Birhanu, Gebremariam (PhD, Department of Pharmaceutics and Social Pharmacy)Mulugeta, Eyobel(PhD)Workye, Mulualem2022-02-062023-11-062022-02-062023-11-062021-12http://etd.aau.edu.et/handle/123456789/29926Ciprofloxacin is clinically important fluoroquinolone, effective against Escherichia coli (E. coli) infections across the globe. However, many clinical isolates of E. coli have emerged as resistant to ciprofloxacin, restricting therapeutic options. Due to the paucity of new antimicrobial agents in the drug development pipeline, it is imperative to develop new alternative approaches that improve antibacterial efficacy of the available antibiotics. The aim of the current study was therefore to biosynthesize silver nanoparticles (AgNPs) using aqueous extract of Aloe camperi for ciprofloxacin delivery, thereby enhancing its efficacy against ciprofloxacin resistant E.coli. In this study, the aqueous extract of Aloe camperi was utilized as a reducing and capping agent for the synthesis of AgNPs. Crucial operational parameters were controlled. Ciprofloxacin was loaded on the surface of AgNPs and the encapsulation efficiency was determined. Free and ciprofloxacin loaded particles were characterized by VU-visible spectroscopy, fourier-transform infrared, dynamic light scattering, scanning electron microscope, X-ray diffraction and simultaneous differential scanning calorimeter-thermogravimetric analysis. The in vitro release profile of ciprofloxacin from the surface of AgNPs was investigated. Furthermore, the in vitro susceptibility test of the loaded particles as compared to its individual components was evaluated by employing disk diffusion test. The results of characterizations revealed a successful synthesis of crystalline AgNPs with an average hydrodynamic diameter of 98.9 nm ± 0.3. Ciprofloxacin was also effectively loaded on the surface of AgNPs with a maximum encapsulation efficiency of 60.94 %. The in vitro releasing profile of ciprofloxacin exhibited a biphasic pattern at all study pH conditions. However, the releasing rate was pH dependent. After loading, the susceptibility of E.coli against ciprofloxacin was transformed from resistant to intermediate. Therefore, this study demonstrated that biosynthesized AgNPs using Aloe camperi aqueous extract could be a potential nano carrier for ciprofloxacin delivery to enhance its efficacy against ciprofloxacin resistant E.coli.en-USAloe camperi, antimicrobial resistance, ciprofloxacin, E. coli, functionalized silver nanoparticles, green synthesis, and silver nanoparticlesThesis