Electronic Theses and Dissertations

Date of Award

1-1-2022

Document Type

Dissertation

Degree Name

Ph.D. in Chemistry

Department

Chemistry and Biochemistry

First Advisor

Davita Watkins

Second Advisor

Jared Delcamp

Third Advisor

James Cizdziel

Relational Format

dissertation/thesis

Abstract

Amphiphilic hybrid polymers have attracted significant interest as biomaterials for both fundamental research and practical clinical applications due to their unique polymer structure and properties relative to the conventional symmetric polymers. Often referred to as “Janus” polymers combine two different polymer segments (hydrophilic and hydrophobic) of varying degrees, sizes, and functionalities to obtain a single amphiphilic or hetero-functional macromolecule with characteristic features. In particular, amphiphilic “Janus” polymers and their self-assemblies have shown apparent success in nanomedicine owing to their ability to provide highly ordered nanoscale multimolecular aggregates, including micelles and vesicles. However, engineering these polymeric materials on a large scale with nanoaggregates of desirable size and morphology remains challenging. Herein novel synthetic routes and characterization for amphiphilic Janus polymer libraries and their nanoaggregates are presented. The first library discusses the design, synthesis, and characterization of self-assembling amphiphilic Janus dendrimers, which consisted of NH3+ (cationic), COO- (anionic), and OH (neutral) polyamidoamine (PAMAM) as hydrophilic segments and fatty acid branches as the hydrophobic segment. The results of this study afford opportunities to evaluate in-vivo efficacy as well as stability and interactions with bloodstream components. The second system involves in-situ self-assembly, known as polymerization-induced self-assembly (PISA). Using the PISA approach, we designed the first cationic dendritic macro chain transfer agent to synthesize a Janus-type hybrid polymer called a linear dendritic block copolymer (LDBCs). These studies offer a one-pot polymerization method for a new class of fluorinated Janus-type LDBC for a 19F magnetic resonance imaging (MRI) agent. These results showcase novel yet efficient pathways toward building next-generation biomaterials with unique morphologies and tunable properties.

Available for download on Wednesday, August 16, 2023

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