Atomic Force Microscopic and electrochemical study of polymeric microgels as a prototype for temperature-sensitive drug-releasing carriers
Crosslinked hydroxypropylcellulose (HPC) form unique microgel particles that display reversible temperature-driven volume change with a critical temperature (Tc) right around values of human fever (~39oC). Heating these microgel particles above Tc results in volume contraction upon internal hydrophobic collapse and expulsion of water. HPC is FDA-approved and thus represents a perfect candidate for a drug-releasing carrier in response to systemic temperature change. This summer undergraduate subproject is one part of a cross-disciplinary project between labs of Dr. Bayachou (Chemistry) and Dr. Streletzky (Physics). The overall project uses a combination of light scattering (Streletzky Lab), and atomic force microscopy (AFM) and electrochemistry (Bayachou lab) to study temperature-driven shape changes and uptake/release of therapeutic agents by HPC microgels. In this part of the project, we will present results of investigations by AFM imaging of various HPC microgel particles both in air and in liquid suspensions. Volume contraction of HPC particles as triggered by temperature increases on the AFM stage provides us with the opportunity to monitor particle size changes as a function of temperature. Detailed analysis of shapes and cross-section of features observed by AFM (Bayachou Lab) will be compared and contrasted with independent measurements by dynamic light scattering studies (Streletzky Lab).
Mino, Janna; Flaherty, Justin; Koneru, Pratheek; and Streletzky, Kiril A. Ph.D., "Atomic Force Microscopic and electrochemical study of polymeric microgels as a prototype for temperature-sensitive drug-releasing carriers" (2013). Undergraduate Research Posters 2013. 26.