The poly(N-isopropylacrylamide-co-1-vinylimidazole) hydrogel nanoparticles (nanogels; 30-300 nm in diameter) with hydrophobic N-octadecylacrylamide chains exposed on their surfaces have been prepared by UV-induced polymerization. The internal reservoir of liposomes was used as a container for the water-soluble components of a gel-forming medium while the interlayer space of the liposomal lipid membrane was used as a container for the water-insoluble components. The abrupt collapsing of the nanogels was accompanied with their aggregation above the volume phase transition temperature, as was observed by dynamic light scattering (DLS). The combined DLS and atomic force microscopy (AFM) study shows that the obtained hydrogel nanoparticles were highly compatible with the lipid bilayer. This compatibility led to a self-initiated coating of the hydrogel particles by a lipid layer upon mixing of liposomes and nanogels. Swollen and collapsed states of the nanogels at different pH values were visualized by AFM. The flattening of the liposomes and nanogels was compared upon their deposition onto a mica surface in air. The quantitative characteristics of the nanogels in swollen and collapsed states were revealed by cross sectioning of AFM images. The findings indicate great potential for using the spherical nanoparticles (liposomes and nanogels) as starting materials for the fabrication of planar and hemispherical biophysical nanodevices.
|Original language||English (US)|
|Number of pages||8|
|State||Published - Sep 16 2003|
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Surfaces and Interfaces