Iron oxide-based conjugates for cancer theragnostics

Xuan Phuc Nguyen, Dai Lam Tran, Phuong Thu Ha, Hong Nam Pham, Thu Trang Mai, Hoai Linh Pham, Van Hong Le, Hung Manh Do, Thi Bich Hoa Phan, Thi Ha Giang Pham, Dac Tu Nguyen, Thi My Nhung Hoang, Khanh Lam and Thi Quy Nguyen

Abstract

In this paper we first summarize our recent research on fabrication and structure characterization of conjugates of Fe₃O₄ nanoparticles (MNPs) encapsulated by several organic materials such as oleic acid (OL), starch (ST), dextran (D), chitosan (CS), O-carboxymethyl chitosan (OCMCS) and the copolymer of poly(styrene-co-acrylic acid (St-co-AA)). The ferrofluids stability and toxicity were also considered. The magnetic inductive heating (MIH) curves were measured using a set up with an alternating (ac) magnetic field of strength of 40–100 Oe and frequency of 180–240 kHz. We then present new results dealing with attempting to apply the MNP/copolymer ferrofluid for treatment of Sarcoma 180 tumor. In vitro as well as ex vivo MIH experiments were carried out as preparation steps in order to estimate the proper conditions for the in vivo MIH experiment. As for the latter, we have successfully carried out the treatment of solid tumor of size around 6 × 6 mm inoculated on Swiss mice with use of a dose of 0.3–0.4 mg ml⁻¹ ferrofluid injected subcutaneously into the tumor and field-irradiated for 30 min. Two groups of treated mice recovered in three weeks from MIH treatment three times during the first week. We finally show that curcumin loaded MNP-based conjugates showed themselves to be a potential agent for application as a bimodal contrast enhancer of magnetic resonance imaging (MRI) and fluorescence imaging. Additionally, in vitro and ex vivo studies by these two techniques evidenced that macrophage is capable of uptake and tends to carry the MNPs into a tumor