Figure 7.

Application of aptamers in cancer diagnostics and therapeutics. (A) Schematic illustration of aptamer-based cancer diagnostic and therapeutic applications. (B) Representative results from the study carried out by Li et al. where microPET/CT images of ⁶⁴Cu-DOTA-AS1411 or ⁶⁴Cu-CB-TE2A-AS1411 at multiple time points shown that ⁶⁴Cu-CB-TE2A-AS1411 was stable in tumor site and was cleared rapidly from the blood, liver, and kidneys 1 h post-injection, resulting in a much higher tumor-to-liver ratio (0.56) and the tumor-to-kidney ratio (1.57) than that of 0.12 and 0.21 for that for ⁶⁴Cu-DOTA-AS1411, respectively. a) microPET image slices obtained at different time points for ⁶⁴Cu-DOTA-AS1411; b) and c) Quantitative results from PET imaging for the liver, kidney, tumor, and muscle uptake of ⁶⁴Cu-DOTA-AS1411 and ⁶⁴Cu-CB-TE2A-AS1411; d) microPET image slices obtained at different time points for ⁶⁴Cu-CB-TE2A-AS1411; e) Overview of microCT (left), microPET (middle), and microPET/CT fusion images (right) 1 h post-injection of ⁶⁴Cu-CB-TE2A-AS1411. Reproduced from Ref. 180, Copyright (2014), with permission from Elsevier. (C) Representative results from the study carried out by Charlton and co-workers where in vivo imaging of inflammation sites in a rat reverse passive Arthus reaction model by (^99mTc) aptamer NX21909 indicated that the aptamer achieved a significantly higher target-to-background ratio (4.3 ± 0.6 in 2 hours) in less time than IgG (3.1 ± 0.1 at 3 hours). Reproduced from Ref. 181, Copyright (1997), with permission from Elsevier.