Physically crosslinked composite hydrogels of PVA with natural macromolecules: Structure, mechanical properties, and endothelial cell compatibility

Abstract

Polyvinyl alcohol (PVA) hydrogels have been considered potentially suitable for applications as engineered blood vessels because of their structure and mechanical properties. However, PVA's hydrophilicity hinders its capacity to act as a substrate for cell attachment. As a remedy, PVA was blended with chitosan, gelatin, or starch, and hydrogels were formed by subjecting the solutions to freeze-thaw cycles followed by coagulation bath immersion. The structure-property relationships for these hydrogels were examined by measurement of their swelling, rehydration, degradation, and mechanical properties. For the case of pure PVA hydrogels, the equilibrium swelling ratio was used to predict the effect of freeze thaw cycles and coagulation bath on average molecular weights between crosslinks and on mesh size. For all hydrogels, trends for the reswelling ratio, which is indicative of the crosslinked polymer fraction, were consistent with relative tensile properties. The coagulation bath treatment increased the degradation resistance of the hydrogels significantly. The suitability of each hydrogel for cell attachment and proliferation was examined by protein adsorption and bovine vascular endothelial cell culture experiments. Protein adsorption and cell proliferation was highest on the PVA/gelatin hydrogels. This study demonstrates that the potential of PVA hydrogels for artificial blood vessel applications can be improved by the addition of natural polymers, and that freeze-thawing and coagulation bath treatment can be utilized for fine adjustment of the physical characteristics.

Poly(Vinyl Alcohol) Cryogels for Biomedical Applications

“…It is a cationic polysaccharide, and has been proposed as a good material for addition to the PVA matrix for cryogel composite production in order to enhance protein absorption [79]. Due to the hydrophilicity of PVA, cell adhesion proteins are not able to absorb, preventing cell adhesion [79]. Because of this, work to create a more favorable environment for cell growth while still maintaining the beneficial mechanical properties of the PVA cryogel structure is important for certain applications.…”

“…Chitosan is obtained from chitin by alkaline deacetylation. It is a cationic polysaccharide, and has been proposed as a good material for addition to the PVA matrix for cryogel composite production in order to enhance protein absorption [79]. Due to the hydrophilicity of PVA, cell adhesion proteins are not able to absorb, preventing cell adhesion [79].…”

“…A comparison of composite materials using chitosan, gelatin, and starch added to PVA was reported [79]. A sample for each different component added to PVA was prepared and treated with freeze-thaw cycling and coagulation techniques for application as artificial blood vessels.…”

Bioactive 3D-Shaped Wound Dressings Synthesized from Bacterial Cellulose: Effect on Cell Adhesion of Polyvinyl Alcohol Integrated In Situ

“…These dressings are designed to prevent wound dehydration, promote healing [6], and reduce inflammatory and immune responses [7][8][9][10][11][12]. Modern wound dressings are classified as passive, interactive, or bioactive [6].…”

1H MRI study of small-diameter silk vascular grafts in water

“…2 To overcome these limitations, various tissue-engineered VG have been developed, including poly-L-lactic acid, polyglycolic acid, polyurethane (PU), poly-e-caprolactone, cellulose, chitosan, poly(vinylalcohol) and their composites. 1,[3][4][5][6][7][8] However, at present, no materials satisfy the strict requirements of small-diameter grafts.…”