ChBE Seminar Series: Wei Li, Texas Tech
Biodegradable multilayered nanofilms for cell isolation and recovery
Abstract: Selective isolation and purification of circulating tumor cells (CTCs) from whole blood is an important capability for both clinical medicine and biological research. Current techniques to perform this task place the isolated cells under excessive stresses that reduce cell viability, and potentially induce phenotype change, therefore losing valuable information about the isolated cells. The goal of our work is to effectively isolate as well as non-inversely recover cancer cells using a microfluidic device coated with a biodegradable multilayered nanofilm. To this end, we have applied layer-by-layer (LbL) assembly to create a library of ultrathin coatings using a broad range of materials through complementary interactions. We systematically studied the effect of various flow conditions and channel geometries on the thickness and surface roughness of the resulting films. We also investigated the biocompatibility and degradation behaviors of a series of enzymatically-degradable films made from naturally derived polymers. By developing an LbL nano-film coating with an affinity-based cell-capture surface that is capable of selectively isolating cancer cells from whole blood, and that can be rapidly degraded on command, we are able to gently isolate cancer cells and recover them without compromising cell viability or proliferative potential. Our approach has the capability to overcome practical hurdles and provide viable cancer cells for downstream analyses.
Bio: Wei Li is an assistant professor in the Chemical Engineering department at Texas Tech University. He obtained his Ph.D. in Polymer Chemistry and Materials at the University of Toronto in 2010. His doctoral thesis focused on the development of droplet-based microfluidic systems for complex reactions and processes. Following his graduate studies, he received a Natural Sciences and Engineering Research Council of Canada (NSERC) Postdoctoral Fellowship to work at MIT. His work at MIT involved biomimetic 3D cell culture of pancreatic beta cells and layer-by-layer nanofilms for controlled released of anticancer drugs. Dr. Li’s research at Texas Tech is combine microfluidics and nanoassembly techniques to develop novel biofunctional polymer surfaces and microdevices for biological applications. He group is currently working on 3D cell microenvironments, interactions between cells and surfaces, capture and release of rare cancer cells from blood, bio-imaging sensors, and cancer drug screening. He was recently awarded two “High Risk/High Impact” grants from the Cancer Prevention and Research Institute Texas (CPRIT) to develop 1) a marker-free approach for the identification of circulating tumor cells, and 2) a microchip comprising multiple cascading modules for the investigation of the mechanism of cellular drug-exclusion.