Effect of Modification of Poly(vinyl alcohol) Hydrogels on Mouse Fibroblast Cell Growth in Culture

Abstract

Hydrogels prepared by crosslinking of natural or synthetic polymers have many biomedical applications. In the treatment of severe skin defects caused by disease or accidents, it is desirable to have the hydrogel surface modified to support cell growth which may enhance healing. To prepare and test such an hydrogel in vitro, 5 g of poly (vinyl alcohol) granules were suspended in 40 mL ethanol for reaction with 9 g of glycidyltrimethyl ammonium chloride at 60°C for 6 hr to graft the trimethyl-2-hydroxyaminopropyl (abbrev. TMHAP) function onto some of the hydroxyl groups. The 5 g of modified poly(vinyl alcohol) granules was then dissolved in 35 mL of water and 3.6 mL of 10 N sodium hydroxide for crosslinking by 2.8 g of epichlorohydrin to form a gel sheet in 20 hr having about 2% solids content. The amount of TMHAP groups thereon was determined by exchange of the chloride ions with a 10% sodium sulfate solution, followed by titration with silver nitrate using potassium chromate as indicator. Hydrogels with about 0.15 mM TMHAP group/g dry solid and diameter of 3.5 cm were inoculated with about 2 × 10⁵ cells. On the next day, 20% of the cells attached thereto grew to 1.6, 3.1, and 6.5 × 10⁵ cells on days 3, 5, and 7, respectively. The growth depended on the pre-conditioning of the hydrogel in culture medium and frequency of its change, but much less on cell inoculation density.