Induced Pluripotent Stem Cell-derived Mesenchymal Stem Cell Seeding on Biofunctionalized Calcium Phosphate Cements

Induced pluripotent stem ceils （iPSCs） have great potential due to their proliferation and differentiation capability. The objectives of this study were to generate iPSC-derived mesenchymal stem cells （iPSC-MSCs）, and investigate iPSC-MSC proliferation and osteogenic differentiation on calcium phosphate cement （CPC） containing biofunctional agents for the first time. Human iPSCs were derived from marrow CD34＋ cells which were reprogrammed by a single episomal vector, iPSCs were cultured to form embryoid bodies （EBs）, and MSCs migrated out of EBs. Five biofunctional agents were incorporated into CPC： RGD （Arg-Gly-Asp） peptides, fibronectin （Fn）, fibronectin-like engineered polymer protein （FEPP）, extracellular matrix Geltrex, and platelet concentrate, iPSC-MSCs were seeded on five biofunctionalized CPCs： CPC-RGD, CPC-Fn, CPC- FEPP, CPC-Geltrex, and CPC-Platelets. iPSC-MSCs on biofunctional CPCs had enhanced proliferation, actin fiber expression, osteogenic differentiation and mineralization, compared to control. Cell proliferation was greatly increased on biofunctional CPCs. iPSC-MSCs underwent osteogenic differentiation with increased alkaline phosphatase, Runx2 and coUagen-I expressions. Mineral synthesis by iPSC-MSCs on CPC-Platelets was 3-fold that of CPC control. In conclusion, iPSCs showed high potential for bone engineering, iPSC- MSCs on biofunctionalized CPCs had cell proliferation and bone mineralization that were much better than traditional CPC. iPSC-MSC-CPC constructs are promising to promote bone regeneration in craniofacial/ orthopedic repairs.

政府会计改革与行政事业单位运营管理绩效

随着我国政府会计权责发生制改革将加强问责、提升绩效提上日程,现有改革的作用效果成为理论界和实务界关注的焦点。文章以广东省1418个行政事业单位为研究对象,考察政府会计改革对行政事业单位运营管理绩效的影响。研究发现,政府会计改革有效提高了行政事业单位运营管理绩效。机制检验表明,政府会计改革主要通过优化内部控制和提高职工组织认同度,进而提升单位运营管理绩效。异质性检验发现,政府会计改革显著提升单位运营管理绩效的效应不因行政隶属、单位类型、公益类型和地区经济状况的不同而存在差异。上述研究结论为政府会计准则制度的顺利实施提供了理论支持,也为提高行政事业单位运营管理绩效提供了参考建议。