The efficiency of magnetic hyperthermia and in vivo histocompatibility for human-like collagen protein-coated magnetic nanoparticles

Magnetic hyperthermia is a promising technique for the minimally invasive elimination of solid tumors. In this study, uniform magnetite nanoparticles (MNPs) with different particle sizes were used as a model system to investigate the size and surface effects of human-like collagen protein-coated MNPs (HLC-MNPs) on specific absorption rate and biocompatibility. It was found that these HLC-MNPs possess rapid heating capacity upon alternating magnetic field exposure compared to that of MNPs without HLC coating, irrespective of the size of MNPs. The significant enhancement of specific absorption rate is favorable for larger sized nanoparticles. Such behavior is attributed to the reduced aggregation and increased stability of the HLC-MNPs. By coating HLC on the surface of certain sized MNPs, a significant increase in cell viability (up to 2.5-fold) can be achieved. After subcutaneous injection of HLC-MNPs into the back of Kunming mice, it was observed that the inflammatory reaction hardly occurred in the injection site. However, there was a significant presence of phagocytes and endocytosis after the injection of nonconjugated counterparts. The overall strategy to fabricate HLC-MNPs can serve as a general guideline to address the current challenges in clinical magnetic hyperthermia, improved biocompatibility, and enhanced heating characteristics through protein coating.