Diamanika Moss - Southern University at New Orleans
Co-Author(s): April Harding, Pamela Marshall, Christian Clement, and Illya Tietzel, Southern University at New Orleans, New Orleans, LA
The worm Caenorhabditis elegans has been used to conduct many different types of basic research in various fields of study. C. elegans is a non-parasitic nematode and feeds primarily on bacteria. Recently, there has been cases where microbes have been found on many spacecraft. It has been thought of that nanoparticles can potentially destroy these microbes, but it is unknown if the nanoparticles themselves are harmful or toxic. This important research is to test the hypothesis whether or not nanoparticles intended for spacecraft are toxic using a C-elegans model. Non-toxic nanoparticles could reduce the percentage of microbes found on the spacecraft and the health of the astronauts would not be at risk.
Several procedures were used: C. elegans was grown on agar plates containing a nematode growth agar with Escherichia coli as a food source. Growth, size, and worm counts were analyzed using a microscope with a Motic camera attached, Image J software, and documented with Excel. Analysis of uptake of nanoparticles used fluorescent nanoparticles and amino (NH2) nanoparticles as a non-fluorescent control. Types of nanoparticles used were amino (NH2), carboxylate (COOH), sulfate (SO4), silver (Ag), and fluorescent nanoparticles. Water was used as a control since the nanoparticles were already mixed with water.
The results for the COOH, NH2, and S04 experiment showed that for day 1 amino started off with a size average of 0.31 (arbitrary area units) and a worm count of 89, however by day 8 the average size and worm count lowered to 0.24 and 22. When compared to the water control whose day 1 average started off at 0.23 and worm count at 49 and ended up with an average of 0.7 and lowered worm count of 38 by day 8. For the 10nm and 50nm Ag experiment, day 1 average sizes for water were 1.15 and 1.40, 10nm Ag was 1, and 50nm Ag was 1.03. By day 4, all average sizes ended up as 2.64 and 2.03 for water, 10nm was 2.16, and 50nm was 1.64. The average sizes of the C. elegans for COOH, NH2, and SO4 treatment showed inconclusive results when compared to the H20 control. However with the 10nm and 50nm Silver nanoparticles the average C. elegans sizes were smaller than worms treated with H2O. For the uptake experiment, fluorescent nanoparticles were ingested and even though size differences were observed, conclusions about toxicity can’t be made yet. In the future, experiments will include potassium dichromate as a positive control for toxicity and age synchronized worms.
Funder Acknowledgement(s): This research was supported by a grant from the NASA EPSCoR program with special thanks to Dr. Illya Tietzel. Additional funding originated from NASA CAN NNX13AR32 - subcontracts OSP-14-216821-00E and OSP-14216821-02E to I. Tietzel.
Faculty Advisor: Illya Tietzel,