The chitosan-gelatin (bio)polyelectrolyte complexes formation in an acidic medium

Abstract

The interaction of cationic polysaccharide chitosan and gelatin accompanied by the stoichiometric (bio)polyelectrolyte complexes formation has been studied by the methods of capillary viscometry, UV and FTIR spectroscopy and dispersion of light scattering. Complexes were formed in the aqueous phase, with pH being less than the isoelectric point of gelatin (pIgel). The particle size of the disperse phase increases along with the growth of the relative viscosity in comparison with sols of the individual components-polysaccharide and gelatin. Possible models and mechanism of (bio)polyelectrolyte complexes formation have been discussed. It was shown that the complex formation takes place not only due to the hydrogen bonds, but also due to the electrostatic interactions between the positively charged amino-groups of chitosan and negatively charged amino acid residues (glutamic Glu and aspartic Asp acids) of gelatin.

Keywords: (Bio)polyelectrolyte complexes; Absorption spectra; Acetic acid (PubChem CID: 176); Arginine (PubChem CID: 6322); Aspartic acid (PubChem CID: 424); Calcium polystyrene sulfonate (PubChem CID: 169893); Chitosan; Chitosan (PubChem CID: 21896651; DNA, i.e. deoxyribonucleic acid (PubChem CID: 44135672); Gelatin; Gelatin, i.e. Collagen I, alpha chain (PubChem CID: 6913668); Glutamic acid (PubChem CID: 611); Histidine (PubChem CID: 6274); Hydroxylysine (PubChem CID: 439437); Lysine (PubChem CID: 5962); Potassium bromide (PubChem CID: 253877); Sodium CMC i.e. Sodium carboxymethylcellulose (PubChem CID: 6328154); Sodium acetate (PubChem CID: 517045); Sodium alginate (PubChem CID: 6850754); Sodium dextransulfate (PubChem CID: 3084656); Sodium polymethacrylate (PubChem CID: 3255932); Viscosity; Water (PubChem CID: 962); κ-Carrageenan (PubChem CID: 11966249).