Table 3. . Blood half life and tumor accumulation.

Nanoparticle	Surface coating	Blood half life	Tumor accumulation
2 nm Gold nanoparticles [38] 2 nm Gold nanoparticles 2 nm Gold nanoparticles	TEG-Hydroxyl TEG-Amine TEG-Carboxyl	5 h 24 h 18 m	25 μg† Au/g tumor 5 μg† Au/g tumor 15 μg† Au/g tumor
22 nm Gold nanoparticles [48] 40 nm Gold nanoparticles 99 nm Gold nanoparticles 82 nm Gold nanoparticles 61 nm Gold nanoparticles	PEG2000-SH PEG2000-SH PEG10,000-SH PEG10,000-SH PEG5000-SH	2.5 h 4 h 7.2 h 11.6 h 16.5 h	0.3% injected dose·h/g 15.8% injected dose·h/g 17.9% injected dose·h/g 20.4% injected dose·h/g 26.5% injected dose·h/g
Gold nanorods (hd = 42) [62] Gold nanorods (hd = 44) Gold nanorods (hd = 22)	SiO2-PEG SiO2-BSA BSA	18.6 m 3.3 m 34 s	0.83% injected dose 0.45% injected dose 0.3% injected dose
Gold nanorods (13nm × 47nm) [63]	PEG	17 h	7% injected dose/g

Studies in the table are limited to gold nanoparticle studies that used inductively coupled plasma methodologies to quantify both blood circulation and tumor accumulation.

^†Estimated from bar graphs in the publication.

PEG: Polyethylene glycol, TEG: Tetraethylene glycol.