Abstract

Non-healing wounds represent a serious health care burden with major socioeconomic impacts. Bacterial infection of the wound site further complicates the healing process as it stimulates the immune system which in turn prolongs tissue inflammation thus further delaying the healing process. Moreover, wound associated bacterial contamination usually develops resistance to commonly used antibacterials leading to increased risk of systemic infections. Treatment of infected wounds is being achieved via different kinds of dressings in association with antibacterials, antiseptics and wound healing materials. Currently, however there has been a noticeable shift towards advanced antimicrobial wound care as a possible solution for the problem. Advanced antimicrobial wound care are dressings that can be loaded with either antibiotics or antiseptics and are able to reduce or eliminate the bacterial load at the wound site. However, one of the major challenges associated with such dressings is the continuous emergence of antibiotic resistant strains as well as the observed damage of healthy tissues in case of antiseptics. Moreover, it has been argued that the antimicrobial efficacy alone of an advanced dressing is insufficient and other properties that enhance the wound healing process are also required. To help provide a solution for this challenge, this study aims to investigate the development of a novel series of advanced antimicrobial wound dressings that are based on honey and chitosan and fabricated in the nanofibrous form. Honey and chitosan are well known for their wound healing and antibacterial properties. Moreover, developing the dressings in the nanofibrous structure allows enhancement of the wound healing process. Electrospinning technique was adopted to fabricate novel nanofibrous wound dressings based on high honey and chitosan concentrations (HPCS). Natural extracts namely: Cleome droserifolia (CE) and Allium sativum (AE) and apitherapeutics namely: bee venom (BV) and propolis (Pr) as well as bacteriophages (PS1) were loaded within the fabricated honey chitosan based nanofibrous dressings to enhance their antibacterial activity and extend it against resistant bacterial strains as well as increase their wound healing abilities. The fabricated series of nanofibrous dressings, HPCS, HPCS-AE, HPCS-CE, HPCS-AE/CE, HPCS-BV, HPCS-Pr and HPCS-BV/PS1 demonstrated enhanced wound healing abilities and variable antibacterial effects against the examined bacterial strains as compared to the commercial wound dressing Aquacel Ag. Most importantly, the developed series of nanofibrous dressings demonstrated enhanced biocompatibility as compared to the Aquacel Ag that demonstrated noticeable cytotoxicity. Thus, the developed series of nanofibrous wound dressings that are based on natural materials represent competitive candidates to be used as effective wound dressings.

Department

Nanotechnology Program

Graduation Date

6-1-2016

Submission Date

5-22-2016

First Advisor

Azazzy, Hassan

Committee Member 1

Ramadan, Adham

Committee Member 2

Madkour, Tarek

Extent

122 p.

Document Type

Doctoral Dissertation

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.

Institutional Review Board (IRB) Approval

Not necessary for this item

Comments

This Work was funded By a Research Grant from The American University in Cairo. My PhD was funded by Youssef Jameel Fellowship. ACKNOWLEDGEMENTS First and foremost I would like to thank Allah for His guidance, love, and support in every step of my life, for being always there, for lifting me up throughout my weakness, for guiding me throughout my hesitations and for giving me strength to go on throughout the difficulties. I would like to express my sincere gratitude to my advisor Prof. Hassan Azazzy for his continuous support throughout my PhD, for giving me the freedom to explore on my own and at the same time the guidance when I lose the way. Dr. Azzazy has taught me the true meanings of hard work, accuracy and innovation and inspired me to dream big, take difficult challenges and work for them. I would like to extend my thanks to my advisory committee: Prof. Adham Ramadan and Prof. Tarek Madkour for being always supportive, encouraging and helpful throughout the different steps of my PhD. My deepest thanks is extended to Prof. Ibrahim Elsherbiny for giving me the opportunity to work in his labs at Zewil City for Science and Technology and for his encouraging comments and continuous support to me. My deepest gratitude is also extended to Mr. Youssef Jameel, for it was because of the support I received through the Youssef Jameel fellowship, that I was able to complete my PhD and dedicate my full time to my PhD research. My deepest thanks is extended to my friends Walaa Wahbi, Sara Omar, Israa Hussien, Asmaa Gamal, and Huda Makki for being always there, for their care, love and support and for making my PhD journey the most joyful one. I would also like to thank my family for their continuous support, encouragement, and believe in me. Special thanks to: my parents, Awad Sarhan and Asmaa Elsherbiny, my mother in law, Fatma Elsherbiny and my sister, Basma Awad for each of them has helped me in every possible way to allow me to fulfill my goals and achieve my PhD. No words could ever express my gratitude to: my husband, Wael Mansy and my sons, Omar, Adam and Youssef for enduring me through these past few years and allowing me to reach my goals through their overwhelming love and support. Finally, I recognize that this research would not have been possible without the nurturing, friendly, inspiring and supportive environment of the American University in Cairo (AUC) as well as its highly advanced facilities, well equipped labs and its highly qualified staff members.

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