Described herein is the synthesis of adhesive from simple adhesive coacervates and their uses thereof. The adhesives are produced by (a) preparing a solution comprising (1) a polyelectrolyte, wherein the polyelectrolyte comprises a polyanion or polycation but not a combination thereof, the polyeletrolyte comprises at least one crosslinking group, and (2) a sufficient amount of a complimentary counterion to produce a simple adhesive coacervate； and (b) crosslinking the simple adhesive coacervate to produce the adhesive. The adhesives have numerous medical and non-medical applications.
