Novel Drug Delivery System Based on Ginsenoside Rb1 Loaded to Chitosan/Alginate Nanocomposite Films.

Recently, drug delivery using natural and biodegradable nanoparticles has attracted huge attention. This study focused to deliver an anti-cancer and anti-inflammatory drug Ginsenoside Rb1 through chitosan-Alginate nanocomposite film prepared by solution method. Ginsenoside Rb1 is a dammaran saponin group, which is extracted from an herbaceous plant Panax notoginseng. Ginsenoside loaded alginate-chitosan nanocomposite films were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) methods. The FTIR spectra of alginate/chitosan/ginsenoside Rb1 nanocomposite films show that chitosan, alginate, and ginsenoside Rb1 are linked through the hydrogen bonding and dipolar-dipolar interactions. The FESEM image indicates that the chitosan and ginsenoside Rb1 dispersed well in the alginate matrix. The DSC diagrams display that melting temperature of alginate/chitosan/ginsenoside Rb1 nanocomposite films higher than that of chitosan and lower than that of alginate. It means that alginate and chitosan interact together. Investigation of the ginsenoside Rb1 release from alginate/chitosan/ginsenoside Rb1 nanocomposite films at different pH solutions and different ginsenoside Rb1 content has been carried out by ultraviolet-visible spectroscopy method. The rate of drug release is proportional to the increase in pH solution and inversely proportional to the content of loaded ginsenoside Rb1. The Rb1 release process includes two stages: burst release in the first 10 hours, then constant release afterwards. The suitable ratio of alginate/chitosan to prepare the alginate/chitosan/ginsenoside Rb1 nanocomposite films for further investigations was found out to be 8:2. Ginsenoside Rb1 release process from alginate/chitosan/ginsenoside Rb1 nanocomposite films was believed to be first-order kinetics in the first stage, and then the Rb1 release complies with Higuchi kinetic model in the slow release stage. This study demonstrated the novel synthesis methodology to design drug delivery system based on ginsenoside Rb1 loaded to chitosan/alginate nanocomposite films.

Tensile, Thermal, Dielectric and Morphological Properties of Polyoxymethylene/Silica Nanocomposites.

This paper presents the tensile, thermal, dielectric and morphological properties of composites based on polyoxymethylene (POM) and nanosilica (NS) prepared by melt mixing method at 190 °C. Based on the torque readings, the processing of POM/NS composites were found to be easier in comparison to only POM. The FT-IR spectra analysis of the POM/NS nanocomposites showed the presence of peak at approximately 910 cm-1, attributed to the Si-O and C-O groups in NS and POM on the POM/NS nanocomposite. The absorption at these peaks increased on gradually increasing the content of NS. Tensile property testing (tensile strength, elongation at break, and Young's modulus) indicated that the tensile strength of POM/NS nanocomposites increases as the NS content increases from 0.5 wt.% to 1.5 wt.%, and sharply dropped when the NS content was more than 2 wt.%. A similar trend was observed for Young's modulus and elongation at break of the nanocomposites. The DSC analysis of the nanocomposites showed that the melting temperature (Tm) of POM/NC composites increased in the presence of low weight % of NS which can be attributed to the interaction between POM and NS leading to the rising crystallinity of all nanocomposites. POM/NS have a slightly higher temperature resistance as confirmed from the TGA analysis and POM/NS 1.5 wt.% had the maximum degradation temperature (Tmax) value and consequently the lowest weight loss. The dielectric constant of the nanocomposites increased from 3.26 to 3.56, while the dielectric loss tangent and volume resistivity were dropped, corresponding to the NS content from 0.5 to 2 wt.%. The SEM images of POM/NS nanocomposites demonstrated that the NS particles were dispersed relatively regularly into POM with a size in the range of 100 to 500 nm. They were dispersed more regularly into the polymer matrix at 1.5 wt.% NS. Based on the obtained results, the suitable NS content for the preparation of the POM/NS nanocomposites was found to be 1.5 wt.%.