Gold nanoparticles (AuNPs) are extensively used as cancer treatments, drug delivery agents, therapeutics, biochemical sensors, and imaging. Since we are commonly exposed to AuNPs, it is integral that we study how they impact the cytotoxicity of our bodies. Past research has shown that AuNPs can increase the cytotoxicity of human cell lines, but there is no research on how AuNPs impact sex-specific cell lines. It is known that our biology differs based on sex, yet this is never accounted for when conducting cytotoxicity research. To safely use AuNPs in biological applications, it is imperative to understand if they affect male and female cells the same way. For this project, we synthesized a library of AuNPs in various shapes and surface coatings and characterized them using UV-Vis, Zeta Potential, and Transmission Electron Microscopy (TEM), to measure their aggregation, and surface charge, and size. We found that acute exposure (24 hrs) of gold nanospheres (AuNSs) to male human lung fibroblasts (MRC-5 cells) seems to decrease cell viability as their concentration increases. However, these results are not statistically significant and require further trials. Due to time constraints, we were unable to conduct cell viability assays using the entirety of the AuNP library. We also did not receive the female human lung fibroblasts to compare cell viability. In future work, we will continue cell viability assays for both cell lines and begin cellular uptake studies.