Does platelet lysate switch cryopreserved human tissues on?

Objective To compare the effects of platelet rich plasma(PRP)and platelet lysate(PL)on proliferation and cell cycle of cultured rat bone marrow stem cells(BMSCs).Methods BMSCs were obtained from twenty 4-week-old SD rats using the whole bone marrow isolation and cultivation method and were identified with flow cytometry.Blood samples were taken from the hearts of thirty 12-week-old SD rats and gradient centrifugation was used to prepare PRP,and PL was obtained after three times of centrifugation and repeated freezing and thawing.The third generation of BMSCs with good growth state were divided into seven groups according to different culture media:ordinary complete medium(A group),1% PRPconditioned medium(B group),1% PL-conditioned medium(C group),5% PRP-conditioned medium(D group),5% PLconditioned medium(E group),10% PRP-conditioned medium(F group),and 10% PL-conditioned medium(G group). The proliferation of BMSCs was assessed by MTT assay.The PCNA protein expression was assessed by immunofluorescence method.Cell cycle of BMSCs was tested by flow cytometry.Western blotting analysis was used to analyze CyclinD1and p27 Kip1protein expression of BMSCs.Results The proliferation of BMSCs was significantly promoted by 1%,5%,10% PRPand 1%,5%,10% PL-conditioned media after cultured for 24h,48h,and 72hin a time-and dose-dependent manner(P 0.05),with the effect of PRP and PL being similar at the same concentration(P0.05).Immunofluorescence assay showed that PRP and PL both significantly promoted PCNA protein expression in a dose-dependent manner(P0.01).Flow cytometry showed that different concentrations of PRP- and PL-conditioned media,compared with the ordinary complete medium,resulted in gradually reduced cells in G0/G1 phase,gradually increased cells in S,G2 /M phase,and significantly increased PI(P0.05),with the changes in a dose-dependent manner.However,the effects of the same concentration of PRP and PL on cell cycle were not significantly different(P0.05).Western blotting analysis showed that 5% PRP and 5% PL significantly up-regulated CyclinD1and down-regulated the expression of p27Kip1.Conclusion Different concentrations of PL and PRP can accelerate cell cycle progression of cultured rat BMSCs by up-regulation CyclinD1and inhibiting p27Kip1, promoting the proliferation of BMSCs in a time-and dose-dependent manner.PL and PRP at the same concentration have the same proliferation-promoting effect,indicating that PL may be used as an alternative of PRP to promote the repair of bone defects.

The effects of human platelet lysate on dental pulp stem cells derived from impacted human third molars

Platelet Lysate Promotes Proliferation and Angiogenic Activity of Dental Pulp Stem Cells via Store-operated Ca2+ Entry

Background: Mesenchymal stromal cells (MSCs) are employed in various different clinical settings in order to modulate immune response. Human autologous and allogeneic supplements including platelet derivatives such as platelet lysate (PL), platelet-released factors (PRF) and serum are assessed in clinical studies to replace fetal bovine serum (FBS). The immunosuppressive activity and multi-potential characteristic of MSCs appear to be maintained when the cells are expanded in platelet derivatives.Materials and Methods: Platelet-rich plasma was collected from umbrical cord blood (UCB). Platelet-derived growth factors obtained by freeze and thaw methods. CD62P expression was determined by flow cytometry. The concentration of PDGF-BB and PDGF-AB was detemined by ELISA. We tested the ability of a different concentration of PL-supplemented medium to support the ex vivo expansion of Wharton's jelly derived MSCs. We also investigated the biological/functional properties of expanded MSCs in presence of different concentration of PL. The conventional karyotyping was performed in order to study the chromosomal stability. The gene expression of Collagen I and II aggrecan and SOX-9 in the presence of different concentrations of PL was evaluated by Real-time PCR.Results: We observed 5% and 10% PL, causing greater effects on proliferation of MSCs .These cells exhibited typical morphology, immunophenotype and differentiation capacity. The genetic stability of these derivative cells from Wharton's jelly was demonstrated by a normal karyotype. Furthermore, the results of Real-time PCR analysis showed that the expression of chondrocyte specific genes was higher in MSCs in the presence of 5% and 10% PL, compared with FBS supplement.Conclusions: We demonstrated that PL could be used as an alternative safe source of growth factors for expansion of MSCs and also maintained similar growing potential and phenotype without any effect on chromosomal stability.

ObjectivesPlatelet-rich plasma (PRP) is being used increasingly often in the clinical setting to treat tendon-related pathologies. Yet the optimal PRP preparations to promote tendon healing in different patient populations are poorly defined. Here, we sought to determine whether increasing the concentration of platelet-derived proteins within a derivative of PRP, platelet lysate (PL), enhances tenocyte proliferation and migration in vitro, and whether the mitogenic properties of PL change with donor age.MethodsConcentrated PLs from both young (< 50 years) and aged (> 50 years) donors were prepared by exposing pooled PRP to a series of freeze-thaw cycles followed by dilution in plasma, and the levels of several platelet-derived proteins were measured using multiplex immunoassay technology. Human tenocytes were cultured with PLs to simulate a clinically relevant PRP treatment range, and cell growth and migration were assessed using DNA quantitation and gap closure assays, respectively.ResultsPlatelet-derived protein levels increased alongside higher PL concentrations, and PLs from both age groups improved tenocyte proliferation relative to control conditions. However, PLs from aged donors yielded a dose-response relationship in tenocyte behaviour, with higher PL concentrations resulting in increased tenocyte proliferation and migration. Conversely, no significant differences in tenocyte behaviour were detected when increasing the concentration of PLs from younger donors.ConclusionHigher PL concentrations, when prepared from the PRP of aged but not young donors, were more effective than lower PL concentrations at promoting tenocyte proliferation and migration in vitro.Cite this article: D. R. Berger, C. J. Centeno, N. J. Steinmetz. Platelet lysates from aged donors promote human tenocyte proliferation and migration in a concentration-dependent manner. Bone Joint Res 2019;8:32–40. DOI: 10.1302/2046-3758.81.BJR-2018-0164.R1.

Platelet lysate reduces the chondrocyte dedifferentiation during in vitro expansion: Implications for cartilage tissue engineering

Platelet lysate is beneficial for chondrocyte expansion but ineffective in 3d culture

BACKGROUND: Mesenchymal stem cells (MSCs) have been considered for human regenerative therapy applications, and safe culture and expansion protocols are needed especially in the context of interspecies contamination. Human platelet lysate (PL) has been proposed as animal serum substitute during in vitro MSC expansion. In this work, a simplified and efficient method to obtain autologous PL to replace animal serum in cell culture applications is described.STUDY DESIGN AND METHODS: PL obtained by freezing and centrifugation procedures was tested as medium supplement for human adipose mesenchymal stem cell (hASC) culture. Differential proliferation, immunophenotypic changes, and differentiation under PL or fetal bovine serum (FBS) were assessed.RESULTS: In contrast to 10% FBS supplementation, cell population doubling time was significantly lower when hASCs were cultured with the same concentration of PL (PL 22.9 ± 1.5 hr vs. FBS 106.7 ± 6.5 hr, t test, p &lt; 0.05). Furthermore, hASCs maintained with 2.5% PL supplementation also showed satisfactory results. Immunophenotypic analysis revealed no differences between hASCs cultivated with PL or FBS supplementation and both cultures retained the potential to differentiate into adipose cells. These results demonstrate that autologous PL obtained from the same donor can be used as animal serum substitute in hASC culture.CONCLUSIONS: Taken together, evidence is provided that platelets provided by a single donor are sufficient to obtain PL for hASC propagation for clinical‐scale applications mitigating the potential untoward side effects associated with the use of animal‐derived reagents.

Multipotent mesenchymal stromal cells (MSC) are often culture-expanded invitro. Presently, expansion medium (EM) for MSC is supplemented with fetal bovine serum (FBS). However, increasing cost, variable composition and potential risks associated with bovine antigens call for alternatives. Platelet lysate (PL) has shown promise as an alternative supplement. To determine how equine umbilical cord blood (CB) MSC proliferate in EM enriched with PL or FBS at various concentrations. Randomised dose escalation study. Platelet concentrate was generated from 5 equine whole blood samples through a double centrifugation method and standardised to 1×10(12) platelets/l prior to a freeze/thaw cycle to produce PL. Pooled PL or pooled FBS was added to EM at concentrations of 5% to 60%. Proliferation of 4 equine CB-MSC cultures was determined after 4days using a resazurin semiquantitative assay. Cord blood-MSC proliferated with a dose-dependent response with no significant difference found between PL and FBS up to a 30% concentration. Beyond 30%, proliferation fell in the PL-cultured cells, while continued dose-dependent proliferation was noted in the FBS-cultured cells. Despite reduced cell numbers in high PL concentrations, live/dead staining revealed that adherent cells remained viable. Expansion medium enriched with PL can support short-term equine CB-MSC proliferation at conventional culture concentrations. Based on the unexpected suppression of CB-MSC at higher PL concentrations, an invivo dose study is indicated to investigate if combinational therapies of CB-MSC and platelet-rich plasma are associated with synergistic or antagonistic effect on CB-MSC function.

Mesenchymal stem cells (MSCs) are highly preferred in clinical therapy for repair and regeneration of diseased tissues for their multipotent properties. Conventionally, MSCs have been cultured in media supplemented with animal derived serum, however, it is ideal to expand MSCs in media containing supplements of human origin for clinical therapy. Currently, a number of human derived products are being studied as an alternative to animal sources. Amongst these, platelet lysate (PL) has gained interest in the culture of MSCs without affecting their phenotypic property. In this study, we used various concentration of PL (2.5, 5, 7.5 & 10%) in the growth medium of MSCs to identify the least concentration of PL that could be an effective alternative to animal products. MSCs were isolated from Wharton's Jelly by using explant method and expanded in various concentration of PL supplemented medium against the standard FBS containing medium. WJ-MSCs were characterised as per the minimal criteria proposed by International Society for Cell therapy (ISCT), Proliferation study by BrdU assay, gene expression study by qRT-PCR, sterility test for bacteria, Mycoplasma by PCR and endotoxin detection by LAL assay. Whartons jelly derived MSCs (WJ-MSCs) cultured using standard medium supplemented with various concentration of PL exhibited enhanced proliferation and differentiation potential, unaltered immunophenotypic property and genetic stability when compared with the commercial medium containing 10% FBS. The least concentration of PL for an ideal expansion of MSCs was found to be 2.5% and was comparable to FBS.

Poor viability of mesenchymal stem cells (MSCs) at the transplanted site often hinders the efficacy of MSCs-based therapy. Platelet lysate (PL) contains rich amounts of growth factors, which benefits cell growth. This study aimed to explore how human PL benefits umbilical cord-derived MSCs (huc-MSCs), and whether they have synergistic potential in osteoarthritis (OA) treatment. As quality control, flow cytometry and specific staining were performed to identify huc-MSCs, and ELISA was used to quantify growth factors in PL. CCK-8 and flow cytometry assays were performed to evaluate the effects of PL on the cell viability and cell cycle progression of huc-MSCs. Wound healing and transwell assays were conducted to assess the migration of huc-MSCs. RNA sequencing, real time PCR, and Western blot assays were conducted to explore the growth factors-based mechanism of PL. The in vitro results showed that PL significantly promoted the proliferation, cell cycle, and migration of huc-MSCs by upregulating relevant genes/proteins and activating beclin1-dependent autophagy via the AMPK/mTOR signaling pathway. The main growth factors (PDGF-AA, IGF-1, TGF-β, EGF, and FGF) contributed to the effects of PL in varying degrees. The in vivo data showed that combined PL and huc-MSCs exerted significant synergistic effect against OA. The overall study determined the beneficial effects and mechanism of PL on huc-MSCs and indicated PL as an adjuvant for huc-MSCs in treating OA. This is the first report on the growth factors-based mechanism of PL on huc-MSCs and their synergistic application. It provides novel knowledge of PLʹs roles and offers a promising strategy for stem cell-based OA therapy by combining PL and huc-MSCs.

Background: Thrombocytosis in breast cancer (BC) patient was thought to play a role in the invasiveness of breast cancer stem cells (BCSCs). Modification of tumor microenvironment was proposed to increase the efficacy of anticancer therapy. This study was aimed to analyze the effect of platelet lysate (PL) as well as its PDGF-AB content as a tumor microenvironment on (CD24-/CD44+) BCSC proliferation.Methods: This was an experimental study that treated culture of BCSCs with PL from breast cancer (BC) patients or healthy donors. Venous blood from all subjects were subjected to prior hematology test and then processed to obtain platelet rich plasma (PRP). Platelet counts in PRP were determined. PRP was processed to obtain PL. PDGF-AB contents in PL were measured. PL at concentrations of 0.01% (v/v) was supplemented into DMEM-F12 medium and used for culturing BCSCs (CD24-/CD44+ cells). After 48 hours, total cell count, population doubling time (PDT), and cell viability were calculated and their correlation with platelet count and PDGF-AB levels were analyzed.Results: BC patients (n=5) had higher platelet counts and PDGF-AB levels in PL compared to healthy donors (n=15), (p=0.02). PL from BC patients could stimulate the proliferation of BCSCs higher than healthy donors (p&lt;0.001) and showed lower PDT value (p=0.001). Cell proliferation and PDT showed strong correlation with PDGF-AB level. This observation suggests that PDGF-AB has a role on BCSCs proliferation. PL showed no effect on BCSCs viability.Conclusion: Breast cancer patient platelet lysate stimulated BCSC proliferation.

Background: More understanding of the physiological needs of the embryo during its growth from the zygote to the blastocyst stage, as well as the composition of the uterine and fallopian tubal secretions, has led to the development of single-step or sequential culture media. Objectives: The present study aimed to investigate the utilization of mCR2aa culture medium as a sequential culture medium for embryo development, supplemented with platelet lysate (PL) to decrease the concentration of fetal bovine serum (FBS) in the embryo culture medium. Methods: After maturation and fertilization of sheep oocytes obtained from a slaughterhouse, potential zygotes were cultured in mCR2aa medium without FBS for two days (C1, 1 - 3 days of culture). In the second two days of culture (C2, 3 - 5 days of culture), 2.5% or 5% of FBS and 5% or 10% of PL were used. In the remaining days of culture (C3, 5 - 9 days of culture), 2.5%, 5%, or 10% of FBS, and 0%, 2.5%, 5%, or 10% of PL were used. These percentages were compared to the commercial BO-IVC™ medium and mCR2aa medium, both of which contained 10% of FBS. Results: No significant difference was observed in the number of produced blastocysts between different treatments and the control. However, the number of hatched blastocysts in BO-IVC™, as a single-step culture medium, significantly differed from that of the other treatments. The number of hatched blastocysts in the sequential culture medium was higher in media supplemented with 2.5% FBS and 10% PL in the C2 mCR2aa medium, and 2.5% FBS without PL in the C3 mCR2aa medium, but no significant difference was observed in other treatments. However, increasing the concentration of FBS and PL in the C3 mCR2aa medium significantly decreased the number of hatched blastocysts. Conclusions: An increase in the percentage of PL to 10% necessitated a decrease in FBS to 2.5% in the C2 mCR2aa medium, while PL in the C3 mCR2aa medium was not required in the presence of 2.5% FBS.

BackgroundPlatelet lysate (PL) had a remarkable therapeutic effect on bone repair related diseases, such as delayed fracture healing, femoral head necrosis and meniscal tear. In this study, we investigated the effect of PL on patients with nonunion, cartilage repair and osteonecrosis, and to evaluate the effect of PL on nonunion cells proliferation and the effect of PL on OPG/RANKL signaling pathway in nonunion cell of male rats. To reveal the molecular mechanism of PL for bone healing.MethodsWe used different concentrations of PL to treat nonunion cells, then detected cell proliferation and protein expression levels of osteoprotegerin (OPG), RANKL, osteopontin (OPN), osteocalcin (OCN) and alkaline phosphatase (ALP).ResultsThe proliferation rate of nonunion cells treated by 5% PL, was significantly higher than that of the control group (P<0.05). Surprisingly, there were no significant difference among the proliferation rates of nonunion cells treated by 8% PL, 10% FBS and the control group (P>0.05). the results of western blot analysis and immunofluorescence analysis showed that PL improved the expression of OPG, OPN, OCN and ALP proteins in nonunion cells, but PL had no effect on the expression of nuclear factor-κB ligand (RANKL) protein.ConclusionsWe found that PL had a remarkable therapeutic effect on bone repair related diseases; 5% PL significantly improved the proliferation rate of the nonunion cells; 10% PL had a significantly positive effect on improving the expression levels of osteogenic related genes.

Background: Fetal bovine serum (FBS) is rich in nutrients, growth factors, hormones, and other essential compounds necessary for cell growth. However, its use has several disadvantages. Platelets in particular contain the majority of the potent mitogenic factors found in serum. Objectives: The present study aimed to evaluate the effect of platelet lysate (PL) on in vitro embryo production by replacing FBS, to determine if this modified Charles Rosenkrans medium (mCR2aa) can support ovine embryo development compared to the commercially available BO-IVC medium. Methods: In the first experiment, varying concentrations of FBS (0%, 2.5%, 5%, and 10%) and PL (0%, 2.5%, 5%, and 10%) were investigated in the mCR2aa culture medium. In the second experiment, the optimized mCR2aa medium was compared to the BO-IVC medium. Ovine oocytes were matured and fertilized in vitro using BO-IVM Bioscience medium and Brackett and Oliphant medium, respectively. Subsequently, the resulting zygotes were cultured in either mCR2aa medium supplemented with amino acids or BO-IVC medium, according to the experimental design, under a humidified atmosphere of 5% CO2, 5% O2, and 90% N2 at 38.5ºC. Results: The results indicated that using 5% PL in the mCR2aa culture medium reduced the serum percentage to 2.5%. Conclusions: It was not possible to completely eliminate serum from the mCR2aa medium solely by substituting it with PL. Further studies are needed to explore other serum properties such as chelating agents and antioxidant activities to fully optimize the mCR2aa medium without serum.