(188cu) Development and Characterization of Tunable Zein-Based Tissue Adhesives

In medical practice, surgeries are daily procedures that require sutures for incision closure. Sutures are effective in joining tissues, but they are often associated with inflammation, irritation, and infections. Tissue adhesives are promising substitutes for sutures, but today’s tissue adhesive options are either cytotoxic (i.e., cyanoacrylates) or do not function on their own for effective incision closure (i.e., fibrin sealants used as suture complements).

Here, we present a protein-based tissue adhesive made from zein, the main protein of maize. This protein is a close-to-ideal raw material for surgical adhesives, as it is naturally adhesive, stable under wet conditions, biocompatible, biodegradable, of plant origin (which reduces viral-transition risks), low cost, and easy to process. We developed a set of zein-based adhesives by dissolving zein powder in ethanol, and a subsequent concentration step (by solvent evaporation) that led to a viscous, sticky fluid. We used PEG 400 as a plasticizer and acetic acid as a co-solvent to obtain a range of zein-adhesives with different mechanical properties. Lap shear tests (performed according to the ASTM F2255-05 standard) showed that our set of adhesives exhibited a wide range of mechanical properties. We also used scanning electron microscopy to investigate the microtopographical features of the adhesives and their interface with the tissue. In vitro proliferation assays using human gingival cell showed that zein-based materials could sustain cell attachment and healthy cell growth for more than 7 days. Our results suggest that zein is a promising material for the cost-effective development of tissue adhesives whose characteristics can be easily tuned to match the mechanical properties of different tissues for a wide variety of applications.