Smart pH-responsive magnetic iron oxide nanoflower–chitosan nanogels for controlled drug delivery in cancer therapy

There has been a recent surge in the development of drug delivery systems that are specifically targeted towards tumors. The primary objective of these systems is to enhance the efficacy of anti-tumor drugs while simultaneously reducing any potential harmful side effects. This study focuses on designing a surface coating that is pH-responsive for iron oxide nanoflower (IONF) cores, allowing the controlled release of the drug doxorubicin (DOX). To achieve this, IONFs were coated with chitosan (CS) using NaOH, tripolyphosphate (TPP), and glutaraldehyde (GLU) as crosslinking agents. XRD and FTIR techniques were utilized to confirm the structure of the CS-IONF particles and determine the physical interaction and chemical bonding. TEM imaging was used to examine the morphology of the prepared CS-covered IONFs and drug-loaded CS-covered IONFs. The pH-responsive nature of the particles was characterized using the dynamic light scattering (DLS) technique in different pH media (pH 4, 5.5, and 7.4). The results showed that the CS-coated IONF nanogels exhibited excellent controlled pH-responsive release profiles, with a higher release in a pH 4 medium. Moreover, the CS-coated IONF nanogels demonstrated a high DOX loading capacity and efficiency of 67.3 ± 5.7% and 84.1 ± 7.2%, respectively. The biocompatibility of the developed formulation was also investigated through the MTT assay, which revealed the safety of the formulation in biological systems. Finally, flow cytometry analysis was performed to evaluate the efficiency of the drug delivery system.