Term of Award
Fall 2025
Degree Name
Master of Science in Biology (M.S.)
Document Type and Release Option
Thesis (open access)
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution 4.0 License.
Department
Department of Biology
Committee Chair
Robert Mans
Committee Member 1
Sara Gremillion
Committee Member 2
Anthony Siccardi
Abstract
Plastic is a ubiquitous material used in many domestic and commercial applications. Widespread use of plastic has led to environmental accumulation of plastic waste, and microplastics have inundated human food and water sources. Once consumed, it is well established that microplastics translocate from the gut to other tissues, including the brain, via the circulatory system. However, it is unknown if nanoplastics persist permanently in the brain. Additionally, it is not known if microplastics can be enzymatically degraded by phagocytic cells in the CNS, such as microglia and astrocytes. Alkane monooxygenase-homolog 7 (Alkbh7) is a mitochondrial enzyme that may be capable of degrading the chemical bonds in polystyrene (PS). We hypothesized that full clearance of nanoplastics from the brain may be possible and that feeding zebrafish a PS-infused diet would lead to increased expression of Alkbh7 in the brain as part of an endogenous clearance response. To begin evaluating these predictions, we developed a novel high-throughput method for making PS-infused zebrafish food. We concluded that the brain exhibits some ability to clear nanoplastic particles after exposure, but full disposal was not observed in the time-course tested. Expression of target gene Alkbh7 was measured using reverse transcription quantitative polymerase chain reaction (RT-qPCR). RT-qPCR results suggested for the first time that Alkbh7 is expressed in the brain of adult zebrafish. Additionally, Alkbh7 expression increased in the brain after a 14-day exposure to PS-infused food.
Recommended Citation
Mauersberg, Callie C., "Disposal of Nanoplastics by the Brain: Plastic Persistence and Upregulation of a Putative Plastic-Degrading Enzyme After Exposure to Polystyrene-Infused Food" (2025). College of Graduate Studies: Theses & Dissertations. 3058.
https://digitalcommons.georgiasouthern.edu/etd/3058
Research Data and Supplementary Material
No
