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Showing papers on "Self-healing hydrogels published in 1980"


Journal ArticleDOI
TL;DR: The patient literature relating to contact lenses is reviewed and the development of the composition of hydrogel materials is thereby traced and compared with the range of lens materials currently available.
Abstract: The nature of hydrogel polymers is described together with the range of biomedical applications in which their use has been suggested or described in the literature. The field of contact lens materials has provided the greatest variety of synthetic hydrogels and the material requirements for extended wear lenses present problems that are typical of those encountered in biomedical applications in general. The patient literature relating to contact lenses is reviewed and the development of the composition of hydrogel materials is thereby traced and compared with the range of lens materials currently available. In contrast the most commonly encountered, in fact almost the sole, hydrogel material in the literature relating to those areas more conventionally regarded as biomedical, is poly(2-hydroxeythyl methacrylate) or polyHEMA. The use of this and related hydrogels in various applications including prostheses, ocular surgery, sature coatings, artificial internal organs and drug delivery systems is reviewed.

159 citations


Patent
28 Jul 1980
TL;DR: In this article, a non-uniform water-insoluble interpenetrating polymer blend composition is proposed, comprising a first permeable water swellable polymer substrate and a second less permeable condensation polymer to form a diffusion rate controlling membrane therein.
Abstract: Non-uniform water-insoluble interpenetrating polymer blend compositions comprising a first permeable water swellable polymer substrate interpenetrated in a gradient substantially normal to the substrate surface by a second less permeable condensation polymer to form a diffusion rate controlling membrane therein. Such compositions are useful as polymers with reduced permeabilities for water and organic solvents and therefore for the controlled delivery of active ingredients such as fragrances and bio-affecting agents into air or aqueous environments, or in membrane separation processes.

89 citations


Journal ArticleDOI
TL;DR: Collagen-hydroxyethylmethacrylate hydrogels provide the foundation for a relatively easy procedure to probe mechanisms of cell adhesion and cell differentiation and could be constructed quite readily by the use of appropriate hydrogles.
Abstract: Collagen-hydroxyethylmethacrylate hydrogels were prepared by polymerizing monomeric hydroxyethylmethacrylate in the presence of various concentrations of soluble native collagen. The resulting transparent hydrogels were evaluated as substrata for growth of IMR-90 human embryonic lung fibroblasts. Without collagen no significant growth occurred, whereas a dose-response curve expressing maximal cell growth against collagen concentration could be constructed quite readily by the use of appropriate hydrogels. The method allows for quantification of the collagen contribution to cell growth and, in a more general sense, provides the foundation for a relatively easy procedure to probe mechanisms of cell adhesion and cell differentiation.

64 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the relationship between water content and diffusion coefficient in copolymers of MEMA and MEEMA with poly(2-hydroxyethyl methacrylate) (pHEMA).

31 citations


Book ChapterDOI
W.R. Good1
01 Jan 1980

17 citations


Book ChapterDOI
01 Jan 1980
TL;DR: It has been shown that both reservoir and combined reservoir-monolithic type devices release progesterone at zero-order rates and that the release rates can be varied by changes in the crosslinker content and the copolymer composition.
Abstract: Hydrogels prepared from polyhydroxyethyl methacrylate poly(HEMA) are known as good biocompatible polymers and have potential for use in a wide variety of biomedical applications including controlled release drug delivery systems. In this study, the release of progesterone has been examined from reservoir and combined reservoir-monolithic type controlled release devices as a function of the composition of the polymers used in the preparation of the devices. It has been shown that both reservoir and combined reservoir-monolithic type devices release progesterone at zero-order rates and that the release rates can be varied by changes in the crosslinker content and the copolymer composition. The measured permeabilities obtained from release studies with reservoir devices were in good agreement with results obtained from membrane transport studies. Predicted release rates from combined reservoir-monolithic devices were in only fair agreement with the experimental values.

9 citations


Patent
05 Sep 1980
TL;DR: In this article, a method of treating hydrogels formed from the polymerization of monomers having reactive olefinic double bonds by contacting them with reactive thiol compounds was proposed.
Abstract: The invention provides a method of treating hydrogels formed from the polymerization of monomers having reactive olefinic double bonds by contacting them with reactive thiol compounds In a preferred embodiment where the hydrogel structure includes a cis-glycol containing unit, a suitable thiol is used in conjunction with a borate buffer The present invention also provides materials that are treated with the above thiol compounds

8 citations


Patent
11 Sep 1980
TL;DR: In this article, a silica hydrogel is prepared by neutralizing a sodium silicate with an acid and then rehydrated to about 30% or more, which provides improved abrasion values over the prior art xerogels and hydrogels.
Abstract: Silicas that provide improved abrasive action when incorporated in dentifrice compositions can be prepared by dehydrating a silica hydrogel to a low water content and then reintroducing water to gel. The silica hydrogel is prepared by neutralizing a sodium silicate with an acid. This hydrogel is dried by any convenient method so that the gel contains about 15% water or less. This dried gel is rehydrated to about 30% or more. The rehydrated gel provides improved abrasion values over the prior art xerogels and hydrogels.

5 citations


Journal ArticleDOI
TL;DR: In this paper, a study was made of the sorption of serum albumin using two hydrophilic polymers: polyacrylamide and polymethyl methacrylic gels.
Abstract: A study was made of sorption of serum albumin using two hydrophilic polymers: polyacrylamide and polymethylmethacrylic gels. For comparison, adsorption of albumin was examined on PE surface. It was shown that in the case of hydrogels albumin is sorbed by the gel volume. The extent of sorption depends on the chemical nature and structure of gel. The coefficient of diffusion of albumin in polymethyl methacrylic gel was calculated from results of permeability and kinetic data and found to be (5–9) × 10 −11 cm 2 /sec.

4 citations


Journal ArticleDOI
Mineo Watase1
15 Jan 1980

2 citations


Journal ArticleDOI
TL;DR: In this article, several γ-alkoxy-β-hydroxypropyl acrylates were synthesized and polymerized using poly(MHPA) and poly(MHPMA) (IVa) hydrogels.
Abstract: Several γ-alkoxy-β-hydroxypropyl acrylates were synthesized and polymerized. Both poly(MHPA) (IVd) and poly(MHPMA) (IVa) hydrogels possess high values of equilibrium water content, about seven and three times, respectively, that of the poly(β-hydroxyethyl methacrylate) hydrogel. These rather high values are attributed tentatively to the presence of a hydrophilic γ-methoxy-β-hydroxypropyl side group on the acrylic backbone.