Platelet-Rich Plasma as an Alternative to Xenogeneic Sera in Cell-Based Therapies: A Need for Standardization

There has been an explosion in scientific interest in using human-platelet-rich plasma (PRP) as a substitute of xenogeneic sera in cell-based therapies. However, there is a need to create standardization in this field. This systematic review is based on literature searches in PubMed and Web of Science databases until June 2021. Forty-one studies completed the selection criteria. The composition of PRP was completely reported in less than 30% of the studies. PRP has been used as PRP-derived supernatant or non-activated PRP. Two ranges could be identified for platelet concentration, the first between 0.14 × 10⁶ and 0.80 × 10⁶ platelets/µL and the second between 1.086 × 10⁶ and 10 × 10⁶ platelets/µL. Several studies have pooled PRP with a pool size varying from four to nine donors. The optimal dose for the PRP or PRP supernatant is 10%. PRP or PRP-derived supernatants a have positive effect on MSC colony number and size, cell proliferation, cell differentiation and genetic stability. The use of leukocyte-depleted PRP has been demonstrated to be a feasible alternative to xenogeneic sera. However, there is a need to improve the description of the PRP preparation methodology as well as its composition. Several items are identified and reported to create guidelines for future research.

Xanthine oxidoreductase activity in platelet-poor and rich plasma as a oxidative stress indicator in patients required renal replacement therapy

Background

Xanthine oxidoreductase (XOR) is a hydroxylase enzyme involved in the metabolism of purines. XOR activity can vary: the homodimer protein can be converted into two different isoforms XD (antioxidant) and XO (prooxidant). Oxidative stress and inflammation that accompanying chronic kidney disease (CKD), dialysis, and kidney transplantation, resulted in platelet activation. Present study aimed to determine the influence of applied renal replacement therapy on xanthine oxidoreductase and its isoforms activity.

Materials and Methods

The study group consisted of 117 patients, divided into 4 groups: hemodialysis - 30 patients, peritoneal dialysis - 30 patients, kidney transplant patients - 27 and conservative treatment - 30 patients. The control group consisted of 30 healthy volunteers.

Results

Significant differences were found in XOR activity in platelet-poor plasma (PPP) within the groups studied (p = 0.001). There was a relationship between the type of renal replacement therapy of all oxidoreductase isoforms in PPP (p < 0.001 all isoforms) and XD (p = 0.008), XO (p < 0.001) in platelet rich-plasma (PRP). A relationship was observed between the activity of all oxidoreductase isoforms in PPP and PRP, and the type of renal replacement therapy and the duration of dialysis and the age of patients. The cause of chronic kidney disease was also reflected differences in XD and XO activity in PPP.

Conclusions

The type of renal replacement therapy used in CKD patients, age of patients, duration of dialysis, CKD causes, and stage of progression significantly affect the activity of XOR and its isoforms.

Healing through the lens of immunothrombosis: Biology-inspired, evolution-tailored, and human-engineered biomimetic therapies

Evolution, from invertebrates to mammals, has yielded and shaped immunoclotting as a defense and repair response against trauma and infection. This mosaic of immediate and local wound-sealing and pathogen-killing mechanisms results in survival, restoration of homeostasis, and tissue repair. In mammals, immunoclotting has been complemented with the neuroendocrine system, platelets, and contact system among other embellishments, adding layers of complexity through interconnecting blood-born proteolytic cascades, blood cells, and the neuroendocrine system. In doing so, immunothrombosis endows humans with survival advantages, but entails vulnerabilities in the current unprecedented and increasingly challenging environment. Immunothrombosis and tissue repair appear to go hand in hand with common mechanisms mediating both processes, a fact that is underlined by recent advances that are deciphering the mechanisms of the repair process and of the biochemical pathways that underpins coagulation, hemostasis and thrombosis. This review is intended to frame both the universal aspects of tissue repair and the therapeutic use of autologous fibrin matrix as a biology-as-a-drug approach in the context of the evolutionary changes in coagulation and hemostasis. In addition, we will try to shed some light on the molecular mechanisms underlying the use of the autologous fibrin matrix as a biology-inspired, evolution-tailored, and human-engineered biomimetic therapy.

Phase II multicenter randomized controlled clinical trial on the efficacy of intra-articular injection of autologous bone marrow mesenchymal stem cells with platelet rich plasma for the treatment of knee osteoarthritis

Background

Mesenchymal stromal cells are a safe and promising option to treat knee osteoarthritis as previously demonstrated in different clinical trials. However, their efficacy, optimal dose and addition of adjuvants must be determined. Here, we evaluated the clinical effects of a dose of 100 × 10⁶ bone marrow mesenchymal stromal cells (BM-MSCs) in combination with Platelet Rich Plasma (PRGF®) as adjuvant in a randomized clinical trial.

Methods

A phase II, multicenter, randomized clinical trial with active control was conducted. Sixty patients diagnosed with knee OA were randomly assigned to 3 weekly doses of PRGF® or intraarticular administration of 100 × 10⁶ cultured autologous BM-MSCs plus PRGF®. Patients were followed up for 12 months, and pain and function were assessed using VAS and WOMAC and by measuring the knee range of motion range. X-ray and magnetic resonance imaging analyses were performed to analyze joint damage.

Results

No adverse effects were reported after BM-MSC administration or during follow-up. According to VAS, the mean value (SD) for PRGF® and BM-MSC with PRGF® went from 5 (1.8) to 4.5 (2.2) (p = 0.389) and from 5.3 (1.9) to 3.5 (2.5) (p = 0.01), respectively at 12 months. In WOMAC, the mean (SD) baseline and 12-month overall WOMAC scores in patients treated with PRGF® was 31.9 (16.2) and 22.3 (15.8) respectively (p = 0.002) while that for patients treated with BM-MSC plus PRGF® was 33.4 (18.7) and 23.0 (16.6) (p = 0.053). Although statistical significances between groups have been not detected, only patients being treated with BM-MSC plus PRGF® could be considered as a OA treatment responders following OARSI criteria. X-ray and MRI (WORMS protocol) revealed no changes in knee joint space width or joint damage.

Conclusions

Treatment with BM-MSC associated with PRGF® was shown to be a viable therapeutic option for osteoarthritis of the knee, with clinical improvement at the end of follow-up. Further phase III clinical trials would be necessary to confirm the efficacy.

Trial registration Clinical Trials.gov identifier NCT02365142. Nº EudraCT: 2011-006036-23

The Effects of Platelet-Rich and Platelet-Poor Plasma on Biological Characteristics of BM-MSCs In Vitro

Platelet-rich plasma (PRP) and its byproduct platelet-poor plasma (PPP) are rich sources of cytokines in tissue damage repair. Bone marrow-derived mesenchymal stem cells (BM-MSCs) have received more and more attention for their ability to treat multiple diseases. The purpose of our study was to investigate the biologic action of PPP and PRP on BM-MSCs. The adipogenic potential of BM-MSCs revealed no obvious change, but the osteogenic ability of BM-MSCs was enhanced after treated with PRP. CCK8 assays and cell colony formation assays showed that PRP promoted cell proliferation, while this effect of PPP was not obvious. No obvious difference was found in cell cycle and apoptosis of BM-MSCs between PRP and PPP treatment. Expression of β-galactosidase, a biological marker of senescence, was decreased upon PRP treatment which indicated that PRP provided significant protection against cellular senescence. The migratory capacity of BM-MSCs was detected by scratch and transwell assays. The results indicated that PRP could affect the migration ability of BM-MSCs. From immunofluorescence detection and western blot, we demonstrated that the level of epithelial-mesenchymal transition-related proteins was changed and several pluripotency marker genes, including Sox2, Sall4, Oct4, and Nanog, were increased. Finally, the expression of the key signal pathway such as PI3K/AKT was examined. Our findings suggested that PRP promoted cell migration of BM-MSCs via stimulating the signaling pathway of PI3K/AKT.

Application effect of lattice laser in facial rejuvenation: A protocol for systematic review and meta-analysis

BACKGROUND

Various techniques have been applied in facial rejuvenation and lattice laser is the most accepted. However, the application effect of lattice laser in facial rejuvenation is unclear. This study aims to evaluate the application effect of lattice laser in facial rejuvenation.

METHODS

Randomized controlled trials of lattice laser in facial rejuvenation will be searched in PubMed, EMbase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, WanFang, the Chongqing VIP Chinese Science and Technology Periodical Database, and China biomedical literature database from inception to July 2020. And Baidu Scholar, International Clinical Trials Registry Platform, Google Scholar, and Chinese Clinical Trials Registry will be searched to obtain more relevant studies comprehensively. Two researchers will perform data extraction and risk of bias assessment independently. Statistical analysis will be conducted in RevMan 5.3.

RESULTS

This study will sum up the present evidence so far by exploring the application effect of lattice laser in facial rejuvenation.

CONCLUSIONS

The findings of the study will provide helpful evidence for the application effect of lattice laser in facial rejuvenation, promoting clinical practice, and further scientific research.

ETHICS AND DISSEMINATION

The private information from individuals will not publish. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/QF6H5.

Randomised, prospective clinical trial of platelet-rich plasma injection in the management of severe dry eye

BACKGROUND

To evaluate the effectiveness of platelet-rich plasma (PRP) injections in the treatment of severe dry eye.

METHODS

This prospective, intervention study included patients with severe dry eye who had been diagnosed with Sjogren syndrome. Patients were divided into two groups. The intervention group received PRP (n=15) injections on days 0, 30, 60 and 90, as well as hyaluronic acid five times per day. The comparison group received hyaluronic acid (n=15) five times per day. Subjects were measured at baseline and at 30, 60 and 90 days. The primary outcome measures were changes in corneal staining according to the Oxford classification, results of the Schirmer test and tear break-up time (TBUT). The secondary outcome measures were changes in the Ocular Surface Disease Index (OSDI) and treatment compliance.

RESULTS

All subjects completed the study. The intervention group showed improvements in all primary outcome measures when compared with the control group, including a reduction in corneal staining (p<0.001), increase in the mean Schirmer value from 5.6±0.7 to 9.0±1.1 mm, and an increase in TBUT from 4.0±0.4 to 6.4±0.4 s at day 90. An improvement in subjective OSDI values was also found.

CONCLUSION

PRP injection is safe and effective in improving tear parameters as well as subjective parameters, and was found to be superior to hyaluronic acid alone in the management of patients with severe dry eye. This represent a novel alternative treatment for severe dry eye.

TRIAL REGISTRATION NUMBER

NCT02257957.

Investigation of modified platelet-rich plasma (mPRP) in promoting the proliferation and differentiation of dental pulp stem cells from deciduous teeth

Stem cells from human exfoliated deciduous teeth (SHEDs) have great potential to treat various dental-related diseases in regenerative medicine. They are usually maintained with 10% fetal bovine serum (FBS) in vitro. Modified platelet-rich plasma (mPRP) would be a safe alternative to 10% FBS during SHEDs culture. Therefore, our study aimed to compare the proliferation and differentiation of SHEDs cultured in mPRP and FBS medium to explore an optimal concentration of mPRP for SHEDs maintenance. Platelets were harvested by automatic blood cell analyzer and activated by repeated liquid nitrogen freezing and thawing. The platelet-related cytokines were examined and analyzed by ELISA. SHEDs were extracted and cultured with different concentrations of mPRP or 10% FBS medium. Alkaline phosphatase (ALP) activity was measured. Mineralization factors, RUNX2 and OCN, were measured by real-time PCR. SHEDs were characterized with mesenchymal stem cells (MSCs) markers including vimentin, CD44, and CD105. mPRP at different concentrations (2, 5, 10, and 20%) enhanced the growth of SHEDs. Moreover, mPRP significantly stimulated ALP activity and promoted expression of RUNX2 and OCN compared with 10% FBS. mPRP could efficiently facilitate proliferation and differentiation of SHEDs, and 2% mPRP would be an optimal substitute for 10% FBS during SHEDs expansion and differentiation in clinical scale manufacturing.

Platelet lysate supports the in vitro expansion of human periodontal ligament stem cells for cytotherapeutic use

Human platelet lysate (PL) produced under optimal conditions of standardization and safety has been increasingly suggested as the future 'gold standard' supplement to replace fetal bovine serum (FBS) for the ex vivo propagation of mesenchymal stem cells for translational medicine and cell therapy applications. However, the multifaceted effects of PL on tissue-specific stem cells remain largely unexplored. In the present study, we investigated the stem cell behaviours of human periodontal ligament stem cells (PDLSCs) in media with or without PL. Our data indicate that human PL, either as an adjuvant for culture media or as a substitute for FBS, supports the proliferation and expansion of human PDLSCs derived from either 'young' or 'old' donors to the same extent as FBS, without interfering with their immunomodulatory capacities. Although PL appears to inhibit the in vitro differentiation of 'young' or 'old' PDLSCs, their decreased osteogenic potential may be restored to similar or higher levels compared with FBS-expanded cells. PL- and FBS-expanded PDLSCs exhibited a similar potential to form mineralized nodules and expressed similar levels of osteogenic genes. Our data indicate that large clinically relevant quantities of PDLSCs may be yielded by the use of human PL; however, further analysis of its precise composition and function will pave the way for determining optimized, defined culture conditions. In addition to the potential increase in patient safety, our findings highlight the need for further research to develop the potential of PL-expanded PDLSCs for clinical use. Copyright © 2016 John Wiley & Sons, Ltd.

Infiltration of plasma rich in growth factors enhances in vivo angiogenesis and improves reperfusion and tissue remodeling after severe hind limb ischemia

PRGF is a platelet concentrate within a plasma suspension that forms an in situ-generated fibrin-matrix delivery system, releasing multiple growth factors and other bioactive molecules that play key roles in tissue regeneration. This study was aimed at exploring the angiogenic and myogenic effects of PRGF on in vitro endothelial cells (HUVEC) and skeletal myoblasts (hSkMb) as well as on in vivo mouse subcutaneously implanted matrigel and on limb muscles after a severe ischemia. Human PRGF was prepared and characterized. Both proliferative and anti-apoptotic responses to PRGF were assessed in vitro in HUVEC and hSkMb. In vivo murine matrigel plug assay was conducted to determine the angiogenic capacity of PRGF, whereas in vivo ischemic hind limb model was carried out to demonstrate PRGF-driven vascular and myogenic regeneration. Primary HUVEC and hSkMb incubated with PRGF showed a dose dependent proliferative and anti-apoptotic effect and the PRGF matrigel plugs triggered an early and significant sustained angiogenesis compared with the control group. Moreover, mice treated with PRGF intramuscular infiltrations displayed a substantial reperfusion enhancement at day 28 associated with a fibrotic tissue reduction. These findings suggest that PRGF-induced angiogenesis is functionally effective at expanding the perfusion capacity of the new vasculature and attenuating the endogenous tissue fibrosis after a severe-induced skeletal muscle ischemia.