Fasermatrices aus synthetischen und natürlichen Polymeren für Tissue Engineering und Wirkstofffreisetzung

In dieser Arbeit wurden nanostrukturierte und funktionalisierte Fasermatrices auf polymerbasis für Anwendungen im Bereich des Tissue Engineerings von Knochen- und Muskelgewebe und zur Wirkstofffreisetzung präpariert und untersucht. Die Polymerfaser wurde mit der Technik des Elektrospinnens erzeugt. So wurden unter anderen orientierte und wachstumsfaktorbeladene Fasermatrices auf ihre Eignung zur Zellbesiedelung getestet. Des Weiteren wurden für die pulmonale Applikation von therapeutischen DNA- und siRNA-Komplexen Polymerfasern als mögliche Trägersysteme betrachtet

Biofunctionalized nanofibers using Arthrospira (Spirulina) biomass and biopolymer

Electrospun nanofibers composed of polymers have been extensively researched because of their scientific and technical applications. Commercially available polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHB-HV) copolymers are good choices for such nanofibers. We used a highly integrated method, by adjusting the properties of the spinning solutions, where the cyanophyte Arthrospira (formally Spirulina) was the single source for nanofiber biofunctionalization. We investigated nanofibers using PHB extracted from Spirulina and the bacteria Cupriavidus necator and compared the nanofibers to those made from commercially available PHB and PHB-HV. Our study assessed nanofiber formation and their selected thermal, mechanical, and optical properties. We found that nanofibers produced from Spirulina PHB and biofunctionalized with Spirulina biomass exhibited properties which were equal to or better than nanofibers made with commercially available PHB or PHB-HV. Our methodology is highly promising for nanofiber production and biofunctionalization and can be used in many industrial and life science applications

Extraction of poly(3-hydroxybutyrate) from Spirulina LEB 18 for developing nanofibers

The objective of this study was to extract poly(3-hydroxybutyrate) (PHB) from the microalgal biomass of Spirulina LEB 18 for the development of nanofibers by electrospinning method. Different extraction methods were tested. The maximum yield obtained was 30.1 ± 2%. It was possible to produce nanofibers with diameters between 826 ± 188 nm and 1,675 ± 194 nm. An increase in the nanofiber diameter occurred when a flow rate of 4.8 μL min-1 and a capillary diameter of 0.90 mm were used. The nanofibers produced had up to 34.4% of biomass additives, i.e., non-PHB materials. This can be advantageous, because it enables the conservation of microalgal biomass compounds with bioactive functions

Influence of Poly(L-Lactic Acid) Nanofibers and BMP-2–Containing Poly(L-Lactic Acid) Nanofibers on Growth and Osteogenic Differentiation of Human Mesenchymal Stem Cells

The aim of this study was to characterize synthetic poly-(L-lactic acid) (PLLA) nanofibers concerning their ability to promote growth and osteogenic differentiation of stem cells in vitro, as well as to test their suitability as a carrier system for growth factors. Fiber matrices composed of PLLA or BMP-2–incorporated PLLA were seeded with human mesenchymal stem cells and cultivated over a period of 22 days under growth and osteoinductive conditions, and analyzed during the course of culture, with respect to gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and collagen I (COL-I). Furthermore, COL-I and OC deposition, as well as cell densities and proliferation, were analyzed using fluorescence microscopy. Although the presence of nanofibers diminished the dexamethasone-induced proliferation, there were no differences in cell densities or deposition of either COL-I or OC after 22 days of culture. The gene expression of ALP, OC, and COL-I decreased in the initial phase of cell cultivation on PLLA nanofibers as compared to cover slip control, but normalized during the course of cultivation. The initial down-regulation was not observed when BMP-2 was directly incorporated into PLLA nanofibers by electrospinning, indicating that growth factors like BMP-2 might survive the spinning process in a bioactive form

Characterization of a PLLA-Collagen I Blend Nanofiber Scaffold with Respect to Growth and Osteogenic Differentiation of Human Mesenchymal Stem Cells

The aim of this study was to enhance synthetic poly(L-lactic acid) (PLLA) nanofibers by blending with collagen I (COLI) in order to improve their ability to promote growth and osteogenic differentiation of stem cells in vitro. Fiber matrices composed of PLLA and COLI in different ratios were characterized with respect to their morphology, as well as their ability to promote growth of human mesenchymal stem cells (hMSC) over a period of 22 days. Furthermore, the course of differentiation was analyzed by gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and COLI. The PLLA-COLI blend nanofibers presented themselves with a relatively smooth surface. They were more hydrophilic as compared to PLLA nanofibers alone and formed a gel-like structure with a stable nanofiber backbone when incubated in aqueous solutions. We examined nanofibers composed of different PLLA and COLI ratios. A composition of 4:1 ratio of PLLA:COLI showed the best results. When hMSC were cultured on the PLLA-COLI nanofiber blend, growth as well as osteoblast differentiation (determined as gene expression of ALP, OC, and COLI) was enhanced when compared to PLLA nanofibers alone. Therefore, the blending of PLLA with COLI might be a suitable tool to enhance PLLA nanofibers with respect to bone tissue engineering

Fasermatrices aus synthetischen und natürlichen Polymeren für Tissue Engineering und Wirkstofffreisetzung

In dieser Arbeit wurden nanostrukturierte und funktionalisierte Fasermatrices auf polymerbasis für Anwendungen im Bereich des Tissue Engineerings von Knochen- und Muskelgewebe und zur Wirkstofffreisetzung präpariert und untersucht. Die Polymerfaser wurde mit der Technik des Elektrospinnens erzeugt. So wurden unter anderen orientierte und wachstumsfaktorbeladene Fasermatrices auf ihre Eignung zur Zellbesiedelung getestet. Des Weiteren wurden für die pulmonale Applikation von therapeutischen DNA- und siRNA-Komplexen Polymerfasern als mögliche Trägersysteme betrachtet

Matrizes de micro-e/ou nanofibras biodegradáveis para desenvolvimento de células-tronco ou diferenciadas oriundas de biopolímeros extraídos de microalga(s) e/ou cianobactéria(s)

Universidade Federal de Rio GrandeUniversidade Federal do Rio Grande do SulFarmáciaCiências Básicas da SaúdeDepositad