Scientists from Wageningen University & Research have overcome the challenge of underwater adhesion. 

Adhesives loosen their mechanical properties in the presence of water. Wet surroundings affect the development of injectable adhesives that include wound closure and human body-soft tissue repair. Much has to be learned on methods in replacing surgery techniques that include stapling and suturing. 

According to Phys, "Pressure-sensitive adhesives work effectively on almost any dry surface. But as soon as the surface gets wet, its performance is greatly undermined." Natural organisms that include mussels and sandcastle worms provide a solution as they that have the capacity to release a fluid phase underwater. Organisms attach to surfaces because of the hardening of the substance caused by changes in the environmental conditions. Protein domains comprise natural glue. A fluid and water-immiscible phase called complex coacervate stores the natural glue. Previous studies by scientists from the Wageningen Physical Chemistry and Soft Matter have used these organisms in forming this natural glue. 

 Oppositely charged polymers enhanced with thermosensitive units are used to prepare the adhesive. The natural glue is in a liquid form at room temperature and converts into a solid when the temperature exceeds 32 degrees Celsius. 

The natural glue is effective when tested underwater as it cleaves to teflon, glass, or charged surfaces. There is a great potential for the glue to be used in gluing tissues inside the human body. 

Optimization of the material properties is currently done that would allow the real testing of the glue on real biological tissues.