Protein-based polymers Gelatin

Elastic, plastic, and hydrogel-forming protein-based polymers Gelatin... 

Polysaccharides are among the most versatile polymers because of their vast structural diversity and nontoxicity. Among polysaccharides, chitosan, alginate, pectin, hylauronic acid, and dextran have received much attention. Protein-based polymers such as albumin, casein, and gelatin have also been investigated for oral peptide delivery. 

Proteins are naturally occurring polymers of a-amino acids joined together by peptide bonds. They are long chain molecules typically folded into globular or fibrous form. These materials are the building blocks of animal tissues while some of them are formed from vegetable sources also. Most of the protein-based polymers are water soluble even at lower temperatures. Out of several proteins, gelatin is the most important polymer in this class used for nanocomposite preparation. 

For fabrication of biomimetic hydrogel for biomedical and pharmaceutical applications, a range of synthetic and protein-based polymer scaffolds, such as albumin, collagen, gelatin, elastin, proteoglycan, hyaluronan, laminin, silk fibroin, soybean, fibrinogen, and fibrin have been widely used (Rajangam and An, 2013). 

Apart from salivary proteins, other proteins have been used in the tannin-protein interaction studies due to some characteristics that make them similar to PRPs, like casein, gelatin, polyproline (Jobstl et al. 2004 Calderon et al. 1968 Luck et al. 1994 Poncet-Legrand et al. 2006 Siebert et al. 1996). Although it is not a protein, the polymer polyvinylpolypyrrolidone as also been used in these studies (Hagerman and Butler 1981 Laborde et al. 2006). Recently, an electronic tongue based on protein-tannin interactions has been developed to measure astringency (Edelmann and Lendl 2002). Despite the unquestionable importance of all these works to understand the interaction between tannins and proteins, extrapolation to the real context of wine sensory should be done with care. 

There are many polymers that are suitable for the production of nanoparticles employed for drug delivery, which can generally be divided into two groups natural polymers, e.g., polysaccharides (chitosan), proteins (albumin, gelatin), as well as synthetic polymers, e.g., polyesters (poly(lactic add), poly(glycolic add), poly(hydroxy butyrate), poly-e-caprolactone, poly-p-malic add, poly(dioxanones)) polyanhydrides (poly(adipic add)) polyamides (poly(amino acids)) phosphorous-based polymers (polyphosphate) poly(cyano acrylates) polyurethanes polyortho esters and polyacetals. Extreme attention has to be paid to the biodegradability and biocompatibility of the polymers. It is essential that polymers used for medical applications are not detrimental for the tissue or cells and that they can be easily decomposed into simple harmless molecules and eliminated by the human body [ 18-22]. 

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