Synthesis And Characterization Of Silver-Coated Polyester Dendrimers With Potential Antimicorbial Properties

Author

Che’darria Lacey, Prairie View A&M University

Date of Award

12-2023

Document Type

Thesis

Degree Name

Master of Science

Degree Discipline

Chemistry

Abstract

As bacterial cell lines continue to develop resistance to conventional antibiotic medications, the threat of untreatable bacterial infections continues to grow. The limited manufacture of new pharmaceuticals further exacerbates this severe health risk. This risk has facilitated numerous investigations to counter microbial species’ antibiotic resistance. The use of silver, a well-known natural remedy, has grown significant attraction through its use in the nanoparticle form or even as silver ions.

This thesis project involves the synthesis of branched polymers that were suitably functionalized to enable the complexation of silver ions to develop antimicrobial materials. Polyester dendrimers were synthesized utilizing divergent dendronization. The dendrimer surface was then functionalized via photo-initiated thiol-yne click chemistry to incorporate n-acetyl cysteine, which has reported silver-chelating activity. Dendrimers are constructed in an iterative or stepwise fashion and include many branching groups – known as generations or layers – emanating from a multi-functional core. This dendrimer core was comprised of 1,1,1-tris(hydroxymethyl) ethane. The branching groups were derived from the monomer, 2,2-bis(hydroxymethyl) propionic acid, otherwise known as Bis-MPA. These core and monomer group components are biocompatible and used extensively in polymer chemistry and material science communities for biomedical applications. Because the dendrimer increases the number of surface functional groups with each dendritic growth layer, the concentration of silver-chelating ligands also increases. Thus, this study compared the overall silver chelating affinity of polyester dendrimers due to the varying number of chelating moieties on the dendrimer surface.

Silver nitrate was added to aqueous solutions of the dendrimer chelator to induce silver complexation. After 2 hours, the complex was precipitated from acetone, and the precipitate was analyzed by SEM microscopy to observe the silver loading affinity of the polymeric system.

Index Terms----Antibiotics, antimicrobial resistance (AMR), branched polymers, chelator, n-acetyl cysteine, nanoparticles (NPs), pentanoic acid, pentynoic acid, dendrimers, polyester dendrimers, silver, silver chelation, silver nitrate, thiol-Michael addition, thiol-yne click chemistry.

Committee Chair/Advisor

Ananda Amarasekara

Committee Member

Marco D. Giles

Committee Member

Andrea Oseolorun

Committee Member

Matthew Minus

Publisher

Prairie View A&M University

Rights

Date of Digitization

1-10-2024

Contributing Institution

John B Coleman Library

City of Publication

Prairie View

MIME Type

Application/PDF

Recommended Citation

Lacey, C. (2023). Synthesis And Characterization Of Silver-Coated Polyester Dendrimers With Potential Antimicorbial Properties. Retrieved from https://digitalcommons.pvamu.edu/pvamu-theses/1528