(Sunday, 7/12/2020) [Eastern Time (GMT-4)]
Room: AAPM ePoster Library
Purpose: To synthesize the Nucleus-Targeted Pd-103/Au Nanoparticles for higher cellular uptake and to study local dose enhancement
Methods: Cubic shaped core palladium-103 with gold shell structured nanoparticles were synthesized by using a successive reduction method. Then, PEG and a peptide containing integrin-binding domain, RGD, were attached to the surface of nanoparticles. After synthesizing Pd-103/Au nanoparticles, characteristics of nanoparticles, including size distribution, stability, cytotoxicity, and cellular uptake, were measured. Then we investigated the relative nanoscale dose deposition around nanoparticle by varying the gold shell thickness using a TOPAS/GEANT-4.
Results: Synthesized Pd-103/Au nanoparticles showed a mono-dispersed size of 50±5 nm, smooth and equal thickness of the gold layer and sphere-shaped morphology. PdAuNPs were highly stable, with no sign of aggregations and cytotoxicity in a biological system. Nucleus-Targeted nanoparticles showed a 53±4 % increase in cellular uptake compared to a non-targeted nanoparticle. There was significant dose enhancement between 0nm to 250nm from the surface of the nanoparticle. Compared to nanoparticles with 20nm shell, nanoparticles with 10nm showed higher dose enhancement between 0nm to 250m. Compared to the conventional seed, Pd-103/AuNP with 10nm and 20nm gold shells were able to deliver approximately 70 times and 60 times more dose, respectively
Conclusion: We showed higher local dose deposition from Auger electrons occurs when the gold shell thickness decreases (less than 10nm), suggesting that gold shell thickness should be less than 10 nm for potential local dose enhancement. Also, we have shown that Auger and internal conversion electrons from the Pd-103 decay are the major contributors of the local dose enhancement, rather than Auger electrons generated from the gold shell and photon interactions. However, local dose enhancement effects were limited to the short-range. In overall, our studies have shown that PdAuNP has the potential to be a great candidate for an Auger emitting radionuclide brachytherapy source.
Keywords
Monte Carlo, Dosimetry, Pd-103
Taxonomy
IM/TH- Radiopharmaceutical Therapy: Dose estimation: Monte Carlo
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