Hydrogels characteristics

Allcock HR, Kwon S, Riding GH, Fitzpatrick RJ, and Bennett JL. Hydrophilic polyphosphazenes as hydrogels Ration cross-linking and hydrogel characteristics of poly [bis(methoxyethoxyethoxy)phos-phazene. Biomaterials, 1988, 9, 509. 

Allcock, H. R., Kwon, S., Riding, G. H., Fitzpatrick, R. J., and Bennett, J. L., Hydrophilic poiyphosphazenes as hydrogels Radiation crosslinking and hydrogel characteristics of poly[bis-(methoxyethoxyethoxy)phosphazene], Biomaterials. 19, 509, 1988. 

H Brpndsted, J Kopecek. pH sensitive hydrogels Characteristics and potential in drug delivery. ACS Symp Ser 480 285-304, 1992. 

Cross-linked versions of water-soluble polymers swollen in aqueous media are broadly referred to as hydrogels (52) and have a growing commercial utility in such apphcations as oxygen-permeable soft contact lenses (qv) (53) (Table 4) and controUed-release pharmaceutical dmg deflvery devices (54). Cross-linked PVP and selected copolymers fit this definition and are of interest because of the following stmcture/performance characteristics ... 

Water content indirectly affects other lens characteristics. Water evaporation from the lens can result in a dry eye sensation and subsequent desiccative erosion of the cornea. Clinical studies have shown the incidence of corneal erosion as a result of lens desiccation to be a material-dependent and water-content-dependent phenomenon (25,26). The nature of water and sodium ions in hydrogels has been studied primarily by nmr and thermal techniques (27,28). An empirical relationship between water mobility in contact lens polymers and desiccative staining has been proposed (29). 

Knowledge of the network parameters is important for understanding gelation processes, and relationships between the molecular structure and hydrogel synthesis conditions. The principles for the optimization of SAH characteristics for various application purposes can also be based on these parameters. 

Table 10. Characteristics of hydrogel swelling and efficiency as a soil additive1 [139]...

Lutolf MP, Lauer-Fields JL, Schmoekel HG et al (2003) Synthetic matrix metalloproteinase-sensitive hydrogels for the conduction of tissue regeneration Engineering cell-invasion characteristics. Proc Natl Acad Sci 100 5413-5418... 

Heller A. 2006. Electron-conducting redox hydrogels design, characteristics and synthesis. Curr Opin Chem Biol 10 664-672. 

JH Kou, GL Amidon, PI Lee. pH dependent swelling and solute diffusion characteristics of poly(hydroxyethyl methacrylate-co-methacrylic acid) hydrogels. Pharm Res 5 592-597, 1988. 

PI Lee. Synthetic hydrogels for drug delivery Preparation, characterization and release characteristics. In DST Hsieh, ed. Controlled Release Systems Fabrication Technology, Vol II. Boca Raton, FL CRC Press, 1988, pp 83-110. 

DC Harsh, SH Gehrke. Controlling the swelling characteristics of temperature-sensitive cellulose ether hydrogels. J Controlled Release 17 175-186, 1991. 

In consideration of the clinical importance of being able to visualize any implant material within the body, radio-opaque hydrogels for NPR have been formulated [69]. Copolymers of iodobenzoyl-oxo-ethyl methacrylate (4IEMA) and hydrophilic PVP or hydroxylethyl methacrylate (HEMA) exhibit appropriate swelling characteristics, viscoelastic mechanical properties, and excellent cytocompatibility [69]. Moreover, inclusion of the covalently attached iodine molecules allowed for hydrogel visualization via X-ray in a porcine cadaveric spine model [69],... 

---