Glass-coated ferromagnetic microwire-induced magnetic hyperthermia for in vitro cancer cell treatment.

Limitations in effectiveness and the invasive nature of current cancer treatment options emphasize the need for further clinical advancements. Among other approaches, targeted hyperthermia is as a new strategy aimed at targeting cancerous cells to improve the efficacy of radiotherapy or cytotoxic drugs. However, the testing of magnetic vehicles has mainly focused on the use of nanoparticles. In this work, Fe77B10Si10C3 glass-coated amorphous magnetic microwires were assessed for the first time as magnetic vehicles with high potential for the localized heating of osteosarcoma cells by means of an AC magnetic field. The results from the in vitro assays performed inside a microfluidic device demonstrated the ability of these magnetic microwires to induce malignant cell death. Exposing the system to different magnetic fields for less than 1 h provoked a reduction up to 89% of the osteosarcoma cell population, whereas healthy myoblastoma cells remained nearly unaffected. The proposed technology demonstrates in vitro the effectiveness of these microwires as vehicles for targeted magnetic hyperthermia.

Effectiveness of nanoencapsulated methotrexate against osteosarcoma cells: in vitro cytotoxicity under dynamic conditions.

Cancer is a leading cause of mortality in the world, with osteosarcoma being one of the most common types among children between 1 and 14 years old. Current treatments including preoperative chemotherapy, surgery and postoperative chemotherapy produce several side effects with limited effectiveness. The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment. However, in vitro validation of these vehicles is limited due to fluid stagnation in current techniques, in which nanoparticles sediment onto the bottom of the wells killing the cells by asphyxiation. In the current series of experiments, results obtained with methotrexate-lipid nanoparticles under dynamic assay conditions are presented as a promising alternative to current free drug based therapies. Effects on the viability of the U-2 OS osteosarcoma cell line of recirculation of cell media, free methotrexate and blank and methotrexate containing lipid nanoparticles in a 11 µM concentration were successfully assessed. In addition, several designs for the microfluidic platform used were simulated using COMSOL-Multiphysics, optimized devices were fabricated using soft-lithography and simulated parameters were experimentally validated. Nanoparticles did not sediment to the bottom of the platform, demonstrating the effectiveness of the proposed system. Moreover, encapsulated methotrexate was the most effective treatment, as after 72 h the cell population was reduced nearly 40% while under free methotrexate circulation the cell population doubled. Overall, these results indicate that methotrexate-lipid nanoparticles are a promising targeted therapy for osteosarcoma treatment.