Date of Graduation

Summer 2022

Degree

Master of Science in Chemistry

Department

Chemistry and Biochemistry

Committee Chair

Keiichi Yoshimatsu

Abstract

I herein report the preparation and characterization of PEG-b-PLA block copolymer micelles and PEG-b-PLA/PLA mixed micelles as potential “plastic antidotes” for a toxic peptide, melittin. PEG-b-PLA micelles have been used in a number of biomedical applications for their biodegradability and biocompatibility. Along these lines, I investigated the colloidal stability and the peptide absorption properties of PEG-b-PLA/PLA mixed micelles. A series of PEG-b-PLA block copolymer micelles and PEG-b-PLA/PLA mixed micelles were prepared, and their colloidal stability was studied. The hydrodynamic diameters of stable micelles were determined by using Dynamic Light Scattering (DLS). The capability of the micelles to capture and neutralize a hydrophobic toxic peptide derived from bee venom, melittin, was evaluated by hemolytic assay. The micelles consisting solely of PEG-b-PLA block copolymer were only found to inhibit melittin-induced hemolysis to a limited degree. Meanwhile, the micelles that consist of both PEG-b-PLA and PLA completely neutralize the effects of melittin. We attributed the contributing factor in melittin neutralization to the chemical nature of the micelle surface rather than the surface-to-volume ratio of the nanoparticle. The micelle mixture that exhibited the highest neutralization was comprised of 75% PLA and 25% PEG-b-PLA.

Keywords

block copolymer micelles, FRET, melittin, PEG-PLA, synthetic antidote, toxin neutralization

Subject Categories

Materials Chemistry | Other Chemistry | Polymer Chemistry

Copyright

© Giselle Campos

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