Biomineralization and osteogenic differentiation modulated by substrate stiffness

Abstract

It is well known that extracellular matrix stiffness can affect cell proliferation and differentiation. However, when substrates of different stiffness are transferred into organisms, they affect cell behavior, and at the same time, the substrates themselves also undergo biomineralization owing to the extracellular matrix, this process of biomineralization during osteogenic differentiation adjusted by substrate stiffness has seldom been investigated. In this paper, we copolymerized 2-vinyl-terephthalic acid bis-[4-(2-carboxy-ethyl)-phenyl] ester (LCPE) as rigid chains and butyl acrylate (BA) as flexible chains to prepare a series of polymer materials. Films based on these copolymers are prepared by dip-coating method with controllable stiffness. Vickers indentation hardness tester was used to verify the stiffness of the films (199.9–5.3 kPa) with different ratio of LCPE and BA. Polymer coated substrates with different stiffness on biomimetic mineralization demonstrated that a moderate stiffness substrate (14.9 kPa) can induce the best biomimetic mineralized hydroxyapatite (HA), and further promote the proliferation and differentiation behavior of osteoblasts.