The benefits of folic acid-modified gold nanoparticles in CT-based molecular imaging: radiation dose reduction and image contrast enhancement

Figures & data

Figure 1. TEM image of the synthesized FA-AuNPs, suggesting that the nanoparticles are well dispersed and appear to be spherical in shape with a size distribution of 10–30 nm.

Figure 2. (a) Size distribution of the synthesized FA-AuNPs (peak: 33.8 nm). (b) Zeta potential distribution of the synthesized FA-AuNPs (peak: −12.5 mV).

Figure 3. UV–visible spectrum of AuNPs with and without conjugation with folic acid [Reprinted with permission from Elsevier].

Figure 4. FTIR spectra of folic acid, AuNPs stabilized with trisodium citrate and FA-AuNPs [Reprinted with permission from Elsevier].

Figure 5. The viability of KB cells after 12-h incubation with AuNPs and FA-AuNPs at different concentrations.

Figure 6. The CT values of KB cells treated with AuNPs and FA-AuNPs (12 h) at different concentrations (tube voltage of 130 kVp and tube current–time product of 60 mAs).

Figure 7. The CT values of KB cells treated with AuNPs and FA-AuNPs (12 h) at different concentrations (tube voltage of 130 kVp and tube current–time product of 90 mAs).

Figure 8. The CT values of KB cells treated with AuNPs and FA-AuNPs (12 h) at different concentrations (tube voltage of 130 kVp and tube current–time product of 120 mAs).

Figure 9. The CT values of KB cells treated with AuNPs and FA-AuNPs (12 h) at different concentrations (tube voltage of 130 kVp and tube current–time product of 160 mAs).

Figure 10. The CT values of KB cells treated with AuNPs and FA-AuNPs (12 h) at different concentrations (tube voltage of 130 kVp and tube current–time product of 250 mAs).

Figure 11. The CTDI values measured from the CT scanning of a head phantom at different mAs products and fixed peak tube voltage of 130 kVp.

Table 1. The resultant increase in the CT value of KB cells caused by the FA modification of AuNPs (ΔHU _FA-AuNPs – ΔHU _AuNPs). ΔHU _FA-AuNPs and ΔHU _AuNPs stand for the increase in the CT value of KB cells due to treatment with FA-AuNPs and AuNPs at the same Au concentration relative to the CT value of the control group, respectively.

Au concentration mAs product	20 µg/ml	30 µg/ml	45 µg/ml	90 µg/ml
60	92	112	104	82
90	91	109	80	115
120	74	73	74	71
160	92	120	65	67
250	85	115	80	75

Table 2. The effects of elevating the mAs product, AuNPs and FA-AuNPs on the CT value enhancement of KB cells. ΔHU stands for the resultant increase in the CT value of KB cells due to the mentioned effects relative to the control group.

	mAs product	Dose (mGy)	Au concentration (µg/ml)	ΔHU
Effect of mAs product	60→90	18→27	0	10↑
	60→120	18→36		23↑
	60→160	18→48		36↑
	60→250	18→75		40↑
Effect of AuNPs	60	18	0→20	38↑
			0→30	41↑
			0→45	161↑
			0→90	584↑
Effect of FA-AuNPs			0→20	130↑
			0→30	153↑
			0→45	265↑
			0→90	666↑