Amino-functionalized cellulose nanoparticles: preparation, characterization, and interactions with living cells.

Spherical nanoparticles with sizes from 80 to 200 nm are obtained by self-assembly of highly functionalized 6-deoxy-6-(ω-aminoalkyl)aminocellulosecarbamates. The particles are very stable, nontoxic, and possess primary amino groups that are accessible to further modifications in aqueous suspension. The particles can be labeled with rhodamine B isothiocyanate without changing their size, stability, and shape. The nanoparticles obtained are investigated by means of photo correlation spectroscopy, zeta potential measurements, SEM and fluorescence spectroscopy. Incorporation of the nanoparticles in human foreskin fibroblasts BJ-1-htert and breast carcinoma MCF-7 cells without any transfection reagent is proved by means of confocal laser scanning microscopy.