Biodegradable polymeric nanoparticles are highly regarded in drug delivery due to bioavailability، better encapsulation، controlled release and low toxicity. Drug encapsulation in polymeric nanoparticles may improve the therapeutic effects of these compounds. Polymers are divided in two types: natural and synthetic. Chitosan، as a natural polymer، can have many applications in drug delivery due to good properies. The purpose of this study is to optimization of the production of chitosan nanoparticles for drug delivery. Chitosan nanoparticles were prepared according to ionic gelation method and characterized. Prepared nanoparticle morphology investigated using SEM and particle size distribution، and surface charge and polydispersity index (PDI) were determined by Nanozeta Sizer. FTIR spectra of the lyophilized samples were recorded and proved the formation of nanoparticles. This study has shown that the particle size and zeta potential can be controlled by a change in the ratio of the weight and volume of chitosan and pH adjustment.

Introduction: Considering the broad spectrum of using nanoparticles in food coatings as a potent antimicrobial agent and their possible cytotoxic effects and accidental consumption of these toxic materials, this study was performed. The present study aimed to investigate the cytotoxicity of chitosan and nano-chitosan in vitro. Material & Methods: This cross-sectional study was conducted in 2019 in the Laboratory of the Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Shiraz, Iran. The XRD and FITR techniques were employed to study the characteristics of these nanoparticles. Moreover, two cell lines, HT-29 and Vero, were used to study the cytotoxic effects of chitosan and nano-chitosan by MTT assay, acridine orange, and ethidium bromide staining. One-way ANOVA and independent t-test were used to analyze the collected data with the help of SPSS software (version 19). Results: Based on the obtained findings, the maximum values of XRD at the angle of θ2 were observed at 20°. The highest peak appeared at 1530 cm-1, which was associated with tensile vibration of N-P-N. The spectrum diagram of chitosan due to the tensile vibration of synthetic nanochitosan of N-H bound appeared at 1646 cm-1. The results showed a proportional increase in the cytotoxicity with time and concentration of nanoparticles in the cells. Discussion & Conclusion: Since by increase in time and concentration of nanoparticles, toxicity was observed in cells,therefore, the time and concentration of chitosan nanoparticles are important in causing cytotoxicity. Considering the toxic effects of these nanocomposites on cancer cells, they can be used in cancer treatment, which requires further studies.

Background & Objectives: Salmonella enteritidis causes a number of infections in humans and other animals. Though different antibiotics are used to eliminate bacterial infections, due to the development of antibiotic resistance after a while, the use of nanoparticles has been considered as suitable alternatives. Chitosan nanoparticles are appropriate options for the intended strategy due to some properties including low molecular weight and biodegradability. Therefore, the aim of this study was to evaluate the antibacterial effect of chitosan nanoparticles against S. enteritidis. Materials & Methods: Standard bacterial strain was prepared and subsequently confirmed by PCR technique. Ionic gelation method was used to fabricate chitosan nanoparticles and Hole-Plate and tube dilution methods were used to check the chitosan nanoparticles anti-microbial properties with antibiotics. At last Zeta's analysis techniques, dynamic optical scanning, and electron microscopy were used to evaluate nanoparticles. Results: A 214 base pair band confirmed the presence of bacteria. Chitosan nanoparticles with low molecular weight were produced by analyzing the results of optical dynamics scattering (111. 7 nm), zeta analysis (20. 8 mV) and microscopy (<200 nm). The diameter of the non-growth halo at different concentrations indicated that chitosan and antibiotic nanoparticles are highly effective on bacteria. The same result was confirmed using the tube dilution method. Conclusion: There is a significant relationship between the chitosan nanoparticles resistance and antibiotics against bacteria. In other words, the nanoparticles antibacterial properties were higher than antibiotics. It is deduced that chitosan nanoparticles can be used to control diseases and to destroy resistant bacterial species.

Listeria monocytogenes is the cause of listeriosis, which has many complications, especially in pregnant women. Due to the antibiotic resistance of this bacterium, many attempts have been made to introduce different medicinal compounds, including nanoparticles based on biological compounds. This research aimed to examine the mechanism of the effect of chitosan nanoparticles on L. monocytogenes in vivo (in the body of a living organism). The standard strain of L. monocytogenes (ATCC 7644) was prepared and analyzed in the Day Hospital Laboratory (Iran). The bacteria were examined based on biochemical tests. Then, the antibacterial activity of concentrations of 4. 88 to 5000 µ, g/mL of chitosan nanoparticles against L. monocytogenes standard (ATCC 7644) was calculated with the investigated methods and the lowest inhibitory and bactericidal concentrations (MIC and MBC, respectively). The effects of different nanoparticle concentrations and ampicillin in mice infected with bacteria were also investigated. In infected mice, the therapeutic effect increased with increasing the nanoparticle concentration, and the concentration of 156. 25 /mL was the most effective compared to other treatments. Also, ampicillin chitosan nanoparticles with a concentration of 39. 06 g/mL had almost the same therapeutic effect. With the timely identification of listeria contamination in pregnant women and the proper use of chitosan nanoparticles instead of common drugs, a new solution can be found for the treatment of listeriosis.

Currently, one of the most common ways to use the drug is to take it orally. It is easier and less painful than other common methods, such as intravenous or intramuscular injections. However, the effectiveness of drugs in these conditions is very limited due to poor pharmacokinetic behaviors and the sensitive structures of the drug molecules. Therefore, drugs need to be protected along the way to reach the drug delivery destination. It is important to design nanocarriers that are resistant to the acidic fluid of the stomach while changes in the intestinal fluid due to the environment of the gastrointestinal tract, such as the significant difference in the pH of the gastric and intestines. Chitosan (CS), a cationic polysaccharide, has received widespread attention due to its inherent mucosal adhesion properties, modulation of epithelial tight junction integrity, biocompatibility, biodegradability, improved stability, low toxicity, simple and gentle preparation methods, and various drug delivery solutions. Chitosan nanoparticles are prepared and characterized by different techniques. In addition, chitosan derivatives such as thiolated and carboxylated chitosan have been investigated to increase the effectiveness of oral drug absorption, effective dose control, and reduced side effects. Moreover, the synthesis of chitosan nanoparticles, different synthesis methods, their widespread applications as oral drug delivery carriers, and their effects on drug delivery were investigated. This study aims to further development of these nanoparticles as effective therapeutic and diagnostic carriers in the future.

Background: Chitosan is a biodegradable, biocompatible polymer regarded as safe for human dietary. Nanoparticles (NP) prepared with chitosan derivatives typically possess a positive surface charge and mucoadhesive properties such that can adhere to mucus membranes and release the drug payload in a sustained release manner. Current study is focused on preparation several kinds of chitosan formulations and different concentrations of cross linking agents in various conditions and characterization for achievement of most stable and biocompatible nanoparticle which labeled by FITC for in vitro tracking. Analysis method: In order to better investigate, in addition to chitosan, carboxymethyl chitosan was used. Preparation of chitosan nanoparticles is done by Ionotropic gelation method using different concentration of sodium tripolyphosphate (TPP) as cross-linking agent. Moreover, the synthesis of FITC-labeled chitosan at a combination of time, pH, different concentrations of salt and enzyme was investigated to produce stable nanoparticles for intestinal drug delivery. Physical characterization of nanoparticles were estimated by DLS and TEM as well as conjugation and covalent links were confirmed by FITR. Results: The size of the nanoparticles by transmission electron microscopy (TEM) was about 100± 50. Hydrodynamic diameter was measured by DLS around 150± ٥ 0 nm. In FTIR, covalent conjugation to the chitosan nanoparticles with control samples was confirmed. UV spectroscopy was used to determine the efficiency of conjugation which was over 70%. Conclusion: All of these findings favor the notion that the FITC conjugated chitosan nanoparticles produced in our work may offer promise for the development of an efficient therapeutic and diagnosis carrier for colon cancer in the future. However, further investigation is required to provide more evidence on di􀀀 erent aspects of the targeting activity and stability of this nanoparticle in in vivo.

Background and Objectives: Cancer is one of the leading causes of death around the world with a very high degree of mortality. Conventional therapies by cytotoxic drugs have high levels of side-effects for patient. Chitosan is a biocompatible and biodegradable compound. Thus, according to the minimum systemic toxicity for peptide and drug delivery, it is considered in applied programs. In this study, the Immunological effect of chitosan nanoparticles, was investigated on breast cancer cells in animal model.Methods: In this experimental model, chitosan nanoparticles were synthesized. The size and electrical charge were determined using DLS apparatus and SEM. After creation of tumor model in female BALB/c mice. Injections in the test and control groups, were performed intraperitoneally. IL-4 and IFN-γ were assayed using ELISA method to investigate the immunomodulatory effects of the nanoparticles.Results: Electric charge and size of the nanoparticles were determined and confirmed to be+11 mv and 200 nm, respectively. The nanoparticle-treated group produced large amounts of IFN-γ (213 pg/ml), while IL-4 level decreased (p<0.5).Conclusion: These nanoparticles has the potential to shift immune responses from a Th2 to Th1 through IFN-g production. Hence, these nanoparticles may be an appropriate and effective candidate for cancer therapy.