Versatile Octapod-Shaped Hollow Porous Manganese(II) Oxide Nanoplatform for Real-Time Visualization of Cargo Delivery

Multifunctional nanoplatforms featuring promising properties including excellent loading efficiency, real-time monitoring, and improved cargo bioavailability and bioselectivity are in great demand by the biomedical research community. During the development of such nanoplatforms, stimuli-responsive nanoparticles (NPs) as a smart nanoplatform have recently received extensive attention. Herein, we report small-sized octapod-shaped hollow porous manganese(II) oxide (HPMO) NPs as a stimuli-responsive T₁-activatable nanoplatform for tumor-specific cargo delivery and real-time monitoring. The HPMO NPs functionalized by zwitterionic dopamine sulfonate (ZDS) can act as a versatile platform to load organic dyes or chemotherapeutic drugs with high loading efficiency. The obtained Cargo@HPMO would decompose into paramagnetic Mn²⁺ ions and subsequently release cargoes in mild acidic conditions, especially in tumor microenvironment and lysosome. The released Mn²⁺ can enhance T₁ magnetic resonance signal for real-time monitoring of the cargo delivery in vivo. This octapod-shaped Cargo@HPMO can act as a smart and versatile nanoplatform with pH-responsive multimodal imaging and site-specific drug delivery for the development of accurate diagnosis and effective therapy for cancer.