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Pharmacokinetics and bio-distribution are crucial factors affecting the performance of an intravenous drug. In this study, we explore the combined use of glucose and polyethylene glycol (PEG) ligands to further improve gold nanoparticle (GNP) pharmacokinetics and bio-distribution, with the aim of using the drug for in-vivo radiotherapy. The inclusion of PEG was found to significantly prolong the half-life period, where PEG-Glu-GNPs achieved 6.17 +/- 3.71 h, compared to 1.23 +/- 0.14 h for Glu-GNPs and 1.07 +/- 0.22 h for uncoated GNPs. Our data indicates that nanoparticle size impacts cell uptake performance, with 20 nm being the optimal diameter for cancer treatment applications. Although PEG-Glu-GNPs mainly distributed in the spleen, liver, lung, and kidneys, the concentration of PEG-Glu-GNPs in tumour tissue was 20 times higher than healthy cells in the uterus and ovaries, reaching 9.22 +/- 2.41 microg/g cancer tissue at 48 h after injection. This difference in uptake holds promise for selective tumor targeting which can in turn lead to more effective radiotherapy through the interaction of X-rays and GNPs. Specifically tumor size after 47 days of treatment had reduced to (769 +/- 92) mm3 compared to (1432 +/- 269) mm3 using X-rays alone and (3514 +/- 1818) mm3 without any treatment. Moreover, the mice remained healthy without statistically significant weight loss. Results of our pharmacokinetic and bio-distribution study as well as therapeutic data for PEG-Glu-GNPs in our tumor bearing animal model demonstrate that PEG-Glu-GNPs provide excellent in-vivo stability, tumor targeting function, and radiotherapeutic enhancement effects, providing useful insights for further clinical studies.

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Angular discretization impacts nearly every aspect of a deterministic solution to the linear Boltzmann transport equation, especially in the presence of magnetic fields, as modeled by a streaming operator in angle. In this work a novel stabilization treatment of the magnetic field term is developed for an angular finite element discretization on the unit sphere, specifically involving piecewise partitioning of path integrals along curved element edges into uninterrupted segments of incoming and outgoing flux, with outgoing components updated iteratively. Correct order-of-accuracy for this angular framework is verified using the method of manufactured solutions for linear, quadratic, and cubic basis functions in angle. Higher order basis functions were found to reduce the error especially in strong magnetic fields and low density media. We combine an angular finite element mesh respecting octant boundaries on the unit sphere to spatial Cartesian voxel elements to guarantee an unambiguous transport sweep ordering in space. Accuracy for a dosimetrically challenging scenario involving bone and air in the presence of a 1.5 T parallel magnetic field is validated against the Monte Carlo package GEANT4. Accuracy and relative computational efficiency were investigated for various angular discretization parameters. 32 angular elements with quadratic basis functions yielded a reasonable compromise, with gamma passing rates of 99.96% (96.22%) for a 2%/2 mm (1%/1 mm) criterion. A rotational transformation of the spatial calculation geometry is performed to orient an arbitrary magnetic field vector to be along the z-axis, a requirement for a constant azimuthal angular sweep ordering. Working on the unit sphere, we apply the same rotational transformation to the angular domain to align its octants with the rotated Cartesian mesh. Simulating an oblique 1.5 T magnetic field against GEANT4 yielded gamma passing rates of 99.42% (95.45%) for a 2%/2 mm (1%/1 mm) criterion.