Real-time investigation of interactions between nanoparticles and cell membrane model.

Understanding the internal cellular processes of micron/nanoparticles will be important for particles toxicity studies or drug-delivery systems designing. The details and mechanisms of the cellular up-take process of micron/nano particles can hardly be described in real-time. In this study, cellular internalization of micron/nanoparticles was investigated by fluorescence spectroscopy, flow cytometry and sum frequency generation vibrational spectroscopy (SFG). Model cell membranes such as substrate supported lipid bilayers and lipid vesicles were used in this research. Especially, SFG was used to examine the behavior of each leaflet of the lipid bilayer while interacting with micron/nanoparticles. Experiments of SFG show direct evidences that micron/nanoparticles attachment lead to the lipid orientation. Vesicle dye-leakage model were used to study long-term interactions on model membrane. Results from this study provide in-depth insight into the molecular interactions between micron/nanoparticles and cell membranes, which will help to understand the particles toxicity and will be useful for the designing of micron/nanoparticles for applications.