Table 2. Physicochemical properties and half-life in the blood of hydrolyzed POZ-ICG with different hydrolysis ratios.
| Sample | Molecular weighta (kDa) | Hydrolysis ratio (%) | pKab | Electric conductivityb (mS/cm) | Number of ICG molecules conjugated to POZ | Half-life in the bloodc (h) |
|---|---|---|---|---|---|---|
| P8-ICG1.5 | 25 | 2.5 | 10.1 | 3.9 | 1.5 | 4.9 ± 1.2 |
| P9-ICG0.6 | 25 | 5 | 10.2 | 3.8 | 0.6 | 4.6 ± 0.6 |
| P10-ICG0.6 | 25 | 10 | 10.2 | 3.4 | 0.6 | 3.8 ± 0.5 |
| P11-ICG0.7 | 25 | 15 | 10.3 | 3.1 | 0.7 | 2.1 ± 0.4 |
| P12-ICG1.9 | 25 | 20 | 10.2 | 2.9 | 1.9 | 1.1 ± 0.0 |
| P13-ICG1.7 | 50 | 2.5 | 10.3 | 3.7 | 1.7 | 4.8 ± 1.2 |
| P14-ICG0.5 | 50 | 5 | 10.2 | 3.4 | 0.5 | 4.5 ± 0.1 |
| P15-ICG1.0 | 50 | 10 | 10.4 | 2.7 | 1.0 | 3.4 ± 0.4 |
| P16-ICG1.1 | 50 | 15 | 10.3 | 2.4 | 1.1 | 2.0 ± 0.4 |
| P17-ICG1.9 | 50 | 20 | 10.4 | 1.7 | 1.9 | 1.1 ± 0.2 |
aMolecular weight was determined by gel permeation chromatography (GPC) and expressed as weight-average molecular weight.
bpKa and electric conductivity were determined before ICG conjugation.
cHalf-life of POZ-ICG in the blood was calculated based on probe concentration in blood collected from tumor-bearing mice.