Ryszard Fryczkowski

Characterization of Olfactory Ensheathing Glial Cells Cultured on Polyurethane/Polylactide Electrospun Nonwovens

The aim of this research was to evaluate novel biomaterials for neural regeneration. The investigated materials were composed of polyurethane (PU) and polylactide (PLDL) blended at three different w/w ratios, that is, 5/5, 6/4, and 8/2 of PU/PLDL. Ultrathin fibrous scaffolds were prepared using electrospinning. The scaffolds were investigated for their applicability for nerve regeneration by culturing rat olfactory ensheathing glial cells. Cells were cultured on the materials for seven days, during which cellular morphology, phenotype, and metabolic activity were analysed. SEM analysis of the fabricated fibrous scaffolds showed fibers of a diameter mainly lower than 600 μm with unimportant volume of protrusions situated along the fibers, with nonsignificant differences between all analysed materials. Cells cultured on the materials showed differences in their morphology and metabolic activity, depending on the blend composition. The most proper morphology, with numerous p75

Preparation and Properties of Composite PAN/PANI Membranes

The methods of modifying PAN membranes have been known and used for many years. An interesting solution seems to be to give the sensory properties to this type of membranes. This paper presents the results of research on the method of obtaining PAN/PANI membranes using phase inversion method from a solution in DMF, following two methods: () dissolving both polymers (PAN and PANI) and then coagulating in water or in an aqueous solution of CSA and () forming the membranes from polyacrylonitrile solution and coagulation in water, followed by coating of CSA with a solution of TFE. The membranes obtained as a result of the experiment were tested for physical and chemical properties, transport properties, surface morphology, degree of dispersion of composite components, and sensitivity to the presence of dilute acids and bases. FTIR microspectroscopy and scanning electron microscopy were used to study the surface morphology. The sensory properties of membranes that are inherently colored were determined visually and by UV-Vis spectrophotometry. Furthermore, when choosing the method of membrane forming, we can obtain membranes with good physical and chemical and transport properties or ones characterized by high sensitivity to the pH of the solution.

Morphology of Highly Porous Conducting Polyaniline Nanofibres Synthesized in a Multi-phase System

Polyaniline nanofibres are typically synthesized in a two-phase system with aniline placed in one liquid phase and the initiator in the other. The authors modified this method by introducing the monomer as a salt, thus creating a third, solid phase. This salt is in the organic phase as acetonitrile. Salts of aniline+DBSA and aniline+CSA were examined. As both these salts have limited solubility in acetonitrile, they do not dissolve during polymerization. To further reduce their solubility, acid was also added to both liquid phases. DBSA and CSA were used in the organic phase while in the aqueous phase, hydrochloric acid, sulfuric acid, DBSA and CSA were used along with the initiator (APS). Numerous polymerizations were carried out to examine various phase compositions. SEM, FTIR and UV-Vis observations revealed interesting properties of the polyaniline obtained in this way. Its morphology and spectroscopic properties strongly depend on the combination of the components used in each phase. Amorphous polyaniline was obtained as were well-developed spatial forms such as blades, spheres or nanofibres.

Formation of the Porous Polyaniline Structures

The conductivity of polyaniline can be controlled depending on the doping mechanism. Porosity of polyaniline seems to be one of the important factors of solid state doping, and depends on several synthesis process parameters as well as subsequent refining steps. Results of studies on polyaniline refinement with common solvents: methanol, chloroform, DMF and THF are presented. The effect of solvent type used for extraction on the polyaniline porosity is discussed.

Polyurethane/polylactide-based electrospun nonwovens as carriers for human adipose derived stromal stem cells and chondrogenic progenitor cells

ABSTRACT Articular cartilage dysfunctions are major cause of pain and disability and lead to serious health complications. Cell-based therapies are proposed as treatment methods for cartilage regeneration. In this study, we proposed polyurethane/poly(L-lactide-co-D, L-lactide)-based electrospun nonwovens as carriers for the delivery of human adipose-derived stromal stem cells. We found that 6:4 and 8:2 polyurethane/poly(L-lactide-co-D, L-lactide) initially enhance proliferative rate of human adipose-derived stromal stem cells, shorten their population doubling time, promote creation of functional chondrogenic nodules during chondrogenic differentiation, improve the collagen-2-to-collagen-1 protein ratio, and upregulate the expression of collagen-2 and aggrecan genes. GRAPHICAL ABSTRACT