A soft-tissue bioadhesive was prepared with gelatin reinforced with proteinoids containing high proportions of carboxyl groups and amine groups. Proteinoids are synthetic copolymers of naturally occurring amino acids. Proteinoids were mixed with gelatin, the base material, and glutaraldehyde, a cross-linking agent, was added to form an imide linkage. The bond strength of the gelatin-thermal protein-glutaraldehyde (GTPG) adhesive was measured by applying the adhesive between the dermal sides of two excised rat skin sheets. An enhanced bond strength of the adhesive was observed in proteinoid formulations. The adhesive characteristics of gelatin reinforced with a proteinoid showed a higher bond strength than those of commercial sealants.