Qiuyue Huang, Ruoxuan Xu, Yanchen Liu, Na Li, Yuanyuan Sun, Rongxia Liu
Oxidative stress and dysregulated vascular smooth muscle cell (VSMC) proliferation drive atherosclerotic (AS) progression and plaque development. Natural phytochemicals, including evodiamine (Evo) and curcumin (Cur), show anti-atherosclerotic potential, but poor aqueous solubility and insufficient intestinal absorption limit their oral use. Here, Evo and Cur were co-assembled into carrier-free Evo-Cur nanoparticles (EC NPs) and coated with chitosan oligosaccharide (COS) to obtain COS-coated EC nanoparticles (COS@EC NPs). Spectroscopic analyses and molecular dynamics simulations indicated that hydrophobic interactions, hydrogen bonding, and π-π stacking mediated Evo-Cur nanoassembly. Under simulated gastrointestinal conditions, COS@EC NPs reduced gastric Cur release and increased intestinal Cur release. After oral administration, COS@EC NPs prolonged intestinal residence and increased systemic exposure. In platelet-derived growth factor-BB (PDGF-BB)-stimulated VSMCs, COS@EC NPs suppressed excessive proliferation, reduced intracellular reactive oxygen species (ROS), elevated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) expression, and restrained cell-cycle progression. This antiproliferative effect was partially reversed by the HO-1 inhibitor zinc protoporphyrin IX, suggesting HO-1 involvement. Cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) analyses showed treatment-associated increases in the apparent thermal and proteolytic stability of HO-1, further supporting its involvement. In high-fat diet-fed ApoE-/- mice, oral administration of COS@EC NPs reduced plaque burden, improved lipid profiles, and alleviated oxidative stress without detectable systemic toxicity. Overall, these findings support COS@EC NPs as a potential carrier-free oral nanomedicine strategy for AS therapy and suggest that HO-1-associated redox regulation contributes to their vascular protective effects.