Multicomponent, semi-interpenetrating-polymer-network and interpenetrating-polymer-network hydrogels: Smart materials for biomedical applications

Abstract

Multicomponent, semi-IPN, or IPN hydrogels are interesting materials which are composed of at least two different components and are able to respond to various stimuli, that is the change in certain properties of the medium such as temperature, pH, ion concentration, and so on. Based on this unique feature, these environmentally responsive materials may find use in biomedical applications in terms of changes in the properties of the medium in the human organism which occur naturally or induced by an outside source. Environmentally responsive hydrogels respond to changes in the physical, chemical, or biological properties of the medium by exhibiting a change in their size, shape, color, solubility, and so on. They can be fabricated from natural or synthetic components by a number of production methods including physical cross-linking and chemical cross-linking techniques as well as other novel fabrication methods such as cross-linking with genetically engineered protein domains. Environmentally responsive hydrogels have found in various subfields of the biomedical research area including drug delivery, biosensors, tissue engineering, actuators, and so on. Whereas hydrogels are promising materials, there are some drawbacks which should be overcome before these materials can be used clinically. To address the major concerns, the response rates should be increased while maintaining the necessary mechanical performance. Biodegradability and biocompatibility are other development fields. Environmentally responsive hydrogels with the desired properties can be prepared by use of the right components, production methods and forming the right polymer architecture.