Targeting and retention enhancement of quantum dots decorated with amino acids in an invertebrate model organism

Abstract

The use of quantum dots (QDs) in biological imaging applications and targeted drug delivery is expected to increase. However, the efficiency of QDs in drug targeting needs to be improved. Here, we show that amino acids linked to CdTe QDs significantly increased the targeted transfer efficiency and biological safety in the invertebrate model Bombyx mori. Compared with bare QDs530, the transfer efficiency of Ala- and Gly-conjugated QDs (QDs530-Ala and QDs530-Gly) in circulatory system increased by 2.6 ± 0.3 and 1.5 ± 0.3 times, and increased by 7.8 ± 0.9 and 2.9 ± 0.2 times in target tissue silk glands, respectively, after 24 h of QDs exposure. Meanwhile, the amount of conjugated QDs decreased by (68.4 ± 4.4)% and (46.7 ± 9.1)% in the non-target tissue fat body, and the speed at which they entered non-target circulating blood cells significantly decreased. The resultant QDs530-Ala revealed a better structural integrity in tissues and a longer retention time in hemolymph than that of QDs530 after exposure via the dorsal vessel. On the other hand, QDs530-Ala significantly reduced the toxicity to hemocytes, silk gland, and fat body, and reduced the amount of reactive oxygen species (ROS) in tissues.

Metabolomics differences between silkworms (Bombyx mori) reared on fresh mulberry (Morus) leaves or artificial diets

“…At the same time, the contents of alanine, glycine, asparagine, and serine, which are the most abundant amino acids, in silk protein, differed significantly in the hemolymph of silkworms reared on the artificial diet. These four amino acids accounted for 85.5% of the amino acids in silk fibroin and 71.6% in sericin, and the glycine content in silk fibroin reached 46.5% 55 , 56 . These results show that the abundance of glycine in the hemolymph of the silkworms reared on the artificial diet was 43.5% lower in females and 29.0% lower in males compared with those of the silkworms reared on mulberry leaves, while the contents of alanine, asparagine, and serine were significantly higher, suggesting that the low efficiency of silk protein synthesis in the silkworms reared on the artificial diet may be related to the lack of glycine.…”

Influence of hyperproteinemia on reproductive development in an invertebrate model

“…There is currently no reliable animal disease model or modeling method for hyperproteinemia in mammals, and we therefore used an invertebrate silkworm model [31][32][33] . We created an animal model of hyperproteinemia (AM) with no primary disease, in which hyperproteinemia could be generated by controlling PPC levels.…”

Reproductive toxicity and gender differences induced by cadmium telluride quantum dots in an invertebrate model organism

“…In our previous study, the tracking analysis of CdTe-QDs or amino acid-modified QDs in multiple tissues of silkworm were performed 15 . And the dynamic distribution of QDs in testes or ovaries are supposedly-written-by the findings.…”

“…Observations of reproductive toxicity are used to evaluate the ecological impact and chronic toxicity in organisms, which are imperative for the application and development of nanochemicals in basic research 8 9 . Various QDs are known to be toxic to cells 10 11 12 13 and different animal species, such as Caenorhabditis elegans 14 , Bombyx mori 6 15 , Hydra vulgaris 16 , zebrafish 17 18 19 , and mice 20 21 22 , but the reproductive toxicity of QDs and the mechanism of QD toxicity in animals are unclear, especially in males.…”