Design of a Multifunctional Nanozyme for Resolving the Proinflammatory Plaque Microenvironment and Attenuating Atherosclerosis.

Persistent inflammation within atherosclerotic plaques is a crucial factor contributing to plaque vulnerability and rupture. It has become increasingly evident that the proinflammatory microenvironment of the plaque, characterized by heightened monocyte recruitment, oxidative stress, and impaired clearance of apoptotic cells, plays a significant role in perpetuating inflammation and impeding its resolution. Consequently, targeting and eliminating these proinflammatory features within the plaque microenvironment have emerged as a promising therapeutic approach to restore inflammation resolution and mitigate the progression of atherosclerosis. While recent advancements in nanotherapeutics have demonstrated promising results in targeting individual proinflammatory characteristics, the development of an effective therapeutic strategy capable of simultaneously addressing multiple proinflammatory features remains a challenge. In this study, we developed a multifunctional nanozyme based on Prussian blue, termed PBNZ@PP-Man, to simultaneously target and eliminate various proinflammatory factors within the plaque microenvironment. Through systematic investigations, we have elucidated the antiatherosclerotic mechanisms of PBNZ@PP-Man. Our results demonstrate that PBNZ@PP-Man possesses the ability to accumulate within atherosclerotic plaques and effectively eliminate multiple proinflammatory factors, leading to inflammation resolution. Specifically, PBNZ@PP-Man suppresses monocyte recruitment, scavenges reactive oxygen species, and enhances efferocytosis. Notably, PBNZ@PP-Man exhibits a much stronger efficacy to resolve the proinflammatory plaque microenvironment and attenuate atherosclerosis in comparison to the approach that merely eliminates one single risky factor in the plaque. It significantly enhances the inflammation resolution capabilities of macrophages and attenuates atherosclerosis. These results collectively underscore the importance of modulating the proinflammatory plaque microenvironment as a complementary strategy for resolving inflammation in atherosclerosis.

Hyaluronic acid-guided assembly of ceria nanozymes as plaque-targeting ROS scavengers for anti-atherosclerotic therapy.

Oxidative stress is a distinguishing feature in atherosclerosis disease. Reactive oxygen species (ROS) can increase the oxidized low density lipoprotein (ox-LDL) and oxidative damage to macrophages in the plaque. Although antioxidant agents such as N-acetylcysteine are used to treat atherosclerosis, but provide a poor clinical benefit to the majority of patients with atherosclerosis. Here we have designed hyaluronic acid-guided assemblies of ceria nanozymes (HA-CeO2 NPs) as novel plaque-targeting ROS scavengers. The introduction of hyaluronic acid not only provide the stability and biocompatibility, but also surprisingly enhance SOD-mimic activities of ceria nanozymes compared to bare CeO2 precipitates, dextran or poly-aspartic acid coated ceria nanozymes. Interestingly, we find HA-CeO2 NPs not only actively target plaque-associated macrophages in atherosclerosis to remove superfluous ROS and protect macrophages from ROS-caused damages, but also effectively inhibit endocytosis of ox-LDL by activated macrophages. We believe HA-CeO2 nanozymes can serve as a simple and promising platform for anti-atherosclerotic therapy.

Plaque-Targeted Rapamycin Spherical Nucleic Acids for Synergistic Atherosclerosis Treatment.

Atherosclerosis with unstable plaques is the dominant pathological basis of lethal cardio-cerebrovascular diseases, which can cause acute death due to the rupture of plaques. Plaque-targeted drug delivery to achieve promoted treatment remains the main challenge because of the systemic occurrence of atheroma. Herein, a rapamycin (RAP) spherical nucleic acid (SNA) structure, capable of specifically accumulating in plaques for synergistic atherosclerosis treatment is constructed. By designing consecutive phosphorothioate (PS) at 3' terminus of the deoxyribonucleic acid (DNA) strand, multiple hydrophobic RAPs are covalently grafted onto the PS segment to form an amphiphilic drug-grafted DNA (RAP-DNA), which successively self-assembles into micellar SNA (RAP-SNA). Moreover, the phosphodiester-DNA segment constitutes the outer shell of RAP-SNA, enabling further hybridization with functional siRNA (targeting lectin-like oxidized low-density lipoprotein receptor-1, LOX-1) to obtain the drug codelivered SNA (LOX-1/RAP-SNA). With two active ingredients inside, LOX-1/RAP-SNA can not only induce robust autophagy and decrease the evil apoptosis of the pathological macrophages, but also simultaneously prohibit the LOX-1-mediated formation of damageable foam cells, realizing the effect of synergistic therapy. As a result, the LOX-1/RAP-SNA significantly reduces the progression of atheroma and stabilizes the plaques, providing a new strategy for synergistically targeted atherosclerosis treatment.

Dynamically enhancing plaque targeting via a positive feedback loop using multifunctional biomimetic nanoparticles for plaque regression.

A paradigm shift from preventive therapy to aggressive plaque regression and eventual eradication is much needed to address increasing atherosclerotic burden and risks. Herein, we report a biologically inspired dual-targeting multifunctional recombinant high-density lipoprotein (rHDL)-mimicking core-shell nanoplatform. It is composed of an ATP-responsive ternary polyplexes core for SR-A siRNA and catalase complexation, and a phosphatidylserine-modified rHDL-based outer shell for SR-BI and CD36 targeting, in which pitavastatin is packaged. We demonstrated that dual-targeting biomimetic core-shell nanoparticles dynamically enhanced macrophage CD36 targeting in the plaques by establishing a positive feedback loop via the reciprocal regulation of SR-A and CD36. Positive feedback-enabled accumulation of the nanoparticles in the atherosclerotic plaques increased by 3.3-fold following 4-week repeated administration. A 3-month dosage regimen of the dual-targeting rHDL-mimicking nanoparticles reduced plaque areas by 65.8%, and decreased macrophages by 57.3%. Collectively, this work shows that dynamically enhancing plaque targeting via a positive feedback loop and dual action of cholesterol deposition inhibition and efflux enhancement accomplished with our novel multifunctional biomimetic nanoparticles provides a new way to regress plaques and alleviate the atherosclerotic burden.

Rational Design of Lovastatin-Loaded Spherical Reconstituted High Density Lipoprotein for Efficient and Safe Anti-Atherosclerotic Therapy.

Reconstituted high density lipoprotein (rHDL) is a biomimetic nanoparticle with plaque targeting and anti-atherosclerotic efficacy. In this work, we report on a strategy to rational design of lovastatin (LOV)-loaded spherical rHDL (LOV-s-rHDL) for efficient and safe anti-atherosclerotic therapy. Briefly, three LOV-s-rHDLs were formulated with LOV/s-rHDL at ratios of 8:1, 10:1, and 15:1 upon their respective median-effect values ( Dm). The combined inhibitory effect between LOV and s-rHDL of different LOV-s-rHDL formulations on DiI-labeled oxLDL internalization was systemically investigated in RAW 264.7 cells based on the median-effect principle. Median-effect analysis demonstrated that the optimized LOV-s-rHDL was formulated with a ratio of 10:1 ( Dm LOV: Dm s-rHDL), in which LOV and s-rHDL carrier showed the best synergistic effect, presumably ascribed to their inhibitory effect on CD36 and SR-A expression according to the Western blot analysis. In vivo pharmacodynamics studies showed that the optimized LOV-s-rHDL displayed the most pronounced anti-atherosclerotic effect on decreasing plaque area and reducing the MMP level following an 8-week dosing regimen. In vivo atherosclerotic plaque targeting analysis revealed that s-rHDL had potent plaque targeting efficacy, probably owing to the interaction between apoA-I and scavenger receptor B-I. Furthermore, we observed that the optimized LOV-s-rHDL exhibited a favorable safety profile as evidenced by the results of a hemolysis assay, cell cytotoxicity study, and in vivo safety test. Collectively, the rational design of the biomimetic LOV-s-rHDL based on the median-effect analysis provides an efficient strategy to achieve a synergistic and safe anti-atherosclerotic therapy.