E-Beam Processing of Collagen-Poly(N-vinyl-2-pyrrolidone) Double-Network Superabsorbent Hydrogels: Structural and Rheological Investigations

Collagen (C)-poly(N-vinyl-2-pyrrolidone) (PVP) double-network superabsorbent hydrogels were synthesized by e-beam (electron beam) radiation processing, both with the addition of water-soluble cross-linking agents (CA), as well as without CA. The aim of the study was to develop a hydrogel for future application as wound dressings via e-beam radiation cross-linking of two biocompatible polymers. The formation of C-PVP hydrogels was confirmed by Fourier transform infrared (FTIR) spectroscopy and their performance was determined from morphological and rheological experiments, such as sol-gel analysis, swelling capacity, storage (G′) and viscous (G″) moduli, cross-linking density, and pore size. Sol-gel analysis was performed in order to determine the gel properties as function of absorbed dose and it was found that the degradation density (p0)/cross-linking density (q0) ratio indicates a negligible contribution of chain scission processes. The rheological data confirmed that the elastic properties were predominant: G′ moduli were larger than G″ moduli, as is specific to elastic solids and indicate the formation of a permanent hydrogel network were cross-links are present. Moreover, the swelling studies indicated that the hydrogels have good stability both in deionized water and phosphate-buffered saline (PBS) solution at 37 °C, and superabsorbent properties. The hydrogels network parameters obtained with lower content of CA, could be controlled by changing the absorbed dose.