Magnetic iron oxide nanoparticles/10-hydroxy camptothecin co-loaded nanogel for enhanced photothermal-chemo therapy

Abstract Iron oxide nanoparticle is a promising nano-biomaterial for treating iron deficiency, or as drug carriers and contrast agent as well as stimulator to elicit ROS generation. However, because of their intrinsic structure, therapeutic agents are hard to be loaded by them alone. Nanogel is a promising candidate for co-loading of iron oxide and therapeutic drug, due to its network structure and permeability. In this study, we use pre-prepared nanogel as surfactant to co-load hydrophobic magnetic nanoparticles (MNPs) and anti-cancer drug (10-hydroxy camptothecin, HCPT) to construct MNPs/HCPT-nanogel for cancer diagnosis and therapy. By in vitro and in vivo evaluation, we reveal that the obtained MNPs/HCPT-nanogel are stable in aqueous environment and can be served as drug delivery system to efficiently inhibit the tumor growth as well as MRI contrast agent for MR imaging. The introduction of MNPs elicits the generation of ROS with the presence of macrophage, which can further inhibit the growth of cancer cell. Furthermore, the introduction of extra-magnetic field can further enhance the enrichment of MNPs/HCPT-nanogel in the tumor site, which further improves the chemotherapeutic outcome. Besides, the obtained MNP/HCPT-nanogel can be used as nanocarrier for photothermal therapy for its absorption at NIR region. With the combination of PTT and chemotherapy, not only can the growth primary tumor be inhibited, but also the metastasis can be alleviated. It demonstrates that the MNP/HCPT-nanogel can be served as a promising candidate for cancer PTT/chemotherapy to inhibit tumor growth and alleviate metastasis.