Engineering Research Center for Biomedical Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Material Science & Engineering, East China University of Science and Technology, Shanghai 200237, China.
Centre for Biomedical Technologies, Queensland University of Technology, Brisbane 4059, Australia.
J Mater Chem B. 2022 Aug 31;10(34):6464-6471. doi: 10.1039/d2tb01198k.
Biodegradable microspheres have been widely applied as cell carriers for tissue engineering and regenerative medicine. However, most cell carriers only have a simple planar structure and show poor biological activity and cell adherence, resulting in low cell density and unfavorable application effect. How to develop size-controllable microspheres with an open-porous structure remains a challenge, and is a key factor to extend their employment as cell/drug delivery vehicles to boost regeneration of tissues (, bone). Herein, well-defined open porous microspheres of poly(lactic--glycolic acid) (PLGA with good biocompatibility approved by the Food and Drug Administration (FDA)) were developed by using a gas-assisted-emulsion and surface-alkalization-treatment technology (GEST). The gas-assisted-emulsion strategy enables the formation of microspheres with a large size of 200-300 μm, meanwhile, the microspheres have a large amount of micropores with diameter in the range of 10-60 μm. The following alkalization-treatment on the surface makes the microspheres form a good porous interconnectivity throughout both the surface and the interior of the microspheres. The good porous interconnectivity endows the microspheres with a highly open pore structure and a large specific surface area for nutrient exchange and cell attachment, thus promoting cell proliferation and nutrient transportation, promising their potential as an ideal cell carrier to increase cell density and bioactivity for cell therapy-based tissue engineering.
可生物降解的微球已广泛应用于组织工程和再生医学的细胞载体。然而，大多数细胞载体仅具有简单的平面结构，生物活性和细胞黏附性差，导致细胞密度低，应用效果不佳。如何开发具有开放多孔结构的尺寸可控的微球仍然是一个挑战，也是将其作为细胞/药物输送载体扩展应用以促进组织（、骨）再生的关键因素。在此，通过使用气体辅助乳液和表面碱化处理技术（GEST）开发了具有良好生物相容性的聚（乳酸-乙醇酸）（PLGA）的明确定义的开放多孔微球（已获得美国食品和药物管理局（FDA）批准）。气体辅助乳液策略可使微球形成 200-300μm 的大尺寸，同时，微球具有大量直径在 10-60μm 范围内的微孔。随后对表面进行碱化处理，使微球在微球的表面和内部形成良好的多孔连通性。良好的多孔连通性赋予微球高度开放的孔结构和大的比表面积，用于营养物质交换和细胞附着，从而促进细胞增殖和营养物质运输，有望成为增加细胞密度和细胞治疗为基础的组织工程中细胞活性的理想细胞载体。
