Biosynthesis of positively charged bacterial cellulose hydrogel with antibacterial and anti-inflammatory function for efficient wound healing.

In bacterial cellulose (BC)-based living materials, the effective and permanent incorporation of bactericidal agents into BC remains a persistent challenge. In this study, midazole quaternary ammonium salt was grafted onto a dispersion of bacterial cellulose, which was subsequently directly added to the fermentation medium of BC-producing bacteria to obtain BC-based hydrogel materials (BC/BC-[PQVI]Br) with inherent antibacterial properties. The BC/BC-[PQVI]Br hydrogel prepared in this study exhibits favorable tensile properties, with a maximum tensile stress of 970 KPa and water retention for up to 6 h. Moreover, it demonstrates acceptable antibacterial activity against S. aureus (93 %) and E. coli (71 %), respectively. Additionally, the hydrogel displays a high cell survival rate of 98 % after contact with NIH3T3 cells, indicating its non-cytotoxic nature. Furthermore, the mouse wound experiment confirms the excellent wound healing effect of the hydrogel. This research presents an innovative approach towards developing environmentally friendly active wound dressings with microbial-derived antibacterial functionality.

Recent advances in bacterial cellulose-based antibacterial composites for infected wound therapy.

Wound infection arising from pathogenic bacteria brought serious trouble to the patient and medical system. Among various wound dressings that are effective in killing pathogenic bacteria, antimicrobial composites based on bacterial cellulose (BC) are becoming the most popular materials due to their success in eliminating pathogenic bacteria, preventing wound infection, and promoting wound healing. However, as an extracellular natural polymer, BC is not inherently antimicrobial, which means that it must be combined with other antimicrobials to be effective against pathogens. BC has many advantages over other polymers, including nano-structure, significant moisture retention, non-adhesion to the wound surface, which has made it superior to other biopolymers. This review introduces the recent advances in BC-based composites for the treatment of wound infection, including the classification and preparation methods of composites, the mechanism of wound treatment, and commercial application. Moreover, their wound therapy applications include hydrogel dressing, surgical sutures, wound healing bandages, and patches are summarized in detail. Finally, the challenges and future prospects of BC-based antibacterial composites for the treatment of infected wounds are discussed.

Physical Contact-Triggered In Situ Reactivation of Antibacterial Hydrogels.

In situ reactivation of hydrogels remains a long-standing key challenge in chemistry and materials science. Herein, we first report an ultraconvenient in situ renewable antibacterial hydrogel prepared via a facile physical contact-triggered strategy based on an ultrafast chlorine transfer pathway. We discover that the as-proposed hydrogel with a programmable 3D network cross-linked by noncovalent bonds and physical interactions can serve as a smart platform for selective active chlorine transfer at the hydrogel/hydrogel interface. Systematic experiments and density functional theory prove that the N-halamine glycopolymers integrated into the hydrogel system work as a specific renewable biocide, permitting the final hydrogel to be recharged in situ within 1 min under ambient conditions. Due to its strength and durability, pathogen specificity, and biocompatibility, coupled with its rapid in situ reactivation, this antibacterial hydrogel holds great potential for in vivo biomedical use and circulating water disinfection. We envision this proposed strategy will pave a new avenue for the development of in situ renewable smart hydrogels for real-world applications.

Silver nanoparticles modified by water-soluble leaning tower[6]arenes for sensing and catalysis.

A carboxylated leaning tower[6]arene sodium salt is used as an efficient stabiliser for the one-pot synthesis of silver nanoparticles. The resulting hybrid material with good dispersion, excellent stability and narrow size distribution could serve as a multifunctional platform for sensing and catalysis applications.