Cytocompatible performance of thermosensitive poly(N-isopropylacrylamide) nanoparticles.

The development of biomedical materials with biocompatibility, especially cytocompatibility, is the frontal research field for material science, biology, medicine, pharmacology and related interdisciplines. We have successfully synthesized a new biomedical material, PNIPAM-g-P(NIPAMco-St) (PNNS) core-shell nanoparticles, and investigated its thermosensitive and fluorescent properties. In order to evaluate the cytocompatibility of the PNNS nanoparticles, the effect of the PNNS nanoparticles on the human ether-àgo-go-related gene (hERG) K(+) channel in HEK-293 cells was investigated for the first time with the inverted fluorescence microscope and the whole-cell patch-clamp technique. The PNNS nanoparticles can be adsorbed on the surface of the cell membrane of HEK-293 cells, and cannot change the structure of HEK-293 cells. The low concentration of the PNNS nanoparticles can slightly inhibit the stable and tail current of the hERG K(+) channel, left-shift the activation curve of the hERG K(+) channel and decrease the deactivation time constant (τ)of the hERG K(+) channel. However, in the presence of the high concentration of the PNNS nanoparticles, the changes mentioned above gradually return to the level in the absence of the PNNS nanoparticles. These results indicated that the PNNS nanoparticles can not damage the cells. Thus, the PNNS nanoparticles have a good cytocompatibility and might be applied as a biomedical material.