Understanding Charged Polymers to Enable Advanced Adhesives and Drug Delivery
UC Santa Barbara’s Professor Omar Saleh has received a $441,000 NSF grant to study complex coacervates—charged polymer mixtures that form microscopic droplets. His research focuses on biopolymer systems like hyaluronic acid and RNA and uses advanced nanoscale magnetic tweezer measurements to explore polymer conformations and interactions. The insights aim to enable applications such as drug delivery and adhesives.
Omar Saleh, chair of the Materials Department at UC Santa Barbara, is leading research funded by a three-year, $441,000 grant from the National Science Foundation to investigate complex coacervates—mixtures of oppositely charged polymers that form microgel droplets with unique properties. These polymers, including biological types like hyaluronic acid and RNA, behave like tangled soft noodles and coacervate to create sticky, semi-liquid structures that could potentially deliver drugs or serve as surgical glues. Saleh’s team employs a sophisticated custom-built instrument known as magnetic tweezers, capable of applying tiny, precise stretching forces and measuring polymer extensions with nanometer accuracy. This allows detailed observation of polymer conformational changes and interactions in real time, which is crucial because these soft polymer droplets lack the crystalline structure needed for traditional analysis techniques. The research combines experimental work with simulations from Sandia National Laboratories expert Mark Stevens to interpret the experimental geometry and results. Saleh emphasizes that this foundational science, while not immediately targeting specific products, will foster a better understanding of polymer phase behavior influenced by factors such as ionic strength, temperature, and polymer architecture. Beyond advancing material science, the project provides significant training opportunities for graduate students, enhancing their quantitative measurement skills relevant across scientific fields. Ultimately, this work aims to establish a new physical framework for tension-modulated complex coacervation, unlocking innovative applications in medicine and technology.
