Kaylee Drake Prepping a Mucin Sample for Pendant Drop
Author: Kaylee Drake | Major: Chemical Engineering | Semester: Spring 2025
My name is Kaylee Drake, and I am wrapping up my junior year in the College of Engineering as an honors chemical engineering major. I had the opportunity to spend the past two semesters conducting research in Dr. Keisha Walters’s PolyNEL Research Lab. In the future, I plan to pursue medical school and continue my research career in biomaterials with an emphasis on tissue engineering for cleft lip and palate applications.
Mucus is an essential biopolymer that provides the human body with lubrication and protection from pathogens; however, mucus is one of the greatest challenges in non-invasive drug delivery. Acting as a selectively permeable barrier that prevents drug absorption, my research explores how the integration of silica nanoparticles into mucin can enhance drug transportation through its network by disrupting the mucin nanostructure. Porcine gastric mucin (PGM) is a biopolymer isolated from the stomach lining of a pig and is similar to the native mucus in humans, making it an ideal model for predicting drug delivery and will be used in this study. By modifying the mucin structure without harming its protective function, there are opportunities to advance mucoadhesive drug delivery for therapeutic treatment of respiratory diseases like asthma and COPD to improve dug concentration in the lungs.
During my first semester of my junior year, I had the opportunity to perform research in the chemical engineering department under my advisor, Dr. Keisha Walters. Having always been interested in nanoscale biomaterials, the PolyNEL lab was aligned with my research interests of material science and potential biomedical applications. With the guidance of my graduate student, David Chem, I developed a research project that involved the synthesis of silica nanoparticles (SiNPs) and subsequent surface modification to incorporate into PGM to identify structural changes in the mucin nanostructure. Together, Dr. Walters and David Chem’s effort made me feel supported and welcome in the world of research.
My project began with the synthesis of silica nanoparticles using the Stober process which created uniform particles. To ensure proper synthesis, the particles underwent characterization techniques like FTIR, DLS, and SEM. Once the structure was confirmed, the SiNPs were functionalized with (3-aminopropyl) triethoxysilane (APTES) which grafted amine groups onto the surface of the particle. The addition of APTES enhanced the SiNPs interaction with mucin by increasing particle hydrophilicity and wettability to improve dispersion in aqueous solutions. Proper modification was determined using FTIR to confirm the presence of amine groups, DLS to demonstrate an increase in particle size and a net positive surface charge, SEM to reveal smoother dispersion, and TGA to demonstrate the loss of an amine group in the APTES-modified SiNPs. After synthesis and subsequent functionalization, the bare and APTES-modified SiNPs were incorporated into a mucin solution at varying concentrations to observe how particle loads would influence the mucin nanostructure. The initial trials showed no significant effect on the mucin structure, indicating that the mucin was too dilute or that a higher particle concentration must be used to identify any noticeable impact. Plans to increase mucin solution concentration and incorporate a broader range of bare/APTES-modified SiNPs concentrations are in place. Additionally, future trials will explore the role of temperature and pH to mimic various body environments like the stomach and bloodstream. The varying conditions are crucial to identifying ideal particle-to-mucin interaction conditions where mucosal surfaces can differ drastically.
One of the greatest challenges throughout this experiment was functionalizing the SiNPs with APTES. Several trials were conducted using different solvents and temperature conditions, many of which yielded unsuccessful. Once realizing that exposure to oxygen caused the SiNPs to remain unreactive on the surface, modifications were made to limit exposure by suspending the particles in solutions and using anhydrous solvents. From this, I discovered that research is not only about patience and persistence, but also precision. After having to repeat the functionalization of the SiNPs several times before successful modification, I learned how important it is to troubleshoot and remain adaptable when experimentation does not go as planned.
Throughout the past year, the support from the Honors College Research Grant has enriched my engineering education. While my research is still in its early stages, I am beginning to lay the groundwork for a deeper understanding of how nanomaterials interact with biopolymers. My ability to synthesize, characterize, and functionalize nanoparticles exemplifies the invaluable skills that I have gained via my hands-on experience in research. Though I faced numerous challenges along the way, these obstacles encouraged me to think creatively and embrace the true nature of learning—trial and error. I prepared a research poster in collaboration with my lab partner, Riley Thayer, that was presented at the AIChE Mid-America Student Regional Conference. I intend to present additional findings at the Southeastern and Southwest Regional Meeting 2025 hosted by the American Chemical Society. Sharing my research with others has boosted my confidence and deepened my passion for scientific discovery. This grant has been a defining part of my academic journey, and I look forward to continuing my exploration in the world of research.