Radiobiological Implications of Nanoparticles Following Radiation Treatment

Abstract

clinically due to the number of variables that need to be investigated to control and optimize the effect. Various groups have investigated different aspects, such as varying NP size or radiation beam energy. Even with knowledge from these studies, there is still a considerable amount of variability in reported findings. Differences are caused by the diversity in cell lines, NPs with their respective coatings, incubated NP concentrations, incubation times, irradiation parameters, as well as the assays used to demonstrate the effects. This has led to variations in the results, where significant enhancements of a factor of 25 were shown by Rahman et al., with Aurovist 1.9 nm gold nanoparticles (AuNPs) at a concentration of 1 mm with bovine aortic endothelial cells (BAEC) and 80 kV X-rays, [3] compared to smaller enhancements shown by Chithrani et al., where they synthesized 50 nm AuNPs at a concentration of approximately 1 nm in HeLa cells and found an enhancement factor of 1.17 with 6 MV X-rays. [4] As well as this, there are also differences in protocols between research groups, in both maintenance of cells and assays reported.A review by Her et al. reported on the different mechanisms associated with NP-enhanced radiotherapy, where the overall effect is a combination of physical, chemical, and biological -7 and U87) and three commercially available nanoparticles (gold, gadolinium, and iron oxide) irradiated by 6 MV X-rays. To assess cell survival, clonogenic assays are carried out for all variables considered, with a concentration of 0.5 mg mL -1 for each nanoparticle material used. This study demonstrates differences in cell survival between nanoparticles and cell line. U87 shows the greatest enhancement with gadolinium nanoparticles (2.02 ± 0.36), whereas MCF-7 cells have higher enhancement with gold nanoparticles (1.74 ± 0.08). Materials with a high atomic number (Z) are shown to cause an increase in the level of cell kill by ionizing radiation when introduced into tumor cells. This study uses in vitro experiments to investigate the differences in radiosensitization between two cell lines (MCFMass spectrometry, however, shows highest elemental uptake with iron oxide and U87 cells with 4.95 ± 0.82 pg of iron oxide per cell. A complex relationship between cellular elemental uptake is demonstrated, highlighting an inverse correlation with the enhancement, but a positive relation with DNA damage when comparing the same nanoparticle between the two cell lines.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.

Impact of Superparamagnetic Iron Oxide Nanoparticles on In Vitro and In Vivo Radiosensitisation of Cancer Cells

“…Cell lines had taken up varying quantities of SPIONs (measured by ICP-MS), but the cell-specific sensitivity of the cell to the SPIONs seems not be solely due to the concentration within the cell, as demonstrated by U87 cells. Ahmad et al appears to disagree with these results, finding a positive correlation between levels of DNA damage and uptake with ICP-MS, for Iron Oxide nanoparticles with a mean diameter of 140 ± 4 nm at a concentration of 0.5 mg/ml, which is much higher than the concentration used for this study [69]. However, Ahmad et al finds a complex relationship between uptake and radiosensitivity, as there is a negative relationship between dose enhancement and uptake, and this was carried out for 6 MV, not the 225 kVp used in this study.…”

Impact of Superparamagnetic Iron Oxide Nanoparticles on In Vitro and In Vivo Radiosensitisation of Cancer Cells

“…The median tumour volume was taken using linear interpolation for days between measurements. To quantify tumour growth delay, the time taken for each subgroup to reach a tumour size of 300 mm3 is represented in Figure 10, with statistics carried out using Ahmad et al appears to disagree with these results, finding a positive correlation between levels of DNA damage and uptake with ICP-MS, for Iron Oxide nanoparticles with a mean diameter of 140 ± 4 nm at a concentration of 0.5 mg/ml, which is much higher than the concentration used for this study (61). However, Ahmad et al finds a complex relationship between uptake and radiosensitivity, as there is a negative relationship between dose enhancement and uptake.…”

Mechanisms of nanoparticle radiosensitization

“…In a study comparing three commercial nanoparticles (AGuIX ® , Aurovist™ and RCL-01, being a gadolinium-, goldand iron oxide-based nanoparticle respectively) between MCF-7 and U87 cell lines, the complex differences between cells and the function of nanoparticles was highlighted (Ahmad et al, 2020). For exposure to a constant mass concentration between nanoparticles, the two cell lines preferentially internalized different nanoparticles and exhibited different trends with respect to enhancement based on clonogenic assays.…”