Reversible Bioadhesives Using Tannic Acid Primed Thermally-Responsive Polymers

A two-layer approach is reported for the formation of a thermally triggered reversible adhesive, involving a thermally-responsive polymer matrix coated on tannic acid-pretreated substrates/tissues. Interfacial adhesion originates from strong molecular interactions of tannic acid with both the polymer matrix and the substrate/tissue. The reversibility is due to a temperature-triggered phase transition of the polymer matrix, leading to cohesive failure. Depending on different gelation mechanisms, the polymer forms a highly cohesive gel or soft solid upon either warming or cooling, leading to a strong adhesion to the tissues at physiological temperatures. Detachment of the adhesive is triggered by a temperature-induced compromise of cohesive strength of the polymer matrix, by the opposite gel-to-sol transition. This facile, low-cost, and modular design offers a reversible adhesive platform which is useful for biomedical and industrial applications.