Multifunctional Nanomaterial-alginate Drug Delivery and Imaging System for Cancer Therapy

Although chemotherapy is mostly performed by direct injection of the chemotherapeutic agents systemically, this approach can cause undesirable side effects in normal tissues and lacks targeting efficiency. In this study, we have developed a micron-sized, bead-type multifunctional anticancer-drug carrier that can be injected in the vicinity of a lesion using a syringe. The multifunctional anticancer-drug carrier bead was fabricated by incorporating functional nanomaterials, such as near-infrared (NIR)-responsive gold nanorod (GNR) and superparamagnetic iron oxide nanoparticles (IONP) that work as a magnetic resonance imaging (MRI) contrast agent, into an alginate hydrogel bead. The carrier bead containing GNR and IONP was spherical, with an average size of 362.2 ± 22.7 µm. These multifunctional anticancer-drug carrier beads could successfully release doxorubicin (Dox) into the external environment upon irradiation with an NIR laser. The laser responsive on-demand release profile demonstrated well-controlled and sustained release of Dox, and the effectiveness of this drug delivery system can be confirmed in vitro by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Additionally, the control experiments evidenced that the thermal effect of GNR was insignificant and the cytotoxic action of Dox was expressed only after irradiation with the NIR laser. The multifunctional anticancer-drug carrier beads can be precisely monitored with the MRI T2 imaging mode.