用软刻蚀制备组织工程3D 聚合物微结构

软刻蚀制备组织工程3D可生物降解、生物相容性好的几何图案聚合物微结构,方法简单,使用聚二甲基硅氧烷(PDMS)作为弹性铸膜.高分辨率透明掩膜图案用CorelDraw软件绘制并用高分辨率行式打印在塑料片上.制备微结构的聚合物材料为摩尔比85/15的聚乳酸/乙醇酸(PLGA)共聚物,对其进行预处理使之具有适当的硬度和柔韧性.用铸造、旋涂两种成模方法制备形体尺寸为10～100 μm的PLGA肢手架.对影响肢手架结构完整及横向分辨率的因素进行了讨论和优化,并对两种成型方法的横向、纵向分辨率进行了比较.作为脚手架在组织工程上应用的概念验证,用热层压方法制造用于细胞培养的多层聚合物结构.实验结果表明,软刻蚀技术提供了一种实现组织工程微尺度3D聚合物结构的有效工具.

Microfabrication of 3D-Polymeric Structures Using Soft Lithography for Tissue Engineering

Simple methods for fabricating 3D biodegradable, biocompatible micro polymeric structures with well-defined geometry for tissue engineering have been developed using the soft lithography, which utilized an elastomeric poly-dimethylsiloxane (PDMS) mold. A high-resolution transparency mask was drawn with CorelDraw software and printed on a plastic slide using a high-resolution line printer. The copolymers of poly-lactic-co-glycolic acid (PLGA 85/15) were pretreated with moderate stiffness and flexibility. The PLGA scaffolds with feature sizes of approximately 10～100 μm were fabricated using two molding methods: polymer casting and spin coating. The factors that influenced the integrity and the lateral resolution of scaffolds are discussed and optimized. The two different methods have been compared in terms of lateral and vertical resolution. As a proof-of-concept for scaffold utility in tissue engineering applications, multilayer structures for cell culture were formed by thermal lamination. In conclusion, the soft-lithographic technique provides a useful tool to realize microscale 3D structures with little islands of polymers for tissue engineering.