tailieunhanh - Báo cáo khoa hoc:" Single wall carbon nanotubes enter cells by endocytosis and not membrane penetration"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Single wall carbon nanotubes enter cells by endocytosis and not membrane penetration | Yaron et al. Journal of Nanobiotechnology 2011 9 45 http content 9 1 45 JOURNAL OF NANOBIOTECHNOLOGY RESEARCH Open Access Single wall carbon nanotubes enter cells by endocytosis and not membrane penetration 1 2 2 234 5 12 Peter N Yaron Brian D Holt Philip A Short Mathias Losche Mohammad F Islam and Kris Noel Dahl Abstract Background Carbon nanotubes are increasingly being tested for use in cellular applications. Determining the mode of entry is essential to control and regulate specific interactions with cells to understand toxicological effects of nanotubes and to develop nanotube-based cellular technologies. We investigated cellular uptake of Pluronic copolymer-stabilized purified 145 nm long single wall carbon nanotubes SWCNTs through a series of complementary cellular cell-mimetic and in vitro model membrane experiments. Results SWCNTs localized within fluorescently labeled endosomes and confocal Raman spectroscopy showed a dramatic reduction in SWCNT uptake into cells at 4 C compared with 37 C. These data suggest energy-dependent endocytosis as shown previously. We also examined the possibility for non-specific physical penetration of SWCNTs through the plasma membrane. Electrochemical impedance spectroscopy and Langmuir monolayer film balance measurements showed that Pluronic-stabilized SWCNTs associated with membranes but did not possess sufficient insertion energy to penetrate through the membrane. SWCNTs associated with vesicles made from plasma membranes but did not rupture the vesicles. Conclusions These measurements combined demonstrate that Pluronic-stabilized SWCNTs only enter cells via energy-dependent endocytosis and association of SWCNTs to membrane likely increases uptake. Background Carbon nanotubes CNTs have recently been explored for potential uses in biology and medicine. Their small size high surface area inert chemical composition and unique physical properties have made them extensively investigated for transport