Inhalation of macrophage membrane-coated hydrogel microparticles for inflammation alleviation of acute lung injury in vivo.

Hydrogel microparticles (HMPs) have many advantages for biomedical applications, particularly for minimally invasive therapy, for example, acute lung injury (ALI) that is characterized by high levels of reactive oxygen species (ROS) and pro-inflammatory mediators in the microenvironment. In this study, ROS-scavenging and pro-inflammatory cytokine-neutralizing HMPs were designed and prepared by using a membrane emulsification device. The HMPs were composed of double bond-modified hyaluronic acid and ROS-cleavable hyperbranched poly(acrylate-capped thioketone-containing ethylene glycol) (HBPAK) containing thioketal linkages and unsaturated double bonds. Surface-coating of inflammatory macrophage (M1) cell membranes was performed to obtain the membrane-coated HBPAK HMPs (mem HMPs) via electrostatic force. The mem HMPs exhibited strong ROS-scavenging and anti-inflammatory properties both in vitro and in vivo. After administered by inhalation in an ALI mouse model, the mem HMPs reduced neutrophil infiltration and tissue oxidative damage, thereby alleviating lung inflammation. Our results suggest that the mem HMPs could serve as a potential therapeutic platform for treating inflammatory diseases with high efficiency. STATEMENT OF SIGNIFICANCE: Hydrogel microparticles (HMPs) with minimally invasive delivery are advantageous for acute lung injury (ALI) characterized by high levels of reactive oxygen species (ROS) and pro-inflammatory mediators. Herein, ROS-scavenging and pro-inflammatory cytokine-neutralizing HMPs were prepared by copolymerizing double bond-modified hyaluronic acid and ROS-cleavable hyperbranched poly(acrylate-capped thioketone-containing ethylene glycol) (HBPAK) containing thioketal bonds and unsaturated double bonds in a membrane emulsification device. The HMPs covered with inflammatory macrophage (M1) cell membranes (mem HMPs) exhibited strong ROS-scavenging and anti-inflammation properties, reduced neutrophil infiltration and tissue oxidative damage, thereby alleviating lung inflammation.