Synthetic electrospun nanofibers as a supportive matrix in osteogenic differentiation of induced pluripotent stem cells

Continuous remodeling is not able to repair large bone defects. Bone tissue engineering is aimed to repair these defects by creating bone grafts. To do this, several technologies and biomaterials have been employed to fabricate an in vivo-like supportive matrix. Electrospinning is a versatile technique to fabricate porous matrices with interconnected pores and high surface area, replicating in vivo microenvironment. Electrospun scaffolds have been used in a large number of studies to provide a matrix for bone regeneration and osteogenic differentiation of stem cells such as induced pluripotent stem cells (iPSCs). Electrospinning uses both natural and synthetic polymers, either alone or in combination, to fabricate scaffolds. Among them, synthetic polymers have had a great promise in bone regeneration and repair. They allow the fabrication of biocompatible and biodegradable scaffolds with high mechanical properties, suitable for bone engineering. Furthermore, several attempts have done to increase the osteogenic properties of these scaffolds. This paper reviewed the potential of synthetic electrospun scaffolds in osteogenic differentiation of iPSCs. In addition, the approaches to improve the osteogenic differentiation of these scaffolds are addressed.

PVC membrane sensor for diclofenac: applications in pharmaceutical analysis and drug binding studies

A PVC membrane sensor for diclofenac based on its ion pair complex with silver is prepared. The influences of membrane composition (PVC, plasticizer, and ion pair complex), pH of test solution and presence of other anions on the performance of the electrode were investigated. The optimized membrane demonstrates Nernstian response (-58.9 +/- 0.2 mV/decade) for diclofenac anions over a wide linear range from 5.2 x 10(-5) to 1.1 x 10(-2) M at 25 +/- 1 degree C. The potentiometric response is independent from pH at the range of 6.0-9.5. The advantages of the proposed sensor are: easy preparation, good selectivity and fast response time. It was successfully used for determination of diclofenac in pharmaceuticals and also in potentiometric study of interaction of diclofenac with bovine serum albumin. The results of diclofenac assay with the proposed sensor were in good agreement with the official HPLC method.

Mathematical representation of analyte's capacity factor in binary solvent mobile phases using the Jouyban-Acree model

Applicability of a solution model, namely the Jouyban-Acree model, for mathematical representation of capacity factors of phenobarbital, phenytoin and carbamazepine in mobile phases containing water and the organic modifiers: methanol, acetonitrile, acetone and tetrahydrofuran and also a number of data sets collected from the literature has been shown. The accuracy of the proposed model is compared with those of the linear model and the quadratic equation using average percentage deviation (APD) as an accuracy criterion. The obtained mean and standard deviation of APDs of the Jouyban-Acree, linear and quadratic models are 8.1 +/- 8.4, 25.2 +/- 18.0 and 14.5 +/- 16.2%, respectively. The results showed that the Jouyban-Acree model provided more accurate calculations than the previously published models and the mean differences were statistically significant (p < 0.002).

A simple spectrophotometric method for determination of sodium diclofenac in pharmaceutical formulations

A new, simple, rapid and accurate spectrophotometric method is proposed for determination of sodium diclofenac (SD) in pharmaceutical preparations based on its reaction with concentrated nitric acid (63% w/v). The reaction product is a yellowish compound with maximum absorbance at 380 nm. The corresponding calibration curve is linear over the range of 1-30 mg l(-1), while the limit of detection is 0.46 mg l(-1).