Study on hydrophilic properties of gelatin as a clinical wound dressing. I. Hydrophilic properties of gelatin as a wound dressing.

A basic study on hydrophilicity of gelatin was made of the fitness, water-absorbing ability, water-holding ability, affinity and stability of included water in order to utilize it as a protective covering for medical use. Gelatin No. 3, being highly viscous and having a lower jelly strength, was strongly viscous and flexible, and thus, it stuck close to the surface of a lesioned site such as a wound or a burn. Since the melting point of a gelatin containing 50% water was in the range of 43 to 45 degrees C, the gelatin will be fully used as a protective covering for a wound. Below 20% relative humidity, water molecules were bound to the polar amino acid side chains of gelatin and the bound water caused a swelling of the gelatin, which is maintained by capillary sorption of water into its collagen-like four-dimensional structure. The amount of water sorbed at a relative humidity of 80% at 11 degrees C was higher by 50 to 80 mg/g compared to that at 37 degrees C. Gelatin No. 3 had a very high water-holding ability and it was very hard for it to release the sorbed water at a relative humidity of 80 to 90%. Water molecules were bound to the strong active sites of the gelatin at low relative humidity. The gelatin swelled and then, newly active sites appeared on the surface of the gelatin. The hydrophilic activity decreased with an increase in moisture content, whereas the stability of water molecules in the gelatin increased.(ABSTRACT TRUNCATED AT 250 WORDS)