Synthetic hydrogels features

A direct implication of this hypothesis is that phase transition of the mucus gel should be reversible, and it should exhibit the characteristic features of a critical phenomenon. Studies conducted in isolated giant mucin secretory granules of the terrestrial slug revealed that hydrated mucin gels, released from individual secretory granules, can indeed be recondensed. Recondensation/ decondensation is reversible and exhibits the typical features of a polymer gel phase transition. Namely, it is discontinuous, and is affected by pH, temperature and Ca2 + concentration in a fashion that mimics phase transition in synthetic polymer hydrogels [32, 33] (see Fig. 3). 

As in the case of hydrogels, SELP-47K films have been demonstrated to be extremely biocompatible while allowing cell proliferation [65]. This biocompatible feature, together with mechanical properties, allows SELPs to be explored for several applications, namely contact lenses, synthetic corneas, intraocular lenses, ophthalmic drug delivery matrices, and so on. Although methanol is routinely used to render aqueous insolubility as well as to improve the mechanical properties, autoclaving has been shown to stabilize electrospun nanoflbres and therefore can be an alternative nonchemical method for the stabilization of the film stmcture. 

The following sections describe the preparation and characterization of supramolecular polymer networks, particularly emphasizing their physical-chemical features with regard to the type and strength of physical chain cross-linking and the resulting macroscopic material properties. Furthermore, recent work on the formation and characterization of supramolecular hydrogels based on synthetic and natural precursors is summarized with a focus on their application and potential in biomedicine. 

PEG (also known as poly(ethylene oxide)) is one of the most widely used materials in tissue engineering (Drury and Mooney 2003). As a result of its extreme hydrophilicity, PEG is highly resistant to protein adsorption and therefore works well as a non-fouling, non-immunogenic surface in a biological environment. This makes PEG materials a blank slate so that cellular interactions can be precisely controlled through added features (e.g., peptides). Eurthermore, because it is one of the few synthetic hydrophilic materials available, it has become a prime candidate for use in many soft tissue applications, where hydrogels are preferable to hard materials. 

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