Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

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


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.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Characterization of phospholipid micelle-encapsulated CdSe/CdS/ZnS quantum dot formulation.
Figure 2: Blood test results for treated rhesus macaques.
Figure 3: ICP-MS analysis of the major organs of treated (n = 3) and control (n = 1) rhesus macaques.
Figure 4: Histological images from the major organs of the rhesus macaques three months after intravenous injection of the QD formulation.


  1. Medintz, I. L., Uyeda, H. T., Goldman, E. R. & Mattoussi, H. Quantum dot bioconjugates for imaging, labelling and sensing. Nature Mater. 4, 435–446 (2005).

    CAS  Article  Google Scholar 

  2. Yong, K-T. Mn-doped near-infrared quantum dots as multimodal targeted probes for pancreatic cancer imaging. Nanotechnology 20, 015102 (2009).

    Article  Google Scholar 

  3. Michalet, X. et al. Quantum dots for live cells, in vivo imaging, and diagnostics. Science 307, 538–544 (2005).

    CAS  Article  Google Scholar 

  4. Bruchez, M., Moronne, M., Gin, P., Weiss, S. & Alivisatos, A. P. Semiconductor nanocrystals as fluorescent biological labels. Science 281, 2013–2016 (1998).

    CAS  Article  Google Scholar 

  5. Chan, W. C. W. & Nie, S. Quantum dot bioconjugates for ultrasensitive nonisotopic detection. Science 281, 2016–2018 (1998).

    CAS  Article  Google Scholar 

  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, 138–166 (2012).

    CAS  Article  Google Scholar 

  7. Derfus, A. M., Chan, W. C. W. & Bhatia, S. N. Probing the cytotoxicity of semiconductor quantum dots. Nano Lett. 4, 11–18 (2004).

    CAS  Article  Google Scholar 

  8. Choi, H. S. et al. Tissue- and organ-selective biodistribution of NIR fluorescent quantum dots. Nano Lett. 9, 2354–2359 (2009).

    CAS  Article  Google Scholar 

  9. Cho, S. J. et al. Long-term exposure to CdTe quantum dots causes functional impairments in live cells. Langmuir 23, 1974–1980 (2007).

    CAS  Article  Google Scholar 

  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, 1997–2004 (2009).

    CAS  Article  Google Scholar 

  11. Hauck, T. S., Anderson, R. E., Fischer, H. C., Newbigging, S. & Chan, W. C. W. In vivo quantum-dot toxicity assessment. Small 6, 138–144 (2010).

    CAS  Article  Google Scholar 

  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, 79–86 (2004).

    CAS  Article  Google Scholar 

  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, 1299–1305 (2006).

    CAS  Article  Google Scholar 

  14. Dubertret, B. et al. In vivo imaging of quantum dots encapsulated in phospholipid micelles. Science 298, 1759–1762 (2002).

    CAS  Article  Google Scholar 

  15. Colvin, V. L. The potential environmental impact of engineered nanomaterials. Nature Biotechnol. 21, 1166–1170 (2003).

    CAS  Article  Google Scholar 

  16. Werlin, R. et al. Biomagnification of cadmium selenide quantum dots in a simple experimental microbial food chain. Nature Nanotech. 6, 65–71 (2011).

    CAS  Article  Google Scholar 

  17. Hardman, R. A toxicologic review of quantum dots: toxicity depends on physicochemical and environmental factors. Environ. Health Perspect. 114, 165–172 (2006).

    Article  Google Scholar 

  18. Choi, H. S. et al. Renal clearance of quantum dots. Nature Biotechnol. 25, 1165–1170 (2007).

    CAS  Article  Google Scholar 

  19. Hoshino, A. et al. Physicochemical properties and cellular toxicity of nanocrystal quantum dots depend on their surface modification. Nano Lett. 4, 2163–2169 (2004).

    CAS  Article  Google Scholar 

  20. Kirchner, C. et al. Cytotoxicity of colloidal CdSe and CdSe/ZnS nanoparticles. Nano Lett. 5, 331–338 (2005).

    CAS  Article  Google Scholar 

  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, 433–440 (2009).

    Article  Google Scholar 

  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, 159–165 (2009).

    Article  Google Scholar 

  23. Ho, C-C. et al. Quantum dot 705, a cadmium-based nanoparticle, induces persistent inflammation and granuloma formation in the mouse lung. Nanotoxicology (2011).

  24. Fitzpatrick, J. A. J. et al. Long-term persistence and spectral blue shifting of quantum dots in vivo. Nano Lett. 9, 2736–2741 (2009).

    CAS  Article  Google Scholar 

  25. Schipper, M. L. et al. Particle size, surface coating, and PEGylation influence the biodistribution of quantum dots in living mice. Small 5, 126–134 (2009).

    CAS  Article  Google Scholar 

  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, 1696–1702 (2009).

    CAS  Article  Google Scholar 

  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, 1339–1343 (2007).

    CAS  Article  Google Scholar 

  28. Larson, D. R. et al. Water-soluble quantum dots for multiphoton fluorescence imaging in vivo. Science 300, 1434–1436 (2003).

    CAS  Article  Google Scholar 

  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, 969–976 (2004).

    CAS  Article  Google Scholar 

  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, 7136–7145 (2002).

    CAS  Article  Google Scholar 

Download references


This work was supported by The John R. Oishei Foundation, Air Force Office of Scientific Research (grant no. FA95500610398), the Singapore Ministry of Education (Grants Tier 2 MOE2010-T2-2-010 (M4020020.040 ARC2/11) and Tier 1 M4010360.040 RG29/10), Nanyang Technological University (start-up grant no. M4080141.040), the Beijing Natural Science Foundation (no. 7092097) and the National Natural Science Foundation of China (no. 21071150). The authors thank A. Maitra of Johns Hopkins University for helpful discussions.

Author information

Authors and Affiliations



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.

Corresponding authors

Correspondence to Ling Ye, Ken-Tye Yong or Paras N. Prasad.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 21264 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ye, L., Yong, KT., Liu, L. et al. A pilot study in non-human primates shows no adverse response to intravenous injection of quantum dots. Nature Nanotech 7, 453–458 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research