Bacterial infections exacerbate the formation of bacterial biofilms, leading to resistance to traditional drugs, persistent infection, and even threatening patient’s life. Efficient antimicrobial materials against drug-resistant bacterial biofilms are highly desired. In this study, a photodynamic nanodrug with bacterial targeting was constructed by cooperative coordination of zinc ion with an antimicrobial peptide with hydrophobic tripeptides on the side chains and the photosensitizer chlorin e6. The supramolecular nanodrug with a uniform spherical structure possessed high photosensitizer loading capacity and enhanced photodynamic efficacy, which could deep penetrate and eradicate methicillin-resistant Staphylococcus aureus (MRSA) biofilms upon 655 nm laser irradiation. Furthermore, in vivo experiments verified the efficient elimination of MRSA biofilms on implanted catheters. This study provides a novel strategy to fabricate metalloprotein-inspired supramolecular photodynamic nanodrugs against drug-resistant bacterial biofilms-associated infections in vivo.

A solvent annealing-induced structural reengineering approach is exploited to fabricate polymersomes from block copolymers that are hard to form vesicles through the traditional solution self-assembly route. More specifically, polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP) particles with sphere-within-sphere structure (SS particles) are prepared by three-dimensional (3D) soft-confined assembly through emulsion-solvent evaporation, followed by 3D soft-confined solvent annealing upon the SS particles in aqueous dispersions for structural engineering. A water-miscible solvent (e.g., THF) is employed for annealing, which results in dramatic transitions of the assemblies, e.g., from SS particles to polymersomes. This approach works for PS-b-P4VP in a wide range of block ratios. Moreover, this method enables effective encapsulation/loading of cargoes such as fluorescent dyes and metal nanoparticles, which offers a new route to prepare polymersomes that could be applied for cargo release, diagnostic imaging, and nanoreactor, etc.

Wound management is a crucial measure for skin wound healing and is significantly important to maintaining the integrity of skins and their functions. Electrical stimulation at the wound site is a compelling strategy for skin wound repair. However, there has been an urgent need for wearable and point-of-care electrical stimulation devices that have self-adhesive and mechanical properties comparable to wound tissue. Herein, we develop a bioinspired hybrid patch with self-adhesive and piezoelectric nanogenerator (HPSP) for promoting skin wound healing, which is composed of a mussel-inspired hydrogel matrix and a piezoelectric nanogenerator based on aligned electrospun poly(vinylidene fluoride) nanofibers. The device with optimized modulus and permeability for skin wear can self-adhere to the wound site and locally produce a dynamic voltage caused by motion. We show that the HPSP not only promotes fibroblast proliferation and migration in vitro, but also effectively facilitates the collagen deposition, angiogenesis, and re-epithelialization in vivo with the increased expressions of crucial growth factors. The HPSP reduces the wound closure time of full-thickness skin defects by about 1/3, greatly accelerating the healing process. This patch can serve as wearable and real-time electrical stimulation devices, potentially useful in clinical applications of skin wound healing.