Adam Blake Dunaway

Date: Thursday Nov 20, 2014
Time: 1:30-3:30pm
Location:  MoSE 2100F


Advisor:
Valeria T. Milam, PhD
School of Materials Science and Engineering
Georgia Institute of Technology, GA

Committee:
Johnna S. Temenoff, PhD
Department of Biomedical Engineering 
Georgia Institute of Technology, GA

Meisha Shorner, PhD
School of Materials Science and Engineering
Georgia Institute of Technology, GA
 
Characterization of the Binding Activity of Immobilized DNA Aptamers for
Nucleotide and Non-nucleotide Targets

Deoxyribonucleic acid (DNA) aptamers are oligonucleotides with high
specificity and affinity for non-nucleotide targets ranging from molecular
species to cellular proteins. Their high affinity, rapid synthesis, and
the ease with which they can be chemically modified to include convenient
chemical groups (e.g. amine group on 5' end) make them excellent adaptable
ligands for use in colloidal drug delivery vehicles for both uptake and
release of therapeutic agents. This work uses pre-identified aptamers for
vascular endothelial growth factor (VEGF) to investigate the design of one
such vehicle for controlled uptake and release of target therapeutics and
analyzes the ability of particle-immobilized aptamers to bind both
nucleotide and non-nucleotide targets. Aptamer sequences are immobilized
on colloidal microspheres and binding activity of both the primary DNA and
protein targets are directly monitored using flow cytometry. Additionally,
the dual nature of aptamer-target binding is further investigated by
evaluating the effects of simultaneous and serial incubation of the
primary targets. Finally, the ability to recover the functionality of the
aptamer is evaluated after displacement of the primary DNA target through
DNA mediated interactions.  It has been shown that the nature of
aptamer-target interactions are complex in nature, requiring optimization
for each species incorporated into a delivery vehicle; however, partial
recovery of aptamer functionality was achieved after hybridization with
the primary DNA target.