Light-to-Heat Photothermal Dynamic Properties of Polypyrrole-Based Coating for Regenerative Therapy and Lab-on-a-Chip Applications

Abstract

Targeted delivery and release of biomolecules, e.g., bone morphogenetic protein (BMP-2), are gaining high interest due to the application for tissue engineering, diagnostics, surface-enhanced therapy and lab-on-a-chip. Here, a new hybrid temperature-responsive system consisting of polypyrrole (PPy) layer, mesoporous titania surface (TMS), and BMP-2 is proposed. The PPy layer has the light-to-heat photothermal property. Dynamic behavior of the PPy layer in response to light can regulate release of BMP-2. The PPy-based coatings on TMS have shown to be efficient for storage of BMP-2 and can be tuned to release BMP-2 under irradiation. Moreover, the possibility of local delivery and generation of a gradual release of BMP-2 for regulated cell growth is shown. Furthermore, the fabricated surfaces possess excellent biocompatibility and low cytotoxicity for MC3T3-E1 cells. It is shown that the released BMP-2 can effectively promote osteogenic differentiation of MC3T3-E1 cells. Thus, the TMS/PPy–BMP-2 is suggested to prolong targeted release of the BMP-2 for more than 25 days which stimulates osteoblasts’ proliferation. The new stimuli-responsive hybrid system is promising for targeted, localized, sustained drug release and application in bone tissue engineering.