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Abnormal scar identification with spherical-nucleic-acid technology

Nature Biomedical Engineeringvolume 2pages227238 (2018) | Download Citation


The accurate diagnosis of scar type and severity relies on histopathology of biopsied tissue, which is invasive and time-consuming, causes discomfort and may exacerbate scarring. Here, we show that imaging nanoprobes for the live-cell detection of intracellular messenger RNA (mRNA) (also known as NanoFlares) enable measurements of the expression of connective tissue growth factor (CTGF) as a visual indicator of hypertrophic scars and keloids. During cell culture, NanoFlares enabled the distinction of hypertrophic and keloidal fibroblasts from normal fibroblasts, and the detection of changes in CTGF expression resulting from the regulatory effects of transforming growth factor-β (TGF-β) agonists and TGF-β antagonists. We also applied the NanoFlares topically to the skin of live mice and rabbits, and to ex vivo human skin models. Transepidermal penetration of the NanoFlares enabled the visual and spectroscopic quantification of underlying abnormal fibroblasts on the basis of CTGF mRNA expression. Our proof-of-concept studies of topically applied NanoFlare technology as a means of biopsy-free scar diagnosis may eventually inform therapeutic decisions on the basis of the mRNA-expression patterns of skin disorders.

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This work was supported by the NTU-Northwestern Institute for Nanomedicine. We thank G. Yu (current location: Nanjing University of Posts and Telecommunications, China) for assistance with animal handling.

Author information


  1. School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore

    • David C. Yeo
    • , Christian Wiraja
    •  & Chenjie Xu
  2. NTU-Northwestern Institute for Nanomedicine, Nanyang Technological University, Singapore, Singapore

    • Amy S. Paller
    • , Chad A. Mirkin
    •  & Chenjie Xu
  3. Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA

    • Amy S. Paller
  4. Department of Chemistry, Northwestern University, Evanston, IL, USA

    • Chad A. Mirkin
  5. International Institute for Nanotechnology, Northwestern University, Evanston, IL, USA

    • Chad A. Mirkin


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C.A.M., A.S.P., C.X. and D.C.Y. conceived and designed the experiments. D.C.Y. and C.W. performed the experiments. D.C.Y., C.W. and C.X. analysed and interpreted the data. D.C.Y., C.X., A.S.P. and C.A.M. wrote the manuscript. All authors read and approved the final manuscript.

Competing interests

A patent application based on the reported data has been filed. C.A.M. is a cofounder of Aurasense (the company that co-developed and licensed the NanoFlare technology to Merck–Millipore, which produced over 1,600 commercial versions of NanoFlares sold under the trade name SmartFlares).

Corresponding authors

Correspondence to Amy S. Paller or Chad A. Mirkin or Chenjie Xu.

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