Controlled release and antibioticeffect of vancomycin-loaded poly(N-isopropylacrylamide) nanoparticles as a smart...

Numerous studies have addressed the use of vancomycin (VA) to effectively treat bacterial infections. However, VA is known to cause side effects when administered intravenously. Herein, monodisperse poly(N-isopropylacrylamide) (PNIPAAm) hollow nanocapsules were synthesized at the interface of a water-in-oil (W/O) single emulsion via Shirasu porous glass (SPG) membrane emulsification and UV-initiated polymerization. In water solutions, the PNIPAAm nanocapsules were able to encapsulate VA and form a new nanoscale water-soluble drug delivery system, namely, PNIPAAm-VA. In vitro experiments showed that PNIPAAm and PNIPAAm-VA had no cytotoxicity toward human bone marrow mesenchymal stem cells. In addition, the slow hydrolysis of PNIPAAm-VA in vitro led to the progressive release of VA, which was discharged at more than 50% and 80% of its initial concentration within 10 days at 37°C and 40°C, respectively; this subsequently inhibited the growth of methicillin-resistant Staphylococcus aureus bacteria. We believe that our PNIPAAm-VA nanoparticles can potentially be used as an effective injectable for temperature-sensitive materials in vivo to achieve the localized controlled release of drugs as safe and specific therapeutic agents.