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Size effect of Au/PAMAM contrast agent on CT imaging of reticuloendothelial system and tumor tissue

View Article: PubMed Central - PubMed

ABSTRACT

Polyamidoamine (PAMAM)-entrapped Au nanoparticles were synthesized with distinct sizes to figure out the size effect of Au-based contrast agent on CT imaging of passively targeted tissues. Au/PAMAM nanoparticles were first synthesized with narrow distribution of particles size of 22.2 ± 3.1, 54.2 ± 3.7, and 104.9 ± 4.7 nm in diameters. Size effect leads no significant difference on X-ray attenuation when Au/PAMAM was ≤0.05 mol/L. For CT imaging of a tumor model, small Au/PAMAM were more easily internalized via endocytosis in the liver, leading to more obviously enhanced contrast. Similarly, contrast agents with small sizes were more effective in tumor imaging because of the enhanced permeability and retention effect. Overall, the particle size of Au/PAMAM heavily affected the efficiency of CT enhancement in imaging RES and tumors.

No MeSH data available.


Size effect of Au/PAMAM contrast agent on CT imaging of reticuloendothelial system. a Size effect on liver imaging, the typical images of transverse slices of the top of liver were given. b Detailed CT values of liver imaging. c Au content in corresponding livers detected via ICP-AES at 4 h post injection. d In vitro verification of size effect on endocytosis tested after 1 h co-incubation (blank columns) and after 4 h co-incubation (grey columns) with Au/PAMAM concentration at 10−7 μg/cell
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Fig3: Size effect of Au/PAMAM contrast agent on CT imaging of reticuloendothelial system. a Size effect on liver imaging, the typical images of transverse slices of the top of liver were given. b Detailed CT values of liver imaging. c Au content in corresponding livers detected via ICP-AES at 4 h post injection. d In vitro verification of size effect on endocytosis tested after 1 h co-incubation (blank columns) and after 4 h co-incubation (grey columns) with Au/PAMAM concentration at 10−7 μg/cell

Mentions: The mean CT values of soft tissues were 33.6 Hounsfield unit (HU) (before injection), 36.9 HU (for 22.2 nm), 36.2 HU (for 54.2 nm), and 35.9 HU (for 104.9 nm) at 4 h post injection, and no significant difference was detected. For the enhanced CT imaging of the liver (Fig. 3a), CT values increased along with the accumulation of Au/PAMAM, meanwhile, the increase depended on the particle size (Fig. 3b), where the relatively small Au/PAMAM accumulated in the liver more than the bigger ones significantly (Fig. 3c). Size effect on enhancement of liver imaging was observed that ΔHU = 48.0 for 22.2 nm, ΔHU = 41.6 for 54.2 nm, and ΔHU = 37.3 for 104.9 nm were detected at 4 h post injection. For the in vitro verification of the size effect on endocytosis tested after 1 or 4 h co-incubation, a more obvious size effect-induced difference on cellular uptake was detected that Au/PAMAM with small sizes tended to uptake more than others (Fig. 3d).Fig. 3


Size effect of Au/PAMAM contrast agent on CT imaging of reticuloendothelial system and tumor tissue
Size effect of Au/PAMAM contrast agent on CT imaging of reticuloendothelial system. a Size effect on liver imaging, the typical images of transverse slices of the top of liver were given. b Detailed CT values of liver imaging. c Au content in corresponding livers detected via ICP-AES at 4 h post injection. d In vitro verification of size effect on endocytosis tested after 1 h co-incubation (blank columns) and after 4 h co-incubation (grey columns) with Au/PAMAM concentration at 10−7 μg/cell
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Fig3: Size effect of Au/PAMAM contrast agent on CT imaging of reticuloendothelial system. a Size effect on liver imaging, the typical images of transverse slices of the top of liver were given. b Detailed CT values of liver imaging. c Au content in corresponding livers detected via ICP-AES at 4 h post injection. d In vitro verification of size effect on endocytosis tested after 1 h co-incubation (blank columns) and after 4 h co-incubation (grey columns) with Au/PAMAM concentration at 10−7 μg/cell
Mentions: The mean CT values of soft tissues were 33.6 Hounsfield unit (HU) (before injection), 36.9 HU (for 22.2 nm), 36.2 HU (for 54.2 nm), and 35.9 HU (for 104.9 nm) at 4 h post injection, and no significant difference was detected. For the enhanced CT imaging of the liver (Fig. 3a), CT values increased along with the accumulation of Au/PAMAM, meanwhile, the increase depended on the particle size (Fig. 3b), where the relatively small Au/PAMAM accumulated in the liver more than the bigger ones significantly (Fig. 3c). Size effect on enhancement of liver imaging was observed that ΔHU = 48.0 for 22.2 nm, ΔHU = 41.6 for 54.2 nm, and ΔHU = 37.3 for 104.9 nm were detected at 4 h post injection. For the in vitro verification of the size effect on endocytosis tested after 1 or 4 h co-incubation, a more obvious size effect-induced difference on cellular uptake was detected that Au/PAMAM with small sizes tended to uptake more than others (Fig. 3d).Fig. 3

View Article: PubMed Central - PubMed

ABSTRACT

Polyamidoamine (PAMAM)-entrapped Au nanoparticles were synthesized with distinct sizes to figure out the size effect of Au-based contrast agent on CT imaging of passively targeted tissues. Au/PAMAM nanoparticles were first synthesized with narrow distribution of particles size of 22.2 ± 3.1, 54.2 ± 3.7, and 104.9 ± 4.7 nm in diameters. Size effect leads no significant difference on X-ray attenuation when Au/PAMAM was ≤0.05 mol/L. For CT imaging of a tumor model, small Au/PAMAM were more easily internalized via endocytosis in the liver, leading to more obviously enhanced contrast. Similarly, contrast agents with small sizes were more effective in tumor imaging because of the enhanced permeability and retention effect. Overall, the particle size of Au/PAMAM heavily affected the efficiency of CT enhancement in imaging RES and tumors.

No MeSH data available.