Neutrophil membranes coated, antibiotic agent loaded nanoparticles targeting to the lung inflammation.

Natural cellular membranes, with the outstanding qualities of biocompatibility and specificity, have gained growing attentions in the system of drug delivery. Nanoparticles coated with cellular membranes are starting to be applied as drug-loaded-vehicles to target tumors. Here, neutrophil membranes were selected to apply in the treatment of inflammation because neutrophils can participate in various inflammatory responses and accumulate at inflammatory sites to eliminate pathogens. Through extracting neutrophil membranes from natural neutrophils without affecting their biological properties, nanoparticles loaded with sparfloxacin (SPX) were coated with these membranes and disguised as neutrophils. Compared with traditional nano-medicines, the neutrophil membrane-coated nanoparticles (NM-NP-SPX) possessed precise targeting ability just like the neutrophils could accumulate at inflammatory sites when inflammation burst. In addition, NM-NP-SPX could prolong the circulation time and had the property of controlled-release. Through in vivo experiments, we found that the concentration of three representative inflammatory cytokines in blood, bacteria and inflammatory cells in lungs of the mice with pneumonia reduced significantly in the initial 24 h after the injection of NM-NP-SPX, which meant that NM-NP-SPX could greatly reduce the risk of death for the patients with inflammation. Moreover, the infected lungs could recover rapidly without any side effects to other organs due to the low cytotoxicity of NM-NP-SPX against normal cells. Therefore, our developed drug delivery system has enormous advantages in treating inflammations. Not only that, this kind of bionic method may have greater value and application prospects in curing the inflammations arisen from cancers.