Research Article
Investigation into Polyurethane at Varying Dose Rates of
Ionizing Radiation for Clinical Application
Shelley L. Cooke
1
and Abby R. Whittington
1,2
1
Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, Blacksburg,
VA 24061, USA
2
Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
Correspondence should be addressed to Abby R. Whittington; awhit@vt.edu
Received 25 April 2018; Accepted 16 July 2018; Published 1 October 2018
Academic Editor: Yves Grohens
Copyright © 2018 Shelley L. Cooke and Abby R. Whittington. is is an open access article distributed under the Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
Polyurethanes (PUs) are commonly used materials for medical devices. ese devices are exposed repeatedly to radiation when
patients undergo radiotherapy treatments. It has been found that peripherally inserted central catheters (PICCs) and central
venous catheters (CVCs) fail at an increased rate (14.7% and 8.8%, respectively) when radiated. Currently, little research is
available on increased failure seen in conjunction with radiation, but complex invivo environments within a human patient make
it difficult to isolate effects of individual variables. is research investigated effects of radiation in an aqueous environment to
determine whether radiation combined with a mimicked in vivo environment is sufficient to change PU devices. e following
doserateswereusedinthisstudy:3.2Gy·min
-1
,4.5Gy·min
-1
,44Gy·min
-1
,and833Gy·min
-1
. Samples were characterized in four
main ways: cellular response, physical changes, chemical changes, and mechanical changes. Results reveal normal cellular re-
sponse at all dose rates, indicating dose rate does not alter cellular adhesion or proliferation, and biocompatibility of the material is
not being altered. Results from physical, chemical, and mechanical effects confirm that varying dose rates alone do not initiate
material changes, which negates the hypothesis that varying dose rates of radiation contribute to the complications in PICC
and CVCs.
1. Introduction
Polyurethane biomaterials are often studied for use in
fabricating 3D tissue scaffolds, catheters, blood contact
materials (heart valves and artificial veins), hospital bedding,
injection molded implants, and other short-term implants
[1–3]. Polyurethane catheters, specifically PICCs and CVCs,
have been shown to fail at higher rates when exposed to
radiotherapy in cancer patient [4, 5], 14.7% and 8.8%, re-
spectively [4]. Postinsertion complication rate of non-
irradiated PICC lines is 30.4% [4–7]. Previous investigations
in our lab (data not shown) have indicated that varying total
therapeutic radiation doses at a constant dose rate does not
alter PU enough to cause instability in an aqueous envi-
ronment. However, altering radiotherapy dose rate is
commonly used in treating different types of cancer or
targeting specific tumor locations on the body [8] and may
be a contributing factor to material stability invivo [6]. Some
researchers and clinicians have suggested that radiation
should be applied prior to PICC line insertion to reduce
complications believed to occur through radiation exposure
(thrombosis, infection, mechanical occlusion/puncture,
catheter movement, and extravasation), and this study
aims to investigate whether radiation may be the cause of
any complications [6,9–11].
e leading causes of PU catheter complications are
infection and thrombosis (blood clotting). Radiation may
play a role leading up to these biological responses and will
be investigated using cell proliferation and adhesion studies
on PU films [7]. Occlusion and puncture are mainly affected
by the placement of the catheter in the body and may arise
due to improper placement causing pinching of the catheter
from arm movement or pinching between rib and clavicle,
rupture due to pressure from liquid moving through
Hindawi
Journal of Chemistry
Volume 2018, Article ID 7312147, 8 pages
https://doi.org/10.1155/2018/7312147