Gemcitabine-loaded magnetic albumin nanospheres for cancer chemohyperthermia

Eliminating cancer without harming normal body tissue remains a longstanding challenge in medicine. Toward this goal, we prepared nanosized magnetic albumin nanospheres encapsulating magnetic nanoparticles (Fe₃O₄) and antitumor drugs (Gemcitabine, GEM). Magnetic albumin nanospheres (average size ≈ 224 nm) had good magnetic responsiveness upon exposure to an alternating magnetic field even though Fe₃O₄ was encased in nanospheres. Thermodynamic test showed that Fe₃O₄ could serve as a heating source under AMF and lead the nanospheres to reach their steady temperature (45 °C). The release results in vitro indicated that nanospheres had an obvious effect of sustained release of GEM. The result of cytotoxicity assay showed that the toxicity of this material was classified as grade 1, which belongs to no cytotoxicity. The antitumor efficacy of the GEM/Fe₃O₄ albumin nanospheres combined with magnetic fluid hyperthermia on non-small lung cancer cell line GlC-82 was examined by MTT assay and flow cytometry assay. Compared with nanospheres entrapping GEM group, nanospheres entrapping Fe₃O₄ combined with MFH group, and GEM/Fe₃O₄ albumin nanospheres without MFH group, the GEM/Fe₃O₄ albumin nanospheres exhibited enhanced antitumor efficacy. Thus, the GEM/Fe₃O₄ albumin nanospheres have promising applications in cancer treatment.