Peptide‐Engineered AIE Nanofibers with Excellent and Precisely Adjustable Antibacterial Activity

Abstract

Photosensitizers with aggregation‐induced emission properties (AIEgens) can produce reactive oxygen species (ROS) under irradiation, showing great potential in the antibacterial field. However, due to the limited molecular skeletons, the development of AIEgens with precisely adjustable antibacterial activity is still a daunting challenge. Herein, a series of AIE nanofibers (AIE‐NFs) based on the AIEgen of DTPM as the inner core and rationally designed peptides as bacterial recognition ligands (e.g., antimicrobial peptide (AMP) HHC36, ditryptophan, polyarginine, and polylysine) is developed. These AIE‐NFs show precisely adjustable antibacterial behaviors simply by changing the decorated peptides, which can regulate the aggregation and inhibition of different bacteria. By mechanistic analysis, it is demonstrated that this effect can be attributed to the synergistic antibacterial activities of the ROS and the peptides. It is noteworthy that the optimized AIE‐NFs, NFs‐K18, can efficiently aggregate bacteria to cluster and kill four types of clinical bacteria under irradiation in vitro, inhibit the infection of methicillin‐resistant Staphylococcus aureus (MRSA) and promote wound healing in vivo. To the authors’ knowledge, this is the first report of AIE‐NFs with precisely adjustable antibacterial activity, providing new opportunities for photodynamic therapy (PDT) treatment of infection.

In Vivo Fluorescence Imaging‐Guided Development of Near‐Infrared AIEgens

“…(C) Illustration for the preparation of peptide‐engineered AIE‐NFs. Reproduced with permission [61] . Copyright 2022, WILEY‐VCH.…”

“…reported a series of AIE nanofibers (AIE‐NFs) encapsulated with antimicrobial peptides decorated PEG with precisely adjustable antibacterial activity. As shown in Figure 11A, NIR AIEgen 73 was encapsulated with DSPE‐PEG 2000 and maleimide‐end capped PEG (DSPE‐PEG 2000 ‐MAL) [61] . The obtained AIE‐NFs were further decorated with antimicrobial peptides (including Lys‐Arg‐Trp‐Trp‐Lys‐Trp‐Trp‐Arg‐Arg (HHC36), ditryptophan (W2), polyarginine (Rn), and polylysine (Kn)) to render them with bacterial targeting capability.…”

“…Thus, increasing the number of TPE donor in PBIs can effectively improve the DÀ A interaction and therefore redshifted the emission wavelength. The mono-TPE substituted PBI (61) showed red fluorescence with emission peak at 682 nm, and the di-TPE substituted PBI (62) exhibited much longer emission at 706 nm in the solid state. [48] Similarly, increasing the number of electron-donating TPA in a typical ACQ fluorophore BODIPY, could not only enhance DÀ A intensity, but also inhibit π-π interactions between neighboring molecules.…”

Synergistic Combination of Biodegradable Peptide Polymer and Curcumin as Promising Antibiotic Substitution in Aquaculture to Alleviate the Global Challenge of Antimicrobial Resistance

“…[ 28‐30 ] Host defense peptides (HDPs) and their synthetic mimics exhibit broad‐spectrum antibacterial activity, some of which have also been used in synergistic antibacterial studies. [ 31‐49 ] Recently, we developed a promising substitution of antibiotics in aquaculture using HDP‐mimicking peptide polymer that has potent antibacterial activity and complete biodegradability to single amino acid and dipeptide, avoiding antimicrobial residues in aquaculture food and antimicrobial pollutions in the environment. [ 50 ] These merits suggest the antibacterial peptide polymer an ideal choice for combination therapy with curcumin as antibiotic substitutions in aquaculture.…”

Nanomaterials as carriers to improve the photodynamic antibacterial therapy

“…However, developing AlEgens with precisely regulated bacteriostatic activity remains a major challenge due to the limited molecular backbone. Guo et al (2022) developed a series of AIEgens nanofibers by rationally designing peptides such as antimicrobial peptide (AMP) HHC36, ditryptophan, polyarginine, and polylysine as bacterial recognition ligands. These AlEgens exhibit precisely tunable antibacterial behaviors that can be modulated and inhibited by simply changing the modified peptides to recognize different bacteria.…”