Active Anchoring Stimuli‐Responsive Nano‐Craft to Relieve Pulmonary Vasoconstriction by Targeting Smooth Muscle Cell for Hypoxic Pulmonary Hypertension Treatment

Recently, nanotechnology-based drug delivery platforms in treating pulmonary arterial hypertension (PAH) have gradually emerged. However, large mechanical stress and shear stress in blood vessels greatly affect the retention of nanopreparative materials at lesion sites, severely limiting nanotechnology-based drug delivery. Herein, a stimuli-responsive nanocraft is rationally designed by actively anchoring E-selectin overexpressed on pulmonary arterial endothelial cells (PAECs), under hypoxic conditions, allowing effective accumulation and retention of the drug at the lesion site. Briefly, a nitrobenzene group is incorporated into the framework of a nanocarrier, and then it is simultaneously linked with chitosan. Additionally, the surface of the nanocarrier with sialic acid (SA) and encapsulated the clinically used drug ambrisentan (Am), which enables the anchoring of E-selectin and subsequent drug delivery is modifed. This system facilitates intercellular transport to pulmonary artery smooth muscle cells (PASMCs) when targeting PAECs and specifically responds to a reductive hypoxic microenvironment with elevated nitroreductase in PASMCs. Moreover, compared with free Am, nanoencapsulation and SA-PEG