Evaluation of gelatin hydrogel crosslinked with various crosslinking agents as bioadhesives: In vitro study

Bioadhesives are used for tissue adhesion and hemostasis in surgery. A gela tin-resorcinol mixture crosslinked with formaldehyde (GRF glue) and/or glut araldehyde (GRG) is used for this purpose. Although the bonding strength of the GRF glue to tissue is satisfactory, concerns about the cytotoxicity of formaldehyde are reported in the literature. It was suggested that the cyt otoxicity problem of the GRF glue may be overcome by changing its crosslink ing method. The study was therefore undertaken to assess the feasibility of using an epoxy compound (GRE glue), a water-soluble carbodiimide (GAC glue ), or genipin (GG glue) to crosslink with a gelatin hydrogel as new bioadhe sives. GRF glue and GRG glue were used as controls. The results of our cyto toxicity study suggested that the cellular compatibility of the GAC and GG glues was superior to the GRF, GRG, and GRE glues. The gelation time for th e GG glue was relatively longer than the GRF and GRG glues, while no gelati on time could be determined for the GAC glue. Additionally, it took approxi mately 17 h for the GRE glue to become adhesive. The GRF and GRG glues had the greatest bonding strengths to tissue among all test adhesives, while th e bonding strengths of the GAC and GG glues were comparable. In contrast, t here was almost no bonding strength to tissue for the GRE glue, However, th e GRF and GRG glues were less flexible than the GAC and GG glues. Subsequen t to the bonding strength measurement, each test adhesive was found to adhe re firmly to the tissue surface and underwent cohesive failure during the b ond breaking. In conclusion, the GRF and GRG glues may be used as tissue ad hesives when their ability to bind tissue rapidly and tightly is required; the GAC and GG glues are preferable when the adhesive action must be accomp anied with minimal cytotoxicity and stiffness; and the GRE glue is not suit able for bioadhesion in clinical applications. (C) 1999 John Wiley & Sons, Inc.