Microfluidic one-step preparation of alginate microspheres encapsulated with in situ-formed bismuth sulfide nanoparticles and their photothermal effect

摘要

Multifunctional alginate microspheres encapsulated with in situ-formed bismuth sulfide nanoparticles (denoted as Bi2S3@BCA) were developed in this work. In comparison with conventional hybrid polymer microspheres usually involved in complicate preparation process, Bi2S3@BCA microspheres can be easily one-step prepared using a droplet-based microfluidic technique with alginate as a soft template and microspheric matrix. As-prepared Bi2S3@BCA microspheres has unique nano-in-micro structure. The obtained wet microspheres show good uniform size with approximately 170 mu m in diameter. Scanning electron microscopy images show that Bi2S3 nanoparticles with a size of 300 nm were homogeneously distributed in the microspheres. In addition, Bi2S3@BCA microspheres exhibit strong absorption of near-infrared (NIR) light and excellent photothermal effect in vitro. Furthermore, anti-cancer drug (doxorubicin)-loaded Bi2S3@BCA microspheres show sustained drug release behavior and enhanced release rate under NIR laser irradiation. The in vitro cytotoxicity experiments confirm that chemotherapy combined with NIR-induced hyperthermia can act synergistic effect to kill more tumor cells. Therefore, the as-prepared drug-loaded Bi2S3@BCA microspheres may potentially be used as a novel embolic material for tumor therapy due to their multifunction including embolization, hyperthermia and controlled local chemotherapy.