Dopamine functionalized aqueous-based silk protein hydrogel bioadhesive for Biomedical wound closure
Silk fibroin (SF) from the Bombyx mori is a natural macromolecule with remarkable biocompatibility and adhesive ability. For wound healing bio-adhesive applications, it is essential to be have good biodegradability nature. The ideal bio-adhesive is expected to be fixed together in the early stage of wound healing, adhering to the tissues to avoid cracking, requiring slow and favorable degradation at the wound site after healing. The residual adhesives component should be completely degraded after the wound has healed, through absorbed by the body or excreted with biological metabolism. Herein, SF was functionalized with dopamine through one-step method by crosslinkers to enhance adhesive ability. Poly(ethylene glycol) (PEG) was selected to optimize the gelation time (NESFB-Dopa). The ratios between SF and PEG, the ratio of crosslinker, the amount of dopamine and the adhesive environment were tuned and determined the optimal condition. Following the ASTM standard, when the weight ratio of SF to PEG is 5 : 5, the molar ratio of NHS to EDC is 2 : 1, and the content of dopamine is 5 weight %, the tensile strength of the NESFB-Dopa was achieved a greater values as 460.44 ± 18.45 kPa and 503.32 ± 16.54 kPa in dry and wet condition, respectively, which demonstrated that superior adhesive properties compared with the clinically used fibrin sealant.