Sprayable tissue adhesive microparticle-magnetic nanoparticle composites for local cancer hyperthermia.

Incomplete removal of early-stage gastrointestinal cancers by endoscopic treatments often leads to recurrence induced by residual cancer cells. To completely remove or kill cancer tissues and cells and prevent recurrence, chemotherapy, radiotherapy, and hyperthermia using biomaterials with drugs or nanomaterials are usually administered following endoscopic treatments. However, there are few biomaterials that can be applied using endoscopic devices to locally kill cancer tissues and cells. We previously reported that decyl group-modified Alaska pollock gelatin-based microparticles (denoted C10MPs) can adhere to gastrointestinal tissues under wet conditions through the formation of a colloidal gel driven by hydrophobic interactions. In this study, we combined C10MPs with superparamagnetic iron oxide nanoparticles (SPIONs) to develop a sprayable heat-generating nanomaterial (denoted SP/C10MP) for local hyperthermia of gastrointestinal cancers. The rheological property, tissue adhesion strength, burst strength, and underwater stability of SP/C10MP were improved through decyl group modification and SPION addition. Moreover, SP/C10MP that adhered to gastrointestinal tissues formed a colloidal gel, which locally generated heat in response to an alternating magnetic field. SP/C10MP successfully killed cancer tissues and cells in colon cancer-bearing mouse models in vitro and in vivo. Therefore, SP/C10MP has the potential to locally kill residual cancer tissues and cells after endoscopic treatments.