Abstract

The rate of bacterial resistance is increasing at an enormous rate making many antibiotics ineffective and resulting in oxidative stress. Furthermore, synthetic antibiotics have major side effects that can be life-threatening. Recently, scientific research started shifting its interest from targeting synthetic antibiotic products to natural-based products such as essential oils (EOs) that are eco-friendly, biocompatible, biodegradable, and effective when exposed to pathogens. Several reports about ginger essential oil (GEO) and oregano essential oil (ORGEO) have been recently reported that they possess immense antibacterial and antioxidant properties. The main objective of this research was to efficiently synthesize electrospun nanofibers (NFs) using from polyvinyl alcohol (PVA) and the surfactant tween-80 (T80) to form PVA/T80/GEO, PVA/T80/ORGEO, and PVA/T80/GEO/ORGEO. Furthermore, investigation of their potential antioxidant activities and their antibacterial activities against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) was conducted. The fabrication of the nanofibers was accomplished by the electrospinning method by applying high voltages applied to the polymer which forces it to spin-off in the form of spray forming NFs that get collected on the collector plate. Then, characterization of the NFs was successfully performed by the Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FT-IR) spectroscopy technique. Also, to study the antibacterial effect, E. coli and S. aureus were cultured in Lysogeny Broth liquid media for a day at a temperature of 37 °C. After that, the NFs from different nanocomposite were exposed to the two types of bacteria in a three-well plate. Optical density measurements were then taken on hourly basis using a spectrophotometer to analyse the antibacterial effect. In addition, antioxidant activity was tested by adding 2,2-diphenyl-1-picrylhydrazyl (DPPH) to the NFs for 2 hrs and monitoring them using ultraviolet visible spectroscopy (UV-Vis). The results obtained show enhanced antibacterial and antioxidant activities of the nanocomposite NFs obtained from combinations containing either PVA/T80/GEO, PVE/T80/ORGEO, and PVA/T80/GEO/ORGEO. In addition, although GEO and ORGEO have already been well-researched EOs and their antimicrobial and antioxidant properties are vastly known, the nanocomposite NFs proved to be much more efficient as antibacterials and antioxidants than pure EOs to be used efficiently in biomedical applications.

School

School of Sciences and Engineering

Department

Nanotechnology Program

Degree Name

MS in Nanotechnology

Graduation Date

5-20-2019

Submission Date

May 2019

First Advisor

Mamdouh, Wael

Committee Member 1

Tallima, Hatem

Committee Member 2

Al-Ghobashi, Medhat

Extent

108 p.

Document Type

Master's Thesis

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy. The author has granted the American University in Cairo or its agents a non-exclusive license to archive this thesis, dissertation, paper, or record of study, and to make it accessible, in whole or in part, in all forms of media, now or hereafter known.

Institutional Review Board (IRB) Approval

Not necessary for this item

Comments

I would like to start my acknowledgement by thanking my advisor and my mentor, Dr. Wael Mamdouh. Without his continuous assistance, guidance, and understanding, I wouldn’t have gained all the knowledge that I now possess, nor would I have achieved all the work that was accomplished. I’m truly thankful to all the support he always provided me with which helped me accomplish my goals in the best way possible. I would also like to greatly thank my colleagues and friends from the lab research team whom have provided me with assistance whenever needed. Special gratitude goes to Kegere James for helping me with my antibacterial testing and my SEM images which he never refused to assist me with even in his spare time. I would also like to thank Amro Shetta for providing me with several characterization techniques and guidance throughout my research. Also, great appreciation goes to my colleagues Ahmed Emad, Jailan Essam, Omar Zidan, Fatma Nabil, Khadija Sadek, Sara Omar, and Hind Amr for their great support and assistance. Finally, I would like to give all the thanks and love to my mother, Nashwa Hassan, and Father, Essam Hamza, for their continuous and unconditional support, care, and love. Also, deep gratitude goes to my sisters Mahitab, Mayada, Minat-Allah, and my brother Hamza for pushing me to go forward and giving me all the physchological assistance throughout my journey. Truly, I am thankful to all these amazing people for all the help they gave me to reach my goals and to proudly become the person I turned out to be.

Available for download on Tuesday, September 19, 2023

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