Design of tunable gelatin-dopamine based bioadhesives.

Bioadhesives have a potential to modulate the wound closure process with significant biological outcomes. However, none of the currently commercialized adhesives are satisfactory in their performance. It is a challenging task to develop an adhesive system that can work on wet surface and enhances tissue repair and closure. In this study, we have fabricated a series of gelatin-dopamine (Gel-dop) conjugates and studied their adhesive properties after being chemically crosslinked using sodium periodate. The designed material was assessed for its adhesive properties including tensile, lap shear and peeling study by varying the degree of dopamine substitution. It was observed that the adhesive property has a direct correlation with increase in dopamine content until reaching a maximum and then a subsequent decrease. We tested the adhesive strength of the different formulations by varying the degree of substitution and compared against fibrin glue, which is considered as the gold standard of adhesives. The formulation with a moderate substitution degree demonstrated the optimal adhesive property than those formulations with lower and larger substitution degree. Further, the in vitro cytotoxicity study showed that this tunable Gel-dop adhesives are to non-cytotoxic, indicating a potential use in clinic applications. This study illustrates that adhesiveness can be regulated by changing the degree of dopamine substitution.