Title: Combinatorial Synthesis of and Drug Delivery from Biodegradable Polyanhydrides
Speaker: Prof. Balaji Narsimhan, CBE, ISU
Abstract:
We have demonstrated that polycondensation reactions can be carried out in a combinatorial fashion and
that the polymer library can be screened at high throughput using a rapid prototyping technique to fabricate
multiwell substrates. A linearly varying compositional library of 100 different biodegradable polyanhydride
random copolymers that are promising carriers for controlled drug delivery was designed, fabricated, and
characterized by IR microscopy within a few hours. The polyanhydride copolymer library was based on
1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic anhydride (SA) and was characterized with infrared
microspectroscopy to determine the composition within each well. Since degradation and release rates depend
on copolymer composition, we also developed new high-throughput methods to investigate drug release
from this library of copolymers by designing specific wells for each task. A subset of this library was
chosen, and a substrate was designed and fabricated to enable the synthesis and monitoring of dye dissolution
from a range of polyanhydride copolymers in a parallel fashion using a CCD camera. Multisample substrates
were fabricated with a novel rapid prototyping method that consists of an organic solvent-resistant array of
10 X 10 microwells. The libraries were deposited with a custom-built liquid dispensing
system consisting of a series of computer-controlled volume-dispensing pumps and XYZ motion stages. The
parallel dye dissolution study displayed a decreasing rate of release with increasing CPH content. This
result agrees with previously published data for dye release from poly(CPH-co-SA) copolymers. The
methodology described in this work is amenable to numerous applications in the arenas of high-throughput
polymer synthesis and characterization.