Electroactive PVTF films functionalized with collagen enhance osteogenic differentiation and bone regeneration

Bone tissue is mainly composed of collagen and hydroxyapatite, and has intrinsic electroactivity. The ability of biomaterials to mimic physiological microenvironmental cues holds significant potential for enhancing therapeutic outcomes by activating the intrinsic repair capabilities of cells and tissues. The microenvironment of bone tissue contains abundant collagen and electrophysiological signals, which play a crucial role in regulating, repairing, and regenerating its daily homeostasis. Creating surface potentials on biomaterials has proven to be an efficient method for promoting osteogenic differentiation. However, how to construct a collagen rich environment with different surface potentials and its biological effects remains unexplored. In this study, a biomimetic electrical microenvironment was created on the surface of the PVTF film through polarization and collagen modification. In this microenvironment, collagen with varying surface potentials can replicate the extracellular microenvironment of natural bone tissue. The biomimetic microenvironment has the potential to enhance the bioactivity of the material, particularly in terms of improving stem cell adhesion, promoting osteogenic differentiation, and accelerating bone regeneration in vivo. Further integrin inhibition assays and PCR analyses revealed that the biomimetic microenvironment promoted osteogenic differentiation by activating integrin α2β1 on the cell surface, which in turn triggered the FAK/ERK signaling pathway and upregulated the expression of osteogenesis-related genes. These findings provide valuable insights into the biological effects of surface potential and biochemical signals on osteogenesis at the material surface and offer a novel surface modification strategy to enhance the therapeutic efficacy of tissue engineering.