الفهرس 
Overview of Biopolymers and Silver Nanoparticles as Antimicrobial AgentsOnly 14 pages are availabe for public view
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Abstract
Nanometals (NM) frequently possess potent antimicrobial potentials to combat various pathogens, but their elevated biotoxicity limits their direct applications. The biosynthesis of NM and their capping/conjugation with natural biopolymers can effectually enhance NM stability and diminish such toxicity. The β-glucan nanoparticles (βG NPs) were innovatively employed for direct biosynthesis of silver nanoparticles (Ag-NPs) without extra chemical processes. The synthesized βG NPs, Ag-NPs and βG-Ag NPs composite were negatively charged and had minute particles’ size with mean diameters of 58.65, 6.72 and 63.88 nm, respectively. The antimicrobial assays’ results of produced NPs (Ag-NPs and βG-Ag NPs) against Gram+ (Staphylococcus aureus) and Gram‒ (Escherichia coli, Salmonella Typhimurium and Pseudomonas aeruginosa) bacterial pathogens indicate the inventive Ag-NPs biosynthesis with βG NPs and the combined βG-Ag NPs nanocomposites could be impressively recommended as powerful antibacterial candidates with minor potential toxicity.
Skin care and protection is an important target, as the skin is the largest organ and the main responsible for protecting and conditioning human body. The utilizations of natural nano-bioactive compounds (e.g. Carrageenan (CA) and Chitosan (CH) biosynthesized with Ag NPs were investigated for the fabrication of products /formulation to be used in skin protecting, disinfection, healing and control of skin microbial pathogens, Staphylococcus aureus and Candida. The mean particle size diameter of Ag NPs was about 14.2 nm and high negative zeta potential within −27.4 mV. CH/CA nanocomposite displayed a mean particle size in the nanometric range was about 264.3 nm and a positive zeta potential within + 32.6 mV. CH/CA-Ag NPs detected a positive zeta potential within +31 mV. The composite CH/CA-Ag NPs were loaded onto cotton textiles and this composites exhibited powerful antimicrobial activities against skin pathogens. The natural composites used in this thesis are recommended for topical applications and skin-care textiles’ fabrication, toward the optimum skin disinfection and regeneration.
Important results of the research:
1- Efficient extraction of beta-glucan from yeast strain (Saccharomyces cerevisiae) and converting it to the nanoform, which showed desirable properties of the product.
2- Recommending βG nanoparticles combined with nano-silver particles as effective natural compounds to eliminate bacteria.
3- Green synthesis of silver nanoparticles using carrageenan and chitosan, and it is recommended to use them for effective resistance to skin pathogens by applying a simple and environmentally friendly protocol.
4- Recommending the use of natural nano-chitosan/carrageenan/ silver compounds as topical applications for optimal skin cleansing and regeneration.