Dual-functional biomimetic periosteum with electrical activity and antibacterial property: Sulfonated polyaniline/polypyrrole codoped polycaprolactone scaffold for electrically driven bone-nerve regeneration

Periosteal repair is a sophisticated biological process involving the regeneration of bone tissue, blood vessels, and nerve complexes. However, current biomimetic periosteal materials are mainly insulating and only focus on osteogenesis and vascular regulation, often neglecting neural network reconstruction. In this study, we developed an electroactive sulfonated polyaniline/polypyrrole (SP/PPy) co-modified polycaprolactone (PCL) composite as a biomimetic periosteal membrane. Utilizing in-situ oxidative polymerization, SP was functionalized as a precursor layer, effectively addressing the issue of non-uniform PPy deposition on the hydrophobic polyester substrate. This modification enhanced the mechanical strength by 20.41 % and endowed the periosteal membrane a conductivity up to 220 S m −1 , enabling electrostimulation-mediated bidirectional differentiation for osteogenesis and neurogenesis. Experimental results demonstrated key advantages of this electroactive periosteum: 1. Superior Antibacterial Properties: The material achieved an inhibition rate of 98.56 % against Staphylococcus aureus . 2. Enhanced Biological Activity: The viability of rat bone marrow stromal cells (rBMSCs) reached 108.2 % of that of the blank sample. 3. Significant Electrostimulation Responsiveness: Under electrical stimulation, alkaline phosphatase (ALP) activity increased by 150.5 %, and the average axonal growth of PC-12 cells increased by 6.473 μm. This study provides a novel strategy for constructing electroactive multilayer biomimetic periosteal membranes, contributing to neuro-bone composite regeneration.