Biomedical Engineering Reference
In-Depth Information
The viscous movement activation energy is very low
for silicones, and their viscosity is less dependent on
temperature compared to hydrocarbon polymers.
Furthermore, chain entanglements are involved at
higher temperature and contribute to limit the
viscosity reduction (Stark
et al.
, 1982).
siloxane units leads to a wide range of structures. Polymers
are easily cross-linked at room or elevated temperature to
elastomers, without loosing the above properties.
Acknowledgments
Part of this section (here revised) was originally
published in
Chimie Nouvelle,
the journal of the Soci´t´
Royale de Chimie (Belgium), Vol. 8 (30), 847 (1990) by
A. Colas and are reproduced here with the permission of
the editor. The authors thank S. Hoshaw and P. Klein,
both from Dow Corning, for their contribution regarding
breast implant epidemiology.
Conclusion
Polydimethylsiloxanes are often referred to as silicones.
They are used in many applications because of their sta-
bility, low surface tension, and lack of toxicity. Methyl
group substitution or introduction of tri- or tetra-functional
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introduction to fiber and textile fabric technology will be
presented along with discussion of both old and new
application areas. Traditional and nontraditional fiber
and fabric constructions, processing issues, and fabric
testing will be included in order to offer an overview of
the technology associated with the use of textiles in
medicine.
Table 3.2.4-1
illustrates some of the more
common application areas for textiles in medicine. As
can be seen from this table, the products range from the
simplest products (i.e., gauze bandages) to the most
complex textile products such as vascular grafts and
tissue scaffolds.
3.2.4 Medical fibers
and biotextiles
Steven Weinberg and Martin W. King
The term ''medical textiles'' encompasses medical
products and devices ranging from wound dressings and
bandages to high-technology applications such as
biotextiles, tissue engineered scaffolds, and vascular im-
plants (
King, 1991
). The use of textiles in medicine goes
back to the Egyptians and the Native Americans who
used textiles as bandages to cover and draw wound edges
together after injury (
Shalaby, 1985
). Over the past
several decades, the use of fibers and textiles in medicine
has grown dramatically as new and innovative fibers,
structures, and therapies have been developed. Advances
in fabrication techniques, fiber technology, and compo-
sition have led to numerous new concepts for both
products and therapies, some of which are still in
development or in clinical trials. In this section, an
Medical fibers
All textile-based medical devices are composed of
structures fabricated from monofilament; multifila-
ments; or staple fibers formulated from synthetic poly-
mers, natural polymers (biopolymers), or genetically
engineered polymers. When choosing the appropriate
fiber configuration and polymer for a specific application,
