Cell-Selective Binding Zwitterionic Polymeric Micelles Boost the Delivery Efficiency of Antibiotics

Effective accumulation and penetration of antibiotics in the biofilm are critical issues for bacterial infection treatment. Red blood cells (RBCs) have been widely utilized to hitchhike nanocarriers for drug delivery. It is vital and challenging to find a nanocarrier with an appropriate affinity toward RBCs and bacteria for selective hitchhiking and release that determines the drug delivery efficiency and specificity. Herein, we report a zwitterionic polymer poly-(2-(N-oxide-N,N-diethylamino)-ethyl methacrylate) (OPDEA)-based micelle, which can hitchhike on RBCs in blood and preferentially release in the infection site. We found that OPDEA could bind to the RBCs cell membrane via phospholipid-related affinity and transfer to Gram-positive bacteria due to nearly an order of magnitude stronger interaction with the bacteria cell wall. The zwitterionic surface and cell-wall affinity of OPDEA-based micelles also promote their penetration in biofilm. The clarithromycin-loaded OPDEA micelles show efficient drug delivery into the infection site, resulting in excellent therapeutic performance in both peritonitis and pneumonia models by intravenous or spray administration. This simple RBC-selective hitchhiking and releasing antibiotic delivery system provides a promising strategy for the design of antibacterial nanomedicines.

Automated summary

This study reports a nanocarrier based on OPDEA that can hitchhike on red blood cells and preferentially release at the infection site. The nanocarrier achieves selective hitchhiking and release through its affinity with both red blood cell membrane and bacteria cell wall, enabling efficient drug delivery and improved penetration in biofilm.