Search Results (103)

Bioabsorbable scaffolds from synthetic polyesters are widely used in the field of tissue engineering. However, their hydrophobic surface and lack of suitable functional groups are the main limitations related to cell attachment. The aim of this research was to modify the surface of polycaprolactone (PCL) scaffolds using a bioactive coating containing heparin bound via albumin spacer and platelet lysate over heparin. Porous scaffolds were produced by electrospinning from 10% PCL (w/w) solution in methylene chloride (25 kV voltage, 100 mm distance between electrodes and 4 mL/h feedrate), which demonstrated 5.5 ± 1.1 MPa Young’s modulus, 2.5 ± 0.4 MPa tensile strength and 321 ± 29% elongation at break. Bioactive coating does not change the structure and mechanical properties of the scaffolds. Treated scaffolds are biocompatible and have no cytotoxic effect in direct contact with cells. Functionalization also promotes the in vitro adhesion and proliferation of human adipose mesenchymal stromal cells. After 7 days of incubation, the PCL scaffold modified with the heparin–platelet lysate complex had a cell density of 185.6 ± 15.7 cells/mm² compared to 79.5 ± 7.8 cells/mm² for nontreated control. The intramuscular implantation of scaffolds revealed that immobilization of heparin alone prolongs the acute phase of the inflammatory reaction. However, subsequent treatment with platelet lysate minimizes the inflammatory reaction, slows the rate of implant absorption, and accelerates vascularization. The results obtained show that the developed bioactive coating improves the cellular properties of PCL electrospun scaffolds and can be used to form in vivo tissue-engineered constructs. Full article

Human adipose-derived stem cells (hASCs) are widely used in regenerative medicine due to their accessibility and high proliferative capacity. Platelet lysate (PL) has recently emerged as a promising alternative to fetal bovine serum (FBS), offering superior cell expansion potential; however, the molecular basis for its efficacy remains insufficiently elucidated. In this study, we performed RNA sequencing to compare hASCs cultured with PL or FBS, revealing a significant upregulation of genes related to stress response and cell proliferation under PL conditions. These findings were validated by RT–qPCR and supported by functional assays demonstrating enhanced cellular resilience to oxidative and genotoxic stress, reduced doxorubicin-induced senescence, and improved antiapoptotic properties. In a murine wound model, PL-treated wounds showed accelerated healing, characterized by thicker dermis-like tissue formation and increased angiogenesis. Immunohistochemical analysis further revealed elevated expression of chk1, a DNA damage response kinase encoded by CHEK1, which plays a central role in maintaining genomic integrity during stress-induced repair. Collectively, these results highlight PL not only as a viable substitute for FBS in hASC expansion but also as a bioactive supplement that enhances regenerative efficacy by promoting proliferation, stress resistance, and antiaging functions. Full article

Background and Objectives: Complications in wound healing present significant challenges in clinical settings. While platelet-rich plasma from human sources has been extensively used to aid wound recovery, allogeneic or xenogeneic platelet-derived products remain in the research phase. This study aimed to assess both the immunogenicity and therapeutic potential of xenogeneic porcine platelet lysate (pPL) in wound healing, using a rat model. Materials and Methods: Porcine platelet lysates with undetectable levels of antigens, including blood cells and complement factors, were engineered. Rat models simulating wound conditions were employed to investigate the effects of xenogeneic pPL on injured skin tissues. Histological assessments, including re-epithelialization, angiogenesis, and inflammatory cell response, were comprehensively conducted to evaluate the healing process. Results: The application of xenogeneic pPL on rat skin incisions significantly expedited the wound healing process. No rejection reaction was observed. Histological examinations of the xenogeneic pPL-treated wounds revealed enhanced re-epithelialization and angiogenesis compared to the wounds in control groups. Conclusions: These findings support the clinical promise of xenogeneic pPL as a feasible and effective agent for wound repair and tissue regeneration. This study suggests that its potential application in in vivo regeneration appears viable and promising. Full article

Platelet mitochondria have recently been increasingly considered “co-principal” along with platelet growth factors to facilitate tissue regeneration in platelet-rich plasma therapy cooperatively. To develop a convenient method to test this potential, we examined mitochondrial transfer using a simple two-dimensional culture system. Living human platelets were prepared from PRP obtained from 12 non-smoking healthy male adults (age: 28–63 years) and suspended in medium. Platelet lysates were prepared from sonicated platelet suspensions in PBS. After treatment with ultraviolet-C irradiation, a mitochondrial respiration inhibitor, or a synchronized culture reagent, rat dental pulp-derived fibroblasts (RPC-C2A) were co-cultured with platelets or platelet lysates for 24 h. Mitochondrial transfer was evaluated by visualization using a fluorescent dye for mitochondria or an antibody against human mitochondria. Ultraviolet-C-irradiated cells substantially lost their viability, and treatment with living platelets, but not platelet lysates, significantly rescued the damaged fibroblasts. Fibroblast mitochondria appeared to increase after co-culture with resting platelets. Although more microparticles existed around the platelets on the fibroblast surface, the activated platelets did not show significant increases in any parameters of mitochondrial transfer. This simple co-culture system demonstrated mitochondrial transfer between xenogeneic cells, and this phenomenon should be considered as an additional implication in PRP therapy. Full article

Background: Mesenchymal stem cell-based therapy may be indicated in ischaemic heart disease. The use of autologous adipose-derived mesenchymal stromal cells (AdMSCs) offers regenerative potential due to their paracrine effects. The aim of this study was to expand and characterise adult human thymus-derived MSCs harvested during open heart surgery with respect to their stem cell and paracrine properties. Methods: Enzymatically and non-enzymatically isolated human thymic AdMSCs (ThyAdMSCs) were cultured in xeno-free media containing pooled human platelet lysate (pPL). MSC characterisation was performed. Ex vivo expanded ThyAdMSCs were differentiated into three lineages. Proliferative capacity and immunomodulatory properties were assessed by proliferation assays and mixed lymphocyte reaction, respectively. Gene expression analysis was performed by qPCR. Results: Both isolation methods yielded fibroblast-like cells with plastic adherence and high proliferation. Flow cytometry revealed distinct expression of MSC markers in the absence of haematopoietic cell surface markers. Ex vivo expanded ThyAdMSCs could be differentiated into adipocytes, osteocytes, and chondrocytes. Activated peripheral blood mononuclear cells were significantly reduced when co-cultured with ThyAdMSCs, indicating their ability to inhibit immune cells in vitro. Gene expression analysis showed significantly less IFNγ and TNFα, indicating an alteration of the activated and pro-inflammatory state in the presence of ThyAdMSCs. Conclusions: These results demonstrate an efficient method to generate AdMSCs from human thymus. These MSCs have a strong immunomodulatory capacity and are, therefore, a promising cell source for regenerative medicine. The culture conditions are crucial for cells to proliferate in culture. Further research could explore the use of ThyAdMSCs or their secretome in surgical procedures. Full article

Osteoarthritis (OA) remains a leading cause of disability worldwide, with no disease-modifying therapies currently available for treatment. The infrapatellar fat pad (IFP) harbors mesenchymal stem/stromal cells (MSC) with potent immunomodulatory and regenerative properties, making them a promising candidate for OA treatment. A growing body of evidence suggests that the therapeutic effects of MSC are largely mediated by their extracellular vesicles (EVs), which carry bioactive cargo that modulates inflammation and tissue repair. However, optimizing MSC-derived EVs as a cell-free therapeutic approach requires an in-depth understanding of how culture conditions and inflammatory/hormonal priming influence their functional properties. In this study, IFP-MSC were expanded in regulatory-compliant human platelet lysate (HPL) and xeno-/serum-free (XFSF) media and primed with an inflammatory/fibrotic cocktail (TIC) with oxytocin (OXT) to assess the impact on their immunophenotypic profile and EV cargo. The immunophenotype confirmed that TIC+OXT-primed MSC retained key immunomodulatory surface markers, while EV characterization verified the successful isolation of CD63+/CD9+ vesicles. Pathway enrichment analysis of both HPL- and XFSF- TIC+OXT EVs cargo identified key miRNAs associated with immune regulation, tissue repair, and anabolic signaling. Functional assays revealed that TIC+OXT EVs promoted M2-like anti-inflammatory macrophage polarization and exhibited chondroprotective properties in chondrocytes/synoviocytes inflammatory osteoarthritic assay. These findings highlight the therapeutic potential of TIC+OXT-primed IFP-MSC-derived EVs as immunomodulatory and chondroprotective agents, offering a promising strategy for OA treatment through a clinically viable, cell-free approach. Full article

Background/Objectives: Endothelial cell (EC) culture relies on specialized and commercial media with distinct growth supplement compositions. These media are expensive and must be imported, increasing the time to effective use. Human platelet lysate (PL) and platelet lysate serum (PLS) supplemented media are emerging alternatives to commercial media. Methods: Umbilical cords were collected, and human umbilical vein endothelial cells (HUVEC) were isolated and cultured using different media formulations, using Endothelial Cell Growth, Promocell^® (ECGM-Promocell^®) commercial medium, and media supplemented with PL and PLS. Results: A mixed medium combining DMEM-F12 + PLS and ECGM-Promocell^® maintained EC viability, adhesion, and proliferation. Introducing a PL-derived protein substrate enhanced cell adhesion and proliferation by simulating an extracellular matrix. Flow cytometry revealed positive CD31, CD144, and CD146 markers in cells cultured with ECGM-Promocell^® and the mixed medium, with or without the PL-protein substrate. Conclusions: These findings suggest that the mixed medium, especially with the PL protein substrate, offers a cost-effective and efficient approach for EC culture and proliferation, holding promise for research and therapeutic applications. Full article

Introduction: The preservation of mesenchymal stem cell (MSC) viability and biological activity is a key aspect in optimizing advanced therapy medicinal products (ATMPs). Evaluating various excipients to optimize MSC conservation and functionality is essential. Methods: Five excipients with different proportions of human platelet lysate (hPL) and Hypothermosol were evaluated at two different cell concentrations (0.1 × 10⁶ MSC/μL and 0.008 × 10⁶ MSC/μL). Cell viability, adhesion, and proliferation capacity were assessed at 24 and 48 h under hypothermic conditions (2–8 °C). Results: A significant interaction was observed between cell concentration and excipient, where the 0.008 × 10⁶ MSC/μL concentration showed better viability results. Excipients with a combination of 50–75% Hypothermosol improved cell viability and adhesion. No significant differences were found in cell proliferation among the excipients studied. Viability, adhesion, and proliferation decreased significantly at 48 h for all excipients and concentrations evaluated. Conclusions: The combination of hPL and Hypothermosol enhances MSC stability and preserves their functionality, suggesting its potential as an optimized storage solution for cell-based therapies. Additionally, the impact of cell concentration on viability underscores the importance of selecting appropriate dosing. Future studies should further investigate how these findings translate into clinical outcomes, particularly in terms of therapeutic efficacy and patient safety. Full article

Purpose: To evaluate the sterility and biological functionality of platelet lysate eye drops stored in BTI ophthalmic devices for PRGF delivery under different storage conditions and simulated use scenarios. Methods: Eye drops were prepared using platelet lysate and stored in BTI tubes under three different conditions: ≤−15 °C, 2–8 °C, and room temperature (RT) for 72 h. Simulated use was performed for 72 h with controlled drop dispensing. Bacterial contamination was assessed according to European Pharmacopoeia sterility testing principles. The biological activity of the eye drops was assessed using in vitro proliferation assays with primary human keratocytes (HKs) and human corneal epithelial cells (HCEs). Statistical analyses were performed to compare the effects of different storage conditions and application scenarios. Results: No bacterial contamination was detected in platelet lysate eye drops stored under any of the conditions tested, regardless of simulated use. Proliferation assays showed that eye drops enhanced the growth of HK and HCE cells compared to the control medium. No significant differences in proliferation were observed between storage conditions. Conclusions: Platelet lysate eye drops maintain sterility and biological functionality when stored in BTI ophthalmic devices at ≤−15 °C, 2–8 °C and RT for up to 72 h of simulated use. These results support the feasibility of using BTI eye drop devices in clinical settings while ensuring safety and efficacy. Full article

SHEDs have demonstrated significant potential in cell therapy due to their superior proliferation rate, self-renewal and differentiation capacity (particularly neurogenesis attributed to their neural crest origin), and the less invasive procedure required for tissue collection compared to other stem cells. However, there is no established criterion to verify the minimum qualification to select one from numerous candidates, especially for SHEDs’ cultured FBS-free medium for clinic application. For that, we performed a characteristic analysis containing the growth rate, colony-forming unit (CFU) number, average colony size, and migration capacity with hPL-cultured SHEDs from 21 different donors, and we suggest the result as a minimum standard to filter out unqualified candidates. In addition, in the secretome analysis to predict the paracrine effect, it was found that upregulated proteins compared to the control were related to angiogenesis, immune response, and BMP signaling, and this was found to have a strong correlation only with protein concentration. This study presents a minimum standard for selecting cell therapy candidates and suggests the protein concentration of a conditioned medium as a cost-effective tool to expect the paracrine effect of SHEDs. Full article

Background and aims: Enhanced cell proliferation is crucial for reducing production time and cost in cell therapy, and human platelet lysate (HPL) is often used to boost cell proliferation due to its favorable safety profile. Understanding the roles of different HPL components and their effects on cell culture can lead to more informed choices in medium formulation, which in turn can influence cell behavior and outcomes. Therefore, this study aimed to investigate the effects of two types of HPL, i.e., heparin-supplemented HPL (He-HPL) and fibrinogen-depleted HPL without heparin (Fd-HPL), on human osteoblasts. Materials and Methods: He-HPL and Fd-HPL were prepared from expired platelet concentrates. The presence of growth factors, i.e., brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), and cytokines, i.e., interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), in HPL was evaluated. Human fetal osteoblast (hFOB) cells were cultured in Dulbecco’s Modified Eagle Medium supplemented with either He-HPL or Fd-HPL. The cell morphology, viability, calcium deposition, and expression of osteogenic genes were assessed. Results: Comparable levels of BDNF (p > 0.05), VEGF (p > 0.05), and IL-6 (p > 0.05) were detected in both types of HPL, whereas He-HPL exhibited significantly higher levels of TNF-α (p < 0.05). However, there were no notable differences in cell morphology, viability, population doubling time, or total cell yield between the two HPL types. Similarly, no differences were observed in the mineralization of cells treated with He-HPL compared to Fd-HPL. Nonetheless, hFOB cells cultured with He-HPL demonstrated significantly higher expression of osteogenic markers Runx2 and ALP (p < 0.05) compared to those cultured with Fd-HPL. Conclusions: He-HPL and Fd-HPL demonstrate comparable performance in promoting osteoblast proliferation and mineralization, making both usable for bone tissue engineering. However, He-HPL might have a slight edge as it enhances osteogenic gene expression. Full article

Previously, it has been shown that cortisol induces oxidative stress in human platelets, stimulating reactive oxygen species production, superoxide anion formation, lipid peroxidation, and depleting antioxidant defenses. In this study, the cortisol effect on platelet function has been described. Results demonstrate that cortisol stimulates platelet activation and aggregation, leading to CD62P surface exposure and intracellular calcium elevation. Cortisol potentiates its aggregating effect, reducing the level of the powerful anti-aggregating agent nitric oxide (NO). Likewise, cortisol reduces cGMP levels. Moreover, specific inhibitors of the Src/Syk/PI3K/AKT pathways reverse the inhibiting effect of cortisol, partially restoring NO and cGMP levels. Unexpectedly, cortisol stimulates endothelial nitric oxide synthase (eNOS) activity, measured in platelet lysates prepared by whole cells treated with the hormone. The phosphorylation of the Ser1177 eNOS activating-residue is increased by cortisol. The Src/Syk/PI3K/AKT pathways appear to be involved in the phosphorylation of this residue. Moreover, cortisol induces the formation of nitrotyrosine, that can be considered a biomarker for reactive nitrogen species, including peroxynitrite. In conclusion, through these mechanisms, cortisol potentiates its capacity to induce oxidative stress in human platelets. Full article

Fetal bovine serum (FBS) has long been the standard supplement in cell culture media, providing essential growth factors and proteins that support cell growth and differentiation. However, ethical concerns and rising costs associated with FBS have driven researchers to explore alternatives, particularly human platelet lysate (HPL). Among these alternatives, fibrinogen-depleted HPL (FD-HPL) has gained attention due to its reduced thrombogenicity, which minimizes the risk of clot formation in cell cultures and enhances the safety of therapeutic applications. This study investigates two preparation methods for FD-HPL from human platelet concentrates: the calcium chloride method and a mechanical approach. The concentrations of critical growth factors, including vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF), insulin-like growth factor (IGF), and keratinocyte growth factor (KGF), were evaluated for both methods. Additionally, the impact of FD-HPL on the proliferation and morphology of umbilical cord-derived mesenchymal stem cells (UC-MSCs) was assessed. The findings revealed that the calcium chloride method produced significantly higher concentrations of all measured growth factors compared to the mechanical method. Moreover, UC-MSCs cultured in calcium chloride-prepared FD-HPL exhibited enhanced cellular characteristics, including increased cell size, elongation, and improved overall morphology compared to those cultured in mechanically processed FD-HPL. These results indicate that the preparation method significantly influences the biological properties of HPL and the effectiveness of UC-MSC culture. The calcium chloride method emerges as a superior technique for producing FD-HPL, offering a promising alternative to FBS in regenerative medicine applications. This study underscores the importance of preparation methods in optimizing HPL for cell culture and therapeutic uses. Full article

Angiogenesis, the formation of new blood vessels, is a fundamental process in both physiological repair mechanisms and pathological conditions, including cancer and chronic inflammation. Hydrogels are commonly used as in vitro models to mimic the extracellular matrix (ECM) and support endothelial cell behavior during angiogenesis. Mesenchymal stem cells further augment cell and tissue growth and are therefore widely used in regenerative medicine. Here we examined the combination of distinct hydrogel types—fibrin, collagen, and human platelet lysate (HPL)—on the formation of capillaries in a co-culture system containing human umbilical vein endothelial cells (HUVECs) and bone marrow-derived mesenchymal stem cells (BM-MSCs). The mechanical properties and structural changes of the hydrogels were characterized through scanning electron microscopy (SEM) and nanoindentation over 10 days. Fibrin and HPL gels sustained complex network formations, with HPL gels promoting even vascular tube formation of up to 10-fold capillary caliber. Collagen gels supported negligible angiogenesis. Our results suggest that HPL gels in combination with MSC-EC co-culture may be employed to obtain robust vascularization in tissue engineering. This study provides a comparative analysis of fibrin, collagen, and HPL hydrogels, focusing on their ability to support angiogenesis under identical conditions. Our findings demonstrate the superior performance of HPL gels in promoting robust vascular structures, highlighting their potential as a versatile tool for in vitro angiogenesis modeling. Full article

In regenerative medicine, stromal cells are supposed to play an important role by modulating immune responses and differentiating into various tissue types. The aim of this study was to investigate the influence of heparin, frequently used as an anticoagulant in human platelet lysate (HPL)-supplemented cell cultures, on the expression of non-coding RNA species, particularly microRNAs (miRNA), which are pivotal regulators of gene expression. Through genomic analysis and quantitative RT-PCR, we assessed the differential impact of heparin on miRNA expression in various stromal cell types, derived from human bone marrow, umbilical cord and white adipose tissue. Our results demonstrate that heparin significantly alters miRNA expression, with distinct up- and downregulation patterns depending on the original tissue source of human stromal cells. Furthermore, our analyses indicate that these heparin-induced alterations in miRNA expression profiles influence critical cellular processes, including proliferation, apoptosis and differentiation. In conclusion, our study highlights that heparin not only fulfills its primary role as an efficient anticoagulant but can also modulate important regulatory pathways in stromal cells by influencing miRNA expression. This may alter cellular properties and thus influence stromal cell-based therapeutic applications in regenerative medicine. Full article