Chitosan is widely applied in biomedical and cosmetic fields. For this reason, there is a need to modify this biopolymer to achieve new properties of chitosan-based materials. The properties of chitosan can be modified by several cross-linking methods. In this work, we used the chemical cross-linking of chitosan with tannic acid, after which cross-linked chitosan was shaped into a 3D structure ...

Polyelectrolyte-coated nanoparticles or microparticles interact with bioactive molecules (peptides, proteins or nucleic acids) and have been proposed as delivery systems for these molecules. However, the mechanism of adsorption of polyelectrolyte onto particles remains unsolved. In this study, cationic poly(lactide-co-glycolide) (PLGA) nanoparticles were fabricated by adsorption of various conc...

Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activ...

OBJECTIVES Surgical reconstruction of the right ventricular outflow tract (RVOT) often requires implantation of a valved conduit. A single-centre 10-year experience with the Hancock porcine-valved Dacron conduit was retrospectively assessed. METHODS The records of 63 patients who underwent RVOT reconstruction with Hancock conduit implantation between August 2000 and July 2010 were retrospecti...

The karstic Rijab Spring with an average discharge of 3290 l/s is located in the Alvand River basin in the northwest of the Zagros, Iran, which drains Asmari formation. To investigate groundwater flow in the catchment area of the Spring, the physicochemical parameters include major cations and anions, discharge, EC, pH, and temperature were studied from September 2000-2002. The results indicate...

Chitin, chitosan and quaternary chitosan films were prepared, and the mechanical properties and the antibacterial activities of chitosan and quaternary chitosan films were evaluated. The tensile strength of chitin films was 30-40% lower than that of chitosan films, but the crystallinity of the former was much higher than those of the latter. A detailed analysis of the crystallinity and orientat...

For the purpose of obtaining high bone forming efficacy, development of chitosan was attempted as a tool useful as a scaffolding device. Porous chitosan matrices, chitosan-poly(L-lactide) (PLLA) composite matrices and chitosan coated on PLLA matrices were dealt with in this research. Porous chitosan matrix was fabricated by freeze-drying and cross-linking aqueous chitosan solution. Porous chito...

To assess the results of cardiac repair utilizing a right ventricular to pulmonary artery conduit, we reviewed postoperative hemodynamic data in 16 patients catheterized 0.5 to 5 years after repair. In 12 patients, a Hancock conduit (dacron conduit with porcine valve) was used; the conduit in the remaining four patients was made with an aortic homograft. All patients in whom an aortic homograft...

Novel electrospun nanofibrous CS-PEO nerve conduits containing 0, 2.5 and 5% of green tea methanolic extract were developed and characterized by FE-SEM, FT-IR, TGA/DSC as well as tensile strength analysis. The FE-SEM images revealed that all of the nanofibers had an average diameter of ∼80nm. The swelling degree was decreased by increasing the GT amount from 2.5 to 5% and this might be attribut...