Inkjet printing of bioadhesives

Over the past century, synthetic adhesives have largely displaced their natural counterparts in medical applications. However, rising concerns over the environmental and toxicological effects of the solvents, monomers, and additives used in synthetic adhesives have recently led the scientific community to seek natural substitutes. Marine mussel adhesive protein is a formaldehyde-free natural adhesive that demonstrates excellent adhesion to several classes of materials, including glasses, metals, metal oxides, and polymers. In this study, we have demonstrated computer aided design (CAD) patterning of various biological adhesives using piezoelectric inkjet technology. A MEMS-based piezoelectric actuator was used to control the flow of the mussel adhesive protein solution through the ink jet nozzles. Fourier transform infrared spectroscopy (FTIR), microscopy, and adhesion studies were performed to examine the chemical, structural, and functional properties of these patterns, respectively. FTIR revealed the piezoelectric inkjet technology technique to be nondestructive. Atomic force microscopy was used to determine the extent of chelation caused by Fe(III). The adhesive strength in these materials was correlated with the extent of chelation by Fe(III). Piezoelectric inkjet printing of naturally-derived biological adhesives may overcome several problems associated with conventional tissue bonding materials. This technique may significantly improve wound repair in next generation eye repair, fracture fixation, wound closure, and drug delivery devices.