Intratumoral thermo-chemotherapeutic alginate hydrogel containing doxorubicin loaded PLGA nanoparticle and heating agent

Chemotherapy has been widely used to treat cancer; however, the non-specific systemic toxicity of chemotherapeutic agents has always been an issue. Local injection treatment is a strategy used to reduce the undesired adverse effects of chemotherapeutic drugs. In addition, chemotherapeutic agents combined with thermotherapy are effective in further enhancing therapeutic potency. In the present study, we prepared an injectable hydrogel, namely, doxorubicin (DOX)-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticle (DPN) and magnetite nanoparticle (MNP) embedded in alginate hydrogel (DPN/MNP-HG), where DPN and MNP were the chemotherapeutic and heating agents, respectively, for intratumoral thermo-chemotherapy. Injectable DPN/MNP-HG, which possesses solid-like elastic properties, was conveniently prepared via ionic cross-linking at room-temperature. When exposed to an alternating magnetic field (AMF), DPN/MNP-HG exhibited controllable heat generation with a reversible temperature-rise profile. Regarding the kinetics of DOX release, both with and without AMF, DPN/MNP-HG exhibited a slow initial burst and sustained release profile. In cytotoxicity studies and subcutaneous mouse cancer models, successful thermo-chemotherapy with DPN/MNP-HG resulted in significantly lower cell viability and increased tumor-growth suppression; mice also exhibited good tolerance to injected DPN/MNP-HG both with(+) and without AMF application. In conclusion, the proposed thermo-chemotherapeutic DPN/MNP-HG for local intratumoral injection is a promising formulation for cancer treatment.