A novel design of a hybrid hydrogel skin scaffold made from modified PVA/urea oligomer, incorporating protein and polysaccharide.

Urea compounds, which help control bacterial growth and maintain tissue moisture, were used to create a stable polyvinyl alcohol (PVA) hydrogel. By combining urea, sulfamic acid, and phosphorus acid under molten conditions, urea linkage oligomers (ULO) are formed. These compounds, with NH2 and OH as active functional groups at two ends of their chain, can react with the hydroxyl groups of polyvinyl alcohol. Also, crosslinking networks produce a resistant hydrogel in an aqueous medium. Egg white was found to be an ideal protein for the scaffold and was reacted with ULO to enhance mixing and prevent coagulation. The base polymer consisted of 8 g PVA, 5 g ULO, 2 g urea, and 1 g egg white powder, with one gram of a biopolymer (gelatin, collagen, or chitosan) as the sole variable. Characterization involved swelling behavior, gel fraction, and tensile strength measurements in dry states, alongside FT-IR, XRD, SEM, and EDAX analyses. Biodegradation and MTT tests evaluated the growth of fibroblast cells on the hydrogels. The samples made with the selected bio-compounds showed great promise for wound healing, with swelling rates ranging from 300% to 900% and gel factor variations from 43% to 56%. Cell growth exceeded 90-110% after one day of culture. The higher presence of functional groups in the chitosan biopolymer enhanced crosslinking conditions, resulting in better physical, mechanical, and biological properties compared to other biopolymers.