医用细菌纤维素材料微/纳结构设计、调控及应用评价

Bacterial cellulose (BC) has the natural advantages as medical material because of its unique performance. However, the compact structure for its nano network limits the cell ingrowth. This project intends to exploit BC materials suited to clinical medical form the surface structure adjustment to the microporous structure design. Firstly, we focus on establishing a method for surface structure adjustment for BC and illustrating the formation mechanism and influencing factors of diameter, density and branching structure of nanofibers of BC. Then，a three-dimensional microporous template with controlled porosity and pore structure will be prepared based on biological material such as gelatin or silk fibroin. By in-situ composite with BC, three-dimensional micro/nano structure scaffolds with micro pores, nano fiber and mechanical properties for clinical application can be fabricated and overcome the current difficulty that the microporous structure, nano fiber and mechanical properties can’t be harmonized. The scaffolds will be applied for cytologic evaluation, and finally to realize cell adhesion, proliferation and migration, promote vascularization and tissue ingrowth. This research will provide the theoretical support and experimental basis for application of the tissue engineering scaffold material in tissue repair and reconstruction.

细菌纤维素由于其独特性能有作为医用材料的天然优势，但其三维纳米网络结构致密，限制了组织细胞的长入。本项目从细菌纤维素表面结构调控到微孔结构设计，开发适合临床医用的组织修复重建细菌纤维素支架材料。首先建立细菌纤维素表面结构调控方法，阐明细菌纤维素纳米纤维的纤维直径、密度及支化形成机理及影响机制；然后以明胶、丝素蛋白等生物材料构建具有一定孔隙率及孔结构的三维微孔组织工程支架模板，与细菌纤维素进行原位复合，构建兼具微米多孔与纳米纤维与适合临床应用的力学性的三维微/纳结构细菌纤维素支架材料，克服目前细菌纤维素微孔结构、纳米纤维与力学性能难以协调统一难题。并对其进行细胞学评价，研究细胞的黏附、增殖及迁移、促进血管化及组织长入情况，为其在组织修复重建中的应用提供理论与实验依据。

细菌纤维素由于其独特性能有作为医用材料的天然优势，但其三维纳米网络结构致密，限制了组织细胞的长入。本项目首先研究了明胶、丝素蛋白、壳聚糖、PGS等材料制备三维多孔支架模板，原位培养了细菌纤维素，通过材料及菌种密度调控，构建了微米多孔与纳米纤维的三维微/纳结构细菌纤维素基组织工程支架，研究了纳米纤维密度、材料结构及性能对细胞黏附、增殖及迁移、促进血管化及组织长入情况，为构建新型组织工程支架提供里新的研究思路与实验依据。血管化是组织工程成功的关键。本研究在前面构建的三维支架中，通过生长因子复合纳米粒，肝素桥连生长因子及脱细胞基质内在生长因子，构建了具有缓释生长因子，有效促进血管化的三维微/纳组织工程支架，并成功用于长段（1cm）的组织尿道修复。发展了新型自增强细菌纤维素水凝胶，克服了其压缩性能差的缺点，为其用于骨组织工程修复提供了新的研究思路。