Sustained-release System Of Exocrine Proteins Of Stem Cells To Treat Deep Second Degree Scald And Its Extraction Optimization

OBJECTIVE:?A sustained-release system constructed by exocrine proteins of stem cells and PCT-PEG-PCT thermosensitive hydrogel was used for investigating the therapeutic effect on the deep second degree burn of rabbit skin,as well as the regeneration mechanism.?Stem cells were induced to be pyroptosis by the pre-stimulation effect of OPC liquid crystal material to explore the biological changes,and to optimize the scheme of extracting exocrine protein.METHODS:?Functional identification of human umbilical cord mesenchymal stem cell exocrine proteins was performed.The sustained-release system was constructed by thermosensitive hydrogel and injected into deep second-degree burn wounds of rabbits.Observe the differences in wound healing,fibroblast phenotype and endogenous stem cells,and evaluate the overall therapeutic effect.?Liquid crystal material OPC was synthesized,and properties characterization and biocompatibility testing were performanced.Human umbilical cord mesenchymal stem cells were cultured on OPC to detect the expression of pyroptosis,inflammatory factors and growth factors.RESULTS:?Exocrine proteins can promote cell migration and reduce the influence of inflammation on cells in vitro;stably release of the sustained-release system resulted in higher wound closure rate,more regular tissue remodeling and the modulation of endogenous stem cells and fibroblasts.?OPC was biocompatible.The stem cells cultured on it are clustered,and the expression of pyroptosis proteins and inflammatory factors is increased.The expression of growth factors decreased.CONCLUSIONS:?Subcutaneous injection sustained-release system significantly improved the quality of skin healing,effectively mobilized endogenous stem cells around the wound and adjusted dermal fibroblast subtypes.?OPC induced cell pyroptosis and down-regulated the expression of specific cytokines during pyroptosis.