04628ntm a2200373 i 4500 0 0 lcc 0 1 REF 10000 10000 2020-10-16 0 FTKKP .A45 2019 r Thesis T000000976 2021-03-10 00:00:00 1 2020-10-16 THESIS 0 0 lcc 0 0 REF 10000 10000 2020-10-16 0 CD12715 T000000977 2021-12-06 00:00:00 1 2020-10-16 THESIS 94376 94382 MY-KuUP 20251125105738.0 t||||fr|||| 000 0 ta 201016t20192 M a|||fram|| 000 0 eng d THE0008919(Local) hardback UMP eng UMP rda FTKKP .A45 2019 r Thesis Aljbour, Nawzat Deeb, author. Preparation and characterization of chitosan/poly lactic acid nanofibers using electrospinning process for drug delivery applications / Nawzat Deeb Aljbour Kuantan, Pahang : UMP, 2019 © 2019 xxi, 177 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM text rdacontent text rdacontent unmediated rdamedia computer rdamedia volume rdacarrier computer disc rdacarrier text file PDF rda Faculty of Chemical and Process Engineering Technology Thesis (Doctor of Philosophy in Chemical Engineering) -- Universiti Malaysia Pahang – 2019 Includes bibliographical references Nanofibers are considered as a new class of highly important materials in the biomedical field, whereas free surface wire electrospinning system is one of the most versatile technologies for the continuous and mass production of nanofibrous layers. On the other hand, chitosan is a bio-derived, biodegradable and biocompatible polymer. However, the production of chitosan nanofibers is considered difficult because the application of high electric field during electrospinning triggers the repulsive forces between the ionic groups within the polymer backbone, resulting into formation of beads instead of continuous fibers. In addition, the low solubility of chitosan is another major limitation for the production of chitosan nanofibers. In this study high molecular weight chitosan was converted to low molecular weight chitosan with subsequent deacetylation, to produce low molecular weight chitosan with different degrees of deacetylation. These were further blended with a solution of poly(lactic) acid (PLA) in dichloromethane to facilitate the spinning process. The chitosan-PLA blend was electrospun using the free surface wire electrospinning process and the produced nanofibers were characterized for their surface properties using scanning electron miscroscopy (SEM) and contact angle analysis. In addition, the structural properties were determined through fourier transforms infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Furthermore, mechanical and physicochemical characterizations were conducted using different techniques. Fibers with the best performance were then modified for drug delivery applications by loading a model drug, Diclofenac Sodium (DNa), into the nanofibers, after which it was characterized accordingly using different elemental and physicochemical techniques. Then, the potential of the fabricated nanofibers for drug delivery applications was verified through in vitro release studies as well as drug release kinetic studies. Results showed that 25% fully deacetylated chitosan of 15 kDa and 7.5 kDa produces better quality nanofibers compared with the higher molecular weight (30 kDa) chitosan. Significantly, the produced nanofibers showed improved mechanical properties compared with the previously reported chitosan nanofibers prepared using the high molecular weight chitosan. In fact, the tensile strength (3 MPa), Young’s modulus (1.5 MPa), and %Elongation (10%) are comparable to the previously reported values of nanofibrous mats produced using different polymers and used for drug delivery applications. On the other hand, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results reveal that the incorporated DNa is distributed within the nanofibers. Notably, release results showed that chitosan-PLA nanofibers prepared using 25% chitosan (15 kDa) could be used to deliver the model drug (DNa) in a controlled release manner for 96 h with burst release of about 25%, and release kinetics follow the Fickian Diffusion kinetics. Therefore, the nanofibers produced herein can open up a new type of nanofibers with both hydrophilic and hydrophobic properties which are highly desirable for the delivery of drugs with various degrees of polarity. Faculty of Chemical and Process Engineering Technology Dissertations Universities and colleges Dissertations Theses lcc THESIS