Page 357 - 2014 Printable Abstract Book
P. 357
dose for tritium. Current experimental results of these projects, and implications for the protection of
humans against ionizing radiation in the environment, will be presented.
(PS7-6) A facile colorimetric sensor of ionizing radiation using polypeptide mediated nanoparticle
2
1
1
2
formation. Karthik S. Pushpavanam ; John Chang ; Stephen Sapareto ; and Kaushal Rege , Arizona State
2
University, Tempe, AZ and Banner-MD Anderson Cancer Center, Gilbert, AZ
1
Widespread use of ionizing radiation, including X-rays and gamma rays, in food technology,
imaging and cancer therapy necessitates precise control over dose, which in turn motivates the
development of sensors that can detect various energy levels. A variety of dosimeters, including one-
dimensional ion-chambers have been explored for different applications that require ionizing radiation.
However, most available sensors suffer from drawbacks including portability and conformability. A
potential solution to this problem lies in the development of liquid-phase dosimeters and sensors. We
have developed a polypeptide-based sensor which changes color upon irradiation with ionizing radiation.
In this approach, exposure to ionizing radiation results in radiolysis of water, resulting in the formaiton of
free radicals. These, in concert of polypeptides, result in reduction of colorless metal (e.g. gold) salts to
colored plasmonic nanoparticle dispersions. Polypeptides are hypothesized to act as both, templating as
well as stabilizing agents in nanoparticle formation. The effect of radiation dose as well as kinetics of
nanoparticle formation were investigated. The nanoparticles formed were extensively characterized using
TEM, DLS and elemental analysis studies. Our studies on polypeptide-templated plasmonic metal
nanoparticle formation indicate the possibility of developing a new class of dosimeters which can be used
to detect ionizing radiation using a straightforward colorimetric method.
(PS7-7) Evaluating Daily Captopril Dosing for Irradiation-Burn Combined Injury in Mice. Aminul Islam;
David L. Bolduc; Min Zhai; Juliann G. Kiang; and Joshua M. Swift, AFRRI, Bethesda, MD
Past and recent radiation events have involved a high incidence of radiation combined injuries.
Victims of radiation accidents mainly succumb to serious infections as a consequence of bacterial
translocation and subsequent sepsis. Exacerbation of the risk of infection by radiation combined burn
injury further heightens vulnerability. Furthermore, no suitable countermeasures for radiation combined
burn injury (RCBI) have been established. We evaluated captopril, an FDA-approved angiotensin-
converting enzyme inhibitor that was previously reported to stimulate hematopoietic recovery following
irradiation as a potential countermeasure to RCBI. B6D2F1/J female mice (12-weeks old) were subjected
to 9.5 Gy (LD70/30 for RCBI) whole-body bilateral 60Co gamma-photon radiation (dose rate of 0.4
Gy/min), followed by dorsal skin burn injury under anesthesia (approximately 15% total-body-surface area
burn). Mice were provided with acidified drinking water with or without dissolved captopril (CAP; 0.55
g/L) for 30 days immediately post-injury and were administered topical gentamicin (0.1% cream; Days 1-
10) and oral levofloxacin (90-100 mg/kg; Days 3-16). Surviving mice were euthanized on Day 30 following
water consumption, body weight and survival analysis. Our data demonstrated that, while captopril did
mitigate radiation injury (RI)-induced mortality (45% CAP vs. 20% VEH; n = 20), it did not improve survival
after RCBI (22% CAP vs. 41% VEH; n = 22). Moreover, captopril treatment did not affect water consumption
or body mass after RI or RCBI. However, captopril administration via drinking water produced an uneven
dosage pattern amongst the different injury groups ranging from 74 ± 5.4 to 115 ± 2.2 mg/kg/day.
Captopril treatment also did not counteract the negative alterations in hematology, splenocytes, or bone
355 | P a g e
humans against ionizing radiation in the environment, will be presented.
(PS7-6) A facile colorimetric sensor of ionizing radiation using polypeptide mediated nanoparticle
2
1
1
2
formation. Karthik S. Pushpavanam ; John Chang ; Stephen Sapareto ; and Kaushal Rege , Arizona State
2
University, Tempe, AZ and Banner-MD Anderson Cancer Center, Gilbert, AZ
1
Widespread use of ionizing radiation, including X-rays and gamma rays, in food technology,
imaging and cancer therapy necessitates precise control over dose, which in turn motivates the
development of sensors that can detect various energy levels. A variety of dosimeters, including one-
dimensional ion-chambers have been explored for different applications that require ionizing radiation.
However, most available sensors suffer from drawbacks including portability and conformability. A
potential solution to this problem lies in the development of liquid-phase dosimeters and sensors. We
have developed a polypeptide-based sensor which changes color upon irradiation with ionizing radiation.
In this approach, exposure to ionizing radiation results in radiolysis of water, resulting in the formaiton of
free radicals. These, in concert of polypeptides, result in reduction of colorless metal (e.g. gold) salts to
colored plasmonic nanoparticle dispersions. Polypeptides are hypothesized to act as both, templating as
well as stabilizing agents in nanoparticle formation. The effect of radiation dose as well as kinetics of
nanoparticle formation were investigated. The nanoparticles formed were extensively characterized using
TEM, DLS and elemental analysis studies. Our studies on polypeptide-templated plasmonic metal
nanoparticle formation indicate the possibility of developing a new class of dosimeters which can be used
to detect ionizing radiation using a straightforward colorimetric method.
(PS7-7) Evaluating Daily Captopril Dosing for Irradiation-Burn Combined Injury in Mice. Aminul Islam;
David L. Bolduc; Min Zhai; Juliann G. Kiang; and Joshua M. Swift, AFRRI, Bethesda, MD
Past and recent radiation events have involved a high incidence of radiation combined injuries.
Victims of radiation accidents mainly succumb to serious infections as a consequence of bacterial
translocation and subsequent sepsis. Exacerbation of the risk of infection by radiation combined burn
injury further heightens vulnerability. Furthermore, no suitable countermeasures for radiation combined
burn injury (RCBI) have been established. We evaluated captopril, an FDA-approved angiotensin-
converting enzyme inhibitor that was previously reported to stimulate hematopoietic recovery following
irradiation as a potential countermeasure to RCBI. B6D2F1/J female mice (12-weeks old) were subjected
to 9.5 Gy (LD70/30 for RCBI) whole-body bilateral 60Co gamma-photon radiation (dose rate of 0.4
Gy/min), followed by dorsal skin burn injury under anesthesia (approximately 15% total-body-surface area
burn). Mice were provided with acidified drinking water with or without dissolved captopril (CAP; 0.55
g/L) for 30 days immediately post-injury and were administered topical gentamicin (0.1% cream; Days 1-
10) and oral levofloxacin (90-100 mg/kg; Days 3-16). Surviving mice were euthanized on Day 30 following
water consumption, body weight and survival analysis. Our data demonstrated that, while captopril did
mitigate radiation injury (RI)-induced mortality (45% CAP vs. 20% VEH; n = 20), it did not improve survival
after RCBI (22% CAP vs. 41% VEH; n = 22). Moreover, captopril treatment did not affect water consumption
or body mass after RI or RCBI. However, captopril administration via drinking water produced an uneven
dosage pattern amongst the different injury groups ranging from 74 ± 5.4 to 115 ± 2.2 mg/kg/day.
Captopril treatment also did not counteract the negative alterations in hematology, splenocytes, or bone
355 | P a g e
