Bio-inspired liquid crystal gel with adjustable viscoelasticity to modulate cell behaviors and fate

Abstract

Poly( D, l -lactide) (PDLLA) as a kind of bone repair material has been widely concerned, however, the development of PDLLA material with remarkable cell affinity and osteogenic activity is still a big challenge. Inspired by the unique liquid crystal property and viscoelasticity of bone extracellular matrix (ECM), here, a new kind of chitin whisker gel (nCG) with the bone ECM-like liquid crystal phase and viscoelasticity was developed, which was further stably adhered to PDLLA membrane to obtain the nCG-coated composite membrane (PP@nCG) taking advantage of polydopamine. The design of bone ECM-like liquid crystal gel surface on the PDLLA membrane could not only improve cell adhesion and proliferation, but also highly enhance calcium phosphate mineralization. Creatively, the modulus of surface coated nCG can be easily adjusted by changing the degree of deacetylation of chitin whiskers to simulate the viscoelasticity of bone ECM and regulate cell behaviors and fate. Interestingly, the PP@nCG membrane with high-modulus nCG coating shows a stronger effect on promoting cell affinity and osteogenic activity compared with that with low-modulus nCG coating. This study opens a new window to bionic designing novel composite materials with bone ECM-like liquid crystal characteristic and viscoelasticity for bone repair.