Background

Wet adhesives are relevant to all tissue trauma where instant wound closure and hemostasis are needed, especially when time is critical. When blood or body fluid is present at the wound site, instant and strong underwater adhesion performance is required. However, adhesion to wet substrates or underwater surfaces is still a challenge, because water molecules in the boundary layer of the interface impede the contact between adhesives and substrates. To date, in-situ adhesives with short curing time, strong instant underwater adhesion, and high water resistance are still elusive.

Technology Overview

Researchers at the University of Manitoba have developed an underwater and in-situ applicable hydrophobic adhesive (UIHA) comprising of polydimethylsiloxane, entangled macromolecular silicone fluid, and a reactive silane. The hydrophobic fluid repelled the surface water, formed an in-situ gel, bonded to tissues, and achieved exceptional underwater adhesion strength. The underwater lap shear adhesion on porcine skin was significantly higher than that of cyanoacrylate and fibrin glues, demonstrating excellent water resistance. The burst pressure of UIHA on porcine skin was ten times higher than that of fibrin glue. Taken together, the gelation of highly entangled hydrophobic macromolecular fluid provided a means to prepare underwater bioadhesives with strong bonding to tissues and excellent water resistance.

Benefits

• Can be applied to wet surfaces.
• Excellent water resistance.
• Adhesion strength significantly higher than existing glues.
• Burst pressure 10x higher than fibrin glue.
• Extensive animal modelling completed – arteries, skin and lungs in rats, pigs, rabbits, dogs – with highly successful results.
• Safe in the body. Elicited minimal inflammatory response, both at the interface of the UIHA and the tissue.
• Can be applied on soft skin tissue and hard tissue.

Applications

There are many potential applications in the biomedical field:

• sealing ruptured arteries and blood vessels
• wet tissue repair (including in vitro)
• can be used in high-pressure environment, such as lungs and arteries.
• works successfully and quickly on many different wet surfaces, opening up potential for bioelectronic implantation.