Abstract
Combination chemo-photothermal therapy with nanomaterials can reduce the dose of chemotherapeutic drugs required for effective cancer treatment by minimizing toxic side effects while improving survival times. Toward this end, we prepare hyaluronic acid (HA)-modified poly(lactic-co-glycolic acid) (PLGA) magnetic nanoparticles (MNP) for the CD44 receptor-mediated and magnetic field-guided dual-targeted delivery of cisplatin (CDDP). By co-encapsulating the CDDP and oleic acid-coated iron oxide MNP (IOMNP) in PLGA, the PMNPc was first prepared in a single emulsification/solvent evaporation step and successively surface modified with chitosan and HA to prepare the HA/PMNPc. Spherical HA/PMNPc nanoparticles of ~300 nm diameter can be prepared with 18 and 10% (w/w) loading content of CDDP and IOMNP and a pH-sensitive drug release to facilitate the endosomal release of the CDDP after intracellular uptake. This leads to the higher cytotoxicity of the HA/PMNPc toward the U87 glioblastoma cells than free CDDP with reduced IC50, a higher cell apoptosis rate, and the enhanced expression of cell apoptosis marker proteins. Furthermore, the nanoparticles show the hyperthermia effect toward U87 after short-term near-infrared (NIR) light exposure, which can further elevate the cell apoptosis/necrosis rate and upregulate the HSP70 protein expression due to the photothermal effects. The combined cancer therapeutic efficacy was studied in vivo using subcutaneously implanted U87 cells in nude mice. By using dual-targeted chemo-photothermal combination cancer therapy, the intravenously injected HA/PMNPc under magnetic field guidance and followed by NIR laser irradiation was demonstrated to be the most effective treatment modality by inhibiting the tumor growth and prolonging the survival time of the tumor-bearing nude mice.