(E-199) The Application of GNPs to Protect Nasopharynx Tubarial Salivary Glands During Radiotherapy

Introduction:: Tubarial glands were discovered in 2020 by Netherland scientists and are not classified as Organs-at-Risk (OAR) in radiotherapy, causing head and neck cancer patients to suffer from xerostomia and dysphagia due to damage to these non-labeled OARs. In response, our group designed a face mask that can absorb radiation. The face mask is made out of GNPs or gold nanoparticles, a type of nanoparticle that can synthesize radiation. GNPs can absorb and scatter the incoming radiation, thereby reducing the radiation dose delivered to the surrounding normal tissues. This is due to their surface area to volume ratio that allows the excess radiation. Additionally, the high atomic number (Z) of nanoparticles—gold nanoparticles having a Z=79—means that they can efficiently attenuate high-energy photons like X-rays and gamma rays. Therefore, during cancer therapy, GNP will function as a radiation absorber inside the face mask.

Materials and Methods:: We will use a robotic facemask to expose and guide the radiation towards the tumor. Depending on the tumor’s location, designated parts of the face mask will open to guide the radiation to the desired location (tumor). GNPs, specifically Spherical GNPs, will be added to reduce the adverse effects of excess radiation during radiotherapy. Spherical GNPs are between 1 and 100 nanometers in diameter with a large surface area, making them highly reactive. Their round and symmetrical shape makes them easier to manufacture and manipulate. We will use polyethylene PEG GNPs; they have been known to cause a major decrease in cancer cell survival in vitro studies. The face mask will utilize these PEG-GNPs and a robotic lock mechanism that can be connected to an app. This will manually force the GNPs in the targeted position. The app’s features will then upload X-rays, CT scans, and MRIs which will serve as a road map to help precisely direct radiation toward the tumor.

Results, Conclusions, and Discussions:: A study performed by Hainfeld JF found that following the injection of 1.9 nm GNPs and exposure to 250 kVp x-rays, while a high radio sensitization effect of GNPs was observed, EMT-6 mammary xenograft tumors in mice were completely eliminated in 30 days. GNPs have significant advantages in tumor localization and penetration, they are more likely to penetrate into the tumor stroma and tumor microenvironment. PEG GNPs specifically, is a widely used surface modifier. A study done by Xiao-Dong Zhang revealed PEG-coated GP, can cause a significant decrease in cancer cell survival following gamma radiation. PEG-coated GNPS have been shown to significantly reduce tumor weight after 5gy radiation toward the tumor. Therefore, we believe that this GNP mask can help cancer patients worldwide by not only offering a proposed shielding mechanism but also serving to minimize the adverse side effects commonly associated with radiology treatments, thereby potentially enhancing overall patient outcomes.

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References (Optional): : Citations

Jain, S., Hirst, D. G., & O'Sullivan, J. M. (2012, February). Gold nanoparticles as novel agents for cancer therapy. The British journal of radiology. Retrieved March 23, 2023, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3473940/#b13

Bhardwaj, M., &. (2022, December 9). Nanotechnology for the treatment of cancer: Progress and challenges. Nanotechnology and Human Health. Retrieved March 23, 2023, https://www.sciencedirect.com/science/article/pii/B9780323907507000107

Hainfeld, J. F. (2004). The use of gold nanoparticles to enhance radiotherapy in mice. Physics in medicine and biology. Retrieved March 23, 2023,
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Zhang, Xiao-Dong. (2012, September). Size-dependent radiosensitization of peg-coated gold nanoparticles for cancer radiation therapy. Biomaterials. Retrieved March 23, 2023,
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