Date of Award
Spring 2021
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Tran, Chieu D.
Second Advisor
Clark, Joseph R.
Third Advisor
Fiedler, Adam T.
Abstract
In order to be effective dressings for the treatment of infected wounds in the battlefield, it is essential that composite materials made from the biopolymers Cellulose and Chitosan contain broad-spectrum antibiotic drugs. These drugs must first be encapsulated into microcapsules in order to protect them from the manufacturing process, ensuring that they remain in a usable form in the final product. Here we demonstrate the successful encapsulation of Ciprofloxacin HCl into Sporopollenin Exine Capsules (SEC) to produce Cipro@SEC, followed by incorporation of Cipro@SEC into a polymer composite consisting of a mixture of Cellulose and Chitosan dissolved in 1-butylmethylimidazolium chloride, an ionic liquid solvent. We also overcome the challenge that arises from Ciprofloxacin HCl’s solubility in water by developing the use of 2-propanol in the place of water for the gelification of the composites and the removal of the ionic liquid solvent. Ciprofloxacin HCl solution and SEC were mixed together under a high vacuum in order to encapsulate dry Ciprofloxacin HCl into the inner cavity of the SEC, producing Cipro@SEC. Five sequential encapsulations were carried out to ensure complete filling of the SEC. Cellulose and Chitosan were dissolved in 1-butylmethylimidazolium chloride under vigorous stirring at 120 °C to produce a polymer composite ([CEL+CS]). Cipro@SEC was added to the polymer composite at 90 °C to produce [CEL+CS+Cipro@SEC]. [CEL+CS+Cipro@SEC] composites were cast into Teflon molds on Mylar film and allowed to gelify in a desiccated 2-propanol atmosphere. After washing with 2-propanol to remove the 1-butylmethylimidazolium chloride, the composites were dried at high vacuum. The produced Cipro@SEC were characterized with confocal fluorescence microscopy, analysis of SEM images, fluorescence spectra, XRD spectra, and FTIR spectra. The produced [CEL+CS+Cipro@SEC] composites were characterized with analysis of SEM images, fluorescence spectra, XRD spectra, FTIR spectra, and visual analysis. The Cipro@SEC were found to be completely filled with Ciprofloxacin HCl and were observed to be covered with crystallized Ciprofloxacin HCl from the encapsulation process. The dried [CEL+CS+Cipro@SEC] composite was found to contain three different species of Ciprofloxacin: Ciprofloxacin Hydrochloride, Ciprofloxacin, and an anhydrous form of Ciprofloxacin Hydrochloride.