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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.

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The aim of this study, in the first step, was to recover the protein content in wastewater of fish meal factories using chitosan, chitosan nanoparticles and chitosan-aluminum sulphate composition. In the second step, the extracted protein was assessed for its  essential amino acids profile.  Also, the  reduced amount of proteins in the waste water was evaluated by measuring different parameters such as turbidity, pH, COD. Finally, chitosan nanoparticles characteristics were investigated using atomic force microscopy. Results showed that turbidity, COD and soluble protein significantly decreased upon  adding different concentrations of chitosan, nanoparticle of chitosan and chitosan-alum (p<0.05). The maximum protein recovery was related to chitosan-alum composition and chitosan nanoparticles with no significant difference between these two treatments. Evaluation of recovered protein in term of amino acids profiles showed that there were essential amino acids such as histidine, lysine, methionine and phenylalanine in protein of fish meal wastewater.      

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Enzymes of marine organisms are ideal candidates for biomonitoring of pollution in marine environments. For the widespread use of enzymes in industrial processes, carried out under certain physico-chemical conditions, their stability must be improved. In this study, for the first time, chitosan nanoparticles were used as matrices for augmenting the stability of Penaeus vannamei (Whiteleg shrimp)-derived purified proteases against metallic ions. For the electrostatic binding of the enzyme to the chitosan nanoparticles, the protein solution at a concentration of 7mg/ml was added to the nanoparticles, and incubated for 4 hours at 10°C. After 3 times rinsing with phosphate buffer of pH=7.5, the nano-enzyme was dissolved in 1ml phosphate buffer, and used for further studies. The results of this study showed that Fe²⁺ and Mn²⁺ significantly increased the enzyme activity, whereas a strong inhibitory effect was observed in the presence of Cd²⁺, Hg²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺, and a weak inhibitory effect in the presence of Na⁺ and K⁺. The immobilized enzyme exhibited greater resistance to metal ions than its free counterpart. The free enzyme was susceptible to the presence of metal ions, and with the increment of their concentrations, enzyme activity declines. From this nexus, it could be inferred that the high stability of immobilized enzyme is due to the presence of chitosan nanoparticles. Stability retention of the immobilized enzyme at high concentrations of metal ions indicates the efficacy and utility of the immobilization method in industrial enzyme technology.

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Background: Modern science in drug delivery systems has long been paid to effectively design drug delivery systems, to reduce side effects, increasing bioavailability, targeted drug delivery, and passing through blood-brain barriers. Nanoparticles are very important as carriers because they  carry different types of drugs to different parts of the body at the right time. Method: In the present study, thiolated nano chitosan loaded with Biperiden was synthesized by ion gel method using two types of crosslinkers (tripolyphosphate and genipin) and their efficiency was investigated. Results: FTIR analysis confirmed the successful synthesis of various stages of thiolated nano chitosan loaded with Biperiden by both crosslinkers. SEM images showed that as-synthesized nano-carriers have a nanorod structure and nanocarriers crosslinked by genipin had a more regular structure with a size of about 150 nm than nanocarrier crosslinked by TPP with a size of approximately 200 nm. In vitro drug release and cytotoxicity studies showed nano-carriers crosslinked by genipin have had a higher release and less cytotoxicity than nano-carriers crosslinked by TPP. Conclusion: Considering the lower toxicity and delayed release of nanoparticles synthesized with genipine than nanocarriers synthesized with TPP, the use of this nanocarrier increases the bioavailability of the drug and can be used as a suitable drug delivery system.

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The formation of chitosan nanoparticles (CSNPs) with a high stability still remains a main challenge in terms of applying the produced particles in the field of nutraceutical and drug delivery systems. Giving that there are many variables parameters which could affect the size, morphology, and other properties of fabricated CSNPs during ionic gelation process along with using sodium tripolyphosphate (STPP) as the most common cross-linking agent. In this study, after the production of CSNPs under the influence of various independent variables such as chitosan (CS) concentration, STPP concentration, and CS to STPP ratio, in the next step, the physical, rheological, turbidity, and colorimetric properties of the produced nanoparticles were measured. Finally, two artificial neural networks (ANNs) – multilayer perceptron (MLP) and radial basis function (RBF) – with a single hidden layer and different threshold functions, learning algorithms, etc. were employed to predict the CSNPs properties. The results revealed that MLP for the physical, viscosity, b^*, and chroma properties and RBF for other properties – with a Levenberg-Marquardt (LM) learning algorithm of 1000 epochs – well predict them with a very high determination coefficients (R²) and low mean square error (MSE). R² for nanoparticle size, poly dispersity index (PDI), zeta potential, viscosity, and electrical conductivity of CSNPs suspensions were determined 0.9881, 0.9534, 0.9431, 0.9212, and 0.9636, respectively. However, RBF with a single hidden layer comprising a set of 3 inputs, 4 neurons in hidden layer, and 3 outputs with the SigmoidAxon- SigmoidAxon transfer function presented the best results for predicting the L^*, ΔE, and WI properties of CSNPs suspensions. In addition, R² for L^*, ΔE, and WI of CSNPs were calculated 0.9586, 0.9775, and 0.9457, respectively. Also, the flow behavior index of CSNPs suspensions was determined less than 1, which indicates the pseudoplastic behavior of the samples.

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Grape fruit contains some nutrients and high amounts of biologically active phenolic substances, but fungal decay and quality loss are important factors limiting its shelf-life for fresh-consuming and export. Rasheh vine (Vitis vinifera cv. Rasheh) is mainly grown in rainfed vineyards in the western half of Iran, and its berries are rich in anthocyanins, flavonoids and soluble solids. In this study, the effect of natural coatings of nano-chitosan and acetic acid on the post-harvest quality characteristics of Rasheh grape fruit was investigated. Nano-chitosan suspension with a particle size distribution of 5-30 nm was prepared in acetic acid solution by the conventional ionic gelation method. Grape fruits were coated by immersion in the nano-chitosan suspension (0.2%), acetic acid solution (0.5%) or distilled water (control) for 1 min and their microbial, physicochemical and sensory properties were measured during 8 weeks storage at 4 °C and 90% relative humidity. In general, the fruits coated with nano-chitosan or acetic acid had lower aerobic mesophilic bacteria count, mold and yeast count and decay percentage, and higher firmness, soluble solids, titratable acidity and vitamin C, as well as, better sensory properties, compared to the control. The nano-chitosan was more effective than acetic acid in improving the post-harvest quality and shelf life of grape fruit. No significant difference was observed in the weight loss percentage and pH values of the samples. Therefore, the nano-chitosan suspension prepared in acetic acid solution, as a natural and customer-friendly coating, is suitable for improving the shelf-life and post-harvest quality of grape fruit, but some of its beneficial effects are due to acetic acid.

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In interest of increasing demand for natural foods free of artificial preservatives, this study aimed to Controlling the antioxidant properties of green tea extract (GT) through its encapsulation in chitosan nanoparticles (CS-NP) and to investigate its preservative effects on surimi. The results showed that GT-loaded chitosan nanoparticle (CS-NP-GT) was significantly effective in reducing the lipid oxidation of surimi by determination of Thiobarbituric acid and free fatty acids. Chemical, microbial and sensory analyzes of surimi with CS-NP-GT treatment showed a significant difference compared to other treatments (p <0.05). At the end of the storage period, surimi treatment with CS-NP-GT caused 2.6 log cycles reduction of lactic acid bacteria, 2.55 log cycles reduction of Enterobacteriaceae, 4.32 log cycles reduction of aerobic mesophilic bacteria, 3.7 log cycles reduction of Bacillus cereus and 2.61 log cycles reduction of mold and yeast. Also in the sensory evaluation, E-0.1-GT had higher score on the ninth day of storage compared to surimi prepared with other treatments. The results of this study showed that encapsulation of green tea extract with chitosan nanoparticles is a promising technology to control chemical, microbial and adverse sensory changes in surimi and increase the shelf life of this product.

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