Biomimetic micro/nano structures for biomedical applications

Cell behaviors are influenced by the surrounding dynamic microenvironment where the extracellular matrix (ECM) composed of different micro/nano-structures plays a key role. Many micro/nano-structures have been developed to mimic the structure of ECM, but these structures are almost static, and fail to emulate the dynamicity and function of the ECM in vivo. Notably, certain micro/nano-structures based on shape-memory polymers (SMPs), including patterns, fibers, porous scaffolds and microspheres, have attracted increasing attention due to the unique spatiotemporal variations. The dynamical shifting of these biomimetic micro/nano-structures arising from the shape-memory effect endows the materials with unique functions, e.g., regulating cell behaviors and prompting tissue growth. Therefore, the dynamically tunable biomimetic micro/nano-structures based on SMPs can be an ideal platform to mimic dynamic changes in the ECM structure both in vitro and in vivo. This review summarizes the latest advances in the development of the methodologies for fabricating various SMP biomimetic micro/nano structures, spatiotemporal control of cell behaviors, and broad applications in biomedical engineering. Several crucial points for future research are presented. (C) 2020 Elsevier Ltd. All rights reserved.