A Sporosarcina pasteurii-enabled self-powered wound dressing with biomineralization capability

A self-powered wound dressing was constructed by integrating a paper-based microbial fuel cell (MFC) with Sporosarcina pasteurii, a Gram-positive ureolytic bacterium. Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-modified bacterial cellulose served as the anode and MnO₂ as the cathode. In simulated wound fluid containing physiological Ca²⁺ and urea, the dressing produced a cell voltage of 0.79 ± 0.02 V under external load, a current density of 22.5 ± 0.8 μA cm^-2, and an areal power density of 14.6 μW cm^-2. Cyclic voltammetry showed quasi-rectangular loops without distinct redox peaks under the tested two-electrode conditions. The cell-free supernatant of S. pasteurii achieved a bacteriostatic rate of 76.25 ± 0.26% against Staphylococcus aureus in the plate-count assay. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) detected surfactin and fengycin in the supernatant-derived extract. Confocal laser scanning microscopy (CLSM) imaging of SYTO 9/propidium iodide (PI)-stained samples from a synthetic skin infection model showed a progressive shift toward PI-positive staining and a substantial reduction in detectable fluorescence over 6 h, providing evidence of bacterial membrane damage and supporting an antibacterial response under the tested conditions. X-ray Diffraction (XRD) confirmed calcite (CaCO₃) deposition on the operating MFC anode at near-physiological substrate concentrations, consistent with urease-mediated biomineralization by S. pasteurii.