脱细胞生物活性微载体在软骨类器官构建中的尺寸效应和性能优化OA

Objective To evaluate the pro-proliferative and chondrogenic potential of cartilage organoid(CORG)constructed using decellularized extracellular matrix(dECM)microcarriers of varying sizes.Methods dECM microcarriers were prepared and validated for decellularization efficacy,matrix component preservation,and biocompatibility.Two sizes of microcarriers were screened and combined with rat bone marrow mesenchymal stem cell(BMSC)to construct the CORG.DNA quantification,histochemical staining,immunofluo-rescence staining,and real-time quantitative PCR were employed to assess cell proliferation,chondrogenic differentiation,and cell adhe-sion capabilities within the CORG.Results The dECM microcarriers were successfully prepared,achieving complete decellularization while preserving matrix component integrity.Particle size analysis facilitates the effective screening of two distinct microcarrier sizes,both of which demonstrated non-cytotoxicity and excellent biocompatibility.Compared with the CORG constructed from large-sized dECM microcarriers(HCORG group),the CORG constructed from small-sized dECM microcarriers(SCORG group)significantly enhanced cell proliferation,exhibited a more regular spatial structure,and showed superior extracellular matrix secretion,as well as improved inter-cellular and cell-microcarrier interactions and adhesion.Additionally,the expression of SOX9,a key gene in chondrogenesis,was elevated in the SCORG group.Real-time quantitative PCR results indicated that both groups exhibited high expression levels of chondrogenic genes(SOX9,COLⅡ,and ACAN),which peaked on day 14(P<0.001).Notably,the expression levels of both chondrogenesis-and cell adhe-sion-related genes were significantly higher in the SCORG group(P<0.01).Conclusion CORG constructed with small-sized microcar-riers demonstrates enhanced chondrogenic differentiation potential and stronger intercellular adhesion capacity.