Hydrogels in Biomedical Applications

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.

Síntesis de hidrogeles de acrilamida en soluciones acuosas de etanol

“…De la diferencia entre el peso de la muestra seca y el peso de la muestra hinchada se calcula el hinchamiento con la Ecuación 1. − = peso hnmedo peso seco H peso seco (1) Al graficar el hinchamiento contra el tiempo se obtiene la cinética de hinchamiento (Figura 1).…”

“…Los hidrogeles son redes poliméricas que se hinchan considerablemente en presencia de agua manteniendo su forma hasta alcanzar un equilibrio fisicoquímico [1] . El carácter hidrófilo de estos materiales, se debe a la presencia de grupos compatibles con el agua, tales como -OH, -COOH, -CONH2, -SO3H.…”

A Bio-inspired Excitable Cardiac Cell Membrane from Electroactive Polymers: Ion Transport Studies

“…They have been used in a wide variety of applications: as biomaterials in drug release and soft contact lenses [94,103], in agriculture [104] and electrophoresis [105].…”

“…Hydrogels are made from polymers which would be glass-like if produced in the absence of water. In its presence, however, over 20% of its weight in water is absorbed by the polymer matrix, producing an elastic gel material instead [94]. The equilibrium water content, EWC (see Eq.…”

“…To this end, material biocompatibility must be a consideration. Luckily, many examples already exist of hydrogels interfacing with the human body, including soft contacts [94,103], burn dressings [130], cell culture [131], artificial cartilage implants [132,133] and drug delivery [134]. It is the high water content of hydrogels which leads to good biocompatibility; as impurities can easily be washed out before use, the soft and pliable nature of the material reduces mechanical stress on living tissues, and provides low interfacial tension [96].…”