Fe-loaded liquid-solid phase inversion PLGA implantation for magnetic hyperthermal ablation of SKOV3 human ovarian cancer in situ of nude mice

Objective: To prepare Fe-loaded liquid-solid phase inversion poly (lactic-co-glycolic acid, PLGA) implants (Fe-ISFIs), and to observe the ablation efficiency on SKOV3 human ovarian cancer. Methods: 40wt-% filler fractions of Fe in the Fe-ISFIs were prepared. Temperature changes of solid Fe-ISFIs (50 μl, 25 μl, respectively) in alternating magnetic field within 5 min were observed. Then 50 μl and 25 μl of Fe-ISFIs were injected into the isolated bovine liver tissue, and alternating magnetic field was applied for 1, 2, 3, 5 min, respectively. The diameters of the ablated liver tissue were recorded, and optimal treatment regimen was chosen for further in vivo experiment. 50 μl Fe-ISFIs were directly injected into the tumors of 9 nude mice bearing SKOV3 human ovarian cancer, and the mice were then divided into two groups: Group 1 for treatment in alternating magnetic field for 3 min, group 2 without magnetic field. Later, 3 nude mice of group 1 and 1 of group 2 were euthanized, and the tumors were resected for TTC and HE staining. The remaining nude mice were observed for tumor growth. Results: The heating experiment in vitro showed that the temperature of Fe-ISFIs increased with time, and 50 μl of Fe-ISFIs was better. In the isolated bovine liver tissue, 50 μl of Fe-ISFIs got (1.18±0.18)cm of ablated diameter in 3 min, while that of 25 μl only got (0.94±0.10)cm in 5 min. TTC staining of tumor tissue showed parts of nude mice' tumor were completely ablated, while still existed incomplete ablated tumors. HE staining demonstrated the coagulation, which showed cells with pyknotic nuclei or an absence of nuclei. In the observation of tumor growth, the tumors of group 2 grew well with time, while in group 1, the ablated tumors fell off at the 2nd day after treatment and then gradually healed at about 14 days after treatment. Conclusion: Fe-ISFIs combined with alternating magnetic field are able to ablate SKOV3 human ovarian cancer in short time. Copyright © 2013 by the Press of Chinese Journal of Medical Imaging Technology.