Degradable Nanomotors Using Platinum Deposited Complex of Calcium Carbonate and Hyaluronate Nanogels for Targeted Drug Delivery

Recently, micro/nanomotor systems have been widely investigated for biomedical applications especially for the active transport and delivery of specific drugs. However, there are few stimuli-responsive micro/nanomotor systems to enhance the drug delivery efficiency and reduce side effects by the spatiotemporal controllability. Here, a degradable nanomotor is first fabricated for targeted drug delivery using a platinum (Pt)-deposited complex of calcium carbonate and cuccurbit6]uril-conjugated hyaluronate (Pt/CaCO₃@HA-CB6]). The nanomotors could efficiently deliver model drugs to the cells in reactive oxygen species (ROS) abundant environments such as the tumor site. After reaching the tumor site around pH 6.5, Pt/CaCO₃@HA-CB6] nanomotors (≈1 µm) are pH-responsively disintegrated by the dissociation of CaCO₃ and the encapsulated HA-CB6] (≈300 nm) are released for cancer cell uptake. The released HA conjugate are finally uptaken into cancer cells via HA receptor-mediated endocytosis. Moreover, model drugs are modularly loaded into the nanomotors via the host–guest chemistry of CB6] for stable delivery to cancer cells. Taken together, Pt/CaCO₃@HA-CB6] nanomotors systems could be successfully harnessed for active drug delivery to cancer cells.