Enhanced drug-loading potential through silver and strontium doping in iron oxide nanoparticles for drug delivery applications

This study focuses on the drug delivery applications of iron oxide (Fe₃O₄) nanoparticles doped with varying molar ratios of strontium (Sr), silver (Ag), and co-doping of strontium and silver. It examines the effect of increasing strontium and silver content on various properties, including drug loading, drug release, and cytotoxicity. Characterization of these nanoparticles was evaluated by different characterization techniques, including X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray, and vibrating sample magnetometer. Ibuprofen was used as a model drug. UV–vis spectroscopy characterizes drug loading, whereas MTT assay was performed to check the cytotoxicity of nanoparticles against the human cancerous cell line U87-MG by adding them at the density of 1 × 10³ cells per well in the 96-cell culture plate in a humidified incubator having 5% CO₂ at 37 °C. Improved drug loading was observed in the case of Ag_0.25Fe₂O₄, which showed maximum encapsulation efficiency of 62.94%. Strontium-doped Iron oxide nanoparticles showed a rapid drug release profile; Sr_0.25Fe_2.75O₄ released 84.52% drug in 48 h than Fe₃O₄ and silver-doped iron oxide nanoparticles.