Presenter Information

Julianna Hughes BurchettFollow

Faculty Mentor

Steven Ripp

Department (e.g. History, Chemistry, Finance, etc.)

Microbiology

College (e.g. College of Engineering, College of Arts & Sciences, Haslam College of Business, etc.)

College of Arts and Sciences

Year

2016

Abstract

Cellulose nanocrystals (CNCs) are widely used in different industries including pharmaceutical and cosmetic production due to their adept physical and biological properties. Because CNCs are becoming a more prevalent material and have a high potential of being redistributed in the environment, it is important to understand their toxic potentials in biological systems, including organisms of various trophic levels. This study evaluated the cytotoxic effects of CNCs in the lower eukaryotic organism Saccharomyces cerevisiae and human embryonic kidney (HEK293) cells using autobioluminescent yeast and human cell reporters, respectively. The S. cerevisiae and HEK293 reporter cells were engineered to express a synthetic bacterial luciferase operon (luxCDABE) that self-generates all the required substrates for bioluminescent production. As a result, these reporter cells allow for continuous monitoring of the same cell population throughout the period of toxicant exposure, providing a facile means for tracking the temporal dynamics of toxic effects on living cells. When exposed to CNCs at concentrations ranging from 0.001 g/L to 1 g/L, both the yeast and human cells reported time and dose-dependent effects. Exposure to CNCs at 0.001 g/L and 1 g/L reduced bioluminescent output in S. cerevisiae by 5% and 10% compared to untreated control cells 8 hours post-treatment, respectively, and further decreased the signal by 25% and 70% 12 hours post-treatment, respectively. In HEK293 cells, treatment with CNCs at 1 g/L initialized a significant decrease (by 60%) in metabolic activity at 2 days post-treatment, and the bioluminescent output continued to decline to an undetectable level compared to untreated controls at 7 days post-treatment. CNCs at 0.001 g/L and 0.01 g/L did not result in significant changes in metabolic activity throughout the entire period of exposure. These results demonstrate the cytotoxic potential for elevated concentrations of CNCs in varying biological systems.

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Evaluating the Cytotoxic Effects of Cellulose Nanocrystals (CNCs) Using Autobioluminescent Yeast and Human Cells

Cellulose nanocrystals (CNCs) are widely used in different industries including pharmaceutical and cosmetic production due to their adept physical and biological properties. Because CNCs are becoming a more prevalent material and have a high potential of being redistributed in the environment, it is important to understand their toxic potentials in biological systems, including organisms of various trophic levels. This study evaluated the cytotoxic effects of CNCs in the lower eukaryotic organism Saccharomyces cerevisiae and human embryonic kidney (HEK293) cells using autobioluminescent yeast and human cell reporters, respectively. The S. cerevisiae and HEK293 reporter cells were engineered to express a synthetic bacterial luciferase operon (luxCDABE) that self-generates all the required substrates for bioluminescent production. As a result, these reporter cells allow for continuous monitoring of the same cell population throughout the period of toxicant exposure, providing a facile means for tracking the temporal dynamics of toxic effects on living cells. When exposed to CNCs at concentrations ranging from 0.001 g/L to 1 g/L, both the yeast and human cells reported time and dose-dependent effects. Exposure to CNCs at 0.001 g/L and 1 g/L reduced bioluminescent output in S. cerevisiae by 5% and 10% compared to untreated control cells 8 hours post-treatment, respectively, and further decreased the signal by 25% and 70% 12 hours post-treatment, respectively. In HEK293 cells, treatment with CNCs at 1 g/L initialized a significant decrease (by 60%) in metabolic activity at 2 days post-treatment, and the bioluminescent output continued to decline to an undetectable level compared to untreated controls at 7 days post-treatment. CNCs at 0.001 g/L and 0.01 g/L did not result in significant changes in metabolic activity throughout the entire period of exposure. These results demonstrate the cytotoxic potential for elevated concentrations of CNCs in varying biological systems.