Efficient antibacterial polyphosphazene material with potential to prominent wound healing

Abstract

Reducing the toxicity of silver-based antibacterial agents used in gels and improving their biocompatibility are of great significance in the development of wound dressings. Thus, a highly crosslinked organic–inorganic hybrid porous polyphosphazene nanospheres (PRV-HMSs) were prepared via precipitation polymerization. The structures and properties were investigated. The results indicated that PRV-HMSs have uniform particle size about 500 nm, excellent thermal stability, high silver loading (26.5 wt.%) and remarkable sustained-release properties after loading AgNO3 (up to 2 weeks). The antibacterial effects were investigated with zone of inhibition testing, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), Live/Dead bacterial staining assay and bacterial growth curve assays. The silver-loaded nanospheres have excellent bactericidal effects for E. coli or S. aureus and an average bactericidal rate of 94.02% and 94.67% in the 120 hour long-acting antibacterial test. The cytotoxicity and laser confocal immunofluorescence staining experiments indicate that the simple combination of nanospheres and agar not only give low cytotoxicity, but also significantly promote the activation of macrophages, which showing potential application in the wound dressings based on hydrogel.