For my capstone project, I investigated the preparation and characterization of multi-responsive microgels designed for controlled drug release. The main objective was to create a biocompatible, intelligent drug delivery system that could respond to environmental stimuli—specifically temperature and pH changes—to release therapeutics precisely at diseased sites while minimizing off-target effects.
Using oligo (ethylene glycol)-based polymers, I synthesized microgels crosslinked with dynamic boronate ester bonds. These microgels shrank in response to increased temperature and swelled in acidic environments, which simulated conditions like inflammation or tumors. The results demonstrated that drug release could be finely tuned by adjusting environmental conditions and crosslinker density, confirming the potential of these systems for targeted therapeutic delivery across a broad range of diseases.
I initially identified this research area by reading literature about smart biomaterials and their applications in personalized medicine. My primary motivation came from a desire to bridge materials science with healthcare innovation. Having seen firsthand, through volunteering in hospitals, how systemic side effects from cancer treatments affect patients, I became interested in how drug delivery could be made safer and more localized.
At the start, I expected the capstone to mostly involve straightforward lab work: synthesizing polymers, testing drug release, and gathering data. In reality, it was much more iterative and creative. Designing the polymer system required frequent adjustments, from tweaking monomer ratios to troubleshooting purification methods. It wasn't just about following a recipe — it was about understanding the behavior of materials and learning to adapt.
One major challenge was mastering the synthesis conditions. Small variations in temperature, stirring rates, or initiator concentrations drastically affected the size and uniformity of the microgels. Another challenge was learning to interpret dynamic light scattering data; the patterns were sometimes noisy and required careful calibration. On the easier side, preparing buffer solutions and conducting fluorescence measurements for drug loading were relatively straightforward tasks, as these were familiar techniques from previous coursework. A surprising aspect was how sensitive the microgels were to minor pH changes; even slight variations outside of expected ranges caused significant differences in swelling and drug release, underscoring how critical precise control is for real-world applications.
If I were to continue this research, I would explore integrating a third stimulus-responsiveness, such as redox-sensitivity, to make the system even more specific to cellular micro-environments. Redox-responsive bonds could trigger drug release inside cells that have high glutathione concentrations, such as tumor cells, adding another layer of precision. I would also test the microgels in more biologically relevant conditions, like serum-containing media, to understand how proteins might affect their behavior.
What I am taking away from this experience is the realization that research is both meticulous and imaginative. Success doesn't come just from technical skill—it comes from asking the right questions, designing clever experiments, and embracing setbacks as opportunities to learn. Working independently also built my confidence in experimental design and critical analysis. Finally, I developed a deeper appreciation for interdisciplinary research, as this project combined polymer chemistry, biomedical engineering, and pharmaceutical sciences. These lessons will stay with me as I pursue future opportunities in biomedical innovation.