TitleNatural bioactive-based polyanhydrides for controlled release applications
NameCarbone, Ashley Lauren (author), Uhrich, Kathryn (chair), Warmuth, Ralf (internal member), Jimenez, Leslie (internal member), Chikindas, Mikhail (outside member), Rutgers University, Graduate School - New Brunswick,
Controlled release technology,
DescriptionHydrolytically degradable polyanhydrides are of interest for a variety of controlled release applications because of their surface-eroding behavior and tunable degradation rate based on polymer chemical composition. Rather than physical admixtures, bioactives were chemically incorporated either directly into the polymer backbone or as pendant groups via hydrolytically degradable linkages.
A series of poly(anhydride-esters) containing iodinated salicylates were synthesized via both melt-condensation and solution polymerization to generate X-ray opaque polymers. It was found that physical and mechanical properties were affected by polymerization technique, and thermal properties such as glass transition temperature were dependent on the amount of iodine in the polymer.
The degradation rate of salicylic acid (SA)-based polyanhydrides was manipulated to release SA over prolonged periods of time (i.e., months) and over relatively short periods of time (i.e., days). First, a series of copolymers based on a SA-based diacid and highly aromatic comonomers 1,6-bis(o-carboxyphenoxy)hexane (o-CPH) and 1,6-bis(p-carboxyphenoxy)hexane (p-CPH) were developed. By changing the molar ratios of SA-based diacid to o-CPH or p-CPH, the thermal and mechanical properties of the resulting copolymers varied, and the degradation rate was decreased. Alternately, two methods were used to form fast-degrading polymers: changing the structure of the diacid’s “linker” molecule and synthesizing a copolymer containing a more hydrophilic comonomer. These polymers completely degraded in one week or less.
Mono-functional antimicrobials were chemically incorporated as pendant groups via ester linkages to a polyanhydride backbone based on ethylenediaminetetraacetic acid, resulting in a completely bioactive polymer. The polymers degraded in less than 1 week, and some displayed the ability to completely prevent Salmonella biofilm formation.
Lastly, polymers based on antimicrobial and antioxidant preservatives (i.e., hydroxycinnamates) were synthesized and found to release the preservatives over a prolonged period of time (> 1 month). Polymer degradation products exhibited antioxidant activity, and experiments indicated that free bioactives are responsible for antimicrobial activity. Furthermore, the polymers contain double bonds that can be crosslinked to form hydrophobic networks.
NoteIncludes bibliographical references
Noteby Ashley Lauren Carbone
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work