Mesenchymal stem cell-derived extracellular vesicles in skin wound healing: the risk of senescent drift induction in secretome-based therapeutics

Regulatory changes in senescent cells could potentially affect the composition of extracellular vehicles(EVs),specifically altering their size and cargo.As a result,the released senescent EVs contain an unpredictable cocktail of growth factors and cytokines.These biomolecules have dual effects,potentially guiding the induction of senescence in affected cells and promoting an inflammation-related“domino effect”within the cellular environment,ultimately leading to tissue inflammaging.

烧结温度对Q235钢搪瓷涂层组织结构及性能影响

通过一次涂搪法在Q235低碳钢表面制备出700~900℃烧结的搪瓷涂层。采用XRD、SEM、EDS、显微维氏硬度计、落球装置及电化学工作站研究了涂层物相组成、组织形貌、微区成分、机械性能及腐蚀行为。结果表明:搪瓷涂层在烧结过程中表面孔隙率持续减小,截面孔隙率则先减小后增大再减小;磨加物石英逐渐溶解在涂层硅氧四面体[SiO4]网络中,使涂层显微硬度和光泽度提高;涂层与基体界面处氧化层逐渐减小并最终消失,而Fe扩散区逐渐扩大并形成富含Fe-Co和Fe-Ni枝晶的密着层;涂层表面釉质层形成及内部腐蚀通道的闭合使其耐腐蚀性能显著提高。