Self-Assembled Nanogels of Cholesterol-Bearing Hydroxypropyl Cellulose: A Thermoresponsive Building Block for Nanogel Tectonic Materials.

Hydroxypropyl cellulose (HPC) is a fascinating polysaccharide to use in developing a nanogel to be a thermoresponsive building unit for nanogel tectonic materials. Cholesterol-bearing HPC (Ch-HPC) self-assembled to form nanogels through hydrophobic interactions of the cholesteryl groups in water. Ch-HPC nanogels had a lower critical solution temperature in line with that of native HPC. The particle size of Ch-HPC nanogels was reversibly controlled by the temperature and salting-out effect. The thermoresponsive property was also observed in Ch-HPC nanogel-cross-linked macrogels. These results suggest that a Ch-HPC nanogel is an attractive building block for thermoresponsive nanogel tectonic materials.

Surface modification of mammalian cells with stimuli-responsive polymers.

In order to introduce alternative functions into mammalian cells and control them under ambient conditions, poly(N-isopropyl acrylamide) (PNIPAM) was immobilized on the cell surface. Cellular aggregation could be regulated by temperature change. In addition, separation of PNIPAM-conjugated glycoproteins was successfully performed.