Platelet-rich plasma: where are we now and where are we going?

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.

The Biological Effect of Platelet-Rich Plasma on Rotator Cuff Tears: A Prospective Randomized In Vivo Study

The positive effect of platelet-rich plasma (PRP) on tendon metabolism has been extensively investigated and proven in vitro. Additionally, in vivo animal studies have correlated the application of PRP with the enhancement of tenocyte anabolic activity in the setting of tendon degeneration. However, less is known about its in vivo effect on human tendon biology. The purpose of the current prospective randomized comparative study was to evaluate the effect of PRP on torn human supraspinatus tendon. Twenty consecutive eligible patients with painful and magnetic resonance imaging (MRI)-confirmed degenerative supraspinatus tendon tears were randomized in a one-to-one ratio into two groups. The patients in the experimental group (n = 10) underwent an ultrasound-guided autologous PRP injection in the subacromial space 6 weeks before the scheduled operation. In the control group (n = 10), no injection was made prior to surgery. Supraspinatus tendon specimens were harvested from the lateral end of the torn tendon during shoulder arthroscopy and were evaluated under optical and electron microscopy. In the control group, a mixed cell population of oval and rounded tenocytes within disorganized collagen and sites of accumulated inflammatory cells was detected. In contrast, the experimental group yielded abundant oval-shaped cells with multiple cytoplasmic processes within mainly parallel collagen fibers and less marked inflammation, simulating the intact tendon structure. These findings indicate that PRP can induce microscopic changes in the ruptured tendon by stimulating the healing process and can facilitate a more effective recovery.

Platelet lysate for the treatment of osteoarthritis: a systematic review of preclinical and clinical studies

Intra-articular injection-based therapy is often used aside conservative treatment and lifestyle modifications to manage knee osteoarthritis (KO) patients. Conventional injections contain steroids and hyaluronic acid, while more recently multipotential adult stem cell, platelet-rich plasma (PRP), and platelet lysate (PL) injections have been used to promote cartilage regeneration or repair. The aim of the current study is to analyse current evidence on PL injections for the treatment of KO and to determine if these are effective and how these perform compared to other injection regimens. The databases of Scopus, Embase, PubMed, Web of Science, and Cochrane Library were searched on 30 June 2023. Risk of bias was assessed using the SYRCLE tool for animal studies and Cochrane RoB 2 as well as ROBINS-I tool for human studies. Studies were included if these were in English, any year, and regarded animals with osteoarthritis (OA) or human adult patients with OA. In vitro trials and non-adult human studies were excluded. Results on OA symptom stage and severity, and pain were recorded. The research retrieved three human studies (n = 48, n = 25, n = 58) and four animal studies: one rabbit, two studies, and one rat study. PL was found to decrease KO symptoms at follow-up ≤ 1 year with respect to baseline levels and when compared to hyaluronic acid or platelet-rich plasma. Symptoms returned 6 months-1 year after the final administration, with studies showing peak efficacy at approximately 6 months. Animal studies showed clinical improvements, reduction of lameness, and partial effect on the cartilage regeneration of the seven studies, two had a high risk of bias, four were associated to some concerns, and one had low risk. A major source of bias in these studies was the use of questionnaires and scoring that could be subject to interpretation. Overall, PL was well-tolerated and showed efficacy comparable to PRP; when pain control was assessed, it showed similar efficacy compared to hyaluronic acid. These findings may support its use in clinical trials to confirm these initial findings; future research should also focus on the comparison with other non-surgical treatments, on a more detail of the potential regenerative properties, and to optimise the treatment schedule.

Not all platelet-rich plasma are created equal

PURPOSE OF REVIEW

This review aims to elucidate potential variations in clinical outcomes resulting from the use of different types of platelet-rich plasma (PRPs) in reproductive medicine. It seeks to explore the reasons behind the diverse results reported in various studies and assess the general features distinguishing different PRP formulations.

RECENT FINDINGS

PRPs have found applications across diverse medical fields, generating controversy due to the variability in outcomes. The field of reproductive medicine, despite its limited published studies, is encountering a similar challenge as it integrates these treatments.

SUMMARY

The multitude of PRP product brands in the market, coupled with 'home-made' PRPs, poses a significant barrier to establishing a common protocol for the preparation of standardized PRP products. This impediment hinders widespread adoption by clinicians, particularly in endometrial or ovarian treatments. Drawing from evidence in other medical disciplines, this review endeavors to compile essential characteristics that PRPs must possess, aiming to mitigate the impact of variables affecting results in forthcoming studies.

Platelet-Rich Plasma: Advances and Controversies in Hair Restoration and Skin Rejuvenation

BACKGROUND

Platelet-rich plasma (PRP) and its combined therapeutic modalities have catalyzed new possibilities in dermatology; however, limitations in evidence and lack of consensus remain among clinicians regarding optimal composition, protocol, technique, and application.

OBJECTIVE

To provide an update and analysis of the evidence for PRP in hair restoration and skin rejuvenation through review of recent available data, highlighting controversies and expert insights to guide future studies, and stimulate discourse and innovations benefitting patients.

METHODS

A structured review and expert analysis of PubMed publications before October 2023, with a focus on recent literature from January 2020 through October 2023.

RESULTS AND CONCLUSION

Growing literature supports the utility and benefits of PRP and related autologous products for applications for skin and hair, with strongest evidence for androgenetic alopecia and skin rejuvenation. However, this is limited by lack of consensus regarding best practices and protocols. Randomized, controlled trials with uniform metrics comparing outcomes of various compositions of autologous blood products, preparation methods, dosimetry, and frequency of treatments are still required. This will allow the medical discourse to grow beyond the realm of expert opinion into consensus, standardization, and more wide spread adoption of best practices that will benefit patients.

Platelet-derived extracellular vesicles: a new-generation nanostructured tool for chronic wound healing

Chronic nonhealing wounds pose a serious challenge to regaining skin function and integrity. Platelet-derived extracellular vesicles (PEVs) are nanostructured particles with the potential to promote wound healing since they can enhance neovascularization and cell migration and reduce inflammation and scarring. This work provides an innovative overview of the technical laboratory issues in PEV production, PEVs' role in chronic wound healing and the benefits and challenges in its clinical translation. The article also explores the challenges of proper sourcing, extraction techniques and storage conditions, and discusses the necessity of further evaluations and combinational therapeutics, including dressing biomaterials, M2-derived exosomes, mesenchymal stem cells-derived extracellular vesicles and microneedle technology, to boost their therapeutic efficacy as advanced strategies for wound healing.

Platelet-Rich Plasma in the Management of Temporomandibular Joint Pain in Young Adults With Temporomandibular Disorder

BACKGROUND

Temporomandibular disorder (TMD) encompasses a range of conditions affecting the temporomandibular joint (TMJ) and associated structures, with TMJ pain being a prevalent symptom. Conventional management strategies have limitations, which require the exploration of innovative interventions. Platelet-rich plasma (PRP), known for its regenerative properties, presents a potential therapeutic avenue. This study aims to investigate the effectiveness of PRP in reducing the pain associated with mild TMJ in young adults.

METHODOLOGY

Participants (n = 128) aged 18 to 35 years with mild TMD were evenly randomized into PRP treatment and placebo control groups. PRP was prepared using a standardized protocol, and intra-articular injections were administered. Placebo injections mimic PRP. Follow-up evaluations were carried out at four and eight weeks after the intervention.

RESULTS

The study successfully randomized comparable groups, and the PRP treatment group experienced a significant reduction in TMJ pain (visual analog scale [VAS] score: 6.8 ± 1.2 to 2.1 ± 1.0 at eight weeks, P < 0.001). The PRP treatment also increased the largest opening of the mouth (from 38.2 ± 2.5 to 43.5 ± 3.1, P < 0.001) and the number of lateral movements (12.3 ± 1.5 to 14.9 ± 2.0, P < 0.001), while the placebo group had very few changes. Positive patient-reported outcomes on daily activities were observed, with no serious complications reported in either group.

CONCLUSIONS

This study provides evidence supporting the efficacy of PRP in reducing TMJ pain, improving jaw function, and improving quality of life in young adults with mild TMD. The results underscore the potential of PRP as a minimally invasive intervention for TMJ disorders.

a comparison of intra-articular hyaluronic acid and platelet-rich plasma for knee osteoarthritis: a systematic review

Introduction

Knee osteoarthritis (KOA), the most common chronic degenerative condition in an older population, accounts for many disabilities around the world. One of the most popular treatments is intra-articular injection of hyaluronic acid (HA) and platelet-rich plasma (PRP).

Objective

Prior studies have found that both HA and PRP had a therapeutic effect on KOA. This study aims to perform a systematic review regarding whether PRP is superior to HA for KOA.

Method

We conducted a comprehensive literature search using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines for prospective randomized control trials (pRCTs) in three international databases PubMed, Google Scholar, and ScienceDirect from 2019-2022. Two researchers independently searched the reviews, extracted, and cross-checked the data. The disparity when choosing the literature was resolved by discussion. The modified Jadad was scale used to assess the quality of the included studies. Cochrane risk of bias 2 tool (RoB-2) was used for determininzg risk of bias.

Results

Twenty three studies were eligible for inclusion. Four pRCT with the highest Jadad score were selected as best evidence. Risk of bias assesment concluded two studies having a low risk of bias, one is high risk of bias, and the other possesses some concerns.. Three studies found no difference in patient-reported outcomes between PRP and HA group and one study concluded that PRP is more effective than HA in treating KOA.

Conclusion

Intra-articular injections of PRP and HA are effective interventions for KOA. However, there is not enough evidence of PRP superiority over HA.

SYSTEMIC INFLAMMATORY INDICES IN PATIENTS WITH MALIGNANT GLIOMAS AND EFFECTS OF PLATELET SECRETOME IN VITRO

BACKGROUND

To date, no significant clinical progress has been achieved in the treatment of brain malignant gliomas (MG), and the active search for non-invasive circulating biomarkers continues. The prognostic significance of the ratio of the main peripheral blood cell populations of patients with MG is evaluated. Considerable attention is paid to the secretome of platelets (Pt) of peripheral blood.

AIM

To evaluate the indicators of the peripheral blood cell population ratios in patients with brain MG and to study the influence of the secretome of Pt (SPt) of the peripheral blood of patients with brain MG in cell cultures in vitro.

MATERIALS AND METHODS

We studied samples of peripheral blood from patients with glioma CNS WHO grade G2 (n = 5), G3 (n = 12), and G4 (n = 20). The peripheral blood cell counts were analyzed in the preoperative period on an automatic hematology analyzer. The in vitro study of SPt was performed on the U251 human glioblastoma cell line cultured with SPt from MG patients or SPt pre-incubated with anti-TGF-β1 antibody. Cell cultures were observed for 72 h, and mitotic index (MI) was calculated.

RESULTS

In MG patients, the count of peripheral blood leukocytes and neutrophils increased (p < 0.05). The neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII) increased by 2-3 times compared to control. Nevertheless, correlation analysis did not reveal significant relationships between quantitative indicators of peripheral blood cells and the tumor malignancy degree in MG patients. The MI in U251 cells increased under the influence of SPt from patients with MG (p < 0.021), correlated with the tumor degree of malignancy (r = 0.246, p = 0.014). Pre-incubation of SPt with anti-TGF-β1 antibody tends to neutralize this promitotic effect.

CONCLUSION

In MG patients, the integral indicators of NLR and SII increased but no significant relationship with the degree of tumor malignancy was found. In U251 cells, promitotic effects of SPt of MG patients partially decreased by anti-TGF-β1 antibody.

Advances with Platelet-Rich Plasma for Bone Healing

Despite significant advances in the understanding and delivery of osteosynthesis, fracture non-union remains a challenging clinical problem in orthopaedic surgery. To bridge the gap, basic science characterization of fracture healing provides a platform to identify and target biological strategies to enhance fracture healing. Of immense interest, Platelet-rich plasma (PRP) is a point of care orthobiologic that has been extensively studied in bone and soft tissue healing given its relative ease of translation from the benchtop to the clinic. The aim of this narrative review is to describe and relate pre-clinical in-vitro and in-vivo findings to clinical observations investigating the efficacy of PRP to enhance bone healing for primary fracture management and non-union treatment. A particular emphasis is placed on the heterogeneity of PRP preparation techniques, composition, activation strategies, and delivery. In the context of existing data, the routine use of PRP to enhance primary fracture healing and non-union management cannot be supported. However, it is acknowledged that extensive heterogeneity of PRP treatments in clinical studies adds obscurity; ultimately, refinement (and consensus) of PRP treatments for specific clinical indications, including repetition studies are warranted.

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.

A Comprehensive Review of Treatment Strategies for Early Avascular Necrosis

Avascular necrosis (AVN), characterised by compromised blood supply leading to bone necrosis, poses a significant challenge in orthopaedic and rheumatologic practice. This review comprehensively examines early AVN treatment strategies, including aetiology and risk factors, clinical presentation, conservative and surgical approaches, emerging therapies, and rehabilitation. Key findings underscore the importance of early detection, personalised treatment plans, and a multidisciplinary approach involving orthopaedic specialists, rheumatologists, and physical therapists. The implications for clinical practice emphasise individualised care, staying abreast of emerging therapies, and patient education. Recommendations for future management strategies highlight the need for imaging technology advancements, regenerative therapies integration, and ongoing research into genetic and molecular pathways. As the field continues to evolve, translating research findings into clinical practice holds promise for improving outcomes and enhancing the overall quality of life for individuals affected by AVN.

Effect of local administration of injectable platelet-rich fibrin on root resorption during orthodontic tooth movement in dogs

Background

This study aimed to assess the effect of local administration of injectable platelet-rich fibrin (i-PRF) on root resorption during orthodontic tooth movement in dogs.

Materials and Methods

This animal study was conducted on 4 adult male mongrel dogs. The right and left maxillary first premolars of the dogs were extracted, and a Nickel-Titanium closed coil spring was used to connect the canine to the second premolar with 150 g load. Next, 0.5 cc of i-PRF was injected in one quadrant of the maxilla around the second premolar into the periodontal ligament. The other quadrant of the maxilla served as the control group and received saline injection. Injections were performed at 1, 21, and 42 days, and the dogs were sacrificed after 63 days. Histological sections were prepared and cementum resorption, secondary cementum formation, and number of cementoblasts and cementoclasts were compared between the two groups by the Friedman test, Wilcoxon test, and Mann-Whitney test (α = 0.05).

Results

The mean percentage of cementum resorption (17.75% ± 5.56%) and secondary cementum formation (14.50% ± 6.65%), and the mean number of cementoblasts (10.25 ± 2.36) and cementoclasts (9.75 ± 4.71) were insignificantly higher in the i-PRF group than the corresponding values (13.75% ± 4.34%, 8.50% ± 2.88%, 7.75 ± 1.25, and 6.50 ± 3.10, respectively) in the control group (P > 0.05).

Conclusion

Administration of i-PRF insignificantly increased the percentage of cementum resorption, secondary cementum formation, number of cementoblasts, and number of cementoclasts.

[Management of muscle trauma in popular sports]

Muscle injuries make up the majority of injuries in popular sports. The causes for the development are multifactorial and can be divided into functional disorders and a lack of knowledge regarding training control. Insufficient warm-up and overtraining both increase the danger of the occurrence of the injury. Knowledge of the different types of muscle injuries and their incorporation into an exact classification enable the establishment of a correct treatment plan and can have a positive influence on the healing process. In addition to acute treatment the knowledge and application of preventive programs are necessary as these can significantly reduce the prevalence of muscle injuries in sports.

A Preliminary Report on the Combined Effect of Intra-Articular Platelet-Rich Plasma Injections and Photobiomodulation in Canine Osteoarthritis

Osteoarthritis (OA) is highly prevalent in the canine population. Due to the multiple dimensions of the disease, a multimodal approach is usually favored by clinicians. To evaluate the combined treatment with intra-articular platelet-rich plasma (PRP) and photobiomodulation in dogs with bilateral hip OA, thirty dogs were assigned to a PRP group (PRPG, n = 10), a photobiomodulation group (PBMTG, n = 10), or a combined therapies group (PRP+PBMTG, n = 10). The PRPG received two intra-articular administrations of platelet-rich plasma 14 days apart. The PBMTG received photobiomodulation with a therapeutic laser, with three sessions every other day in week one; two sessions in week two; a single session in week three; and one session/month on follow-up evaluation days. The PRP+PBMTG received the two combined therapies. The response to treatment was evaluated with weight-bearing distribution and the Canine Brief Pain Inventory, the Liverpool Osteoarthritis in Dogs, and the Canine Orthopedic Index. Evaluations were conducted before treatment and +8, +15, +30, +60, and +90 days after initial treatment. Normality was assessed with a Shapiro-Wilk test, and the groups' results in each evaluation moment were compared using a Mann-Whitney U test. Animals of both sexes (male n = 19, female n = 11) were included in the sample, with a mean age of 7.8 ± 2.5 years and a body weight of 26.5 ± 4.7 kg. Joints were classified as mild (n = 6, three in PRPG, two in PBMTG, and one in PRP+PBMTG), moderate (n = 18, six in PRPG, five in PBMTG, and seven in PRP+PBMTG), and severe (n = 6, one in PRPG, three in PBMTG, and two in PRP+PBMTG). No differences were found between groups at the initial evaluation. All treatments produced clinically significant improvements compared to the assessment on treatment day. The combination of PRP and photobiomodulation produced greater, longer-lasting improvements. PRP and photobiomodulation can improve objective outcomes and client-reported outcome measures in dogs with OA. Their combined use leads to greater, longer-lasting, clinically significant improvements.

The Effect of Xenograft and Platelet-Rich Plasma in the Surgical Management of Intrabony Defects in Periodontitis Patients: A Systematic Review

When treating intrabony defects to regenerate periodontal structure, platelet-rich plasma (PRP) alone or in conjunction with various grafting materials, enamel matrix proteins, and barrier membranes have shown promising results. This evidence-based review aimed to systematically appraise the efficacy of xenograft in combination with PRP in the surgical treatment of periodontal intrabony defects in comparison to xenograft alone in terms of clinical and radiographic outcomes in adults with periodontitis. Electronic and manual data were searched exhaustively by 2 reviewers, including PubMed-Medline, Cochrane Central Register of Controlled Trials, Embase and Scopus from the earliest available date till January 31, 2023 without restriction on language. Randomized controlled clinical trials of either parallel or a split-mouth design and studies where xenograft and PRP were in the intervention group or as a comparator was included. After screening the articles, 3 studies were included. The current systematic review reveals that PRP used as an adjunct with a xenograft resulted in a significant reduction in pocket depth and greater clinical attachment level gain in comparison to xenograft alone. The analysis of the present review concludes that PRP in conjunction with xenograft for the treatment of intrabony defects shows promising outcomes. However, owing to the short follow-up time and heterogeneity of included studies, caution should be followed while using this material clinically.

Public Interest in Shoulder Platelet-Rich Plasma Injections Is Increasing: A 10-Year Google Trends Analysis

Purpose

To quantify and analyze public interest trends in platelet-rich plasma (PRP) therapy for shoulder pathology between 2011 and 2020 using Google Trends data.

Methods

Google Trends data were queried for online search data ranging from January 2011 to December 2020. Various combinations of terms related to PRP and shoulder pathology were queried. Terms related to corticosteroid therapy in association with shoulder pathology were also generated for comparative analysis. Analyses were performed regarding trends in online search volumes.

Results

Linear models were generated to evaluated trends in the volume of online searches for PRP and corticosteroid therapy for shoulder pathology. For both the PRP and steroid groups, linear models showed a statistically significant increase in search volume for the period studied (P < .001). The PRP group showed a significantly greater growth rate than the steroid group (P < .001). There were no statistically significant differences in online search volume when compared between different geographic and socioeconomic locations.

Conclusions

This study indicates consistently increasing public interest in PRP injections in the shoulder. The rate of online search volume growth of PRP is significantly greater than that of corticosteroid injections for the period studied.

Clinical Relevance

Awareness of patient perceptions has value in informing shared decision making, aligning patient expectations, and guiding areas of future research. Each of these has an impact on patient care. Being aware of patient interest and expectations is particularly important in areas with controversial or emerging research.

Relationship Between the Underlying Factors and the Treatment Results of Platelet-Rich Plasm (PRP) Injection in Degenerative Knee Disease; A Blinded Randomized Study

Background: To investigate the therapeutic effects of PRP injection + conservative treatment as the intervention group versus normal saline injection + conservative treatment as the control group. Objectives: This study we determined the effects of underlying factors, including age, gender, and Body Mass Index (BMI), on the therapeutic effects of PRP. Methods: In this single-blinded randomized clinical trial, 60 patients with grade 2 knee OA with an age of 40 - 65 years were enrolled. In the intervention group, leukocyte-poor PRP with double spinning, and in the control group, normal saline was injected with a similar protocol. All patients in both groups were also provided with a conservative protocol, including oral celecoxib 100 mg BID for four weeks, modifying physical activity, and 15 sessions of physiotherapy. Results: Demographic characteristics (age, gender, and BMI) and pre-treatment scores were similar between the two groups (all P > 0.05). The WOMAC score was improved from pre-treatment to first week post-treatment in both groups (from 54.89 ± 3.4 to 64.9 ± 3.7 in the intervention group and from 53.7 ± 3.1 to 63.8 ± 3.9 in the control group). It means that PRP + conservative treatment was effective, similar to normal saline + conservative treatment. After adjusting BMI as an underlying variable, it was indicated that in the patients with lower BMI, PRP + conservative provided a better outcome in comparison to saline + conservative treatment (P = 0.014 and P = 0.019, respectively). Also, the comparison of functional scores changes with age as an underlying variable, demonstrating that younger cases obtained a better response from PRP + conservative rather than normal saline + conservative (P = 0.012 and P = 0.007, respectively). Conclusions: PRP seems to be an appropriate choice for treatment of moderate osteoarthritis, especially in younger patients and those with lower BMI.

Submucosal Injection of Activated Platelet-Rich Plasma for Treatment of Periodontal Disease in Dogs

Periodontal disease is the most common oral disease seen in dogs, and its routine treatment usually involves dental scaling. Platelet-rich plasma (PRP) therapy may enhance the effectiveness of treatment of periodontal disease, delay the progression of the disease and decrease the time under anesthesia. However, its application in dogs is rarely discussed. The objective of this study was to evaluate the benefits of activated PRP for treatment of periodontal disease in dogs. 43 mL of whole blood was collected from six adult dogs and PRP extracted using the double centrifugation tube method. Subsequently, the PRP was activated using calcium chloride (A-PRP). Significantly elevated concentrations of PDGF-BB (7000.28 pg/mL), TGF-β (378.98 pg/mL), and VEGF (7.14 pg/mL) were detected in the A-PRP. Additionally, three of the dogs with stage 2-3 periodontal disease were enrolled in the clinical trial. Periodontal pocket depth, stage of periodontal disease, gingival index, horizontal bone loss, and alveolar bone density involving the maxillary third and fourth premolar and first molar teeth (107, 108, 109, 207, 208, and 209) were evaluated. Teeth were treated by dental scaling alone (control group) or by dental scaling followed by submucosal injection of 0.1 mL A-PRP per site. After 56 days, significant improvement in periodontal pocket depth, stage of periodontal disease, gingival index, and horizontal bone loss was observed in dogs injected with A-PRP. The high concentrations of growth factors in A-PRP likely contributed to this effect. The use of submucosal injections of A-PRP to treat canine stage 2-3 periodontal disease appears safe and effective for clinical practice.

Current Status of PRP Manufacturing Requirements & European Regulatory Frameworks: Practical Tools for the Appropriate Implementation of PRP Therapies in Musculoskeletal Regenerative Medicine

Providing accurate and up-to-date practical tools enabling oversight of platelet-rich plasma (PRP) legislation and of the appropriate standards to be implemented for its manufacture and use in Europe is a demanding task. This is due to rapid medico-technological advancements, slowness and disparity in legislation updates and enforcement between member states, and many reported gray-zone practices, notably for autologous PRP use. The levels of risk associated with blood manipulation processes generally dictate the manufacturing requirements for PRP preparations, which have gradually shifted toward good manufacturing practices (GMP) for standardization and overall quality enhancement. This work firstly outlines Western European and Swiss legislation for PRP products/preparations, providing key simplified information and recommendations for medical doctors seeking to implement this biological-based therapy for safe use in hospital settings, clinics, or private offices. This work secondly shows the importance of PRP-based product manufacturing standardization, which subsequently enables sound clinical evaluation of therapeutic interventions. Although the applicable legal bases provide guidelines for GMP manufacturing infrastructure and basic process design, paramount importance is set on the definition of workflows, technical specifications, and key parameters for PRP preparation and delivery. Overall, the development of simple and robust technologies and processes for PRP preparation is critical for guaranteeing the high therapeutic quality of the intervention, in collaboration with qualified GMP manufacturing platforms. Importantly, this work aims to serve as a practical tool for clinicians based in Western Europe who are willing to appropriately (i.e., administratively and technically) implement autologous PRP treatments in musculoskeletal regenerative medicine workflows, to ensure they make informed and optimal regulatory or process-based decisions.

Enhanced Bioactive Potential of Functionalized Injectable Platelet-Rich Plasma

Injectable platelet-rich fibrin (iPRF) is a frequently used platelet concentrate used for various medical purposes both in veterinary and human medicine due to the regenerative potential of hard and soft tissues, and also because of its antimicrobial effectiveness. This in vitro study was carried out to assess the cumulative antimicrobial and antibiofilm effect of iPRF functionalized with a multifunctional glycoprotein, human lactoferrin (Lf). Thus, the ability to potentiate cell proliferation was tested on keratinocytes and evaluated by the CCK8 test. The combinations of iPRF and Lf induced an increase in the proliferation rate after 24 h. The average cell viability of treated cultures (all nine variants) was 102.87% ± 1.00, and the growth tendency was maintained even at 48 h. The highest proliferation rate was observed in cultures treated with 7% iPRF in combination with 50 µg/mL of Lf, with an average viability of 102.40% ± 0.80. The antibacterial and antibiofilm activity of iPRF, of human lactoferrin and their combination were tested by agar-well diffusion (Kirby-Bauer assay), broth microdilution, and crystal violet assay against five reference bacterial strains. iPRF showed antimicrobial and antibiofilm potential, but with variations depending on the tested bacterial strain. The global analysis of the results indicates an increased antimicrobial potential at the highest concentration of Lf mixed with iPRF. The study findings confirmed the hypothesized enhanced bioactive properties of functionalized iPRF against both Gram-positive and Gram-negative biofilm-producing bacteria. These findings could be further applied, but additional studies are needed to evaluate the mechanisms that are involved in these specific bioactive properties.

An Updated Review on Current Treatment of Alopecia Areata and Newer Therapeutic Options

Alopecia areata (AA) is a dermatological disease that causes nonscarring hair loss. It can occur at any age and has an unpredictable and variable evolution in individuals. The aim of this review is to provide an update on the novel therapies currently being used, as well as upcoming therapeutic options in the treatment of AA.

Efficacy of autologous platelet-rich plasma on graft uptake in myringoplasty: a single-blinded randomized control trial

Background and aim

Chronic otitis media is defined as a chronic inflammation of the middle ear cleft producing irreversible pathological changes. The myringoplasty aims at the reconstruction of the tympanic membrane using a graft material. Autologous platelet-rich plasma can be used along with the graft to have a successful outcome. The aim of the study was to assess the efficacy of autologous platelet-rich plasma on graft uptake in myringoplasty.

Methods

This was a randomized controlled trial with a sample size of 76 patients. All patients were above 18 and below 55 years of age diagnosed with chronic suppurative otitis media and were planned for myringoplasty. The participants were randomly allotted to two groups by block randomization (block of 4). Intra-operatively, group I (n=38) received platelet-rich plasma–soaked gel foam and group II (n=38) was taken as the control group who received saline-soaked gel foam and examined by a blinded examiner at the end of 1st and 3rd months.

Results

The mean air-bone gap reduction post-operatively in the platelet-rich plasma group was 8.68 ± 4.8 (P value 0.034) and 6.05 ± 4.05 in the control group. The improvement in pure-tone average in the platelet-rich plasma group (P = 0.009) is more than that in the control group. The graft uptake was higher among the platelet-rich plasma group than the control group both at 1st and 3rd months (P value 0.049) which were statistically significant.

Conclusion

The present study concludes that the usage of platelet-rich plasma in the conventional myringoplasty technique has improved the success rate of graft uptake and reduced the graft migration.

Trial registration

Clinical Trials Registry-India (ICMR-NIMS) CTRI/2020/04/024416. Date of registration: 01/04/2020. Date of enrolment of the first participant to the trial: 06/04/2020. URL of the trial registry: http://www.ctri.nic.in.

Highlights

Usage of autologous platelet-rich plasma (PRP) in conventional myringoplasty in underlay technique.

Assessment of graft uptake, percentage of perforation closure, and the audiological outcome.

Significant mean reduction of ABG in the PRP group.

Significant improvement in PTA average in the PRP group.

Graft uptake and percentage of perforation closure were higher in the PRP group and the control group.

PRP is also beneficial in revision cases.

Medium-Term Effect of Treatment with Intra-Articular Injection of Sodium Hyaluronate, Betamethasone and Platelet-Rich Plasma in Patients with Temporomandibular Arthralgia: A Retrospective Cohort Study

Temporomandibular joint disorders are associated with pain and reduced jaw mobility. The aim of this study was to compare the long-term effect on pain of intra-articular TMJ injections of betamethasone, sodium hyaluronate and platelet-rich plasma. The sample was made up of 114 patients, who were randomly distributed into three groups at least three years ago and who achieved a total remission of pain after treatment. We found that the median number of months without pain was, according to each group, as follows: platelet-rich plasma: 33; sodium hyaluronate: 28; betamethasone: 19. Both platelet-rich plasma and sodium hyaluronate lead to significant pain-free time after treatment; when we compare bethametasone with the two other substances, it proved to be very ineffective.

Platelet-derived exosomes induce cell proliferation and wound healing in human endometrial cells

Aim: To investigate the regenerative effects of a platelet-derived purified exosome product (PEP) on human endometrial cells. Materials & methods: Endometrial adenocarcinoma cells (HEC-1A), endometrial stromal cells (T HESC) and menstrual blood-derived stem cells (MenSC) were assessed for exosome absorption and subsequent changes in cell proliferation and wound healing properties over 48 h. Results: Cell proliferation increased in PEP treated T HESC (p < 0.0001) and MenSC (p < 0.001) after 6 h and in HEC-1A (p < 0.01) after 12 h. PEP improved wound healing after 6 h in HEC-1A (p < 0.01) and MenSC (p < 0.0001) and in T HESC between 24 and 36 h (p < 0.05). Conclusion: PEP was absorbed by three different endometrial cell types. PEP treatment increased cell proliferation and wound healing capacity.

Ultrasound-guided platelet-rich-plasma injections for reducing sacroiliac joint pain: A paradigmatic case report and literature review

BACKGROUND

Sacro-iliac joint (SIJ) pain is an often-misdiagnosed cause (up to 30% cases) of atypical low back pain (LBP) that might be treated with a wide range of conservative interventions. However, Platelet-Rich-Plasma (PRP) ultrasound-guided injections at SIJ level in subjects with mitochondrial disorders have not yet been investigated.

CASE PRESENTATION

A 52-year-old Caucasian male with fluoroquinolone-related mitochondrial dysfunction referred to a Physical Medicine and Rehabilitation Outpatient, complaining of severe SIJ pain (Numeric Pain Related Scale, NPRS=8). We performed two bilateral PRP ultrasound-guided injections at the sacro-iliac level. PRP is a simple, efficient, and minimally invasive approach. After the first PRP injection, there was a considerable reduction of pain (NPRS=8 vs 5). The second PRP infiltration was performed after 2 weeks and in both cases no adverse events. At the 6-month follow-up evaluation, the patient showed good physical recovery, with the absence of pain (NPRS=0).

CONCLUSION

To the best of our knowledge, this is the first report in the literature assessing the safety and effectiveness of PRP ultrasound-guided injections for SIJ pain in a patient affected by mitochondrial disorders. Thus, this case report might have relevant clinical implications in the treatment of SIJ pain in patients affected by this rare pathological condition, albeit further observational studies are warranted to confirm these findings.

Autologous Platelet‐Rich Plasma Drops for Evaporative Dry Eye Disease from Meibomian Gland Dysfunction: A Pilot Study

Purpose

To evaluate the effects of autologous platelet‐rich plasma (PRP) drops for evaporative dry eye (EDE) disease from meibomian gland dysfunction (MGD).

Methods

This is a retrospective, consecutive case series of 20 eyes of 10 patients with EDE from MGD treated with PRP drops from November 2020 to November 2021 at a single outpatient clinic in Ontario, Canada. PRP drops were prepared from whole blood using a two-step centrifugation method. Patients were instructed to instill these drops six times daily for 4 weeks. The Canadian Dry Eye Assessment (CDEA) questionnaire score, patient subjective assessment (PSA) score, first and average non-invasive break-up times (f/a NIBUT), tear meniscus height (TMH), bulbar redness (BR), and meibograph grade (MG) were measured before and after the treatment course.

Results

Significant improvements in dry eye symptoms and tear film parameters were observed. Dry eye symptoms significantly improved as per the CDEA (mean difference (MD) = −5.45, 95% confidence interval (CI) = [−7.9, −3.1], p<0.001) and PSA (MD = −2.6, 95% CI = [−3.9, −1.2], p<0.001). There were significant improvements in tear film parameters including fNIBUT (MD = 3.85s, 95% CI = [1.2, 6.8], p=0.006), aNIBUT (MD = −6.81s, 95% CI = [5.7, 11.1], p<0.001) and TMH (MD = 0.08, 95% CI = [0.003, 0.2], p=0.045). There was an improvement in conjunctival injection as measured by BR (MD = −0.36, 95% CI = [−0.4, −0.15], p=0.373). Five eyes experienced a one-grade improvement in MG (p=0.453), and none experienced worsening in MG with treatment. No temporary or permanent adverse effects were noted.

Conclusion

Four weeks of PRP therapy resulted in significant functional improvements in dry eye symptoms and tear film quality and quantity. Improvements in conjunctival injection and microstructural improvements in meibomian glands were also observed in some eyes. Overall, PRP is a promising treatment option for patients with EDE from MGD refractory to conventional treatments.

Platelet-Rich Plasma and Adipose-Derived Mesenchymal Stem Cells in Association with Arthroscopic Microfracture of Knee Articular Cartilage Defects: A Pilot Randomized Controlled Trial

Background

This study aims to compare the effects of platelet-rich plasma (PRP) alone or in combination with adipose-derived mesenchymal stem cells (AD-MSCs) in patients affected by cartilage defects, undergoing knee arthroscopic microfracture.

Methods

Thirty-eight patients diagnosed with a knee monocompartmental cartilage defect (Outerbridge grade IV) on the MRI, underwent an arthroscopic procedure. After the confirmation of the lesion, they all received the same bone marrow stimulation technique (microfracture) and were randomized into two groups: the first one had additional PRP injection (group A), while the second received PRP and AD-MSC injection (group B). Knee assessment and pain score were documented with Knee Injury Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, Short-Form (SF) 12, and Visual Analogue Scale (VAS) before the treatment and at 1, 3, 6, and 12 months of follow-up postoperatively. An additional arthroscopic procedure, performed in four patients for a subsequent meniscal lesion, let us evaluate cartilage evolution by performing a macro/microscopical assessment on cartilage biopsy specimens.

Results

At the 12-month follow-up, both groups showed a comparable functional improvement. The scores on the IKDC form, KOOS, pain VAS, and SF-12 significantly improved from baseline (p < 0.05) to 12 months postoperatively in both treatment groups. The four second-look arthroscopies showed a complete repair of the articular defects by smooth solid cartilage layer, with a good chondrocytic population, in both groups. A thick smooth hyaline-like cartilage with a predominantly viable cell population and normal mineralization (a form closely resembling native tissue) was observed in group B.

Conclusions

Modern regenerative medicine techniques, such as PRP and AD-MSC, associated with traditional arthroscopic bone marrow stimulating techniques, seem to enhance cartilage restoration ability. The preliminary results of this pilot study encourage the synergic use of these regenerative modulating systems to improve the quality of the regenerated cartilage.

Direct Reprograming of Mouse Fibroblasts into Dermal Papilla Cells via Small Molecules

The reprogramming of somatic fibroblasts into alternative cell linages could provide a promising source of cells for regenerative medicine and cell therapy. However, the direct conversion of fibroblasts into other functional cell types is still challenging. In this study, we show that dermal-papilla-cell-like cells (DPC-LCs) can be generated by treating fibroblasts, including L929 mouse fibroblast cell lines and somatic mouse fibroblasts, with small molecules. Based on alkaline phosphatase activity and other molecular markers, different compounds or their combinations are needed for converting the two different fibroblasts into DPC-LCs. Notably, we found that TTNPB alone can efficiently convert primary adult mouse fibroblasts into DPC-LCs. DPC-LCs generated from mouse fibroblasts showed a stronger hair-inducing capacity. Transcriptome analysis reveals that expression of genes associated with a hair-inducing capacity are increased in DPC-LCs. This pharmacological approach to generating functional dermal papilla cells may have many important implications for hair follicle regeneration and hair loss therapy.

Ultrasound-guided injection of platelet-rich plasma or cord blood platelet-rich plasma in nonunion: a randomized controlled trial

Aim: To compare the ability of autologous platelet-rich plasma (PRP) and cord blood PRP (PRPc) to accelerate bone healing. Patients & methods: 71 patients with mechanically stable nonunion were treated weekly (3 consecutive weeks) with ultrasound-guided percutaneous injections of PRP or PRPc in a controlled randomized clinical trial. The primary outcome was healing (12 months) and secondary outcomes were radiological evolution (2 and 6 months) and changes in pain intensity (6 months). Results & conclusion: Bone consolidation was assessed over time without significant differences between PRP and PRPc treatment. In patients with persistent nonunion, pain perception decreased more after PRP treatment. PRPc appears to be a valid alternative when specific clinical conditions suggest avoiding the use of autologous blood products.

Platelet Rich Plasma and Its Use in Hair Regrowth: A Review

Platelet rich plasma (PRP) was described as a small volume of plasma containing higher concentrations of platelets than those found in peripheral blood and initially used as a transfusion product for treatment of thrombocytopenia. To date, it was discovered that there are several growth factors and cytokines that can accelerate wound healing and tissue regeneration, leading to a wider range of applications in the medical field, such as in sport medicine, regenerative medicine, and aesthetic medicine. Several studies have shown that PRP can be used effectively for treatment of hair loss. Although it has been widely used, the exact mechanism of action of PRP is still not fully elucidated. In this article, we aim to review and update current information on the definition, classification, mechanism of action, clinical efficacy in hair regrowth, and adverse events of PRP.

Device-Based Enrichment of Knee Joint Synovial Cells to Drive MSC Chondrogenesis Without Prior Culture Expansion In Vitro: A Step Closer to 1-Stage Orthopaedic Procedures

BACKGROUND

Synovial fluid (SF) mesenchymal stem cells (MSCs) are derived from the synovial membrane and have cartilage repair potential. Their current use in clinical practice is largely exploratory. As their numbers tend to be small, therapeutic procedures using MSCs typically require culture expansion. Previous reports indicate that the stem cell-mobilizing device (STEM device) intraoperatively increases SF-MSCs.

PURPOSE

This study evaluated the chondrogenic potential of non-culture expanded synovium-mobilized MSCs and SF-microfragments obtained after enrichment using the STEM device and ascertained if device-mediated synovial membrane manipulation facilitated ongoing MSC release.

STUDY DESIGN

Controlled laboratory study.

METHODS

Two samples of aspiration fluid were collected intraoperatively before and after STEM device utilization from patients (n = 16) undergoing diagnostic or therapeutic knee arthroscopy. Human knee synovium (n = 5) was collected during total knee replacement, and a suspended culture was performed to assess the effect of the STEM device on ongoing MSC release. Colony forming unit-fibroblastic assays were used to determine the number of MSCs. Additionally, cytometric characterization of stromal and immune cells and chondrogenesis differentiation assay were performed without culture expansion. Filtered platelet concentrates were prepared using the HemaTrate system.

RESULTS

After STEM device use, a significant increase was evident in SF-MSCs (P = .03) and synovial fluid-resident synovial tissue microfragments (P = .03). In vitro-suspended synovium released significantly more MSCs following STEM device use than nonstimulated synovium (P = .01). The STEM device-released total cellular fraction produced greater in vitro chondrogenesis with significantly more glycosaminoglycans (GAGs; P < .0001) when compared with non-STEM device synovial fluid material. Nonexpanded SF-MSCs and SF-microfragments combined with autologous filtered platelet concentrate produced significantly more GAGs than the complete chondrogenic media (P < .0001). The STEM device-mobilized cells contained more M2 macrophage cells and fewer M1 cells.

CONCLUSION

Non-culture expanded SF-MSCs and SF-microfragments had the potential to undergo chondrogenesis without culture expansion, which can be augmented using the STEM device with increased MSC release from manipulated synovium for several days. Although preliminary, these findings offer proof of concept toward manipulation of the knee joint environment to facilitate endogenous repair responses.

CLINICAL RELEVANCE

Although numbers were small, this study highlights 3 factors relevant to 1-stage joint repair using the STEM device: increased SF-MSCs and SF-microfragments and prolonged synovial release of MSCs. Joint repair strategies involving endogenous MSCs for cartilage repair without the need for culture expansion in a 1-stage procedure may be possible.

Intraosseous Injections Are Safe And Effective in Knee Osteoarthritis: A Systematic Review

Purpose

To evaluate clinical outcomes after intraosseous injection for knee osteoarthritis systematically with available clinical evidence.

Methods

A systematic search methodology of the PUBMED, EMBASE, and CINAHL databases was conducted in November 2020. The search workflow was in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The following inclusion criteria were adopted: clinical trials of any level of evidence, reporting clinical outcomes following intraosseous injections of bone substitutes or biologic agents, and mesenchymal stem cells or platelet-rich plasma into the knee as treatment modalities for osteoarthritis. Duplicate data and articles not written in English were excluded from this review.

Results

Six studies were identified and included in this review, with a total of 167 patients. Two studies used subchondroplasty CaP injections, while 4 studies used intraosseous injections of platelet-rich plasma. Two studies provided Level II evidence, 2 studies provided Level III evidence, and a further 2 provided Level IV evidence. Five out of 6 studies reported data using the visual analog scale, 4 studies used the Knee Injury and Osteoarthritis Outcome Score, while 3 studies used the Western Ontario and McMaster Universities Osteoarthritis Index. Clinical improvements in pain and functionality were documented in all trials, with only a few patients experiencing adverse events.

Conclusion

Intraosseous injections for knee osteoarthritis are safe and effective. However, multiple pertinent variables such as safety, cost of treatment, and performance against placebos and other treatment modalities require further evaluation before intraosseous injections can be considered as standard treatment for patients presenting with osteoarthritis of the knee.

OPTIMIZING A PLATELET-RICH PLASMA CONCENTRATION PROTOCOL FOR SOUTH AMERICAN SEA LIONS (OTARIA FLAVESCENS)

Accelerated healing in wild or captive South American sea lions (Otaria flavescens) is a key tool to help minimize infection and complications associated with open wounds, dental disease, and ocular pathology. Platelet-rich plasma (PRP) is an autogenous source for growth factors based on platelet concentration, which can be obtained by centrifuging whole blood collected in sodium citrate anticoagulant. Currently, there are well-defined PRP concentration protocols for humans and most domestic companion animal species. However, there is no clear centrifugation protocol for obtaining PRP in most marine mammal species. This study aimed to optimize the platelet concentration protocol based on whole blood centrifugation using speeds ranging from 500 to 5,000 rpm and times ranging from 3 to 6 min. Blood was drawn from seven adult South American sea lions, placed into 1-ml sodium citrate tubes, and centrifuged following 12 different centrifugation protocols. PRP was designated as the lower third fraction of the centrifuged plasma. Platelet counts were performed using flow cytometry and statistical analysis was carried out to establish a well-defined protocol for efficient PRP production. Transmission electron microscopy (TEM) analysis was performed to evaluate possible platelet degranulation during the different centrifugation protocols and measure platelet areas. Maximum concentration of platelets in PRP was 4.73-fold higher than the number of platelets in equal volume of whole blood, and significant differences in the concentrations obtained were found between the 12 centrifugation protocols evaluated using different speed and time combinations. The best one-step centrifugation protocol resulted from using 900-rpm speed for 3 min. The highest-fold increase was achieved using a two-step centrifugation protocol, which combined the most efficient one-step centrifugation protocol (900 rpm, 3 min) with a second centrifugation using 2,000-rpm speed for 6 min. TEM analysis confirmed that platelets were complete and maintained integrity after the proposed protocol.

Case Report: Rehabilitation After Platelet-Rich Growth Factors' Intra-Articular Injections for Knee Osteoarthritis: Two Case Reports of a Home-Based Protocol

Knee osteoarthritis (KOA) is a chronic progressive disease that can cause pain, functional impairment, and ultimately disability. A novel and promising therapeutic approach to KOA is the so-called regenerative medicine, a set of procedures designed to harness tissue regenerative capacity and optimize functional recovery. Increasing evidence points out that platelet-rich plasma (PRP) intra-articular injections can decrease pain and improve functional abilities in KOA patients. In the present case reports, we analyze two patients who were treated with PRP injections coupled with a posttreatment home-based rehabilitation program. The two patients were selected to represent two different populations: patient 1 was an 85-year-old with severe impairment of functional abilities, while patient 2 was a younger (59 years old) and more active patient. The protocol consisted in a series of exercise to be performed at home, during the five days following PRP injection for two consecutive weeks (10 days in total). The exercises were designed to reduce the inflammation after the injection, enhance the proprioceptive control of the treated lower limb, and strengthen hip and knee flexors and extensors, mainly by isometric work. Results were evaluated at two time points: before and 2 months after the first PRP injection. The outcomes considered were as follows: visual analog scale for pain, EuroQol 5 dimensions questionnaire, Tegner Activity Scale for functioning, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Both patients did not report any side effects from the treatment. Improvement in patient 1 was drastic at the two months follow-up as far as pain and functional abilities are concerned. Patient 2’s improvement was less evident, probably due to the higher starting point in both pain and functionality. Overall, the developed program seemed safe and was tolerated by the patients analyzed in the study, who performed it with good compliance.

A Modified Preparation Method of Ideal Platelet-Rich Fibrin Matrix From Whole Blood

One bioproduct that is widely used in the wound healing process is platelet-rich plasma (PRP). PRP is a liquid solution with high autologous platelet concentration, making it a good source of growth factors to accelerate wound healing. Recent development in PRP had created a new product called platelet-rich fibrin matrix (PRFM), which has a denser and more flexible structure. PRFM is the newest generation of platelet concentrate with a fibrin matrix that holds platelet in it. The key concept in creating PRFM from PRP is the addition of CaCl₂ followed by centrifugation, which converts fibrinogen to fibrin, and the fibrin cross-links to form a matrix that contains viable platelets. There are many commercially available kits to create PRFM, but they are often expensive and uneconomical. This research will test a modified method of making ideal PRFM from PRP without any commercial kits. The modified method will include determining the minimum level of CaCl₂ used, the type of centrifuge, and the speed and duration of centrifugation. By performing a modified preparation method on five samples of whole blood, it was found that the ideal PRFM could be made by mixing PRP with 25 mM CaCl₂ and centrifuging it at a speed of 2,264 × g for 25 min at room temperature. The PRP and PRFM platelet counts of this method tend to be lower than the platelet counts found in other studies. Although visually comparable, further study is needed to compare the performance of PRFMs made with this method and PRFMs made with commercial kits.

Smoking status and the baseline international index of erectile function score can predict satisfactory response to platelet-rich plasma in patients with erectile dysfunction: A prospective pilot study

Erectile dysfunction (ED) is a common condition with a significant impact on the quality of life. Regenerative medicine maladies are intended to repair or replace damaged tissues and organs through different therapeutic mechanisms. Our aim was to study the effect of intra-corporeal injection (ICI) of platelet-rich plasma (PRP) in ED patients. Thirty-four patients' erectile function was evaluated by filling up an abridged form of the international index of erectile function (IIEF-5) before and after PRP therapy. ICI of PRP was done once per week for 2 months. All patients were prescribed PDE5Is for one month after PRP therapy. Penile haemodynamics was assessed using 20 µg of PGE1 before and 3 months after initiating PRP therapy. Interestingly, our study had shown that there was a statistically significant difference in the IIEF-5 score after ICI of PRP (-5.5, ±5.2, p=<0.001). Furthermore, in multiple logistic regression model for PRP responsiveness, smoking and IIEF score before PRP were the only significant independent variables (p = .040, p = .023 respectively). PRP injection for ED patients may be a promising modality as well as baseline IIEF-5, and smoking status can be used as predictors for a satisfactory response to PRP in such patients.

Has platelet-rich plasma any role in partial tears of the anterior cruciate ligament? Prospective comparative study

BACKGROUND

Partial tears of the anterior cruciate ligament (ACL) are frequent, and there is still considerable controversy surrounding their diagnosis, natural history and treatment.

AIM

To examine patient-reported outcomes, physical examination and magnetic resonance imaging (MRI) findings of partial ACL tears treated with an intraarticular injection of platelet-rich plasma (PRP) compared to a control group.

METHODS

From January 2015 to November 2017, consecutive patients from a single institution with partial ACL tears treated nonoperatively were prospectively evaluated. Partial tears were defined as a positive Lachman test with a clear end-point, a negative pivot-shift and less than 3 mm of side-to-side difference using the KT1000 arthrometer. Patients in group 1 were treated with one intraarticular injection of PRP and specific physical therapy protocol. Control group consisted of patients treated only with physical therapy. Prospective analyzed data included physical examination, Tegner activity level and Lysholm and International Knee Documentation Committee scores. Baseline MRI findings and at 6 mo follow-up were reviewed. Failure was defined as those patients with clinical instability at follow-up that required a subsequent ACL reconstruction.

RESULTS

A total of 40 patients where included, 21 treated with PRP injection with a mean follow-up of 25 mo [standard deviation (SD): 3.6] and 19 in the control group with a mean follow-up of 25 mo (SD: 5.68). Overall failure rate was 32.0% (n = 13). No significant differences were observed between groups regarding subjective outcomes, return to sport and failure rate. MRI findings revealed an improvement in the ACL signal in half of the patients of both groups. However, we did not find a significant relationship between MRI findings and clinical outcomes.

CONCLUSION

Overall, 95.0% of patients returned to sports at a mean follow-up of 25 mo. Mean time to return to sports was 4 mo. Out of these patients, almost 30.0% in each group had a new episode of instability and required surgery at a median time of 5 mo in group 1 and 8 mo in group 2. The addition of PRP alone was not sufficient to enhance any of the outcome measures evaluated, including MRI images, clinical evaluation and failure rate.

Platelet-rich plasma therapy in dogs with bilateral hip osteoarthritis

Background

Osteoarthritis (OA) is the most commonly diagnosed joint disease in companion animals, and hip OA is commonly diagnosed in the canine population. The use of platelet-rich plasma has gained increasing interest for the treatment of musculoskeletal conditions in companion animals. To evaluate the effect of the intra-articular administration of platelet-rich plasma in police working dogs with bilateral hip OA compared to a control group, twenty dogs were assigned to a control group (CG, n = 10) or treatment group (PG, n = 10), using the statistical analysis software. PG received two intra-articular administrations of platelet-rich plasma, 14 days apart, while CG received an intra-articular administration of saline, in the same moments. Response to treatment was determined with the Canine Brief Pain Inventory, Liverpool Osteoarthritis in Dogs, Canine Orthopedic Index, and Hudson Visual Analogue Scale, before treatment, + 8, + 15, + 30, + 60, + 90, + 120, 150, and + 180 days after initial treatment. Kaplan-Meier estimators were conducted and compared with the log-rank test. Cox proportional hazard regression analysis was performed to determine treatment survival, p < 0.05.

Results

The sample comprised 20 animals of both sexes (male n = 12, female n = 8), with a mean age of 8.4 ± 2.4 years and a bodyweight of 31.5 ± 5.7 kg. Joints were classified as moderate (13) and severe (7) according to the Orthopedic Foundation for Animals grading scheme. No differences were found between groups at the initial evaluation. Better results with the majority of scores were observed in the PG, in some cases lasting up to the last evaluation moment. Kaplan-Meier estimators showed that PG produced longer periods with better results in all scores compared to CG. Treatment was the covariate influencing all scores in the Cox regression analysis. OFA hip score also influenced two dimensions of the Canine Orthopedic Index.

Conclusion

The intra-articular administration of platelet-rich plasma can improve pain and functional scores of police working dogs with bilateral hip OA, compared with a control group. Its effects lasted for significantly longer periods, and treatment was the main covariate affecting the improvements observed.

Combined use of calcium phosphate cement, mesenchymal stem cells and platelet-rich plasma for bone regeneration in critical-size defect of the femoral condyle in mini-pigs

Aim: To investigate the outcome of autologous bone marrow mesenchymal stem cells (BMMSCs) and platelet-rich plasma in combination with calcium phosphate cement (CPC) scaffold to reconstruct femoral critical bone defects in mini-pigs. Materials & methods: Scanning electron microscopy, micro-computed tomography evaluation and quantitative histological assessment were used. Results & conclusion: BMMSCs were attached to the CPC scaffold after 7 days of culture and decreased the residual CPC material in each group at 12 weeks compared with 6 weeks. The newly formed bone area was higher in the CPC+SC+P group than in the CPC group at each time point (all p < 0.05). The strategy of CPC combined with BMMSCs and platelet-rich plasma might be an effective method to repair bone defects.

Platelet-rich plasma for tendinopathy and osteoarthritis: a narrative review

Background

Musculoskeletal disorders include a wide range of degenerative and inflammatory problems, which can affect any part of the muscular and skeletal system. Platelet-rich plasma (PRP) has been a breakthrough in musculoskeletal medicine, especially with its effects to speed up soft tissue, cartilage, and bone healing. It is now thought that stem cells are able to reverse the degenerative process and promote rapid healing. Platelet-rich plasma (PRP) has received special attention in treating tendinopathy and osteoarthritis. This review aims to do a comprehensive review of the scientific evidence for the efficiency of PRP application in tendinopathy and osteoarthritis.

Main body of the abstract

In osteoarthritis treatment, platelet-rich plasma is thought to influence the whole joint environment by increasing chondrocyte proliferation. The injection of autologous PRP into the joint space and surrounding soft tissues delivers a concentrated dose of these growth factors, which accelerate the healing process and reduce pain.

Short conclusion

Many studies report some benefits in regard to pain and functionality, especially in tendinopathy, but further investigations are needed to incorporate PRP into clinical practice and be a common form of therapy for tendinopathy and osteoarthritis. Caution should be applied with any treatment we use in clinical practice, especially with PRP and other forms of injections.

Management of Osteoarthritis Using 1 Intra-articular Platelet Concentrate Administration in a Canine Osteoarthritis Model

BACKGROUND

Osteoarthritis (OA) represents a significant burden to societies, as it affects quality of life and performance and implies a large cost in terms of health care. Autologous platelets are a regenerative treatment modality for OA that are thought to be a potential stimulation of the natural healing cascade.

PURPOSE

To describe the effect of the platelet concentrate V-PET in the management of OA in a naturally occurring canine model, using several outcome assessment modalities.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 40 joints of active working police dogs with hip OA were randomly assigned to a control group (CG) and a platelet concentrate group (PCG; treatment) and evaluated. At treatment day (T0) and 8, 15, 30, 90, and 180 days after treatment, weight distribution, joint range of motion at flexion and extension, thigh girth, digital thermography, radiographic signs, 4 clinical metrology instruments, and synovial fluid interleukin 1 and C-reactive protein levels were recorded. Results were compared using repeated-measures analysis of variance with a Huynh-Feldt correction, paired-samples t test, or Wilcoxon signed rank test, with P < .05.

RESULTS

Dogs were 6.5 ± 2.4 years old (mean ± SD) and had a body weight of 26.7 ± 5.2 kg. At T0, 32 (80%) joints were graded as having mild OA, 6 (15%) as moderate, and 2 (5%) as severe. No differences were found between groups at T0. Between the PCG and CG, the symmetry index showed significant improvements in the PCG from 8 days (P = .01) to 180 days (P = .01). Joint flexion also improved in the PCG up to 90 days (P < .05) and extension improved up to 180 days (P < .01). Several clinical metrology instrument scores also improved up to 90 to 180 days after treatment. In the CG, radiographic signs progressed, while the PCG showed some improved signs. In both groups, increasing body weight and age corresponded with worse clinical and laboratory findings.

CONCLUSION

A single injection of platelet concentrate had a positive effect, lasting up to 6 months, on several clinical, imaging, and laboratory signs in a naturally occurring canine OA model.

CLINICAL RELEVANCE

We characterized the effects of this platelet concentrate in dogs, considered the gold standard of the study of OA, with a group of working animals with similar high demands as athletes.

The Effect of Plasma Rich in Growth Factors on Microglial Migration, Macroglial Gliosis and Proliferation, and Neuronal Survival

Plasma rich in growth factors (PRGF) is a subtype of platelet-rich plasma that has being employed in the clinic due to its capacity to accelerate tissue regeneration. Autologous PRGF has been used in ophthalmology to repair a range of retinal pathologies with some efficiency. In the present study, we have explored the role of PRGF and its effect on microglial motility, as well as its possible pro-inflammatory effects. Organotypic cultures from adult pig retinas were used to test the effect of the PRGF obtained from human as well as pig blood. Microglial migration, as well as gliosis, proliferation and the survival of retinal ganglion cells (RGCs) were analyzed by immunohistochemistry. The cytokines present in these PRGFs were analyzed by multiplex ELISA. In addition, we set out to determine if blocking some of the inflammatory components of PRGF alter its effect on microglial migration. In organotypic cultures, PRGF induces microglial migration to the outer nuclear layers as a sign of inflammation. This phenomenon could be due to the presence of several cytokines in PRGF that were quantified here, such as the major pro-inflammatory cytokines IL-1β, IL-6 and TNFα. Heterologous PRGF (human) and longer periods of cultured (3 days) induced more microglia migration than autologous porcine PRGF. Moreover, the migratory effect of microglia was partially mitigated by: 1) heat inactivation of the PRGF; 2) the presence of dexamethasone; or 3) anti-cytokine factors. Furthermore, PRGF seems not to affect gliosis, proliferation or RGC survival in organotypic cultures of adult porcine retinas. PRGF can trigger an inflammatory response as witnessed by the activation of microglial migration in the retina. This can be prevented by using autologous PRGF or if this is not possible due to autoimmune diseases, by mitigating its inflammatory effect. In addition, PRGF does not increase either the proliferation rate of microglial cells or the survival of neurons. We cannot discard the possible positive effect of microglial cells on retinal function. Further studies should be performed to warrant the use of PRGF on the nervous system.

The Effect of Intradiscal Platelet-Rich Plasma Injection for Management of Discogenic Lower Back Pain: A Meta-Analysis

Objective

Although several researches of animal and human subjects have yielded promising results regarding intradiscal injection of platelet-rich plasma (PRP) for the management of intervertebral disc (IVD) pathologies, small sample sizes and unstandardized graft preparation procedures hampered these research efforts. Therefore, we conducted a meta-analysis to evaluate the effectiveness of intradiscal PRP injection for the treatment of discogenic lower back pain.

Methods

The PubMed, SCOPUS, Embase, and Cochrane Library databases were systematically searched for relevant studies published from January 01, 1980 to December 14, 2020. The keywords used for the search were (platelet-rich plasma) AND (intradiscal OR back pain OR lumbar spine OR discogenic). Filters were used to select studies with human participants; all study designs were included.

Results

After the systematic review, three articles, including one randomized control trial and two prospective observational studies, were included in the final analysis. Analysis of changes in visual analogue scale (VAS) scores showed that VAS scores were significantly reduced two and six months after intradiscal PRP injection (two months: standardized mean difference [SMD] = −0.837, 95% CI = −1.158 to −0.516, P < 0.001; six months: SMD = −1.430, 95% CI = −2.209 to −0.652, P < 0.001), but not after one month (SMD = −0.661, 95% CI = −1.346 to 0.023, P = 0.058). Regarding changes in Owestry Disability Index (ODI), ODI scores were significantly reduced after six months (SMD = −0.964, 95% CI = −1.885 to −0.043, P = 0.040).

Conclusion

Intradiscal PRP injections are effective in relieving pain and improving disabilities caused by discogenic lower back pain. However, the pain-reducing effect significantly manifests two or six months after the injections, but not after one month.

Intraarticular triamcinolone hexacetonide, stanozolol, Hylan G-F 20 and platelet concentrate in a naturally occurring canine osteoarthritis model

Osteoarthritis (OA) is a disease transversal to all mammals, a source of chronic pain and disability, a huge burden to societies, with a significant toll in healthcare cost, while reducing productivity and quality of life. The dog is considered a useful model for the translational study of the disease, closely matching human OA, with the advantage of a faster disease progression while maintaining the same life stages. In a prospective, longitudinal, double-blinded, negative controlled study, one hundred (N = 100) hip joints were selected and randomly assigned to five groups: control group (CG, n = 20, receiving a saline injection), triamcinolone hexacetonide group (THG, n = 20), platelet concentrate group (PCG, n = 20), stanozolol group (SG, n = 20) and hylan G-F 20 group (HG). Evaluations were conducted on days 0 (T0, treatment day), 8, 15, 30, 60, 90, 120, 150 and 180 days post-treatment, consisting of weight distribution analysis and data from four Clinical Metrology Instruments (CMI). Kaplan-Meier estimators were generated and compared with the Breslow test. Cox proportional hazard regression analysis was used to investigate the influence of variables of interest on treatment survival. All results were analyzed with IBM SPSS Statistics version 20 and a significance level of p < 0.05 was set. Sample included joints of 100 pelvic limbs (of patients with a mean age of 6.5 ± 2.4 years and body weight of 26.7 ± 5.2 kg. Joints were graded as mild (n = 70), moderate (n = 20) and severe (n = 10) OA. No differences were found between groups at T0. Kaplan-Meier analysis showed that all treatments produced longer periods with better results in the various evaluations compared to CG. Patients in HG and PCG took longer to return to baseline values and scores. A higher impact on pain interference was observed in THG, with a 95% improvement over CG. PCG and HG experienced 57-81% improvements in functional evaluation and impairments due to OA, and may be a better options for these cases. This study documented the efficacy of several approaches to relieve OA clinical signs. These approaches varied in intensity and duration. HG and PCG where the groups were more significant improvements were observed throughout the follow-up periods, with lower variation in results.

Intra-articular Injections With Either Triamcinolone Hexacetonide, Stanozolol, Hylan G-F 20, or a Platelet Concentrate Improve Clinical Signs in Police Working Dogs With Bilateral Hip Osteoarthritis

Objectives: To compare the effect of intra-articular treatment with triamcinolone hexacetonide (TH), stanozolol, hyaluronan, and a platelet concentrate in police working dogs with bilateral hip osteoarthritis (OA). Study Design: Prospective, longitudinal, double-blinded, negative controlled study. Sample Population: Fifty police working dogs with naturally occurring hip OA. Methods: Animals were randomly assigned to a control group (CG, n = 10), TH group (THG, n = 10), platelet concentrate group (PCG, n = 10), stanozolol group (SG, n = 10), and Hylan G-F 20 group (HG). On days 0 (T0), 8, 15, 30, 90, and 180 days post-treatment, weight-bearing distribution was evaluated. In those days, and on days 60, 120, and 150, four clinical metrology instruments were completed. Kaplan-Meier estimators were conducted and compared with the log-rank test. Cox proportional hazard regression analysis was performed to determine treatment survival. Significance was set at p < 0.05. Results: Patients had a mean age of 6.5 ± 2.4 years and body weight of 26.7 ± 5.2 kg. At T0, hips were classified as mild (n = 35), moderate (n = 10), and severe (n = 5), according to the Orthopedic Foundation for Animals grading scheme. No differences were found between groups at that moment considering age, body weight, OFA hip score, and all assessments performed. All treatments improved clinical signs in various OA dimensions in some groups, with a broad effect interval. PCG showed a lower range of variation while maintaining a positive result for more extended periods (p < 0.01 for symmetry index and 0.01 < p < 0.04 in the majority of scores). Breed, age, sex, and OFA grade did not significantly influence response to treatment. Conclusions and Clinical Relevance: This is the first prospective, negative controlled, double-blinded study to compare the effect of a single administration of these IA treatments in dogs with hip OA. HG and PCG recorded more significant improvements throughout the 180-day follow-up. In particular, PCG also registered a lower variation in results, seemingly the best therapeutic option. Nevertheless, improvements were still observed in THG and SG, and these treatment options can be considered, mainly when the first two treatments are not available.

Application of platelet-rich plasma for canine osteoarthritis treatment - a clinical series

Osteoarthritis, also known as degenerative joint disease (DJD), is defined as a progressive and permanent long-term deterioration of the cartilage surrounding the joints. There is no known cause for primary DJD. However, there are a wide variety of causes for secondary DJD, such as trauma, abnormal wear of joints and cartilage, or a congenital defect present at birth such as an improperly formed hip. One of the most popular methods used to biologically enhance healing in the fields of orthopaedic surgery and medicine includes the use of autologous blood products, namely, platelet rich plasma (PRP). Reports suggest that PRP, presumably containing high levels of platelet growth factors, may promote the recovery of the affected cartilage. This case series presents clinical and radiographic findings of three dogs with osteoarthritis of the elbow and knee joints. Pain score were assessed by CBPI (Canine Brief Pain Inventory). Treatment with three-fold intra-articular application of PRP, obtained by double centrifugation method, resulted in significant improvement in the function of the affected joint. Therefore, it could be concluded that PRP was clinically effective in the treatment of osteoarthritis in these three cases.