Bioinspired PROTAC-induced macrophage fate determination alleviates atherosclerosis.

Atherosclerosis is a major cause of death and disability in cardiovascular disease. Atherosclerosis associated with lipid accumulation and chronic inflammation leads to plaques formation in arterial walls and luminal stenosis in carotid arteries. Current approaches such as surgery or treatment with statins encounter big challenges in curing atherosclerosis plaque. The infiltration of proinflammatory M1 macrophages plays an essential role in the occurrence and development of atherosclerosis plaque. A recent study shows that TRIM24, an E3 ubiquitin ligase of a Trim family protein, acts as a valve to inhibit the polarization of anti-inflammatory M2 macrophages, and elimination of TRIM24 opens an avenue to achieve the M2 polarization. Proteolysis-targeting chimera (PROTAC) technology has emerged as a novel tool for the selective degradation of targeting proteins. But the low bioavailability and cell specificity of PROTAC reagents hinder their applications in treating atherosclerosis plaque. In this study we constructed a type of bioinspired PROTAC by coating the PROTAC degrader (dTRIM24)-loaded PLGA nanoparticles with M2 macrophage membrane (MELT) for atherosclerosis treatment. MELT was characterized by morphology, size, and stability. MELT displayed enhanced specificity to M1 macrophages as well as acidic-responsive release of dTRIM24. After intravenous administration, MELT showed significantly improved accumulation in atherosclerotic plaque of high fat and high cholesterol diet-fed atherosclerotic (ApoE-/-) mice through binding to M1 macrophages and inducing effective and precise TRIM24 degradation, thus resulting in the polarization of M2 macrophages, which led to great reduction of plaque formation. These results suggest that MELT can be considered a potential therapeutic agent for targeting atherosclerotic plaque and alleviating atherosclerosis progression, providing an effective strategy for targeted atherosclerosis therapy.

CuS Nanodot-Loaded Thermosensitive Hydrogel for Anticancer Photothermal Therapy.

The purpose of this research is to establish an injectable hydrogel encapsulating copper sulfide (CuS) nanodots for photothermal therapy against cancer. The CuS nanodots were prepared by one-pot synthesis, and the thermosensitive Pluronic F127 was used as the hydrogel matrix. The CuS nanodots and the hydrogel were characterized by morphous, particle size, serum stability, photothermal performance upon repeated 808 nm laser irradiation, and rheology features. The effects of the CuS nanodots and the hydrogel were evaluated qualitatively and quantitatively in 4T1 mouse breast cancer cells. The retention, photothermal efficacy, therapeutic effects, and systemic toxicity of the hydrogel were assessed in tumor bearing mouse model. The CuS nanodots with a diameter of about 8 nm exhibited satisfying serum stability, photoheat conversion ability, and repeated laser exposure stability. The hydrogel encapsulation did not negatively influence the above features of the photothermal agent. The nanodot-loaded hydrogel shows a phase transition at body temperature and, as a result, a long retention in vivo. The photothermal-agent-embedded hydrogel played a promising photothermal therapeutic effect in the tumor bearing mouse model with low systemic toxicity after peritumoral administration.