A Multifunctional LED Sensitive Photoinitiator Enables Antibacterial Hydrogel Fabrication with Spatiotemporal Precision

Conventional photoinitiators for hydrogel fabrication suffer from poor water solubility, narrow absorption spectra, and lack of multifunctionality, necessitating supplemental antimicrobial agents. We address these limitations with SPS-T-OXE, a water-soluble pyridinium-oxime ester photoinitiator that combines broad UV–visible absorption (λmax = 345 nm, ε = 36,800 M–1 cm–1) with intrinsic antibacterial properties. This initiator enables rapid, deep curing of acrylamide/polyethylene glycol diacrylate (AM/PEGDA) hydrogels under 405/425 nm LED light while permitting precise mechanical control and high-resolution 3D microstructure fabrication via single-photon (405 nm) and two-photon (532 nm) polymerization. The resulting hydrogels exhibit inherent broad-spectrum antimicrobial activity (99.1% against E. coli; 96.9% against S. aureus) and excellent hemocompatibility (hemolysis rate <5%) without additional agents. By integrating spatiotemporal fabrication control with built-in antibacterial functionality, this platform advances hydrogel engineering for medical applications including wound dressings, antimicrobial coatings, and tissue regeneration scaffolds.