Dual-barrier traversing liposomes with ROS-responsive rigidity tuning for oral ischemic stroke therapy.

For sustained ischemic stroke intervention, oral delivery remains optimal. However, conventional nanocarriers like liposomes fail to overcome both the intestinal epithelial (IEB) and blood-brain barriers (BBB). We engineered dual-functional, butylphthalide (NBP)-loaded liposomes (C-NBP Lip) via amphiphilic cytidine-lipoic acid conjugate (LA-C) functionalization, establishing the first unified nanoplatform for nucleoside transporter-mediated targeting and reactive oxygen species (ROS)-responsive membrane modulation. Our strategy exploits cytidine's dual affinity for apical concentrative (CNT1) and basolateral equilibrative (ENT1) nucleoside transporters on gut epithelia, enabling efficient intestinal translocation and subsequent ENT1-mediated BBB transcytosis via a single ligand. Crucially, hydrophobic interactions between LA-C's dithiolane ring and phospholipids dynamically tuned membrane rigidity of C-NBP Lip. enabling ROS-triggered drug release at ischemic lesions. In rats, C-NBP Lip exhibited 44.61 % oral bioavailability, 137 % higher than free NBP (18.80 %), and demonstrated robust neuroprotection without toxicity in both short- and long-term rat ischemic stroke model. This work pioneers "barrier-adaptive liposomes" that integrate endogenous transporter exploitation with stimulus-responsive membrane engineering for transformative oral brain delivery.