Author ORCID Identifier

https://orcid.org/0009-0009-6736-2595

Date Available

12-19-2027

Year of Publication

2025

Document Type

Master's Thesis

Degree Name

Master of Science in Aerospace Engineering (MSAeroE)

College

Engineering

Department/School/Program

Mechanical Engineering

Faculty

Martha E. Grady

Faculty

Jonathan Wenk

Abstract

Bacterial biofilms are a community of bacteria encased in extracellular polymeric substances (EPS) which make eradication more difficult. This advantage makes biofilms a unique clinical threat on Earth. In space, biofilms also pose a threat to astronauts through potential biofilm-associated infections and equipment compromise. To evaluate the role of microgravity in biofilm structure, Streptococcus mutans, an opportunistic oral pathogen, was cultured under simulated microgravity conditions using a custom 2D clinostat. Single particle tracking (SPT) of PEGylated quantum dots (QDs) inside the biofilms post growth was utilized to quantitatively measure potential changes to diffusivity and particle confinement. Particle choice was made after a nanoparticle characterization study of particle size, shape, and zeta potential, and tracking of the QDs in a glycerol-water solution confirmed the QD hydrodynamic diameter. SPT metrics were also used to investigate the role of the growth substrate on biofilms cultured on physiologically and industrially relevant titanium and stainless-steel surfaces.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2025.620

Funding Information

This material is based upon work supported by:

  • National Science Foundation CAREER Award Grant No. 2045853 in 2021
  • National Science Foundation Graduate Research Fellowship Award No. 2239063 in 2024
  • National Institutes of Health NIDCR funding (R01DE034438) in 2025

Available for download on Sunday, December 19, 2027

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