https://www.cas.cn/syky/202405/t20240524_5015698.shtml

In recent years, the bio-nanomaterials research and development team of the CAS Institute of Physics and Chemistry, has cooperated with many hospitals to design and prepare a variety of antibacterial peptides and related functional materials to address clinical problems caused by microbial infections, and have used them in animals with various infectious diseases. In this context, antibacterial peptides with excellent antibacterial properties against methicillin-resistant Staphylococcus aureus (MRSA) were designed in view of the problems of osteomyelitis, and embedded into an antibacterial hydrogel formed in situ. The hydrogel is composed of four-arm polyethylene glycol maleimide (4-Arm-PEG-Mal), an N-terminal maleimidated antimicrobial peptide, and a collagenase-cleavable peptide containing sulfhydryl groups at both ends through chemical bonds. Due to the rapid bonding between maleimide and sulfhydryl groups, AMP/VPM/PEG hydrogels can be rapidly formed in situ under physiological conditions. In addition, overexpressed collagenase at bacterial infection sites can enzymatically hydrolyze hydrogels to achieve on-demand delivery of antimicrobial peptides, thereby enhancing the activity of antimicrobial peptides against MRSA in infectious environments. In an in vivo rat osteomyelitis model, hydrogel was formed in situ in the bone marrow cavity by simply injecting 4-Arm-PEG-Mal solution and peptide solution into the bone marrow cavity with a 26 G needle. CT results demonstrated that AMP/VPM/PEG hydrogels prevented MRSA-induced osteomyelitis. The above results provided a minimally invasive method for on-demand intramedullary delivery of antimicrobial peptides and are expected to provide a feasible strategy for clinical prevention of osteomyelitis.