摘要

Near-infrared (NIR) light as noninvasive external stimuli to trigger on-demand drug release has attracted great attention in recent years. However, the current existing NIR-related drug delivery systems (DDSs) still have difficulty in controlling the release of the individual drug separately. In the present work, a dot array-like DDS was developed for accurately controlling the release of multiple drugs. Each dot had a drug core and an outer protective layer. The outer protective layer consisted of lauric acid (LA) and polylactic acid (PLA). LA is a kind of phase-change material (PCM) with melting point of 43.8 A degrees C. When loaded with polypyrrole nanoparticles (PPy NPs) that acted as photothermal transducers, the outer protective layer became NIR light responsive and was able to convert light into heat to melt the LA. As a result, the drugs stored inside were released. By changing the PPy loading, NIR light power density, and mass ratio of LA to PLA, the drug release profile could be carefully controlled. Such a NIR-responsive DDS may find great potential applications in treating diseases that require long-term therapies using more than one drug.