Researchers at universities in Texas and Pennsylvania reported a "one-step synthesis of a family of injectable citrate-based mussel-inspired bioadhesives (iCMBAs) for surgical use. Within the formulations investigated, iCMBAs showed 2.5 - 8.0 folds stronger wet tissue adhesion strength over the clinically used fibrin glue, demonstrated controlled degradability and tissue-like elastomeric mechanical properties, and exhibited excellent cyto/tissue-compatibility both in vitro and in vivo. iCMBAs were able to stop bleeding instantly and suturelessly, and close wounds (2 cm long X 0.5 cm deep) created on the back of SpragueeDawley rats, which is impossible when using existing gold standard, fibrin glue, due to its weak wet tissue adhesion strength. Equally important, the new bioadhesives facilitate wound healing, and are completely degraded and absorbed without eliciting significant inflammatory response."The researchers were inspired by the blue mussel. They "synthesized a new family of injectable citrate-based mussel-inspired bioadhesives, iCMBAs. Therationale behind the iCMBA strategy was to react citric acid, poly(ethylene glycol) (PEG), and catechol-containing monomers such as dopamine or L-DOPA via a one-step polycondensation reaction. Such an approach allows [them] to fabricate new adhesive materials with great wet adhesion strength, controllable degradability, improved biocompatibility, and substantially reduced manufacturing costs."Source for quoted information: Mehdizadeh M; Weng H; Gyawali D; Tang L; Yang J. 2012. Injectable citrate-based mussel-inspired tissue bioadhesives with high wet strength for sutureless wound closure. Biomaterials 33(32):7972-7983.
The bioinspired adhesive is made from a material that is biodegradable and biocompatible. It works better than fibrin as a surgical adhesive. Another adhesive, cyanoacrylate (super glue), has some advantages, but there are concerns about the the toxicity of degradation products. The degradation time of the sutures can be timed so that they can dissolve in a week if desired, or longer.
The researchers took inspiration from the blue mussel that can stick on rocks in the ocean. Mussels can hold on tightly without getting dislodged by the waves due to a powerful adhesive protein. The researchers developed their synthetic polymer based on the chemical structure of the mussle protein.
"The existing surgical adhesives are not ideal for wet tissue adhesion required in many surgeries such as those for internal organs. Developing surgical adhesives with strong wet tissue adhesion, controlled degradability and mechanical properties, and excellent biocompatibility has been a significant challenge." An existing biologically derived bioadhesive glue, fibrin, is fast-curing and biodegradable, but doesn't adhere strongly to wet surfaces and there are concerns about risks of blood-borne disease transmission and potential allergic reactions to patients.