Electric stimulus response of chitosan microbeads embedded with magnetic nanoparticles for controlled drug delivery

Drug Delivery Systems (DDS) are suitable for drug delivery over direct pharmaceutical administration of drug due to enhanced bioavailability, precision targeting and localization, and defined characteristics of drug release. It is envisioned that controllable DDS could facilitate maintaining drug concentration within prescribed therapeutic limits over desired duration or provide a burst release of drug when needed. Majority of DDS suffer from an uncontrollable diffusion profile, leading to passive drug release over time, or poor control of external or internal stimuli. In this paper, we demonstrate a novel DDS platform based on chitosan microbeads embedded with magnetic nanoparticles (MNP) that is responsive to electric stimulation. The DDS was fabricated by embedding Fe₃O₄ MNP (φ = 12 nm) within biocompatible chitosan microbeads cross-linked with glyoxal. Various types of electric stimulations (e.g. bipolar rectangular, sinusoidal) were applied with the sample suspended on interdigitated electrodes on a Surface Acoustic Wave (SAW) resonator chip. The spectrophotometric analysis of the absorbance post-stimuli shows statistically significant drug release compared to control samples. The highest drug elution recoded is 6.6 times to control for 20 V_pp, 100 Hz, bipolar rectangular pulse for 30 seconds. These results indicate the possibility of controllable DDS development using electrical stimulus.