Table 2: In vivo QDs genotoxicity studies.
| Citations (references) | Quantum dot types and sizes | Concentration/Exposure time | In vivo systems | Toxicity/Genotoxiciy assays | Findings |
| Aye, et al. [69] | CdSe/ZnS-DOPC/DOTAU | 5.5 × 10-1, 5 × 10-2 and 5 × 10-3 g/kg for 24 hrs |
In vivo QDs injectioned by peritoneal cavity in 6-7 week-old (200-225 g) adult Sprague-Dawley male rats |
Comet assay Micronucleus (MN) Blood reticulocytes (MNRET) |
In Comet assay QDs injection, genotoxic effects were observed in the brain and liver and, only for the highest QDs concentration, in testicles. No genotoxic effect was seen in the kidney and lung. The micronucleated peripheral reticulocyts (MNRET) test showed a dose response induction of micronuclei |
| Khalil, et al. [70] | CdSe (average size 5.0 ± 0.2 nm) modified with mercaptoacetic acid (MAA) doped and undoped with 1% cobalt | 500, 1000, and 2000 mg/kg by weight for two and seven days | In vivo Male mice |
DNA damage MN DNA adduct (8-hydroxy-2 deoxyguanosine, 8-OHdG) | For two days exposure: 2000 mg/kg concentration of MAA-CdSe was significantly induce DNA damage, MN formations, and generation of DNA adduct (8-OHdG) For seven days exposure: However, increasing DNA damage and the frequency of MN formation and the generation of DNA adducts were observed with both the undoped MAA-CdSe (2000 mg/kg) and doped MAA-CdSe (1000 and 2000 mg/kg) |
| Alaraby, et al. [71] | CdSe QDs (Lumidot™ CdSe) with (3-3.5 nm) | Final concentrations were 0.48, 2.4, 12, 48 and 240 μg/g food for CdSe QDs | In vivo D. melanogaster |
Somatic mutation and recombination test-SMART Comet assay |
In the Comet assay CdSe QDs caused a significant dose-dependent increase in DNA strands breaks In SMART assay genotoxic effect was observed |
| Gagné, et al. [57] | CdTe QDs | 1.6, 4, and 8 mg/L exposed 24 hrs | In vivo Freshwater mussels Elliptio complanata |
Olive's alkaline DNA precipitation and lipid peroxidation | DNA strands breaks reduced in gills at ˂ 1.6 mg/L and in digestive glands, a transient but marginal increase in DNA strand breaks occurred at the lowest concentration and dropped significantly at the higher concentrations |
| Rocha, et al. [72] | CdTe coated by carboxyl groups (-COOH) (2-7 nm diameter) | 10 μg/L 14 days |
In vivo | Comet assay Micronucleus test (MN) Nuclear abnormalities assay |
Chromosomal damage induced by both Cd forms after 14 days of exposure was analyzed by MN and nuclear abnormalities assay QDs are more genotoxic than Cd2+ in the first 7 days of exposure while the opposite occurred at the end of the experiment in Comet assay |
| Galeone, et al. [79] | CdSe-ZnS QDs with: mercaptoundecanoic acid (QD-MUA), polymer coating with poly-maleic anhydride octadecene (QD-PC) and polymer and polyethylene glycol (PEG) coating (QD-PC-PEG) QD-MUA (15 ± 1.5 nm) QD-PC (23 ± 1.6 nm) QD-PEG ( 25 ± 1.5 nm) | Fed for seven days with food containing the CdSe-ZnS QDs 0.02 μg/g Cd per day | In vivo Hemocytes of third instar larvae of D. melanogater | Annexin V/PI assay (to reveal apoptotic and/or necrotic cell) TUNEL assay (to reveal DNA damage) |
CdSe-ZnS QDs caused DNA damage and apoptosis in Drosophila hemocytes% DNA damage was compare control samples and results are below: QD-MUA 23%, QD-PC 14% QD-PC-PEG 9% |