| dc.description.abstract | D-Glucose-based polycarbonates represent an attractive class of natural product-based
renewable materials due to their facile syntheses, well-defined structures, tunable
properties, and promising potentials in biomedical applications. This study emphasizes
on advancing the development of D-glucose-based polycarbonates, also named
poly(glucose carbonate)s (PGCs), by comprehensive research on fundamental structure,
physicochemical property, regiochemistry, and application towards therapeutic delivery.
The fundamental aspects of the relationship between polymer structure and
physicochemical property are studied with variation of glass transition temperature (Tg) as
a function of the side-chain structure and molar mass for PGCs. A remarkable range of
Tg values (38-125 °C) was accomplished with a various of six different alkyloxycarbonyl
side chains. The impact of molar mass on Tg was investigated for two series of polymers
and discrete oligomers synthesized and fractionated with precise control over the degrees
of polymerization. The Tg was found to be significantly influenced by a synergistic effect
of the flexibility and volume of the repeating unit side chains, as well as the chain end
relative free volume.
Highly regioregular structures were observed for PGCS with carbonate side chains,
whereas regioregularity was found for PGCs with ether side-chain substituents at the 2-
and 3- positions. The regiochemical details of PGC were demonstrated through a
comprehensive structural investigation using a combination of 1D and 2D NMR
characterizations to reveal the backbone connectivity and to demonstrate the curious side- chain functionality-mediated regiochemical differences. Density functional theory (DFT)
calculations were performed to obtain a deep understanding of the regioselectivity during
organo-base catalyzed ring-opening reactions.
Lastly, the utilization of PGC in the construction of biocompatible silver-bearing
nanocarriers was evaluated. This synthetic polymeric framework focuses upon effective
treatment of bacterial infections by improving nanoparticle cell binding and
internalization. Degradable and biocompatible polymer nanostructures of spherical,
cylindrical, and 2D-platelet-like morphologies were constructed via crystallization-driven
self-assembly (CDSA) method in aqueous solution. These nanoparticles exhibited
negligible toxicity, while offering substantial silver loading capacity, extended release,
and in vitro antimicrobial activity against uropathogenic Escherichia coli. In comparison
to spherical analogs, cylindrical and platelet-like polymeric nanostructures engaged in
significantly higher association with uroepithelial cells. | en |
