Curcumin is an herbal plant with great therapeutic applications. Although it is useful in treating several diseases, its low solubility in water and low bioavailability in living systems are limiting factors in using curcumin as a medicine. One way to overcome these shortcomings is the production of curcumin micro/nano particles. In this research, the particles of curcumin loaded with polycaprolactone (PCL)/chitosan were synthesized by the electrospray technique. To obtain the optimal conditions, Statistical optimization was carried out through Response Surface Method (RSM). The effect of flow rate, polymer concentration and PCL weight percentage on solution properties, mean particle size and particle size distribution were investigated. According to experimental results, the optimal size (471 nm) and size distribution (103) of particles were found at the lowest level of polymer concentration (2%) and flow rate (0. 25 ml/hr) and the highest level of PCL weight percentage (80%). Thus, the result of this study can be used to improve the quality of curcumin based medicine.

Introduction: The applicability of Nanofiber (NF) membranes in air sampling of pollutants for the purpose of determining the airborne concentration has received little attention around the world. The present study aims to optimize the fabrication of NF membrane for the of air sampling application. Materials and methods: The polyvinyl chloride NF membranes were fabricated using needle-based solution electrospinning technique. The experimental design was prepared by Design-Expert v7. 0 and data analysis was done by Central Composite Design (CCD) base on Response Surface Methodology (RSM) technique. The ability of the fabricated membranes in air sampling applications was performed by sampling of airborne crystalline silica by them using the National Institute for Occupational Safety and Health (NIOSH7602) method and then comparing with the commercial PVC membranes. Results: The fabricated NF membranes had a mean porosity of 31. 60% compared to a porosity of 25. 1% in the case of commercial Polyvinyl Chloride (PVC) membranes. The electrospun NF membranes had mean pressure drop of 194. 23 Pa, which is lower than the 204 Pa pressure drop of commercial PVC filters. The mean concentration of silica sampled by the electrospun NF membrane was 0. 14 mg/m 3 while this was 0. 03 mg/m 3 for commercial PVC membrane. The difference concentration of crystalline silica sampled by NF and commercial PVC membranes had the strongest relationship with the electrospinning solution concentration (r=-0. 785, p>0. 05). Conclusion: The NF membrane has high performance in sampling the crystalline silica dust from the air stream compared to commercial PVC membranes.

Polyhydroxyalkanoates are biodegradable polymer materials that accumulate in numerous bacteria. The polyhydroxybutyrate is the most common type of polyhydroxyalkanoates, which potentially serves as precursor for bioplastic production. The most extensively studied polyhydroxybutyrate producing bacteria is Cupriavidus necator due to its capability to accumulate large amounts of this biopolymer in simple culture medium. Accumulation of polyhydroxyalkanoates granules in the cytoplasm of C. necator significantly depended on pH, aeration, carbon sources, nitrogen sources, and minerals in the culture medium. In the present study, the effect of both nutritional and physical variables on polyhydroxybutyrate production was investigated in order to optimize these conditions. At first, on the basis of one-factor-at-a-time experiments, fructose and ammonium chloride were found to be the most suitable sources of carbon and nitrogen for biopolymer production. Then the most significant factors affecting granules accumulation were recognized as fructose, agitation speed, KH2PO4, and initial pH using the Plackett-Burman and central composite design. ANOVA analysis showed significant interaction between fructose and agitation speed. After optimization of the medium, compositions for polyhydroxybutyrate production were determined as follows: fructose 35 g/L, KH2PO4 1.75 g/L, MgSO4 7H2O 1.2 g/L, citric acid 1.7 g/L, trace element 10 mL/L, initial pH=7, and agitation speed 175 rpm. Under this optimal culture conditions, the maximum yield of PHB was 7.48 g/L. The present strategies included in this study could be used for PHB production by this bacterium. These results are the highest values of PHB ever obtained from batch culture of C. necator reported so far.