Microstructure characterization through mechanical, electrokinetic and spectroscopic methods of polyampholyte gelatin hydrogels crosslinked with poly(vinyl alcohol)

PORCARO ANDREA; OTTONE MARIEL L.; DEIBER JULIO A.

POLYMER

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2013 vol. 54 p. 2706 - 2716

0032-3861

The microstructure of polyampholyte gelatin hydrogels crosslinked covalently with fully hydrolyzed poly(vinyl alcohol) are characterized. The experimental methodology involves simple mechanical extension, spectroscopic and thermal methods (FTIR, XRD, DSC, TGA) and equilibrium swelling test to quantify relevant microstructural parameters and electrokinetic properties of this polyampholyte-polypeptide hydrogel, for different crosslinker to gelatin mass ratios. The polyampholytic crosslinked matrices having a positive effective electrical charge are studied within an experimental and theoretical framework of their elastic and swelling properties. Estimations of average mesh size and toughness of the swollen hydrogels are provided, and the feasibility of polyion complexation between positive crosslinked gelatin chains and negative bioactive macromolecules to be delivered through hydrogel biodegradation is analyzed. Several hydrogel properties are estimated like shear modulus, network strand average molecular mass of network strands, swelling ratio, Flory–Huggins interaction parameter, hydrogel electrostatic zeta-potential and average effective charge number per chain before and after the crosslinking process to quantify gelatin chain cationization.