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The Effect of Hard Segment Chemistry on the In-Vivo Biostability of Polyurethanes

Published online by Cambridge University Press:  15 February 2011

Robert W. Hergenrother
Affiliation:
University of Wisconsin-Madison, Dept. of Chemical Engineering, 1415 Johnson Dr., Madison, WI 53706
Stuart L. Cooper
Affiliation:
University of Wisconsin-Madison, Dept. of Chemical Engineering, 1415 Johnson Dr., Madison, WI 53706
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Abstract

Four polyurethanes that were synthesized with different hard segments as well as four commercial polyurethanes were investigated for in-vivo biostability. The four polyurethanes with the varying hard segments were based on a 3/2/1/ mole ratio of methylene diphenylene diisocyanate (MDI) or methylene dicyclohexylene diisocyanate (H12MDI); butanediol (BD) or ethylene diamine (ED); and polytetramethylene oxide (PTMO) (MW=I000). Two commercial polyurethanes were also used: Biomer (Ethicon, Inc.) and Pellethane (Dow).

Films of the polymers were implanted subcutaneously in rats for up to three months to assess their biostability. Polymer films were implanted with either a 100% strain applied or in the unstressed state. Measurement of tensile properties and surface properties before and after implantation was used to assess the stability of each of the polymers. Surface cracking was observed with scanning electron microscopy and the extent and depth of cracking was determined.

It was found that BD chain extended polymers maintained their tensile properties better than the ED chain extended polymers after implantation. H12MDI-based polyurethanes were more susceptible to surface cracking than MDI-based polyurethanes, possibly due to the lack of a crystallizable hard segment.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

REFERENCES

1. Boretos, J.H. and Pierce, W.S., Science 158 1481 (1967).Google Scholar
2. Lelah, M.D. and Cooper, S.L., Polyurethanes in Medicine (CRC Press, Boca Raton, FL, 1986).Google Scholar
3. Ratner, B.D., Gladhill, K.W., and Horbett, T.A., J. Biomed. Mat. Res. 22 509 (1984).Google Scholar
4. Thoma, R.J. and Phillips, P.E., J. Biomed. Mat. Res. 21 525 (1987).Google Scholar
5. Stokes, K.B., in Polyurethanes in Biomedical Engineering, edited by Planck, H. et al. (Elsevier Science Publishers, New York, 1984), p. 243.Google Scholar
6. Takahara, A., Coury, A.J., Hergenrother, R.W. and Cooper, S.L., J. Biomed. Mat. Res. 25 341 (1991).Google Scholar
7. Takahara, A., Hergenrother, R.W., Coury, A.J. and Cooper, S.L., J. Biomed. Mat. Res. in press.Google Scholar
8. Saunders, J.H. and Frisch, K.C., Polyurethanes: Chemistry and Technology (John Wiley and Sons, New York, 1960).Google Scholar
9. Hwang, K.K.S., Wu, G. and Cooper, S.L., J. Polym. Sci, Polym. Chem. Ed. 22 1677 (1984).Google Scholar
10. Hergenrother, R.W., Wabers, H.D. and Cooper, S.L., J. Appl. Biomat. in press.Google Scholar