NSF REU Site Renewal: Interfaces and Surfaces
Summer 2015
Faculty Advisor Project Submission
The role of surface nanolayer architecture on adsorptive membrane performance
Faculty Advisor: Prof. Scott Husson (Department of Chemical & Biomolecular Engineering)
Research Project: Market demand is increasing rapidly for biotherapeutics such as recombinant
proteins and monoclonal antibodies. With the advent of molecular biotechnology and engineered
cell lines, upstream production processes have made unprecedented progress in the last decade,
shifting the production burden to the downstream processing [1]. To improve process economics
and meet market demand, manufacturers will require higher productivity and higher resolution
separation techniques – membrane chromatography fulfills these requirements. The Husson
Research Group at Clemson has made tremendous advances in the development of adsorptive
membranes for this purpose. His lab developed a strategy that uses controlled graft
polymerization to coat the internal membrane pore surfaces with polymer nanolayers that
provide a large number of binding sites [2]. The nanolayers comprise a field of polymeric
‘tentacles’ with adsorptive functionality that extend into membrane pore volume, providing a
scaffold for protein molecules to adsorb. The strategy allows fine control over the nanolayer
structure to avoid pore blocking and hindered transport of large adsorptive compounds, such as
proteins. Work by his group has demonstrated many opportunities and advantages of controlled
graft polymerization for preparing membrane adsorbers and has dispelled two common
misperceptions by showing that (1) membrane chromatography can be a higher capacity process
than resin chromatography in the purification of biologics, and (2) membrane chromatography
can be a higher resolution process than resin chromatography in the purification of protein
therapeutics from cell lysate [3]. The work has provided a training ground for numerous PhD
students and undergraduate researchers, a number of whom have received national recognition
for their work.
REFERENCES
[1] D. Low, R. O’Leary, N. S. Pujar, Future of antibody purification. J. Chromatogr. B 848
(2007) 48-63.
[2] N. Singh, J. Wang, M. Ulbricht, S. R. Wickramasinghe, S. M. Husson, Surface- initiated
atom transfer radical polymerization: A new method for the preparation of polymeric membrane
adsorbers, J. Membr. Sci. 309 (2008) 64-72.
[3] B.V. Bhut, K.A. Christensen, S.M. Husson, Membrane chromatography: Protein purification
from E. Coli lysate using newly designed and commercial anion-exchange stationary phases. J.
Chromatogr. A 1217 (2010) 4946–4957.
Research Expectations for REU Participant: The REU student(s) in this project will conduct
protein binding measurements on multimodal polymer nanolayers using with in-situ
ellipsometry. The objective of the project is to understand how the structural properties of these
nanolayer coatings impact protein binding capacities and adsorption and desorption kinetics.
Knowledge generated in this work will be used by the Husson Research Group in the preparation
of state-of-the-art adsorptive membranes for purification of protein therapeutics. The student will
learn how to use ellipsometry to measure adsorption isotherms and determine thermodynamic
parameters that are needed to build a predictive model for protein breakthrough in a membrane
bed. Kinetic data also will be collected and used to establish the minimum residence time that
NSF REU Site Renewal: Interfaces and Surfaces
Summer 2015
Faculty Advisor Project Submission
can be used for flow through a membrane bed without suffering a decrease in dynamic capacity.
In addition to learning how to use and analyze data from state-of-the-art equipment, the
student(s) will receive high-quality mentoring from a PhD student and Dr. Husson.