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

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

Platelet-Rich Plasma (PRP) for Endometrial Treatment Efficacy and Safety in Assisted Reproductive Technology: A Comprehensive Review

Platelet-rich plasma (PRP) is among the new ground-breaking methods called for endometrial disorders detected in assisted reproductive technology (ART). This research work takes account of both a systematic literature review and an exploration of the molecular connections. The report aims to present the capabilities and benefits of the PRP in ART and the nonconformance and dangers involved in its use in ART. However, all these stages of ART need conducive endometrium, live micro embryo, and coordinated interaction between the blastocyst and the uterus. Despite all ART has achieved, implantation failure still exists as a problem having one quarter being attributed to the absence of the endometrial receptivity level. The review points to a corresponding increase in the role of autologous PRP in promoting cell proliferation, neo-angiogenesis, and anti-inflammatory effects to facilitate effective endometrial receptivity. The outcome of prior trials with the PRP approach proved to be positive for women with adenomyosis, thin endometrial lining, recurring implantation failure, chronic endometritis, and Asherman's syndrome. Challenges still exist in the proper placement of PRP for all women with infertility problems as well as how it works for individuals with blood disorders and infections. This study will look into the safest number of doses, the time of acting, and the possible future health hazards that both mother and child may face.

Women show a positive response to platelet-rich plasma despite presenting more painful knee osteoarthritis than men

PURPOSE

The purpose of this study was to evaluate the impact of gender on the efficacy of platelet-rich plasma (PRP) in patients with knee osteoarthritis (KOA), comparing their short-term response between men and women.

METHODS

Four hundred-eighteen patients (529 knees) were included. Patients were treated with three injections of PRP on a weekly basis. Blood and PRP samples were randomly tested. Patients were asked to complete the knee injury and osteoarthritis outcome score (KOOS) and 12-item short form survey (SF-12), at baseline and 6 months. Success rates were calculated according to a reduction in the pain score of at least 9.3 points [minimal clinically important improvement (MCII)]. Comparative tests and multivariate regression were performed.

RESULTS

The PRP had a platelet concentration factor of 2.0X compared to blood levels, with no leucocytes or erythrocytes. KOOS scores showed an increase from baseline to 6 months (p < 0.0001). There was an increase in the physical component summary (PCS) (p < 0.0001) and mental component summary (MCS) (p < 0.01) of the SF-12. The number of knees of women with MCII was 156 out of 262 (59.6%), whereas the number of knees of men was 136 out of 267 (50.9%) (p = 0.0468). Women had worse baseline scores on pain (p = 0.009), PCS (p < 0.0001) and MCS (p < 0.0001).

CONCLUSION

Although the symptomatology generated by KOA was worse in women when compared to men, treatment with repeated injections of PRP was effective, ultimately achieving a higher improvement in women providing comparable final follow-up outcomes between men and women.

LEVEL OF EVIDENCE

Level IV.

High survival rate after the combination of intrameniscal and intraarticular infiltrations of platelet-rich plasma as conservative treatment for meniscal lesions

PURPOSE

To evaluate the efficacy of applying a combination of intrameniscal and intraarticular infiltrations of Platelet-Rich Plasma (PRP) in patients with meniscal tears, analyzing its failure rate and clinical evolution, as well as factors that may influence the positive response to this treatment.

METHODS

Three hundred and ninety-two cases out of 696 met the inclusion criteria and were included in this work. Survival and patient-reported outcome measure (PROM) were collected and analyzed. Survival rate was defined as the percentage of patients who did not undergo meniscus surgery during their follow-up time. Patients were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 6 months and 18 months. Other patient- and pathology-related variables were collected. Blood and PRP samples were randomly tested as a quality control measure. Survival and comparative statistical tests, and multivariate regression were performed for the analysis of the variables.

RESULTS

The PRP applied had a platelet concentration factor of 1.9X in respect to blood levels, with no leukocytes or erythrocytes. Thirty-eight patients required surgical intervention after treatment reaching a survival rate of 90.3% with an estimated mean survival time of 54.4 months. The type of injury (P = 0.002) and the presence of chondropathy were risk factors for surgical intervention after PRP treatment (P = 0.043). All KOOS scores showed a significant statistical increase from baseline to 6 months (N = 93) and 18 months (N = 66) (P < 0.0001). The number of cases with minimal clinically important improvement (MCII) at 6 months and 18 months post-treatment was 65 (69.9%) and 43 (65.2%), respectively.

CONCLUSION

The combination of intrameniscal and intraarticular PRP infiltrations is a valid conservative treatment for meniscal injuries avoiding the need for surgical intervention. Its efficacy is higher in horizontal tears and decreases when joint degeneration is present.

LEVEL OF EVIDENCE

Level IV.

Real-world evidence to assess the effectiveness of platelet-rich plasma in the treatment of knee degenerative pathology: a prospective observational study

Objective:

The present work aims to analyse the effectiveness of platelet-rich plasma (PRP) in degenerative knee pathology based on real-world data and to evaluate possible factors influencing the response to treatment.

Methods:

In total, 531 cases were analysed collecting data on gender, age, body mass index, pathology location, severity, number of cycles and route of administration. Clinical outcome was evaluated at 6 and 15 months after treatment, using the Knee injury and Osteoarthritis Outcome Score (KOOS) and obtaining percentages of Minimal Clinically Important Improvement (MCII). Blood and PRP samples were randomly tested as a quality control measure to ensure the correct properties. Comparative statistical tests and multivariate regression were performed for the analysis of the variables.

Results:

The PRP applied had a platelet concentration factor of 1.67, with no leukocytes or erythrocytes. The percentage of patients with MCII at 6 and 15 months after PRP application was 59.32% and 70.62%, respectively. Patients with MCII were younger (p = 0.0246) and with lower body mass index (p = 0.0450). The treatment had a better response in mild/moderate cases than in severe cases (p = 0.0002). Intraosseous PRP application in severe cases improved the effect of intraarticular PRP (p = 0.0358). The application of a second cycle of PRP only improved the response in patients without MCII at 6 months (p = 0.0029), especially in mild/moderate cases (p = 0.0357).

Conclusion:

The applications of PRP in degenerative knee pathologies is an effective treatment, but this effectiveness nonetheless depends on several variables. Real-world data can complement that from clinical trials to provide valuable information.

Characterization and Therapeutic Use of Extracellular Vesicles Derived from Platelets

Autologous blood products, such as platelet-rich plasma (PRP), are gaining increasing interest in different fields of regenerative medicine. Although growth factors, the main components of PRP, are thought to stimulate reparation processes, the exact mechanism of action and main effectors of PRP are not fully understood. Plasma contains a high amount of extracellular vesicles (EVs) produced by different cells, including anucleated platelets. Platelet-derived EVs (PL-EVs) are the most abundant type of EVs in circulation. Numerous advantages of PL-EVs, including their ability to be released locally, their ease of travel through the body, their low immunogenicity and tumourigenicity, the modulation of signal transduction as well as the ease with which they can be obtained, has attracted increased attention n. This review focuses briefly on the biological characteristics and isolation methods of PL-EVs, including exosomes derived from platelets (PL-EXOs), and their involvement in the pathology of diseases. Evidence that shows how PL-EVs can be used as a novel tool in medicine, particularly in therapeutic and regenerative medicine, is also discussed in this review.

Platelet-rich plasma injections delay the need for knee arthroplasty: a retrospective study and survival analysis

PURPOSE

The biological action of platelet-rich plasma (PRP) could slow down the osteoarthritis progression, resulting in a delay of joint replacement. This work aims to evaluate the ability of PRP to postpone and even avoid knee replacement in patients with knee osteoarthritis (KOA) analyzing, on the one hand, the time of delay and on the other hand the percentage of patients without undergoing total knee arthroplasty (TKA).

METHODS

A retrospective analysis and a survival analysis were conducted. KOA patients who underwent knee replacement between 2014 and 2019 and previously received PRP infiltrations were included in the retrospective analysis. Regarding survival analysis, KOA patients who received PRP treatment during 2014 and with follow-up until 2019 were included. The dates of PRP treatment and TKA, KOA severity, age of the patients, number of PRP cycles, and administration route were analyzed.

RESULTS

This work included 1084 patients of which 667 met the inclusion criteria. 74.1% of the patients in the retrospective study achieved a delay in the TKA of more than 1.5 years, with a median delay of 5.3 years. The survival analysis showed that 85.7% of the patients did not undergo TKA during the five year follow-up. The severity degree, age, PRP cycles, and administration route had a statistically significant influence on the efficacy of PRP in delaying surgery.

CONCLUSION

These data suggest that the application of PRP in KOA patients is a treatment that could delay TKA, although further studies are needed to understand and improve this therapy.