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Chitosan is a polysaccharide derived from chitin chitin is the second most abundant polysaccharide in the world, after cellulose. Chitosan is biocompatible, biodegradable and non-toxic, so that it can be usedin medicalapplications such as antimicrobial and wound healing biomaterials. It also used as chelating agent due to its ability to bind with cholesterol, fats, proteins and metal ions.Chitosan is difficult to electrospun into a fibrous structure because it has a polycationic character in an acidic aqueous solution due to the many amino groups in its backbone. Fibrous structures were successfully formed by electrospinning chitosan solutions in wt. % aqueous acetic acid solution or trifluoroacetic acid TFA or TFA/dichloromethane DCM in the presence of poly vinyl alcohol PVA or Poly ethylene oxide PEO .Chitosan nanofibers are biocompatible and biodegradable, so they can used as hemostatic and wound healing materials.

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Herein we describe the preparation, characterization and utilization of chitosan nanoparticles for the intracellular delivery of the poorly cell-penetrating antibiotic e.g. Ciprofloxacin, Chlortetracycline hydrochloride and Gentamycin sulfate to improve their treatment of bacterial infections. Chitosan nanoparticles were prepared via the ionic gelation of chitosan with tri polyphosphate anions. Several parameters were studied to optimize the particle size of chitosan nanoparticles, here we select the concentration of chitosan and the concentrations of sodium tri poly phosphate (TPP) as optimizing parameters and the other factors stay constant such as pH of solution and ultrasonication time. Chitosan nanoparticles formed characterized by using FT-IR and transmission electron microscope (TEM). Results show that chitosan nanoparticles and its loaded antibiotics kill and inhibits the growth of gram (+) and gram (-) bacteria tested due to nanoparticles structures, and the antibacterial activity increased with increasing the anti biotic content.

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). We succeeded in preparing disinfectant cellulose-based wipes treated with antimicrobial and antiviral silver nanoparticles to be used for prevention of contamination and transmission of several pathogenic viruses and microbes to human in critical areas such as hospitals and healthcare centers especially coronavirus. In this work, the antimicrobial and antiviral activities of silver nanoparticles (AgNPs) prepared with four different techniques were investigated for the utilization as a disinfectant for cellulose-based wipes. These four methods are namely; 1) trisodium citrate with cotton yarn as a reducing agent, 2) preparing AgNP's using aqueous solution of PVA in the presence of glucose, 3) trisodium citrate with cotton fabric as a reducing agent, and 4) photochemical reaction of polyacrylic acid and silver nitrate solution. Polyester/viscose blended spunlace nonwoven fabrics as cellulose based fabrics were treated with the prepared silver nanoparticles to be used as surfaces disinfection wipes. The properties of the nonwoven fabrics were examined including thickness, tensile strength in dry and wet conditions in both machine direction (MD) and cross-machine direction (CMD), bursting strength, air permeability, water permeability and surface wettability. Characterization of the AgNPs was carried out in terms of UV-VIS spectroscopy, TEM, SEM, and Zeta potential analysis. The assessment of AgNPs active solutions for antimicrobial and antiviral activities was evaluated. The results obtained from the analyses of the AgNPs samples prepared with different techniques showed good uniformity and stability of the particles, as well uniform coating of the AgNPs on the fibers. Additionally, there is a significant effect of the AgNPs preparation method on their disinfectant performance that proved its effectiveness against coronavirus (MERS-CoV), S. aureus and B. subtilis as Gram-positive bacteria, E. coli and P. mirabilis as Gram-negative bacteria, A. niger and C. albicans fungi.

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