Chemical Engineering
 

Shaoyi Jiang
Professor of Chemical Engineering
Adjunct Professor of Bioengineering

 

Contact Information

243 Benson
Box 351750
Seattle, WA 98195-1750		 Phone: 206-616-6509
Fax: 206-685-3451 or 206-543-3778
E-mail: sjiang@u.washington.edu

Education

Ph.D., Cornell University, 1993.
Postdoctoral Fellow, University of California (Berkeley), 1993-1994.
Research Fellow, California Institute of Technology, 1994-1996.

For more information, please see the Jiang Group Home Page.

Research Interests

Molecular Design of Superlow Biofouling Materials: From Molecular Modeling to Product Development

Materials and surfaces will face the undesirable accumulation of various organisms when they are in contact with biological media. While uncontrolled biological encapsulation seriously degrades the performance of many implanted devices, biofouling on ships reduces their speed and maneuverability and increases fuel and maintenance costs. The objective of this work is to develop biocompatible or environmentally benign superlow biofouling materials, particularly zwitterionic or mixed charge compounds.

Molecular simulations provide insights into molecular-level nonfouling mechanisms. Based on the mechanisms, new zwitterions are designed, synthesized, and characterized for their chemical, structural, mechanical, and biological properties. Various approaches to apply these zwitterionic materials onto surfaces have been explored while surface analysis techniques are routinely used to characterize these surfaces. For biomedical applications, these new materials exhibit their unique properties as drug/gene delivery carriers, implanted materials, protein arrays, and antimicrobial agents. For marine applications, long-lasting marine coatings are being developed based on these new materials. The uniqueness of our work is in integrating molecular simulations, material synthesis/characterization, biological studies, and product development for the rational design of superlow biofouling materials and surfaces to meet specific requirements for a given application.

 

Molecular Engineering of Surfaces for Sensing and Detection

Surface plasmon resonance (SPR) sensors provide fast, real-time, sensitive, quantitative, specific and label-free detections in small sample volumes. Surface chemistry for the immobilization of biomolecular recognition elements is the key to the success of a sensor. The major challenges in sensing and detection are the ability of a sensor to (a) achieve the low detection limit for a relevant application (i.e., high sensitivity), (b) avoid false alarms, particularly for the detection in complex media (i.e., high specificity), and (c) detect multiple analytes simulateneously (i.e., arrayed capacity). The objective of this work is to develop surface chemistries, which will address these challenges.

We have developed two approaches to convert DNA arrays into protein arrays, which resolve several key issues encountered in current protein array technologies, particularly chip stability and storage. Furthermore, we are developing zwitterionic-based protein arrays to achieve a high signal-to-noise ratio for detection in complex media. These new surface chemistries will be integrated into our multi-channel SPR sensors and SPR imaging system. Two focused applications are food safety monitoring in collaboration with researchers from U.S. FDA and early cancer diagnostics in collaboration with researchers from the Fred Hutchinson Cancer Research Center in Seattle.

 

Molecular Control of Biomolecular Interfaces

For protein-surface interactions, we focus on the prediction, control and probing of protein orientation and conformation. We proposed a charge-driven protein orientation principle and demonstrated this principle using IgG1 and IgG2a. Molecular simulations were used to map out protein orientation under various conditions, while time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) and SPR were used to probe protein orientation. This principle was applied successfully to control orientations of several cell-binding proteins, including osteopontin (OPN) and fibronectin (FnIII7-10). In addition, we have also used an alternative approach to control protein orientation via specific protein-protein interactions, e.g., OPN/collagen I. Our recent in vivo studies indicate that the orientation of bound OPN indeed has an effect on the foreign body capsule thickness. For protein-protein interactions, we focus on the identification of protein-protein binding pairs using SPR and locations using AFM, particularly for proteins within the extracellular matrix (ECM). For cell-surface interactions, we focus on the control of angiogenesis. We have studied the differentiation of endothelial cells into capillary-like structures induced by patterned surfaces.

 

Selected Recent Publications:

Go to link Recent M.S. Theses
Go to link Recent Ph.D. Dissertations