Elzer Edelman - MIT team aims to tailor surgical glues for specific applications
Researchers look to match material to tissue properties
Elizabeth A. Thomson, News Office
July 9, 2009
Surgical adhesives, which can be used to seal tissues after an operation or
to repair wounds, are becoming increasingly important parts of a doctor's
toolkit. However, their one-size-fits-all nature means that existing
adhesives, or glues, work well in some cases but not in others.
MIT researchers aim to change that with glues tailored to specific tissues.
In a recent issue of Advanced Materials, they identified for the first time how
one kind of glue material bonds to tissue and how that adhesion varies
depending on the tissue involved, from the intestine to the lung. They then
showed how by adjusting certain properties of the materials it was possible
to create a range of adhesives optimized for specific tissues and
"The delineation of tissue-specific mechanisms for material adhesion leads
the way for tailoring materials to individual needs and applications. This
exciting work may well change the clinical use and continued evolution of
soft-tissue sealants and adhesive materials," said Elazer R. Edelman,
principal investigator and MIT's Thomas D. and Virginia W. Cabot
Professor of Health Sciences and Technology.
Adhesive sealants could improve patient care and reduce healthcare costs
by cutting medical complications after surgery, such as leakage through
incisions, and improved wound healing, according to Natalie Artzi, a
postdoctoral associate who led the research in Edelman's lab.
Although there is already a billion-dollar market for such adhesives, "they
haven't reached their true potential," Artzi said. Existing materials have
limitations that often force doctors to compromise between adhesion
strength and tissue reaction. For example, said Artzi, for a given tissue, the
material may be adhesive but release toxins that could affect healing.
Alternatively, the material could be quite tissue compatible, but degrade
quickly, becoming non-adhesive. If the glue doesn't work, a doctor must
switch to sutures or staples.
The problem, according to the MIT team is that while surgical adhesives
rely on intimate interactions between the adhesive and the tissue in
question, the properties of the target tissue have been largely ignored in
designing adhesives. Instead, "one general formulation is proposed for
application to the full range of soft tissues across diverse clinical
applications," Artzi and colleagues wrote in their Advanced Materials paper.
The new work characterized a variety of interactions between one kind of
glue (hyrogels composed of polyethylene glycol and dextran aldehyde, or
PEG: dextran for short) and tissue from a rat's heart, lung, liver and
duodenum (the first section of the intestine). The team found, for example,
that the glue worked well with tissue from the duodenum, but poorly with
that from the lung.
They then went on to "identify the functional groups in the material that are
responsible for adhesion with tissue functional groups, and created a model
to optimize adhesion for each tissue," Artzi said. In particular the paper
explains how variation of chemical reactive groups in the material could be
matched to the variability in the density of respective reactive groups on
different tissues to regulate tissue-material interaction.
The team will use these findings to "develop a platform of adhesive
materials" for specific tissues. Although it could take three to five years
before the work translates into a product, "the concept is there," she
In addition to Edelman and Artzi, co-authors of the paper are Tarek Shazly
(co-first author with Artzi and a graduate student in MIT's Department of
Materials Science and Engineering), Aaron B. Baker (a postdoctoral
associate in Edelman's lab), and Adriana Bon, now at the Universitat
Ramon Llull (Spain).
The work was supported by the MIT-DuPont Alliance and the National
Institutes of Health, as well as the Philip Morris External Research
MIT News article