In vivo degradability of hydrogels prepared from different gelatins by various cross-linking methods.
This study is an investigation to evaluate the in vivo degradation of gelatin hydrogels in terms of their number of cross-links. Various hydrogels were prepared from acidic gelatin, extracted from bovine bone, porcine skin or fish scale, and basic gelatin, extracted from porcine skin, through four types of cross-linking methods, i.e., glutaraldehyde (GA) or dehydrothermal treatment and ultraviolet (UV) or electron beam irradiation. The water content of hydrogels and their number of cross-links, calculated from the tensile modulus of hydrogels, were evaluated as the measure of hydrogel cross-linking extent. Following subcutaneous implantation of 125I-labeled gelatin hydrogels into mice, the radioactivity remaining was measured at different time intervals to assess the in vivo degradability of hydrogels. Irrespective of the gelatin type and cross-linking method, a good correlation was found between the in vivo degradability of hydrogels and their number of cross-links, which is different from the correlation to their water content. This finding indicates that the degradability of hydrogels is governed by their number of cross-links.
Institute for Frontier Medical Sciences, Kyoto University, 53 Kawara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Makoto
M
Ozeki
Yasuhiko
Y
Tabata
D020341:Absorbable Implants; D000818:Animals; D001673:Biodegradation, Environmental; D002417:Cattle; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004583:Electrons; D005780:Gelatin / Q000737:chemistry* / Q000528:radiation effects; D005976:Glutaral / Q000737:chemistry; D006361:Heating; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry* / Q000302:isolation & purification; D007457:Iodine Radioisotopes; D051379:Mice; D013552:Swine; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry*
D003432:Cross-Linking Reagents; D007457:Iodine Radioisotopes; D014867:Water; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D005780:Gelatin; D005976:Glutaral