Optimization of Formulation and Process Variables for the Preparation of Novel Doxorubicin-Loaded Sonosensitive Nanodroplets

In the present study the effect of process (homogenization speed) and formulation (polymer concentration, surfactant concentration, drug amount, perfluorohexane volume fraction and co-surfactant inclusion) variables on particle size, entrapment efficiency, and drug release kinetics of doxorubicin-loaded alginate stabilized perfluorohexane nanodroplets were evaluated. Particle size and doxorubicin entrapment efficiency were highly affected by formulation and process variables. In vitro release profile of doxorubicin from all formulations was an apparently biphasic release process and 7–13 % of drug released from nanodroplets after 24 h incubation in PBS, pH 7.4, depending on the nanodroplets composition but ultrasound exposure for 10 min resulted in triggered release of 85.95 % of doxorubicin fromoptimal formulation (G). The inclusion of Span 60 (0.15 %), Poloxamer 188 (0.15 %) as co-surfactants reduced the particle size of nanodroplets from 51.8 to 42.3 and 35.6 nm, respectively. The entrapment efficiency decreased for span 60, while it did not changed in the case of Poloxamer 188. Comparison of drug release kinetics demonstrated that drug release was delayed for both Span 60 and Poloxamer 188. Thus, it was concluded that the particle size, entrapment efficiency and the doxorubicin release kinetics could easily be adjusted by taking advantage of process and formulation variables.     

Thermodynamic and thermoeconomic analyses and energetic and exergetic optimization of a turbojet engine

Journal of Thermal Analysis and Calorimetry - In this study, a thermal model for a turbojet engine is proposed. Besides the engine’s performance, the cost flow rate of each component is...     

Preparation,Characterization, and In Vitro Biological Evaluation of PLGA/Nano-Fluorohydroxyapatite (FHA) Microsphere-Sintered Scaffolds for Biomedical Applications

In this research, the novel three-dimensional (3D) porous scaffolds made of poly(lactic-co-glycolic acid) (PLGA)/nano-fluorohydroxyapatite (FHA) composite microspheres was prepared and characterize for potential bone repair applications. We employed a microsphere sintering method to produce 3D PLGA/nano-FHA scaffolds composite microspheres. The mechanical properties, pore size, and porosity of the composite scaffolds were controlled by varying parameters, such as sintering temperature, sintering time, and PLGA/nano-FHA ratio. The experimental results showed that the PLGA/nano-FHA (4:1) scaffold sintered at 90 °C for 2 h demonstrated the highest mechanical properties and an appropriate pore structure for bone tissue engineering applications. Furthermore, MTT assay and alkaline phosphatase activity (ALP activity) results ascertained that a general trend of increasing in cell viability was seen for PLGA/nano-FHA (4:1) scaffold sintered at 90 °C for 2 h by time with compared to control group. Eventually, obtained experimental results demonstrated PLGA/nano-FHA microsphere-sintered scaffold deserve attention utilizing for bone tissue engineering.     

Rapid and enhanced functionalization of MWCNTs in a dielectric barrier discharge plasma in presence of diluted CO<Subscript>2</Subscript>

Multiwalled carbon nanotubes (MWCNTs) have been functionalized in dielectric barrier discharge (DBD) plasma in presence of a mixture of carbon dioxide and a diluent gas at room temperature and atmospheric pressure. He, Ar, and N₂ were examined as the diluent gases. Temperature-programmed desorption was used to investigate the influence of various plasma parameters and type of diluent gas as well as the amount of diluent in the plasma gas. It is found that the quantity of functional groups on the surface of MWCNTs is a maximum when He is used as diluent gas. It also passes through a maximum when He content is 60%. The presence of He improves the reactivity of the plasma, which leads to an increase in the quantity of functional groups. However, high percentages of He decrease the CO₂ content, which in turn decreases the number of functional groups. FTIR and Raman spectroscopy showed the presence of Oxygen-containing functional groups on MWCNTs surfaces.     

Controlled synthesis, characterization and optical properties of CdS nanocrystalline thin films via chemical bath deposition (CBD) route

In this study, the CdS nanocrystalline thin films obtained from an ammonia-free chemical bath deposition process. The crystallites with a size range of 10–20 nm in diameter with zinc blend (cubic) and wurtzite (hexagonal) crystal structure and strong photoluminescence were prepared from the mixture solutions of: cadmium chloride dihydrate as a cadmium source, thiourea as a sulfur source and sodium citrate dihydrate as a complexing agent for cadmium ions. The well-cleaned glass used as a substrate for thin films deposition. The obtained samples were characterized by the techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), atomic force microscopy (AFM) and fluorescence spectroscopy. Also, the effect of two parameters such as pH and temperature of reaction on the synthesis of CdS nanocrystals was studied. Finally, it was found the CdS nanocrystals showed sharp excitation features and strong “band-edge” emission.