Chemical Engineering News

Tag: Spring 2012

Apr 13: Dr. Surya K. Mallapragada – Grain Processing Seminar Series in Chemical Engineering

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Friday, April 13, 10:00 a.m.
Chem. Sci. & Engineering, Room 102
Dr. Surya K. Mallapragada, Stanley Professor and Chair
Department of Chemical and Biological Engineering, Iowa State University

Refreshments will be served prior to the lecture

Topic: Self-assembling block copolymers for gene delivery and biomineralization

We have synthesized a family of novel self-assembling pH and temperature sensitive multiblock cationic and anionic copolymers with a variety of nanoarchitectures. The copolymers exhibit pH sensitivity and thermo-reversible gelation at physiological temperatures. The cationic multiblock copolymers exhibit complexation with DNA and serve as excellent gene therapy vectors for cancer therapies. Our studies have shown that these polymeric vectors show sustained gene delivery and selective transfection in cancer cells versus non-cancer cells. Detailed mechanistic studies have shown that the selectivity arises due to intracellular differences in pH be-tween cancer and normal cells. The anionic multiblock copolymers and their micelles also serve as excellent templates for biomineralization. These hierarchically self-assembling copolymers in conjunction with mineralization proteins/peptides, form bioinspired self-assembled nanocomposites. These novel injectable insitu-forming nanocomposites show mechanical properties similar to that of native cartilage, and are being investigated for cartilage rescue to prevent post-traumatic osteoarthritis.

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Dr. Bruce Lee: Mussel-Inspired Adhesives and Coatings

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Chemical Engineering Grain Processing Corporation 2011-12 Lecture Series:
Friday, February 24, 2012; 10:00 a.m. Chem. Sci. & Engineering Room 102;
Dr. Bruce P. Lee, Michigan Tech Department of Biomedical Engineering; Title: “Mussel-Inspired Adhesives and Coatings”

Abstract: Mussel-Inspired Adhesives and Coatings

Bioadhesives have a wide range of important applications in the biomedical field.  Tissue adhesives simplify complex surgical procedures to achieve effective wound closure and surgical repair. Despite these important functions, currently available adhesives seldom meet the basic requirements for because of possible disease transmission, poor adhesive quality, or toxicity concerns. Thus, there is an ongoing need for the development of tissue adhesives with improved characteristics. Nature provides many outstanding examples of adhesive strategies from which chemists and materials scientists can draw inspiration in their pursuit of new biomaterials. Of particular interest is the mussel adhesive protein (MAP) secreted by marine mussels. MAP is initially secreted as a proteinaceous fluid, and then subsequently harden which allow mussels to bind tenaciously to various types of surfaces underwater. One of the unique structural features of MAP is the presence of L-3,4-dihydroxyphenylalanine (DOPA), an amino acid post-translationally modified from tyrosine, which is believed to fulfill the dual role as the adhesive moiety and the crosslinking precursor. My research had focused on the incorporation of DOPA and its derivatives in creating synthetic mimics of MAPs for various medical applications. In this seminar, I will discuss the design and application of these biomimetic adhesive materials.

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Dr. Cornelius F. Ivory, Paul M. Hohenschuh Distinguished Professor – Grain Processing Seminar Series in Chemical Engineering

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Friday, March 23, 2:00 p.m.
Chemical Sciences & Engineering 211

Dr. Cornelius F. Ivory, Paul M. Hohenschuh Distinguished Professor
Gene and Linda Voiland School of Chemical Engineering and Bioengineering
Washington State University

Concentration and isolation of low-abundance proteins from serum using microchip isotachophoresis

Isotachophoresis (ITP) is used to isolate very low-abundance basic proteins from the high-abundance proteins in serum and then concentrate them about 20,000-fold. This is done using a PMMA microchip which contains a reducing union that decreases the channel’s cross-sectional area by a factor of 100. Proteins migrating in ITP “peak” mode will concentrate 200-fold in the approach channel, and then will concentrate another 100-fold as they pass through the reducing union.

This paper reports both the experimental application of ITP under basic,acidic and neutral conditions as well as the 3D numerical simulation of ITP in this type of chip. In particular, several challenges had to be met in each different ITP system including formation of carbonate ion at alkaline pH and the adsorption or precipitation of serum proteins at low pH.

Refreshments will be served

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