Length‐Controlled Construction of Ceria Nanowires with Ultrafine Diameter and Stable Morphology for Targeted Acute Lung Injury Therapy

Abstract The overproduction of reactive oxygen species (ROS) is one of the major reasons for the aggravation of acute lung injury (ALI). Smaller‐sized ceria nanoparticles featured with higher ROS scavenging capability than their bigger‐sized counterparts are potential candidates for ALI therapy. However, smaller‐sized ceria nanoparticles are more easily accumulated in spleen and liver rather than lung. Herein, it is reported that this obstacle can be addressed by constructing ceria into ultrafine nanowires, through which the ultrafine diameter ensures the high ROS scavenging activity and the high aspect ratio promotes the lung targeted accumulation. To demonstrate the feasibility of this conception, a platform is developed to realize length‐controlled ceria nanowires (diameter of ≈1.5 nm) synthesis. These nanowires are PEGylated using a carefully optimized procedure that can preserve their fragile crystal structures. The PEGylated nanowires exhibit higher ROS scavenging capabilities than the ≈3.9 nm sized nanoparticles. Most importantly, lung targeted accumulation can be realized through modulating the length of the nanowires, where the longer nanowires (>100 nm) show much higher lung accumulation. Due to these properties, the longer ceria nanowires can effectively scavenge the overproduced ROS during the progression of ALI, and thereby inhibit the edema and inflammation in the lung tissue.