Manganese-Doped Layered Double Hydroxide: A Biodegradable Theranostic Nanoplatform with Tumor Microenvironment Response for Magnetic Resonance Imaging-Guided Photothermal Therapy

Theranostic nanoplatforms with easy fabrication, high efficiency, and biodegradability are imperative to achieve efficacious and safe cancer treatment outcome. Toward this end, we prepared manganese-doped layered double hydroxide nanoparticles (Mn-LDH NPs) via a facile two-step synthetic method and revealed their excellent photothermal property coupled with simultaneous T1-weighted magnetic resonance imaging enhancement ability. By virtue of these unique properties, imaging-guided photothermal treatment has been achieved to eliminate tumors by using the Mn-LDH NPs without additional photosensitizer, drug, or imaging agent. Specifically, Mn­(ox)-LDH NPs (oxidized Mn-LDH NPs) exhibited highly efficient tumor killing ability by activating apoptosis of tumor cells under external NIR 808 nm laser irradiation with the imaging guidance. More importantly, both the MR imaging and in vitro/vivo testing revealed that the Mn-LDH NPs are able to degrade in physiological conditions and demonstrate a high degree of biosafety. Considering the excellent T1-weighted MRI contrast property, effective photothermal performance, biodegradation, and biosafety, the Mn-LDH NPs have presented a potential generation inorganic biodegradable theranostic nanoplatform for efficacious cancer treatment.