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Author Toomeh, D. ♦ Sajo, E. ♦ Hao, Y. ♦ Gadoue, S. ♦ Ngwa, W.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ RADIATION PROTECTION AND DOSIMETRY ♦ CONCENTRATION RATIO ♦ DIFFUSION ♦ ECOLOGICAL CONCENTRATION ♦ GRAPHENE ♦ IN VIVO ♦ LETHAL DOSES ♦ LYMPH NODES ♦ METASTASES ♦ NEOPLASMS ♦ OXIDES ♦ POTENTIALS ♦ RADIOTHERAPY ♦ STEM CELLS ♦ TUMOR CELLS
Abstract Purpose: An increasing number of studies show that cancer stem cells (CSCs) become more invasive (metastatic) and may escape into the blood stream and lymph nodes during radiotherapy (RT), before they have received a lethal dose during RT. Other Studies have shown that Graphene oxide (GO) can selectively inhibit the proliferative expansion of CSCs across multiplicative tumor types. In this study we investigate the feasibility of using GO during radiotherapy (RT) to minimize the escape of CSCs towards preventing cancer metastasis or recurrence. Methods: We hypothesize that sufficient amount of GO nano-flakes (GONFs) released from new design radiotherapy biomaterials (fiducials or spacers) loaded with the GONFs can reach all tumor cells within typical times of 14 or 21days before the beginning of image-guided radiotherapy (IGRT) following implantation. To test this hypothesis, the space-time diffusion of the GONFs was investigated. Knudsen’s and Cunningham’s numbers were calculated to get the Stokes’ velocities and mobility values, according to these values, diffusion coefficients were calculated. In a previous study it was shown that GONFs concentration of 50 µg/ml were effective. In the diffusion study, 100 µg/ml was chosen as an initial concentration because it has been shown to be relatively non-toxic. Results: The 50 µg/ml concentration in a 2 cm diameter volume of lung tumor could be only achieved using 2 nm and 6 nm GONFs with respective diffusion times of 14 and 21 days. As expected, increased nanoflake size requires longer times to achieve the target 50 µg/ml concentration. Conclusion: The preliminary results indicate the potential of using GONFs delivered via new design radiotherapy biomaterials (e.g. fiducials) to inhibit the proliferative expansion of CSCs. The study avails ongoing in-vivo studies on using GONFs to enhance treatment outcomes for cancer patients.
ISSN 00942405
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-06-15
Publisher Place United States
Journal Medical Physics
Volume Number 43
Issue Number 6


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