Photo-responsive Porphyrin-protein microfibers with Bacteria-triggered drug release for Synergetic sterilization

The emergence of drug-resistant bacteria (DRB) has been a prominent public healthy challenge caused by the overuse of antibiotics. In nature, protein combines with photosensitizer via non-covalent bond forming photo-system for plant protection. Imitation of natural light harvesting system will be efficient materials for sterilization. Here, a photo-responsive microfiber (PCA@BSA) was constructed by the self-assembly of bovine serum albumin (BSA) with the NH2-NH-CO– groups conjugated porphyrin (P) and caffeic acid (CA, a kind of polyphenol). The surface decoration of gold nanoparticles provided the microfibers (PCA@BSA-Au MFs) with photothermal ability and intensive affinity with bacteria. Biological evaluation unveiled excellent photo-driven (808 nm and red LED) antibacterial efficiency. Particularly, CA encapsulated in PCA@BSA-Au MFs could be released by the trigger of acidic environment or active bacteria, resulting in the enhancement of antibacterial effect and a tenuous morphology of PCA@BSA-Au MFs. These results validate the assembly of porphyrin and natural polyphenols templated protein is a novel photosystem toward antisepsis.