Mussels, Inkjet Printer May Hold Key to Faster Healing From Surgeries

Using the natural glue that marine mussels use to stick to rocks, and a variation on the inkjet printer, a team of researchers led by North Carolina State University has devised a new way of making medical adhesives that could replace traditional sutures and result in less scarring and increased precision for exacting operations such as eye surgery.

Traditionally, there have been two ways to join tissue together in the wake of a surgery: sutures and synthetic adhesives. Sutures work well, but require enormous skill and longer operating times. Additionally, the use of sutures is associated with a number of surgical complications, including discomfort, infection and inflammation. Synthetic adhesives are also widely used, but they are the source of increasing concerns over their toxicological and environmental effects. One such concern with some synthetic medical adhesives is that – because they are not biodegradable – they do not break down in the body and therefore may cause inflammation, tissue damage, or other problems.

But new research shows that adhesive proteins found in the “glue” produced by marine mussels may be used in place of the synthetic adhesives without these concerns, because they are non-toxic and biodegradable, according to study co-author Dr. Roger Narayan. In addition, the mussel proteins can be placed in solution and applied using inkjet technology to create customized medical adhesives, which may have a host of applications. For example, Narayan says this technique may “significantly improve wound repair in eye surgery, wound closure and fracture fixation.” Narayan is an associate professor in the joint biomedical engineering department of NC State and the University of North Carolina at Chapel Hill.

“This is an improved way of joining tissues,” Narayan says, “because the use of the inkjet technology gives you greater control over the placement of the adhesive. This helps ensure that the tissues are joined together in just the right spot, forming a better bond that leads to improved healing and less scarring.” This increased control would be a boon for surgery that relies on extreme precision, such as eye repair, Narayan explains.

The study was performed in collaboration with Professor Jon Wilker in the Department of Chemistry at Purdue University. The Journal of Biomedical Materials Research B will publish the study, “Inkjet printing of adhesives,” in April. The National Science Foundation, the National Institutes of Health and the Office of Naval Research funded the research.

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Note to editors: The study abstract follows.

“Inkjet printing of bioadhesives”

Authors: Anand Doraiswamy, Roger J. Narayan, joint biomedical engineering department of North Carolina State University and the University of North Carolina at Chapel Hill; Timothy M. Dunaway, Jonathan J. Wilker, Purdue University

Published: April 2009, in Journal of Biomedical Materials Research B: Applied Biomaterials

Abstract: 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.