Hydrogels polymer-based

We have prepared a synthetic protein polymer based on repeat sequence Lys-25 to investigate the effect of uniformity of crosslink placement on the physical properties of a polymer hydrogel (Figure 1). The design of Lys-25 reflects two essential structural requirements for formation of polymer hydrogels (1) a flexible, hydrated (polyamide) backbone and... 

Tang, C., et al. 2005. New superporous hydrogels composites based on aqueous Carbopol solution (SPHCcs) synthesis, characterization and in vitro bioadhesive force studies. Eur Polym J 41 557. 

Polymer-based (hydrogel cross-linked with hyaluronic acid) Oxidative damage of crosslinker Antiinflammatory drugs Free radicals 4 /, 48... 

Polymer-based colloidal drug delivery carriers include polymeric micelles, nano- and micro- particles, or coated particles, and hydrogels [886,890,891]. These are being developed for vaccines and anti-cancer drugs, for targeting of specific treatment sites within the body, and as vehicles for ophthalmic and oral delivery. Methods for the creation of multi-layer coatings are reviewed by Sukhorukov [892] (see also Figure 14.4). Numerous examples are cited by Ravi Kumar [893]. 

Harmon, M.E., Tang, M., Frank, C.W., A microfluidic actuator based on thermo-responsive hydrogels. Polymer 2003, 44, 4547M556. 

In summary, the steady state and transient performance of the poly(acrylamide) hydrogel with immobilized glucose oxidase and phenol red dye (pAAm/GO/PR) demonstrates phenomena common to all polymer-based sensors and drag delivery systems. The role of the polymer in these systems is to act as a barrier to control the transport of substrates/products and this in turn controls the ultimate signal and the response time. For systems which rely upon the reaction of a substrate for example via an immobilized enzyme, the polymer controls the relative importance of the rate of substrate/analyte delivery and the rate of the reaction. In membrane systems, the thicker the polymer membrane the longer the response time due to substrate diffusion limitations as demonstrated with our pAAm/GO/PR system. However a membrane must not be so thin as to allow convective removal of the substrates before undergoing reaction, or removal of the products before detection. The steady state as well as the transient response of the pAAm/GO/ PR system was used to demonstrate these considerations with the more complicated case in which two substrates are required for the reaction. 

Chacon D, Hsieh YL, Kurth MJ, Krochta JM (2000) Swelling and protein absorp-tion/desorption of thermo-sensitive lactitol-based polyether polyol (LPEP) hydrogels. Polymer 41 8257-8262... 

The most commonly practiced means for fabricating micro-patterned hydrogels is based on in-situ photo-polymerization and photo cross-linking using UV light in a liquid phase. A drawback of this method is that the prepolymer or polymer solution has to be brought into the irradiation set-up. An alternative approach is to cross-link a prefabricated dry film of the sensitive polymer. 

Harmon ME, Tang MF (2003) A microfluidic actuator based on thermosensitive hydrogels. Polymer 44 4547 556... 

Thermoresponsive polymers based on oligo(ethylene glycol) acrylates or methacrylates can be easily prepared by atom transfer radical polymerization under straightforward experimental conditions (i.e. in bulk or in ethanol solution and in the presence of commercially available catalysts). Thus, these stimuli-responsive macromolecules can be exploited for preparing a wide range of smart advanced materials such as thermoreversible hydrogels, thermoresponsive block-copolymer micelles and switchable surfaces. Hence, some of the results... 

Dorkoosh FA, Verhoef JC, Borchard G, Rafiee-Tehrani M, Verheijden JHM, Junginger HE. Intestinal absorption of human insuhn in pigs using delivery systems based on super-porous hydrogel polymers. Int J Pharm 2002 247 47-55. 

Cadee JA, De Kerf M, De Groot CJ, Den Otter W, Hennink WE. Synthesis and characterization of 2-(methacryloylox-y)ethyl-(di)-L-lactate and their application in dextran-based hydrogels. Polymer 1999 40 6877-6881. 

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