Department of Polymer Materials , Shanghai University , 99 Shangda Road , Shanghai 200444 , People's Republic of China.
Department of Orthopedics, Shanghai Tongji Hospital , Tongji University School of Medicine , 389 Xincun Road , Shanghai 200065 , People's Republic of China.
ACS Appl Mater Interfaces. 2018 May 16;10(19):16270-16281. doi: 10.1021/acsami.8b02448. Epub 2018 May 4.
Porous microcarriers have aroused increasing attention recently, which can create a protected environment for sufficient cell seeding density, facilitate oxygen and nutrient transfer, and well support the cell attachment and growth. In this study, porous microcarriers fabricated from the strontium-substituted hydroxyapatite- graft-poly(γ-benzyl-l-glutamate) (Sr10-HA- g-PBLG) hybrid nanocomposite were developed. The surface grating of PBLG, the micromorphology and element distribution, mechanical strength, in vitro degradation, and Sr ion release of the obtained Sr10-HA- g-PBLG porous microcarriers were investigated, respectively. The grafting ratio and the molecular weight of the grafted PBLG of Sr10-HA- g-PBLG could be effectively controlled by varying the initial ratio of BLG-NCA to Sr10-HA-NH. The microcarriers exhibited a highly porous and interconnected microstructure with the porosity of about 90% and overall density of 1.03-1.06 g/cm. Also, the degradation rate of Sr10-HA-PBLG microcarriers could be effectively controlled and long-term Sr release was obtained. The Sr10-HA-PBLG microcarriers allowed cells adhesion, infiltration, and proliferation and promoted the osteogenic differentiation of rabbit adipose-derived stem cells (ADSCs). Successful healing of femoral bone defect was proved by injection of the ADSCs-seeded Sr10-HA-PBLG microcarriers in a rabbit model.
多孔微载体最近引起了越来越多的关注，它可以为充足的细胞接种密度创造一个保护环境，促进氧气和营养物质的转移，并很好地支持细胞的附着和生长。在这项研究中，开发了由锶取代的羟基磷灰石-接枝-聚（γ-苄基-l-谷氨酸）（Sr10-HA-g-PBLG）杂化纳米复合材料制成的多孔微载体。分别研究了所得 Sr10-HA-g-PBLG 多孔微载体的 PBLG 表面接枝、微观形貌和元素分布、机械强度、体外降解和 Sr 离子释放。通过改变 BLG-NCA 与 Sr10-HA-NH 的初始比例，可以有效控制 Sr10-HA-g-PBLG 的接枝率和接枝 PBLG 的分子量。微载体具有高度多孔和互连的微观结构，孔隙率约为 90%，整体密度为 1.03-1.06 g/cm。此外，Sr10-HA-PBLG 微载体的降解速率可以得到有效控制，并获得长期的 Sr 释放。Sr10-HA-PBLG 微载体允许细胞黏附、渗透和增殖，并促进兔脂肪间充质干细胞（ADSCs）的成骨分化。通过向兔模型中注射负载 ADSCs 的 Sr10-HA-PBLG 微载体，证明了股骨骨缺损的成功愈合。
