Near Infrared Light-Triggerd on-Demand Drug Delivery From Non-Toxic Hydrogel Microbeads with Heat Transducer

This paper describes a near-infrared (NIR) light-triggered drug release system using alginate hydrogel microbeads. As a drug carrier, calcium alginate hydrogel microbeads encapsulating heat transducing particle (Fe304 particles) were fabricated by a centrifugal based fabrication method. The Fe304 particles instantly generate heat due to localized surface plasmon resonance when irradiated with NIR light. As a result, the calcium alginate hydrogel is thermally denatured to release a drug model. By irradiating NIR-laser to the hydrogel microbeads, we confirmed the release of fluorescent polystyrene particles (~ 10 nm) as a drug model. This result indicates that the polymer network of the calcium alginate hydrogel responded to the heat at the molecular scale, even though calcium alginate hydrogel is generally stable to heat. This NIR light-triggered drug release system using Fe3O4 particles would be an effectiveand safe platform for on-demand drug delivery.