Synthesis of pH-Sensitive Particles for Local Delivery of an Antibiotic via Dispersion ROMP

The synthesis and the in vitro antibacterial activity of pH-sensitive functionalized nanoparticles for the local delivery of antibiotic are described. Nanoparticles (NPs) are formed by ring-opening metathesis copolymerization (ROMP) in dispersed medium of norbornene (Nb) with α,ω-functionalized macromonomers. Macromonomers are ended with gentamicin sulfate (GS) or carboxylic acid groups. GS, linked thanks to a pH-sensitive bond, can be released in acidic medium whereas acidic function allows the future covalent grafting of these NPs onto biomaterial surface in order to synthesize innovating GS-loaded biomaterials. In this paper, we focused on the synthesis and the characterization of biofunctional NPs and their in vitro antibacterial activities. NPs have been synthesized with a controlled rate of GS and their stability in aqueous medium has been proved. Minimum inhibitory concentration (MIC) measurements using Staphylococcus epidermidis as bacterial strain after the GS release at acidic pH have permitted ...