Cationic porphyrin-based nanoparticles assisted with bio-assembly imaging-guided strategy for efficient inactivation of bacteria and promote wound healing

The increasing emergence of pathogenic bacterial infections, especially multidrug-resistant (MDR) bacteria, has been regarded as an urgent threat. In addition, the invention of safe and effective methods for in-time bacterial diagnosis and treatment remains a considerable problem. To surmount this challenge, a multimode and broad-spectrum antimicrobial system based on cationic polypeptides (PG) functionalized meso-tetra(4-carboxyphenyl)-porphine (TCPP) and in situ self-assembled strategy were established to integrate the bioimaging, electrostatic targeting, and photodynamic antibacterial therapies. TCPP coordinated with cationic PG to facilitate the construction of water-soluble TCPP-PG nanoparticles (NPs) that avoid the self-aggregation of porphyrins and improve their dispersibility in an aqueous solution to ensure the reactive oxygen species (ROS) yield under irradiation for efficient bacterial inactivation. In addition, through the introduction of aqueous gold ions into bacterial cells, the metal precursors (i.e., HAuCl4) could be spontaneously in situ self-assembled to multifunctional gold nanoclusters (NCs) exhibiting luminescence and promoted the image sensitivity and specificity toward the bacterial. As a consequence, besides visualizing the bacteria, the constructed theranostic nanoplatform enabled the sterilization of both Gram-negative and Gram-positive bacteria under white light irradiation while displaying nontoxic against mammalian and red blood cells as reflected from their no significant histopathological toxicity, higher cell viability, and negligible hemolytic effect. This strategy may improve the possibility of establishment of a unique broad-spectrum antimicrobial routes that with significant potential for sterilization of intractable bacterial infections.