The aim of the research was to develop optimal conditions for manufacturing materials based on hyaluronic acid by the electrospun method. The studies were composed of three stages: the process of selection of the optimal solvent (mixture of solvents), the molecular weight of hyaluronic acid, and the concentration of biopolymer in the spinning solution. The influence of variable parameters on the rheological properties of the spinning solutions and electrospinning trails was tested. Depending on the electrospinning regime applied, the fibers obtained were characterised by a diameter of the order of 20 to 400 nm. As a result of the development works presented, an optimal molecular weight of the polymer, its concentration and system of solvents were determined, together with process parameters, ensuring a stable electrospinning process and relatively homogeneous nanofibers. Additionally studies on the residues of solvents used during electrosun formation were done and parameters of drying of the final materials were examined. This approach (verification of the presence oforganic solvent residue in the nanofibrous formed) is important for the suitability of nanofibres as scaffolds for regenerative medicine. This study provides an opportunity for the understanding and identification of process parameters, allowing for predictable manufacturing nanofibers based on natural biopolymers, which makes it tremendously beneficial in terms of customisation.

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Hyaluronate and alginate are non-toxic and biocompatible polymers, which can be used for surface modification and functionalization of many kinds of materials. Electrophoretic deposition (EPD) has several advantages, including its versatility, simplicity, and ability to coat substrates with complex shapes, and is used for the creation of antimicrobial or hydrophobic coatings on metallic biomaterials, among other applications. However, its utilization for applying biopolymer layers on textiles is very limited due to the more complex structure and spatial characteristics of fibrous materials. The aim of this research was to analyze the effects of selected EPD process parameters and the structural characteristics of fibrous carriers on the kinetics of the process and the microscopic characteristics of the deposited layers. The influence of solution characteristics, process parameters, and carrier structures obtained using two different techniques (melt blown and spun-bonded) were analyzed. The morphology and structure of the created deposits were analyzed using scanning electron microscopy and computed tomography, and molecular structure analysis was performed with Fourier Transform Infrared spectroscopy. The surface mass and thickness of fibrous poly (lactic acid)-based carriers were analyzed in accordance with the respective standards. This study serves as a basis for discussion and further development of this method with regard to fibrous materials for medical applications.

Studies related to selection of molar mass of hyaluronic acid and analysis of rheological properties of hyaluronic acid solutions modified with bioactive substances, used in spinning, were undertaken within the presented work. A cephalosporin group antibiotic, Biofuroxime ® , was used, together with the nanoadditives zinc oxide (ZnO) and hydroxyapatite (HAp). Electrospinning studies were performed on selected solutions using a large scale laboratory station, allowing the process to be performed using three nozzles supplying the spinning solution. Optimum electrospinning conditions were selected on the basis of the performed study, which allow fibrous structures made of elementary fibres with diameters below 200 nm to be obtained. Studies showed that the most preferred distance between the nozzle and the collecting manifold was 450 mm and the most preferred applied voltage was 30 kV. The obtained, modified nanofibres of hyaluronic acid comprise structures for use in the production of biomaterials with a wide range of applications in tissue engineering.

For high sensitivity in micro bio-analysis devices (MBD), the fabrication of the micro-structured reaction field using vertically aligned carbon nanotubes (VACNTs) which is pillar-structured by two methods was performed. The first method is the combination of photolithography and thermal chemical vapor deposition (CVD). The second method is the molding process of polydimethylsiloxane (PDMS) substrate with micro-pillars array and the transfer press of VACNTs synthesized by thermal CVD on PDMS substrate for lower cost in mass production compared with photolithography process. In the first method, circular-pattered metal film on silicon (Si) substrate as the catalyst for VACNTs synthesis was fabricated by photolithography and VACNTs-pillars array was successfully fabricated using the substrate with circular-pattered metal film by thermal CVD. Furthermore, the protein adsorption property of these structures was evaluated as the reaction field of MBD by ultraviolet (UV) spectroscopy. The results show that the protein adsorption property was improved considering the design of micro pattern in VACNTs structures. On the other hand, in the second method, pillar-structured PDMS substrate was molded using a photoresist mold by photolithography and VACNTs was transferred on PDMS substrate by transfer-press equipment. The results indicate that VACNTs can be transferred on the top of micro pillar of PDMS substrate controlling the load of transfer press. Furthermore, it is indicated that micro-pillar VACNTs structures can be fabricated by molding and transfer press with lower cost than the combination of photolithography and thermal CVD.

This article concerns the process of obtaining fibers made of sodium alginate containing nanosilver. The general objective was to select the proper forming parameters in order to obtain possibly high rates of tensile properties. The specific objective of this investigation was to determine the effect of basic forming parameters on the macroscopic structure, as well as the determination of the tensile, sorption, and resistivity properties of the obtained fibers. The porous structure and morphology studies were carried out by X-ray diffraction WAXS. Cross-sectional and surface analysis was carried out by SEM (scanning electron microscope) and AFM method (atomic force microscopy). SEM (Scanning electron microscope) + EDS (energy-dispersive X-ray spectroscopy) analysis was applied to assess the uniformity of distribution of nanoadditives on the fibers' surface, and FTIR spectroscopy was applied to confirm the chemical structure of fibers. Within the framework of this article, the impact of specific nanoadditives on the properties of the obtained fibers was also examined. C

The results of studies assessing the influence of the addition of carbon nanofillers, such as multiwalled carbon nanotubes (MWCNTs) and graphene oxide (GO) that differ in size and structure, on the molecular and supramolecular structure and properties of alginate fibers that might be prospective precursors for carbon fiber (PCF) industry are presented in this article. The investigation was carried out by Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), and tension testing. In the frame of the current study, two types of alginate fibers were examined and compared: alginic acid and calcium alginate fibers. Alginic acid fibers were formed by chemical treatment of calcium alginate fibers with hydrochloric acid due to the fact that Ca2+ ions presented in the fibers were expected to adversely affect the prospective carbonization process. This investigation brought important conclusions about the influence of nanofillers on the physical properties of the final material. Understanding the link between the incorporation of carbon nanostructures and a possible influence on the formation of ordered carbon structures in the precursor fibers brings an important opportunity to get insights into the application of alginate fibers as a prospective base material for obtaining cost-efficient carbon fibers.