A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots

Journal name:
Nature Nanotechnology
Volume:
7,
Pages:
453–458
Year published:
DOI:
doi:10.1038/nnano.2012.74
Received
Accepted
Published online

Abstract

Quantum dots have been used in biomedical research for imaging1, 2, diagnostics3, 4 and sensing purposes5, 6. However, concerns over the cytotoxicity of their heavy metal constituents7, 8 and conflicting results from in vitro7, 9 and small animal10, 11, 12, 13, 14 toxicity studies have limited their translation towards clinical applications. Here, we show in a pilot study that rhesus macaques injected with phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dots do not exhibit evidence of toxicity. Blood and biochemical markers remained within normal ranges following treatment, and histology of major organs after 90 days showed no abnormalities. Our results show that acute toxicity of these quantum dots in vivo can be minimal. However, chemical analysis revealed that most of the initial dose of cadmium remained in the liver, spleen and kidneys after 90 days. This means that the breakdown and clearance of quantum dots is quite slow, suggesting that longer-term studies will be required to determine the ultimate fate of these heavy metals and the impact of their persistence in primates.

At a glance

Figures

  1. Characterization of phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dot formulation.
    Figure 1: Characterization of phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dot formulation.

    a, UV–vis absorbance and photoluminescence emission spectra of micelle-encapsulated quantum dots. The excitonic peaks near the absorption edge and the narrow emission peak show that the quantum dots are relatively monodisperse and defect free. b, Dynamic light scattering data showing the distribution of hydrodynamic diameter of the micelles encapsulating the quantum dots. The blue line is a Gaussan fit with a mean of 52 nm and standard deviation of 12.7 nm. c,d, Transmission electron microscopy (TEM) images showing quantum dots before (c) and after (d) micelle encapsulation. The average diameter of the quantum dots is 7–8 nm. TEM grids were prepared by drop-casting from chloroform (c) or water (d) dispersions and allowing the solvent to evaporate. After encapsulation, the particles remain clustered in groups that are representative of single micelles with multiple encapsulated quantum dots.

  2. Blood test results for treated rhesus macaques.
    Figure 2: Blood test results for treated rhesus macaques.

    ax, The results (n = 6, measured weekly) show no abnormalities in immune response, kidney or liver function, blood clotting or blood chemistry over the 90 day period following treatment. The region rendered in pink represents the normal range from the literature, and the blue region represents the range observed in the test subjects before treatment. Error bars represent one standard deviation above or below the mean. Abbreviations: haemoglobin, Hb; red blood cell count, RBC; white blood cell count, WBC; neutrophil granulocyte, NE; lymphocyte, LY; monocyte, MO; eosinophil granulocyte, EOS; basophil granulocyte, BA; platelet count, PLT; haematocrit, Hct; alkaline phosphatase, ALP; total protein, TPROT; albumin, ALB; total bilirubin, TBILI; direct bilirubin, DBIL; alanine transaminase, ALT; aspartate transaminase, AST; gamma glutamyl transferase, γ-GT; prothrombin time, PT; blood urea nitrogen, BUN; creatinine, CRE; blood glucose, GLU; triglyceride, TG; total cholesterol, CHO.

  3. ICP-MS analysis of the major organs of treated (n = 3) and control (n = 1) rhesus macaques.
    Figure 3: ICP-MS analysis of the major organs of treated (n = 3) and control (n = 1) rhesus macaques.

    Most of the injected dose remained in the kidneys, liver and spleen 90 days after injection. ICP-MS analysis of blood samples at select time points showed rapid clearance of quantum dots from the bloodstream. ac, In vivo biodistribution of cadmium (a), selenium (b) and zinc (c). d, Blood clearance profile of quantum dots. Error bars indicate plus and minus one standard deviation of the measurements from the tissues of three treated animals..

  4. Histological images from the major organs of the rhesus macaques three months after intravenous injection of the QD formulation.
    Figure 4: Histological images from the major organs of the rhesus macaques three months after intravenous injection of the QD formulation.

    Evaluations were carried out by pathologists and found no anomalies. In each pair, the left image is from the control animal and the right image is from a treated animal. ai, Tissues were collected from brain (a), heart (b), liver (c), spleen (d), lung (e), kidney (f), lymph (g), intestine (h) and skin (i). Images were taken at ×40 magnification with standard haematoxylin and eosin staining. Histological images from three additional treated monkeys are provided in Supplementary Figs S2–S4.

References

  1. Medintz, I. L., Uyeda, H. T., Goldman, E. R. & Mattoussi, H. Quantum dot bioconjugates for imaging, labelling and sensing. Nature Mater. 4, 435446 (2005).
  2. Yong, K-T. Mn-doped near-infrared quantum dots as multimodal targeted probes for pancreatic cancer imaging. Nanotechnology 20, 015102 (2009).
  3. Michalet, X. et al. Quantum dots for live cells, in vivo imaging, and diagnostics. Science 307, 538544 (2005).
  4. Bruchez, M., Moronne, M., Gin, P., Weiss, S. & Alivisatos, A. P. Semiconductor nanocrystals as fluorescent biological labels. Science 281, 20132016 (1998).
  5. Chan, W. C. W. & Nie, S. Quantum dot bioconjugates for ultrasensitive nonisotopic detection. Science 281, 20162018 (1998).
  6. Mattoussi, H., Palui, G. & Na, H. B. Luminescent quantum dots as platforms for probing in vitro and in vivo biological processes. Adv. Drug Deliv. Rev. 64, 138166 (2012).
  7. Derfus, A. M., Chan, W. C. W. & Bhatia, S. N. Probing the cytotoxicity of semiconductor quantum dots. Nano Lett. 4, 1118 (2004).
  8. Choi, H. S. et al. Tissue- and organ-selective biodistribution of NIR fluorescent quantum dots. Nano Lett. 9, 23542359 (2009).
  9. Cho, S. J. et al. Long-term exposure to CdTe quantum dots causes functional impairments in live cells. Langmuir 23, 19741980 (2007).
  10. Yong, K-T., Roy, I., Ding, H., Bergey, E. J. & Prasad, P. N. Biocompatible near-infrared quantum dots as ultrasensitive probes for long-term in vivo imaging applications. Small 5, 19972004 (2009).
  11. Hauck, T. S., Anderson, R. E., Fischer, H. C., Newbigging, S. & Chan, W. C. W. In vivo quantum-dot toxicity assessment. Small 6, 138144 (2010).
  12. Ballou, B., Lagerholm, B. C., Ernst, L. A., Bruchez, M. P. & Waggoner, A. S. Noninvasive imaging of quantum dots in mice. Bioconj. Chem. 15, 7986 (2004).
  13. Fischer, H. C., Liu, L., Pang, K. S. & Chan, W. C. W. Pharmacokinetics of nanoscale quantum dots: in vivo distribution, sequestration, and clearance in the rat. Adv. Funct. Mater. 16, 12991305 (2006).
  14. Dubertret, B.et al. In vivo imaging of quantum dots encapsulated in phospholipid micelles. Science 298, 17591762 (2002).
  15. Colvin, V. L. The potential environmental impact of engineered nanomaterials. Nature Biotechnol. 21, 11661170 (2003).
  16. Werlin, R. et al. Biomagnification of cadmium selenide quantum dots in a simple experimental microbial food chain. Nature Nanotech. 6, 6571 (2011).
  17. Hardman, R. A toxicologic review of quantum dots: toxicity depends on physicochemical and environmental factors. Environ. Health Perspect. 114, 165172 (2006).
  18. Choi, H. S. et al. Renal clearance of quantum dots. Nature Biotechnol. 25, 11651170 (2007).
  19. Hoshino, A. et al. Physicochemical properties and cellular toxicity of nanocrystal quantum dots depend on their surface modification. Nano Lett. 4, 21632169 (2004).
  20. Kirchner, C. et al. Cytotoxicity of colloidal CdSe and CdSe/ZnS nanoparticles. Nano Lett. 5, 331338 (2005).
  21. Xia, H-J., Zhang, G-H., Wang, R-R. & Zheng, Y-T. The influence of age and sex on the cell counts of peripheral blood leukocyte subpopulations in Chinese rhesus macaques. Cell Mol. Immunol. 6, 433440 (2009).
  22. Xia, H., Liu, H., Zhang, G. & Zheng, Y. Phenotype and function of monocyte-derived dendritic cells from Chinese rhesus macaques. Cell Mol. Immunol. 6, 159165 (2009).
  23. Ho, C-C. et al. Quantum dot 705, a cadmium-based nanoparticle, induces persistent inflammation and granuloma formation in the mouse lung. Nanotoxicology http://dx.doi.org/10.3109/17435390.2011.635814 (2011).
  24. Fitzpatrick, J. A. J. et al. Long-term persistence and spectral blue shifting of quantum dots in vivo. Nano Lett. 9, 27362741 (2009).
  25. Schipper, M. L. et al. Particle size, surface coating, and PEGylation influence the biodistribution of quantum dots in living mice. Small 5, 126134 (2009).
  26. Al-Jamal, W. T., Al-Jamal, K. T., Cakebread, A., Halket, J. M. & Kostarelos, K. Blood circulation and tissue biodistribution of lipid–quantum dot (L-QD) hybrid vesicles intravenously administered in mice. Bioconj. Chem. 20, 16961702 (2009).
  27. Yang, R. S. H. et al. Persistent tissue kinetics and redistribution of nanoparticles, quantum dot 705, in mice: ICP-MS quantitative assessment. Environ. Health Perspect. 115, 13391343 (2007).
  28. Larson, D. R. et al. Water-soluble quantum dots for multiphoton fluorescence imaging in vivo. Science 300, 14341436 (2003).
  29. Gao, X., Cui, Y., Levenson, R. M., Chung, L. W. K. & Nie, S. In vivo cancer targeting and imaging with semiconductor quantum dots. Nature Biotechnol. 22, 969976 (2004).
  30. Manna, L., Scher, E. C., Li, L-S. & Alivisatos, A. P. Epitaxial growth and photochemical annealing of graded CdS/ZnS shells on colloidal CdSe nanorods. J. Am. Chem. Soc. 124, 71367145 (2002).

Download references

Author information

  1. These authors contributed equally to this work

    • Ling Ye &
    • Ken-Tye Yong

Affiliations

  1. Institute of Gerontology and Geriatrics, Laboratory Animal Center, Chinese PLA General Hospital, Beijing 100853, PR China

    • Ling Ye,
    • Jianwei Liu,
    • Kai Wang,
    • Jing Liu,
    • Yaqian Liu &
    • Yazhuo Hu
  2. School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore

    • Ken-Tye Yong &
    • Rui Hu
  3. Institute for Lasers, Photonics and Biophotonics, University at Buffalo, The State University of New York, Buffalo, New York 14260-4200, USA

    • Ken-Tye Yong,
    • Indrajit Roy,
    • Rui Hu,
    • Jing Zhu,
    • Wing-Cheung Law,
    • Mark T. Swihart &
    • Paras N. Prasad
  4. ChangChun University of Science and Technology (CUST), ChangChun, Jilin, 130022, PR China

    • Liwei Liu,
    • Hongxing Cai &
    • Xihe Zhang

Contributions

K.T.Y. and L.Y. designed the research. K.T.Y, L.Y., R.H., L.L., J.Z., I.R. W.C.L., J.L., K.W., J.L., Y.L. and Y.H. performed the research. L.Y., K.T.Y., L.L., I.R., R.H., J.Z., H.C., W.C.L., J.L., K.W., J.L., Y.L., Y.H., X.Z., M.T.S. and P.N.P. analysed the data. K.T.Y., L.Y., I.R., M.T.S. and P.N.P. co-wrote the paper.

Competing financial interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to:

Author details

Supplementary information

PDF files

  1. Supplementary information (20.7 MB)

    Supplementary information

Additional data