ICAM-1-targeted and antibacterial peptide modified polymeric nanoparticles for specific combating sepsis

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection and causes high ratios of morbidity and mortality worldwide. Although many potential therapeutic targets have been reported, the therapeutic effect needs to be further improved. Herein, we report a strategy to specifically target inflammation site via anti-ICAM-1 antibody bonded antibacterial peptides polymeric nanoparticle. Antibacterial peptide (KR-12) grafted amphipathic PCL-b-P(OEGMA-co-AMA)-g-Cys-KR-12 block copolymer and PCL-b-P(OEGMA-co-AMA)-g-biotin block copolymer were synthesized by ring-opening polymerization and click chemistry. Then, antibacterial peptides polymeric nanoparticles (AMPNP) were prepared by co-assembly of amphipathic PCL-b-P(OEGMA-co-AMA)-g-Cys-KR-12 and PCL-b-P(OEGMA-co-AMA)-g-biotin in aqueous solution. Intercellular adhesion molecule-1 (ICAM-1) is highly expressed on the surface of inflammatory endothelial cells, and the anti-ICAM-1 antibody can specifically bind to it. To obtain the anti-ICAM-1-AMPNP nanoparticles, biotinylated anti-ICAM-1 antibodies were bonded on the surface of AMPNP nanoparticles through the biotin-avidin system. The anti-ICAM-1-AMPNP nanoparticles had low systemic toxicity and exhibited ideal antibacterial property against drug-resistant bacteria, Gram-negative bacteria and Gram-positive bacteria. The anti-ICAM-1-AMPNP nanoparticles exhibited favorable targeting capabilities to inflammation endothelial cells in vitro and significantly reduced the inflammatory response of CLP mice in vivo. The present investigation might provide a specific strategy for targeting combating sepsis with anti-ICAM-1-AMPNP nanoparticles.