Fe3O4 nanoparticles and cryoablation enhance ice crystal formation to improve the efficiency of killing breast cancer cells

The key problem of cryoablation is that only freezing is often unable to kill the capillaries at tumor edges, leading to a high rate of recurrence. Here, we found that Fe3O4 nanoparticles were highly useful to improve the freezing capability of cryosurgery due to their ability to alter intracellular ice formation (IIF) and growth in tumor cells. The killing efficiency of cryoablation for MCF-7 breast cancer cells can be expected to be enhanced as the Fe3O4 nanoparticles concentration increased, it was mainly because that more IIF was induced by the participation of Fe3O4 nanoparticles during freezing, recrystallization and thawing. Furthermore, our results also showed that recrystallization contributed to the formation of extracellular embryonic crystals, which was capable of enhancing the efficiency of killing MCF-7 cells. This research is to develop an understanding of the mechanism of the cryoablation enhancing the killing efficiency in the presence of the Fe3O4 nanoparticles, and to promote their further application in tumor therapy.