Optimal activation methods for maximizing the concentrations of platelet-derived growth factor-BB and transforming growth factor-β1 in equine platelet-rich plasma

A systematic review and meta-analysis of the efficacy of platelet-rich plasma products for treatment of equine joint disease

BACKGROUND

Equine joint disease including septic arthritis (SA) and osteoarthritis (OA) is a critical cause of equine lameness. Platelet-rich plasma (PRP) is one of the most popular regenerative therapies to treat equine OA, even SA, but the evidence in support of the treatment is conflicting.

OBJECTIVES

The aim of the study was to systematically review the current evidence on PRP products used for SA and OA, as well as the efficacy of PRP products as treatment for OA on the basis of a meta-analysis of the available literature.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search of relevant databases (PubMed, Web of Science, Scopus) was performed to identify studies published from 2013 to 2023, in accordance with the PRISMA guidelines. Randomised controlled trials, non-randomised trials and controlled laboratory studies that used at least one type of PRP products were included. Dichotomous outcomes were presented using odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

A total of 21 publications were identified in the systematic review and 5 of them in the meta-analysis. These publications involved various types of PRP products and reported different outcomes. Although most of the studies were associated with a high risk of bias, the overall estimated effect was consistent with a significant improvement in the PRP products treatment group compared with the control group (OR: 15.32; 95% CI: 3.00-78.15; p < 0.05). There was a significant improvement in clinical performance outcomes between the groups (OR: 36.64; 95% CI: 3.69-364.30; p < 0.05).

CONCLUSION

PRP products as intra-articular treatment are likely efficacious for treatment of equine OA and have potential for treating SA. These conclusions might be affected by the limited number of randomised controlled studies and high variability of different types of PRP products. To better evaluate the efficacy of PRP, a widely recognised classification system and the utilisation of randomised, blinded, equivalency or non-inferiority trials are required.

Use of flow cytometry method to detect contaminations of platelet suspensions

In this study, it was aimed to investigate bacterial contamination in apheresis platelet suspensions (APS) by automated blood culture system and flow cytometry method (FCM).33 spiked APS each using 11 bacterial strains (5 standard strains, 6 clinical isolates), were prepared in three different dilutions (1-10, 10-50, 50-100 cfu/mL), incubated in two different temperatures (35-37 °C and 22-24 °C) and different incubation times (18-96 h) evaluated by FCM. This three different dilutions were also inoculated into special platelet culture bottles (BacT/ALERT® BPA) and loaded into the blood culture system. Additionally 80 APSs routinely prepared in the Transfusion Center were evaluated by both FCM and the blood culture system. Platelets were lysed by freeze-thaw method.All spiked samples were positive with BacT/ALERT® BPA in 12-18 h. In 96 h incubation at 22-24 °C, the presence of bacteria was detected by FCM in all other samples (31/33) except low dilutions (1-10 and 10-100 CFU/ml) of K.pneumoniae standard strain. In the 35-37 °C, the presence of bacteria was detected by FCM in all samples (33/33) after 48 h of incubation. In routine APS one sample detected as positive (Bacillus simplex) with BacT/ALERT® BPA and no positivity was detected by FCM.The freeze-thaw method, which we have optimized for the lysis of platelets, is very practical and can be easily applied. The BacT/ALERT® system has been found to be very sensitive in detecting bacterial contamination in PSs. Flow cytometry method has been found to be successful, fast, easy to use and low cost in detecting bacterial contamination in PSs.

A comparative study of platelet storage lesion in platelet-rich plasma under cryopreservation

Platelet-rich plasma (PRP) has significant potential for various applications and holds clinical value in regenerative medicine. Cryopreservation is used to extend the preservation period of PRP, facilitating its clinical application. However, the potential negative effects of long-term cryopreservation on platelet storage lesion are still uncertain. In this study, PRP was stored at - 30 °C or - 80 °C. Platelet count, apoptosis, reactive oxygen species (ROS) content, and CD62P expression were assessed on the 14th and 28th days. The study also evaluated platelet mitochondria morphology and function, serotonin (5-HT) secretion by platelets, and the inflammatory activating effect of cryopreserved platelets in PRP. The results showed that there were no significant differences in platelet count, the content of 5-HT, and inflammatory effects between fresh PRP and PRP cryopreserved at both - 30 °C and - 80 °C. However, there was an increase in ROS level, apoptosis, and CD62P level after cryopreservation at both temperatures. Additionally, the levels of ROS, apoptosis, and CD62P in platelets were similar after storage at - 30 °C and - 80 °C. The main difference observed was that the morphology and function of mitochondria were severely damaged after storage at - 30 °C, while they were less affected at - 80 °C. Based on these findings, it can be concluded that storing PRP at - 80 °C is more suitable for achieving a better therapeutic effect in clinical applications, but cryopreservation could not replace the current standard.

Equine Platelet-Rich Plasma

Platelet-rich plasma (PRP) is an orthobiologic therapy composed of platelets, leukocytes, red blood cells, and plasma proteins. PRP has been used for 20 years, but progress determining efficacy has been slow. The definitions and classification of PRP are reviewed, and the use of PRP for tendon, ligament, and joint disease is discussed with a focus on findings of basic science and clinical studies, platelet activation, concurrent administration of nonsteroidal anti-inflammatory drugs, and treatment complications. Finally, the advantages of platelet lysates and freeze-dried platelets are discussed. The promising results of a PRP lysate optimized for antibiofilm and antimicrobial properties are introduced.

Improvement of human sperm properties with platelet-rich plasma as a cryoprotectant supplement

PURPOSE

Platelet-rich plasma (PRP) is a remarkable substance, which involves the growth and proliferation of all cell types. As a source of growth factors, we evaluated whether sperm cryopreservation supplemented with PRP improves the rates of sperm motility, viability, and DNA integrity after vitrification compared with conventional cryo-medium.

MATERIALS AND METHODS

20 normal semen specimens were collected from healthy men. After swim-up preparation, each sample was divided into four aliquots. One, as control, received no treatment, and the other three experimental samples were treated with three different concentrations of PRP as cryoprotectant. Sperm parameters were examined before and after freezing procedure.

RESULTS

PRP had no significant effect on sperm count. Meanwhile, the percentage of sperm progressive motility and viability in the PRP treated samples with 1×10⁵ /µL concentration was significantly higher than control group. Besides, the rate of immotile sperms in these samples was significantly lower than the control. Sperm viability was significantly higher in the PRP samples at 1×10⁵/µL concentration. In the case of DNA integrity, CMA3 staining showed that the lower PRP concentration was correlated with the higher rate of abnormal spermatozoa. SCD showed that the rate of abnormal sperms in the PRP samples with 1×10⁵ /µL concentration was significantly lower than control group.

CONCLUSIONS

This study showed a protective effect of PRP on human sperm quality at an optimized concentration after vitrification. Besides, the effects of PRP supplementation of sperms on successful fertility following sperm preservation will be of interest.

Platelet-Rich Plasma as an Orthobiologic: Clinically Relevant Considerations

Platelet-rich plasma (PRP) is an autologous blood-derived product processed to concentrate platelets and the associated growth factors. PRP has been shown to be relatively well-tolerated and safe to use for a number of conditions in humans, equines, and canines. There are multiple commercial systems that have been validated for canine use. These systems use a variety of methodologies to produce a PRP product. However, PRP products have been shown to differ greatly between systems. Further study is needed to fully elucidate optimal component concentrations for various indications.

The protective effect of co-administration of platelet-rich plasma (PRP) and pentoxifylline (PTX) on cyclophosphamide-induced premature ovarian failure in mature and immature rats

Cyclophosphamide (CP), as an antineoplastic agent, causes premature ovarian failure (POF) due to ovarian toxicity and subsequent infertility in women. Platelet-rich plasma (PRP) has accumulated significant attention in regenerative medicine. Pentoxifylline (PTX) as a methylxanthine derivative has been shown to have antioxidant and antiapoptotic properties. The aim of this study was to evaluate the protective effect of PRP and PTX on CP-induced POF. Fifty mature and immature female rats were assigned into five groups: control, CP (75 mg/kg, intraperitoneal [ip] on days 1 and 10 to induce POF), CP + PRP (200 μl, ip, half an hour after CP injection on day 1 and 10), CP + PTX (50 mg/kg, orally, half an hour after CP injection daily for 21 day), and CP + PRP + PTX. At the end of experiments on day 21, measurement of body weight, ovarian parameters (ovarian volume, follicular granulosa cell layers diameter, oocyte diameter, and the number of granulosa cells), measurement of ovarian hormone in sera for estradiol (E₂), and anti-Mullerian hormone (AMH), as well as biochemical assessment were performed.The results showed that CP significantly reduced the ovarian parameters, E₂, AMH, superoxide dismutase (SOD) activity and increased Malondialdehyde (MDA) levels compared to the control group (p < 0.001). Our results also indicated that all histomorphometric parameters and biochemical markers in CP-induced POF, were preserved close to normal by PRP and PTX treatments in both mature and immature rats (p < 0.001). Therefore, it is concluded that the co-administration of PRP and PTX can protect the ovary from CP-induced POF.