Versatile Design of NO-Generating Proteolipid Nanovesicles for Alleviating Vascular Injury

Sprayable Reactive Oxygen Species-Responsive Hydrogel Coatings Restore Endothelial Barrier Integrity for Functional Vascular Healing

Drug-coated balloons are advancing in coronary interventional therapy for stenosis but often cause traumatic vascular injury, leading to late-stage restenosis. A critical pathological event in this process is the early disruption of the endothelial barrier integrity, which triggers inflammation and hyperplasia. However, effective therapeutic strategies to promptly restore endothelial integrity are lacking. Here, we identify the elimination of excess reactive oxygen species (ROS) as a key mechanism for reinforcing intercellular tight junctions (TJs) and restoring the endothelial barrier function. We thus propose a sprayable, ROS-responsive hydrogel coating, OA@G-NO/B-EC, for vascular balloons designed to mitigate late-stage restenosis. This hydrogel, precisely fabricated via ultrasonic spraying, comprises a reversible phenylboronic ester-bearing caffeate prodrug (B-EC) and a macromolecular nitric oxide (NO) donor (G-NO), both dynamically self-cross-linked with dopamine-modified oxidized dextran (OA) through Schiff base chemistry. The dual dynamic covalent linkages enable the hydrogel to gradually disintegrate in response to ROS accumulation at lesion sites, providing controlled, on-demand therapeutic action. Sustained release of herbal antioxidant caffeates effectively scavenges ROS, rescuing TJ integrity and attenuating inflammation. This favorable microenvironment further enhances both endogenous NO production and exogenous NO delivery, facilitating endothelial proliferation and migration. Moreover, this hydrogel's robust adhesion to the arterial wall ensures sufficient drug retention and delivery. In vitro and in vivo results, supported by RNA sequencing analysis, strongly demonstrate the hydrogel's enhanced capacity for vascular healing and restenosis prevention. This system holds broad potential for surface engineering across diverse biomedical materials and devices, advancing localized drug delivery.

Rational Design of Genetically Engineered Mitochondrial-Targeting Nanozymes for Alleviating Myocardial Ischemic-Reperfusion Injury

The development of mitochondria-targeting nanozymes holds significant promise for treating myocardial ischemia-reperfusion (IR) injury but faces significant biological barriers. To overcome these obstacles, we herein utilized genetically engineered ferritin nanocages (i.e., imFTn) to develop mitochondria-targeting nanozymes consisting of three ferritin subunit assembly modules: an IR-injured cardiomyocyte-targeting module, a lysosome-escaping module, and a mitochondria-targeting module. Using imFTn as a nanozyme platform, we developed nanozymes capable of efficiently catalyzing the l-Arg substrate to produce NO. The imFTn-Ru exhibits NO-generating activities, reduces mitochondrial reactive oxygen species generation, inhibits mitochondrial permeability transition pore opening, and enhances mitochondrial membrane potential. Furthermore, imFTn-Ru provides synergistic effects by specifically targeting myocardial IR-injured tissues, facilitating their accumulation in mitochondria, and protecting mitochondria against myocardial IR-induced injury in both in vitro and in vivo models. This study underscores a rational approach to designing nanozymes for targeting specific subcellular organelles in the treatment of IR injury.