生物矿化PIC/HA杂化复合材料的应变硬化性能及其对MC3T3-E1细胞的影响

Abstract

The development of biomimetic extracellular matrix (ECM) with fibrous structure and complex nonlinear mechanics has been attracting intensive attention over the past decades both in material science and tissue engineering. Polyisocyanopeptide (PIC) hydrogels are a class of fully synthetic materials that can mimic biogels, such as fibrin and collagen, in nearly all aspects, particularly the micron-sized gel network and the strong strain-stiffening behavior in the biological regime. Here, a biomimetic PIC/hydroxyapatite (HA) hybrid composite through an enzymatic biomineralization strategy is constructed. HA biominerals grew on PIC bundles in situ catalyzed by the embedded alkaline phosphatase (ALP), which further crosslinked the gel networks and reinforced the mechanical property of PIC hydrogels. Significantly, PIC/HA composites exhibited ultra-responsive nonlinear mechanics with higher sensitivity to mechanical stress compared with those without biomineralization. As a consequence, the presence of HA can provide cell adhesion sites for PIC gels and induce osteogenic differentiation of pre-osteoblasts by virtue of the changes in mechanical properties. With these outstanding properties, therefore, PIC/HA composites present promising prospects in bone tissue engineering as biomimetic ECM.