Modulating the Optical and Enzymatic Properties of Polydopamine via Valence Engineering of Tungsten Affording NIR-II Photoacoustic Imaging and Targeted Therapy of Atherosclerosis.

Abstract

Atherosclerosis (AS) is a risk factor for various cardiovascular diseases (CVD), and early diagnosis and plaque removal are challenges in the management of AS and CVD. To address these challenges, we designed a tungsten‑doped polydopamine nanoparticle (W-PDA NPs). The near-infrared (NIR) optical absorption and enzymatic properties of W-PDA were tuned by adjusting the ratio of W⁶⁺ to PDA. It was found that the W-PDA NPs contain a mixture of W⁶⁺ and W⁵⁺, which generated large amounts of free electrons, thus conferring both second near-infrared (NIR-II) light absorption capability and superoxide dismutase (SOD)- and catalase (CAT)-like activities. Plaque-targeting was conferred by appending an anti-osteopontin antibody via coordination between carboxyl moieties of the antibody with W⁶⁺ ions on the W-PDA surface. The NIR-II light absorption ability can be utilized for photoacoustic diagnosis of AS, while the SOD- and CAT-like activities facilitate the conversion of superoxide into H₂O₂ and subsequently O₂, thereby clearing reactive oxygen species and mitigating inflammation, enabling therapy of AS. Thus, the proposed theranostic agent not only can dynamically report the progression of AS but also can effectively treat AS plaques. This strategy holds broad application prospects in the early and accurate diagnosis and treatment of AS.