survival and may promote cell migration, at least through AQP activation. Thus, hPRP may be useful in canine tissue regeneration and repair, placing as a promising tool for veterinary therapeutic approaches.

Process Optimization and Efficacy Assessment of Standardized PRP for Tendinopathies in Sports Medicine: Retrospective Study of Clinical Files and GMP Manufacturing Records in a Swiss University Hospital

Platelet-rich plasma (PRP) preparations have recently become widely available in sports medicine, facilitating their use in regenerative therapy for ligament and tendon affections. Quality-oriented regulatory constraints for PRP manufacturing and available clinical experiences have underlined the critical importance of process-based standardization, a pre-requisite for sound and homogeneous clinical efficacy evaluation. This retrospective study (2013–2020) considered the standardized GMP manufacturing and sports medicine-related clinical use of autologous PRP for tendinopathies at the Lausanne University Hospital (Lausanne, Switzerland). This study included 48 patients (18–86 years of age, with a mean age of 43.4 years, and various physical activity levels), and the related PRP manufacturing records indicated a platelet concentration factor most frequently in the range of 2.0–2.5. The clinical follow-up showed that 61% of the patients reported favorable efficacy outcomes (full return to activity, with pain disappearance) following a single ultrasound-guided autologous PRP injection, whereas 36% of the patients required two PRP injections. No significant relationship was found between platelet concentration factor values in PRP preparations and clinical efficacy endpoints of the intervention. The results were in line with published reports on tendinopathy management in sports medicine, wherein the efficacy of low-concentration orthobiologic interventions appears to be unrelated to sport activity levels or to patient age and gender. Overall, this study confirmed the effectiveness of standardized autologous PRP preparations for tendinopathies in sports medicine. The results were discussed in light of the critical importance of protocol standardization for both PRP manufacturing and clinical administration to reduce biological material variability (platelet concentrations) and to enhance the robustness of clinical interventions (comparability of efficacy/patient improvement).