ICA/SDF-1α/PBMSCs loaded onto alginate and gelatin cross-linked scaffolds promote damaged cartilage repair

A three-dimensional alginate-coated scaffold (GAIS) was constructed in the present study to showcase the multidifferentiation potential of peripheral blood mesenchymal stem cells (PBMSCs) and to investigate the role and mechanism by which Icariin (ICA)/ Stromal cell-derived factor (SDF-1α)/PBMSCs promote damaged articular repair. In addition, the ability of ICA, in combination with SDF-1α, to promote the migration and proliferation of stem cells was validated through the utilization of CCK-8 and migration experiments. The combination of ICA and SDF-1α inhibited the differentiation of PBMSCs into cartilage, as demonstrated by in vivo experiments and histological staining. Both PCR and western blot experiments showed that GAIS could upregulate the expression of particular genes in chondrocytes. In comparison to scaffolds devoid of alginate (G0), PBMSCs seeded into GAIS scaffolds exhibited a greater rate of proliferation, and the conditioned medium derived from scaffolds containing SDF-1α enhanced the capacity for cell migration. Moreover, after a 12-week treatment period, GAIS, when successfully transplanted into osteochondral defects of mice, was found to promote cartilage regeneration and repair. The findings, therefore, demonstrate that GAIS enhanced the in vitro capabilities of PBMSCs, including proliferation, migration, homing, and chondrogenic differentiation. In addition, ICA and SDF-1α effectively collaborated to support cartilage formation in vivo. Thus, the ICA/SDF-1α/PBMSC-loaded biodegradable alginate-gelatin scaffolds showcase considerable potential for use in cartilage repair.

本研究构建了三维海藻酸盐包覆支架（GAIS），旨在展示外周血间充质干细胞（PBMSCs）的多向分化潜能，并探究淫羊藿苷（ICA）/基质细胞衍生因子（SDF-1α）/PBMSCs促进受损关节修复的作用与机制。此外，本研究通过CCK-8实验与迁移实验，验证了ICA联合SDF-1α促进干细胞迁移与增殖的能力。体内实验与组织学染色结果显示，ICA与SDF-1α联合使用可抑制PBMSCs向软骨细胞分化。PCR与蛋白质印迹（Western Blot）实验均表明，GAIS可上调软骨细胞内特定基因的表达。与不含海藻酸盐的支架（G0）相比，接种于GAIS支架的PBMSCs增殖速率更高，而搭载SDF-1α的支架所分泌的条件培养基可增强细胞迁移能力。此外，在移植12周后，成功植入小鼠骨软骨缺损部位的GAIS可促进软骨再生与修复。综上，本研究结果证实，GAIS可增强PBMSCs的体外增殖、迁移、归巢及软骨分化能力；同时ICA与SDF-1α可协同有效促进体内软骨形成。因此，搭载ICA/SDF-1α/PBMSCs的可降解海藻酸-明胶支架在软骨修复领域具有可观的应用潜力。