Abstract

The emergence of many resistant bacteria causing serious bacterial infections has spread the threat of infectious diseases. These threats have increased the alertness to discover new antimicrobials from natural products, that will counterfeit the chemical diversity of chemical medications. Egypt as well as many developing countries is facing environmental and sanitary problems because of the incomplete food waste management. However, these wastes have vast economical potentials, yet, are considered pollutants if not well utilized. New trends have shown food waste products as natural antimicrobial, prebiotics and antioxidants. The work presented in this thesis aimed to provide a beneficial use of mango fruit wastes for the preparation of nanoparticles with enhanced properties, which can then be used as a natural antibacterial and antioxidant agent with high biocompatibility and lesser side effects. Total phenolic content (TPC) of mango by-products’ (peels & seeds) extracts were determined by Folin-Ciocalteu's assay (FCT), then Poly-(d,l-lactide-co-glycolide) (PLGA) nanoparticles with entrapped Mango seed kernel extract (MSKE) was formulated using emulsion solvent evaporation method and characterized for size, & morphology using different techniques such as Zeta sizer, IR & TEM. Different factors were studied during processing to determine the impact of these factors over the nanoparticles characteristics. Entrapment efficiency, invitro release profile, antibacterial & antioxidant activities of MSKE loaded PLGA NPs were also studied. MSKE showed higher TPC content of (69 mgGAE/1g drymatter) than that in MPE (31 mgGAE/1g drymatter). Spherical MSKE/PLGA NPs with size range of 40-180nm was synthesized and reached entrapment efficiency of 86.4%. In-vitro release profile of MSKE/PLGA NPs showed initial burst effect for the first few hours, followed by balanced release of MSKE from PLGA matrix. MSKE-loaded PLGA NPs showed enhanced & sustained antioxidant activity reaching 97.52% DPPH scavenging activity after 48hrs, whereas free MSKE showed immediate 88.52% DPPH scavenging activity, with no change over time. Both pure MSKE and MSKE-loaded PLGA nanoparticles showed inhibitory effect on growth of Escherichia coli and Staphylococcus aureus bacterial strains. Lower concentration from MSKE/PLGA NPs were needed to reach the same inhibitory effect of pure MSKE in both strains. Results indicate the advantages of encapsulating hydrophobic compounds in PLGA NPs, where these MSKE/PLGA NPs have promising and potential applications in drug delivery and sustained release systems. Utilization of food wastes by-products by this advanced new technology will have a great impact on the economical level in developing countries as well as in their environmental level, by reducing pollutants.

School

School of Sciences and Engineering

Department

Chemistry Department

Degree Name

MS in Chemistry

Graduation Date

Spring 5-3-2018

Submission Date

5-3-2018

First Advisor

Mamdouh, Wael

Committee Member 1

Tallima, Hatem

Committee Member 2

El-Meshad, Aliaa

Extent

132 leaves

Document Type

Master's Thesis

Institutional Review Board (IRB) Approval

Approval has been obtained for this item

Available for download on Friday, November 03, 2023

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