Electronic Theses and Dissertations

Date of Award

5-1-2026

Document Type

Thesis

Degree Name

M.S. in Pharmaceutical Science

First Advisor

Mohammed Maniruzzaman

Second Advisor

Eman Ashour

Third Advisor

Seongbong Jo

School

University of Mississippi

Relational Format

dissertation/thesis

Abstract

Keloids are dermal lesions that occur from abnormal wound healing characterized by excessive collagen deposition, abnormal transforming growth factor-? signaling, and hyperactive fibroblasts. Current treatments for keloids, including intralesional corticosteroids, laser therapy, and cryotherapy, are unsatisfactory because of high recurrence and local adverse effects. Although intralesional 5-fluorouracil (5-FU) has demonstrated clinical efficacy, conventional free-drug injections are restricted by rapid clearance from the lesion, short tissue residence time, and dose-limiting local toxicity. Hence, this study aimed to formulate and evaluate a magnetically guided chitosan-coated Fe3O4 nanoparticle system loaded with 5-FU for intralesional keloid therapy. Magnetite nanoparticles were prepared by chemical co-precipitation and surface-functionalized with oleylamine, and 5-FU-loaded chitosan–Fe3O4 nanoparticles were prepared by ionic gelation with sodium tripolyphosphate and systematically optimized. The formulations were characterized for particle size, polydispersity index, zeta potential, morphology, drug–polymer interactions, magnetic properties, entrapment efficiency, and drug loading, and were further evaluated for in vitro drug release at pH 7.4 and 6.8, magnetic guidance under an external field, and cytotoxicity against keloid-derived fibroblasts. The optimized nanoparticles exhibited nanometric size with narrow size distribution, positive surface charge consistent with chitosan coating, acceptable entrapment efficiency, superparamagnetic behavior, biphasic and pH?responsive drug release, efficient magnetic accumulation, and enhanced antiproliferative activity compared with free 5?FU. Collectively, these findings support 5?FU–chitosan–Fe?O? nanoparticles as a promising magnetically responsive intralesional delivery system for keloid therapy.

Available for download on Wednesday, August 02, 2028

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