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Nontoxic Carbon Dots Potently Inhibit Human Insulin Fibrillation
Chemistry of Materials
  • Shanghao Li, University of Miami
  • Lingyu Wang, University of Miami
  • Charles C. Chusuei, Middle Tennessee State University
  • Valentina M. Suarez, University of Miami
  • Patricia Blackwelder, Nova Southeastern University
  • Miodrag Micic, Cerritos College; MP Biomedicals LLC
  • Jhony Orbulescu, MP Biomedicals LLC
  • Roger M. Leblanc, University of Miami
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One prevention and therapeutic strategy for diseases associated with peptide or protein fibrillation is to inhibit or delay the fibrillation process. Carbon dots (C–Dots) have recently emerged as benign nanoparticles to replace toxic quantum dots and have attracted great attention because of their unique optical properties and potential applications in biological systems. However, the effect of C-Dots on peptide or protein fibrillation has not been explored. In this in vitro study, human insulin was selected as a model to investigate the effect of C-Dots on insulin fibrillation. Water-soluble fluorescent C-Dots with sizes less than 6 nm were prepared from carbon powder and characterized by UV–vis spectroscopy, fluorescence, Fourier transform infrared spectrophotometry, X-ray photoelectron spectrometry, transmission electron microscopy, and atomic force microscopy. These C-Dotswere able to efficiently inhibit insulin fibrillation in a concentration-dependent manner. Theinhibiting effect of C-Dots was even observed at 0.2 μg/mL. Importantly, 40 μg/mL of C-Dots prevent 0.2 mg/mL of human insulin from fibrillation for 5 days under 65 °C, whereas insulin denatures in 3 h under the same conditions without C-Dots. The inhibiting effect is likely due to the interaction between C-Dots and insulin species before elongation. Cytotoxicity study shows that these C-Dots have very low cytotoxicity. Therefore, these C-Dots have the potential to inhibit insulin fibrillation in biological systems and in the pharmaceutical industry for the processing and formulation of insulin.

©2015 American Chemical Society

Citation Information
Shanghao Li, Lingyu Wang, Charles C. Chusuei, Valentina M. Suarez, et al.. "Nontoxic Carbon Dots Potently Inhibit Human Insulin Fibrillation" Chemistry of Materials Vol. 27 Iss. 5 (2015) p. 1764 - 1771 ISSN: 0897-4756
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