Hybrid nanogels for sustainable positive thermosensitive drug release.

A hybrid nanogel has been developed based on interpenetrating networks of thermosensitive poly(N-isopropylacrylamide) gels and tailored nanoporous silica. A sustainable positive thermo-responsive drug release profile is obtained. When the temperature rises, the polymer gel shrinks, squeezing the drug into the porous channels, and at the same time, opening the pores to the outside media. The drug slowly diffuses out of the porous channels. The overall release rate can be adjusted by changing the composition of the nanogel.

[1]  I. Aksay,et al.  Formation of a Silicate L3 Phase with Continuously Adjustable Pore Sizes , 1997 .

[2]  Edward L Cussler,et al.  Diffusion: Mass Transfer in Fluid Systems , 1984 .

[3]  T. Okano,et al.  Positive thermosensitive pulsatile drug release using negative thermosensitive hydrogels , 1994 .

[4]  I. Aksay,et al.  Silica Gels with Tunable Nanopores through Templating of the L3 Phase , 2000 .

[5]  Toyoichi Tanaka,et al.  Volume phase transition in a nonionic gel , 1984 .

[6]  Allan S. Huffman,et al.  Thermally reversible hydrogels: II. Delivery and selective removal of substances from aqueous solutions , 1986 .

[7]  Toyoichi Tanaka,et al.  Collapse of Gels in an Electric Field , 1982, Science.

[8]  M. Akashi,et al.  Graft copolymers having hydrophobic backbone and hydrophilic branches. XI. Preparation and thermosensitive properties of polystyrene microspheres having poly (N‐isopropylacrylamide) branches on their surfaces , 1996 .

[9]  Jong-Duk Kim,et al.  A novel hydrogel-dispersed composite membrane of poly(N-isopropylacrylamide) in a gelatin matrix and its thermally actuated permeation of 4-acetamidophen , 1996 .

[10]  K. Shakesheff,et al.  Polymeric systems for controlled drug release. , 1999, Chemical reviews.

[11]  Teruo Okano,et al.  Thermally on-off switching polymers for drug permeation and release , 1990 .

[12]  Allan S. Hoffman,et al.  Applications of thermally reversible polymers and hydrogels in therapeutics and diagnostics , 1987 .

[13]  Ashutosh Chilkoti,et al.  Control of protein–ligand recognition using a stimuli-responsive polymer , 1995, Nature.

[14]  Toyoichi Tanaka,et al.  Kinetics of discontinuous volume-phase transition of gels , 1988 .

[15]  H. Ichikawa,et al.  A novel positively thermosensitive controlled-release microcapsule with membrane of nano-sized poly(N-isopropylacrylamide) gel dispersed in ethylcellulose matrix. , 2000, Journal of controlled release : official journal of the Controlled Release Society.

[16]  Paul Yager,et al.  Synthesis and characterization of thermally reversible macroporous poly(N‐isopropylacrylamide) hydrogels , 1992 .

[17]  Toyoichi Tanaka,et al.  Phase transitions in crosslinked gels of natural polymers , 1987 .

[18]  Toyoichi Tanaka Collapse of Gels and the Critical Endpoint , 1978 .