Enhanced antibacterial activity of Egyptian local insects' chitosan-based nanoparticles loaded with ciprofloxacin-HCl.

Chitosan (CS), possess enormous properties, being biodegradable, biocompatible, and antimicrobial. CS could be formulated and casted into different forms including 2D films, hydrogels, and nanoparticles. Chitosan-based nanoparticles (CSNPs) showed countless interest as polymeric drug delivery system (DDS) with its improved bioavailability, and stability when compared with traditional DDS. Ciprofloxacin is a prescribed antibiotic for many diseases, but its efficiency was affected by antibacterial resistance. Therefore, in this study, CSNPs loaded with ciprofloxacin (Cipro/CSNPs) were prepared from CS isolated from desert locusts, beetles, honey bee exoskeletons, and shrimp shells were used as a standard control. CSNPs were formulated by ionic crosslinking method, then loaded with ciprofloxacin HCl, and characterized using particle size distribution, zeta potential, and drug entrapment efficiency. The release of ciprofloxacin from CSNPs was evaluated and its kinetic modelling was performed. Antibacterial activity of CSNPs was evaluated against Escherichia coli, Bacillus thuringiensis, Methicillin-resistant Staphylococcus aureus (MRSA) and, Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined and compared between chitosan sources. The Cipro/CSNPs results indicate that the highest antibacterial activity against E. coli and MRSA with MIC varying from 0.0043 to 0.01 µg/ml and from 0.07 to 0.14 µg/ml, respectively. In addition, CSNPs enhanced drug delivery, and allowed its controlled release.

Development of gold nanoparticles biosensor for ultrasensitive diagnosis of foot and mouth disease virus.

BACKGROUND: Nano-PCR is a recent tool that is used in viral diseases diagnosis. The technique depends on the fundamental effects of gold nanoparticles (AuNPs) and is considered a very effective and sensitive tool in the diagnosis of different diseases including viral diseases. Although several techniques are currently available to diagnose foot and mouth disease virus (FMDV), a highly sensitive, highly specific technique is needed for specific diagnosis of the disease. In the present work, a novel AuNPs biosensor has been designed using thiol-linked oligonucleotides that recognize the conserved 3D gene of FMDV. RESULTS: The AuNPs-FMDV biosensor specifically recognizes RNA standards of FMDV, but not that of swine vesicular disease virus (SVDV) isolates. The analytical sensitivity of the AuNPs-FMDV biosensor was 10 copy number RNA standards in RT-PCR and 1 copy number RNA standard in real-time rRT-PCR with a 94.5% efficiency, 0.989 R2, a - 3.544 slope and 100% specificity (no cross-reactivity with SVDV). These findings were confirmed by the specific and sensitive recognition of 31 Egyptian FMDV clinical isolates that represents the three FMDV serotypes (O, A, and SAT2). CONCLUSIONS: The AuNPs-FMDV biosensor presents in this study demonstrates a superior analytical and clinical performance for FMDV diagnosis. In addition, this biosensor has a simple workflow and accelerates epidemiological surveillance, hence, it is qualified as an efficient FMDV diagnosis tool for quarantine stations and farms particularly in FMDV endemic areas.

Isolation and characterization of chitosan from different local insects in Egypt.

Chitin was extracted from four different local sources: the shrimp (Penaeus monodon), the desert locust (Schistocerca gregaria), the honey bee (Apis mellifera) and the beetles (Calosoma rugosa). Chitosan was then obtained by deacetylation of chitin and physicochemically characterized using the Fourier transform infrared (FTIR) and X-ray diffraction. The moisture content, water binding capacity, fats binding capacity, ash content were determined and chitosans morphology was visualized using the scanning electron microscope (SEM). The difference between the obtained chitosans from three insect sources and α-chitosan from shrimp in terms of crystallinity, fibrous structure was discussed.