AAWSAP DIRD, Biomaterials, January 2010

Text

This text came with the file. It may have mistakes. When the text and the image disagree, the image is right.

UNCLASSIFIED// FOR OFFICIAL t:191!! 9HL\I
PLA, or polylactide, is a thermoplastic,
long-chained organic material derived
from renewable resources, such as
corn starch (in the United States) or
sugarcanes (in the rest of the world).
PLA has been recognized for more
than a century and is of commercial
interest primarily because of its
biomedical applications. Figure 11
shows the chemical structure of PLA.
These materials are popular because
they have already been used in many
approved medical implant devices and
have been shown to be safe, nontoxic,
and biocompatible. They have been
used in the development of several
commercially available medical
products, including sutures, tissue
screws and tacks, guided tissue-regeneration membranes for dentistry, internal bone­
fixation devices, microspheres for implantable drug delivery systems, and meniscus and
Figure 11. Structure of Polylactic Acid (a
Biodegradable Polymer)
cartilage repair systems.
These polymers can potentially be
used in the design of vascular and
urological stents and skin substitutes.
This is possible through the
manipulation of the polymer
characteristics of these materials,
such as their three-dimensional
architecture, their mechanical and
structural integrity, and their
biodegradability. The materials can
also be used as scaffolds for tissue
engineering and for tissue
reconstruction.
A medical application of these
materials in thin-sheet form is their
placement as a thin barrier layer that
prevents entry of debris into wounds
and as an underlayer to the skin and
body tissue. Figure 12 is an artist's
conception of a layer of PLA polymer
being placed over the heart after
open-heart surgery.
The Clear Choice
Protection in case there is a re-operation...
Figure 12. Biodegradable PLA as an Antiadhesion
Barrier after Open-Heart Surgery
The PLA sheet acts as a barrier and spacer to prevent the healing heart wall from
growing an attachment to the chest wall and from forming adhesions onto the overlying
UNCLASSIFIED//EAR AEFICIOP I155 CNP X
9