A biodegradable and biocompatible gecko-inspired tissue adhesive

doi:10.1073/pnas.0712117105

A biodegradable and biocompatible gecko-inspired tissue adhesive

*Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139-4307;
^†Center of Neurosciences and Cell Biology, University of Coimbra, and Biocant Biotechnology Innovation Center, 3060-197 Cantanhede, Portugal;
^‡Center for Regenerative Medicine and
Departments of **Pediatric Surgery and
^††Pathology, Massachusetts General Hospital, Boston, MA 02114;
^§Harvard Medical School, Boston, MA 02115;
^¶Harvard–Massachusetts Institute of Technology, Division of Health Science and Technology, Cambridge, MA 02139;
^‖The Charles Stark Draper Laboratory, Cambridge, MA 02139-3563;
^‡‡Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland; and
^¶¶Health Sciences and Technology, Center for Biomedical Engineering, Brigham and Women's Hospital, Boston, MA 02115

Contributed by Robert Langer, December 26, 2007 (received for review November 30, 2007)

Abstract

There is a significant medical need for tough biodegradable polymer adhesives that can adapt to or recover from various mechanical deformations while remaining strongly attached to the underlying tissue. We approached this problem by using a polymer poly(glycerol-co-sebacate acrylate) and modifying the surface to mimic the nanotopography of gecko feet, which allows attachment to vertical surfaces. Translation of existing gecko-inspired adhesives for medical applications is complex, as multiple parameters must be optimized, including: biocompatibility, biodegradation, strong adhesive tissue bonding, as well as compliance and conformability to tissue surfaces. Ideally these adhesives would also have the ability to deliver drugs or growth factors to promote healing. As a first demonstration, we have created a gecko-inspired tissue adhesive from a biocompatible and biodegradable elastomer combined with a thin tissue-reactive biocompatible surface coating. Tissue adhesion was optimized by varying dimensions of the nanoscale pillars, including the ratio of tip diameter to pitch and the ratio of tip diameter to base diameter. Coating these nanomolded pillars of biodegradable elastomers with a thin layer of oxidized dextran significantly increased the interfacial adhesion strength on porcine intestine tissue in vitro and in the rat abdominal subfascial in vivo environment. This gecko-inspired medical adhesive may have potential applications for sealing wounds and for replacement or augmentation of sutures or staples.

Footnotes

^§§To whom correspondence may be addressed. E-mail: rlanger{at}mit.edu or jkarp{at}rics.bwh.harvard.edu
Author contributions: A.M. and L.F. contributed equally to this work; A.M., L.F., C.S., J.W.N., D.J.D.C., C.J.B., A.Z., S.H., J.B., J.V., R.L., and J.M.K. designed research; A.M., L.F., C.S., J.W.N., D.J.D.C., S.P., L.C., E.B.J., A.G., H.P., I.P., and P.T.M. performed research; A.M., L.F., C.S., J.W.N., E.P.C., D.J.D.C., W.F., and J.M.K. analyzed data; and A.M., L.F., C.S., E.P.C., R.L., and J.M.K. wrote the paper.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/cgi/content/full/0712117105/DC1.