Biomedical Engineering Reference
In-Depth Information
other method that has been suggested is the concept of accelerated ageing of
polymers, which involves subjecting polymers to elevated temperatures as a
method of simulating the ageing process (Hukins
et al.
, 2008). It has been
shown that ageing of a material can be accelerated by a factor of 2
DT/10
by
increasing the temperature by an increment DT
T
(Hemmerich, 1998; Hukins
et al.
, 2008). Previous studies (Craig
et al.
, 1980; Goldberg
et al.
, 1978;
Mahomed
et al.
, 2010a; Simmons
et al.
, 2006) reported that accelerated
ageing of polymers resulted in mechanical and physical degradation of its
properties.
In conclusion, polymers degrade and calcify while in the body and the
likelihood and resistance of polymer degradation are important areas for
further future research in medical polymer science (Griesser, 1991).
8.6 Sources of further information and advice
The following texts are recommended for further reading:
∑ Coury, A. J., Levy, R. J., Ratner, B. D., Schoen, F. J., Williams, D. F.
& Williams, R. L. (2004) Degradation of materials in the biological
environment in:
Biomaterials science: an introduction to materials in
medicine
, edited by Ratner, B. D., Hoffman, A. S., Schoen, F. J. & Lemons,
J. E., pp. 411-453, California; London, Elsevier Academic Press.
∑ Griesser, H. J. (1991) Degradation of polyurethanes in biomedical
applications: a review.
Polymer Degradation and Stability
,
33
, 329-
354.
∑ Middleton, J. C. & Tipton, A. J. (2000) Synthetic biodegradable polymers
as orthopedic devices.
Biomaterials
,
21
, 2335-2346
∑ Stokes, K., Mcvenes, R. & Anderson, J. M. (1995) Polyurethane elastomer
biostability.
Journal of Biomaterials Applications
,
9
, 321-354.
8.7 Acknowledgements
I would like to thank Professor David Hukins (University of Birmingham)
for his guidance on writing this chapter and for proofreading.
8.8 References
An, Y. H., Woolf, S. K. & Friedman, R. J. (2000) Pre-clinical
in vivo
evaluation of
orthopaedic bioabsorbable devices.
Biomaterials
,
21
, 2635-2652.
ASTM WK4863: Standard practice/guide for the mechanical characterization of lumbar
nucleus devices. Draft standard edition (2005). American Society for Testing and
Materials.
Bantick, G. L. & Taggart, I. (1995) Mammography and breast implants.
British Journal
of Plastic Surgery
,
48
, 49-52.
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