Gold nanoparticles and electroporation impose both separate and synergistic radiosensitizing effects in HT-29 tumor cells: an in vitro study

Figures & data

Figure 1 The images of GNPs. (A) Transmission electron microscope image, (B) scanning electron microscope image.

Abbreviation: GNPs, gold nanoparticles.

Figure 2 Schematic diagram of the experimental procedures for six different treatment groups.

Abbreviations: IR, ionizing radiation; GNPs, gold nanoparticles; EP, electroporation.

Figure 3 (A) Survival fraction of HT-29 cells incubated with GNPs at a concentration of 0.1 mM for 24, 48, and 72 h compared to nontreated group. None of the groups were statistically significant (P>0.05). (B) Survival fraction of CHO cells incubated with GNPs at concentration of 0.1 mM for 24, 48, and 72 h compared to nontreated group. None of the groups were statistically significant (P>0.05).

Abbreviations: CHO, Chinese hamster ovary; GNPs, gold nanoparticles.

Table 1 Values of α, β, LD₅₀, DEF, and R² values of HT-29 and CHO cells in different groups

Groups	α (Gy^−1)		β (Gy^−2)		LD50 (Gy)		DEF		R^2
	CHO	HT-29	CHO	HT-29	CHO	HT-29	CHO	HT-29	CHO	HT-29
IR	0.064±0.016	0.09±0.013	0.024±0.002	0.021±0.002	4.19	3.97	–	–	0.997	0.997
GNPs+IR	0.099±0.018	0.144±0.013	0.025±0.003	0.018±0.002	3.63	3.37	1.15	1.17	0.996	0.998
GNPs (24 h)+IR	0.17±0.017	0.213±0.013	0.019±0.003	0.016±0.002	3.03	2.69	1.38	1.47	0.997	0.998
EP+IR	0.145±0.02	0.174±0.024	0.02±0.003	0.021±0.004	3.27	2.92	1.28	1.36	0.996	0.998
GNPs+EP+IR	0.27±0.02	0.439±0.022	0.021±0.004	0.008±0.004	2.18	1.52	1.92	2.61	0.995	0.998
GNPs (24 h)+EP+IR	0.319±0.02	0.487±0.029	0.028±0.003	0.011±0.005	1.85	1.37	2.26	2.89	0.998	0.997

Note: The values are expressed as mean ± SEM.

Abbreviations: LD₅₀, 50% lethal dose; CHO, Chinese hamster ovary; IR, ionizing radiation; GNPs, gold nanoparticles; EP, electroporation; DEF, dose enhancement factor; SEM, standard error of mean.

Figure 4 (A) Radiation survival curves of cancerous HT-29 cells treated with six different protocols based on clonogenic assay. (B) Radiation survival curves of CHO cells treated with six different protocols based on clonogenic assay.

Abbreviations: IR, ionizing radiation; GNPs, gold nanoparticles; EP, electroporation; SF, survival fraction.

Figure 5 (A) The viability of HT-29 cells treated with IR, GNPs+IR, GNPs (24 h)+IR, EP+IR, GNPs+EP+IR, and GNPs (24 h)+EP+IR based on MTT assay. *P<0.05. (B) The viability of CHO cells treated with IR, GNPs+IR, GNPs (24 h)+IR, EP+IR, GNPs+EP+IR, and GNPs (24 h)+EP+IR based on MTT assay. *P<0.05.

Abbreviations: CHO, Chinese hamster ovary; IR, ionizing radiation; GNPs, gold nanoparticles; EP, electroporation.