Bacterial infections are considered the second main cause of death worldwide and the third main cause of death in the developed countries and as a result, many antibacterial coatings have been prepared in order to fight the different strains of bacteria and decrease the mortality rates. Natural antibacterial products become of great interest nowadays and their use is preferred over the synthetic products in order to overcome the resistance to the synthetic antibiotics. A wide variety of antibacterial coatings have been developed ranging from polymeric to polymer Nano-composites (PNCs) materials. Using nanomaterials as fillers within polymer matrices have been reported to enhance the antibacterial properties significantly. The polymeric nanoparticles (NPs) are promising for natural antibacterial drug delivery. In this study, two types of Garlic oil nano-composites (GO-NCs) have been developed by using two polymers which are poly lactic-co-glycolic (PLGA) and poly lactic-co-glycolic/poly ethylene glycol (PLGA/PEG) mixed with garlic oil (GO). The two polymer Nano-composites were named PLGA-GO-NCs and PLGA-PEG-GO-NCs respectively. Single emulsion/solvent evaporation (SE/SE) technique was involved in the preparation of the different nanocomposite formulations. The polymers conjugated with GO were prepared at three different homogenization time intervals (5, 10 and 15 min.) at the same homogenization speed of 11,000 rpm. All the preparation parameters, such as the concentration of polymers, concentration of GO, amounts of surfactant used (polaxmer 407) and the homogenization speed, were kept constant to identify the effect of the homogenization time on the physicochemical properties and the antibacterial activities of the PNCs. In addition, the effect of other factors such as the effect of solution settling, the use of Buchner funnel in solution filtration, the use of biological filters in solution filtration and the effect of mechanical shaking the solutions by using vortex stirring on the different formulations were carefully examined. The particle sizes, zeta potential and poly dipsersity index (PDI) and GO% in each formulation have been measured. The morphological examination of the prepared nanocomposite formulations was carried out by using Scanning Electron Microscope (SEM), and the chemical structural characteristics were examined by using Fourier Transform-Infra-red spectroscopy (FT-IR) and Ultraviolet-Visible spectrophotometry (UV-vis). In addition, antibacterial assessment has been carried out against Eichercia Coli (E. coli) (ATCC 8739) as a Gram-negative bacterium, and Staphylococcus aureus (S. aureus) (ATCC 6538) as a Gram-positive bacterium using Colony Counting Method (CCM). The results revealed four important factors that need to be considered during the preparation of GO NPs which are (i) settling of the solutions, (ii) filtration through biological filters, (iii) Buchner filtration and (iv) vortex stirring of solutions. These factors play a crucial role in controlling the size and stability of PNCs. Furthermore, we have observed that the addition of PEG to the PLGA-GO formulations has a significant effect on decreasing the particle sizes and increasing the GO% in the formulations. These results could be promising in producing polymeric drug/extract NPs of small particle sizes, high stability and of pronounced antibacterial activity which is stronger than the original dtug/extract.
MS in Chemistry
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(2015).Fabrication of garlic composites nano-biotics and investigating their anti-bacterial activities [Master’s thesis, the American University in Cairo]. AUC Knowledge Fountain.
Fahmy, Sherif Ashraf Saad. Fabrication of garlic composites nano-biotics and investigating their anti-bacterial activities. 2015. American University in Cairo, Master's thesis. AUC Knowledge Fountain.