Inflammatory endothelium-targeted and cathepsin responsive nanoparticles are effective against atherosclerosis

Rationale: Atherosclerosis is characterized by lipid accumulation, plaque formation, and artery stenosis. The pharmacological treatment is a promising therapy for atherosclerosis, but this approach faces major challenges such as targeted drug delivery, controlled release, and non-specific clearance. Methods: Based on the finding that the cathepsin k (CTSK) enzyme is enriched in atherosclerotic lesions, we constructed an integrin alpha(v)beta(3) targeted and CTSK-responsive nanoparticle to control the release of rapamycin (RAP) locally. The targeted and responsive nanoparticles (T/R NPs) were engineered by the self-assembly of a targeting polymer PLGA-PEG-c(RGDfC) and a CTSK-sensitive polymer PLGA-Pep-PEG. PLGA-Pep-PEG was also modified with a pair of FRET probe to monitor the hydrolysis events. Results: Our results indicated that RAP@T/R NPs accelerated the release of RAP in response to CTSK stimulation in vitro, which significantly inhibited the phagocytosis of OxLDL and the release of cytokines by inflammatory macrophages. Additionally, T/R NPs had prolonged blood retention time and increased accumulation in the early and late stage of atherosclerosis lesions. RAP@T/R NPs significantly blocked the development of atherosclerosis and suppressed the systemic and local inflammation in ApoE(-/-) mice. Conclusions: RAP@T/R NPs hold a great promise as a drug delivery system for safer and more efficient therapy of atherosclerosis.

Automated summary

Targeted and responsive nanoparticles can control the release of drugs and effectively treat atherosclerosis. In vitro experiments showed that these nanoparticles can rapidly release drugs in response to stimulation and effectively inhibit inflammatory responses. In vivo experiments showed that these nanoparticles can slow down the progression of atherosclerosis and reduce inflammation.