Tissue engineering is a promising approach for the repair and regeneration of cartilaginous tissue. Appropriate three-dimensional scaffolding materials that mimic cartilage are ideal for the repair of chondral defects. The emerging decellularized tissue-based scaffolds have the potential to provide essential biochemical signals and structural integrity, which mimics the natural tissue environment and directs cellular fate. Umbilical cord-derived hydrogels function as 3D scaffolding material, which support adherence, proliferation, migration, and differentiation of cells due to their similar biochemical composition to cartilage. Therefore, the present study aimed to establish a protocol for the formulation of a hydrogel from decellularized human umbilical cord (DUC) tissue, and assess its application in the proliferation and differentiation of UC-MSCs along chondrogenic lineage. The results showed that the umbilical cord was efficiently decellularized. Subsequently, DUC hydrogel was prepared, and in vitro chondral differentiation of MSCs seeded on the scaffold was determined. The developed protocol efficiently removed the cellular and nuclear content while retaining the extracellular matrix (ECM). DUC tissue, pre-gel, and hydrogels were evaluated by FTIR spectroscopy, which confirmed the gelation from pre-gel to hydrogel. SEM analysis revealed the fibril morphology and porosity of the DUC hydrogel. Calcein AM and Alamar blue assays confirmed the MSC survival, attachment, and proliferation in the DUC hydrogels. Following seeding of UC-MSCs in the hydrogels, they were cultured in stromal or chondrogenic media for 28 days, and the expression of chondrogenic marker genes including TGF-β1, BMP2, SOX-9, SIX-1, GDF-5, and AGGRECAN was significantly increased (* p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001). Moreover, the hydrogel concentration was found to significantly affect the expression of chondrogenic marker genes. The overall results indicate that the DUC-hydrogel is compatible with MSCs and supports their chondrogenic differentiation in vitro.

Cold burn wounds differ in their pathophysiological spectrum as compared to other types of burn wounds. These wounds have prolonged devastating effects on the body including hypertrophic scars, contracture, and necrosis. Mesenchymal stem cells (MSCs) are considered promising candidates for the complete regeneration of burn wounds. However, transplanted MSCs face the challenge to survive under the harsh tissue conditions. Preconditioning of MSCs with bioactive compounds may enhance their survival and regenerative potential for use in clinical applications. Bioactive compounds of Melia azedarach are well known for their potential role in treating different types of skin wounds due to their anti-inflammatory, anti-viral, anti-cytotoxic, and anti-oxidative properties. This study aims to evaluate the synergistic effects of human umbilical cord derived MSCs (hUC-MSCs) after preconditioning them with bioactive compounds of M. azedarach (quercetin and rutin) for cold induced burn wounds. Human umbilical cord MSCs (hUC-MSCs) were characterized based on their specific cell surface markers and treated with 20 μM of quercetin or rutin. In vitro scratch assay was performed to measure cell migration and wound closure. In vivo cold burn wound model was developed via direct exposure of the dorsal rat skin to liquid nitrogen. hUC-MSCs were subcutaneously transplanted next day of burn wound induction and wound was examined at different time points corresponding to the wound healing phases (days 3, 7, and 14). The regenerative potential of preconditioned hUC-MSCs was assessed in different groups; control (treated only with hUC-MSCs), and treated groups (quercetin or rutin treated hUC-MSCs). Healing potential and wound closure were evaluated by histological, gene expression, and immunohistochemical analyses of the wound tissues before and after treatment. Scratch assay exhibited enhanced cell migration towards wound closure in the treated groups as compared to the control. Macroscopic examination of the wound revealed scab formation at day 14 in control, whereas scab was detached and the wound tissue was remarkably remodeled in the treated groups. Comparison between the treated groups showed that burn wound treated with quercetin significantly increased healing potential than the rutin treated MSCs. Histological findings showed enhanced regeneration of skin layers along with hair follicles in the quercetin group, while increased neovascularization was noted in both treatment groups. Gene profile of wound healing mediators illustrated significant upregulation of IL-5, IL-4, GPX-7, TXNRD-2, PRDX, VEGF, and FGF and downregulation of inflammatory cytokines IL-1β and IL-6. In conclusion, synergistic effect of hUC-MSCs and bioactive compounds of M. azedarach enhances wound healing by reducing the inflammation, mitigating oxidative stress and enhancing neovascularization. The study findings will aid in designing more effective treatment options for cold burn wounds.

Umbilical cord-derived mesenchymal stem cells preconditioned with isorhamnetin: potential therapy for burn wounds

Summary: Background: Mesenchymal stem cells (MSCs) have immense self‐renewal capability. They can be differentiated into many cell types and therefore hold great potential in the field of regenerative medicine. MSCs can be converted into beating cardiomyocytes by treating them with DNA‐demethylating agents. Some of these compounds are nucleoside analogs that are widely used for studying the role of DNA methylation in biological processes as well as for the clinical treatment of leukemia and other carcinomas.Aims: To achieve a better therapeutic option for cardiovascular regeneration, this study was carried out using MSCs treated with two synthetic compounds, zebularine and 5‐azacytidine. It can be expected that treated MSCs prior to transplantation may increase the likelihood of successful regeneration of damaged myocardium.Methods: The optimized concentrations of these compounds were added separately into the culture medium and the treated cells were analyzed for the expression of cardiac‐specific genes by RT‐PCR and cardiac‐specific proteins by immunocytochemistry and flow cytometry. Treated MSCs were cocultured with cardiomyocytes to see the fusion capability of these cells.Results: mRNA and protein expressions of GATA4, Nkx2.5, and cardiac troponin T were observed in the treated MSCs. Coculture studies of MSCs and cardiomyocytes have shown improved fusion with zebularine‐treated MSCs as compared to untreated and 5‐azacytidine‐treated MSCs.Conclusion: The study is expected to put forth another valuable aspect of certain compounds, that is, induction of transdifferentiation of MSCs into cardiomyocytes. This would serve as a tool for modified cellular therapy and may increase the probability of better myocardial regeneration.