Preparación de soportes biomateriales con estructuras fibrilares obtenidas mediante electro-hilatura
- Autores: Maria Salud Erencia Millán
- Directores de la Tesis: Fernando Carrillo Navarrete (dir. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2017
- Idioma: español
- Tribunal Calificador de la Tesis: Joan Josep Suñol Martínez (presid.), Margarita Morillo Cazorla (secret.), Milena Dimtchova Tzvetkova (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The fabrication of scaffolds materials with the ability to mimic the structural and functional properties of extracellular matrix is one of the most important points of interest into the tissue engineering field. Among the several techniques developed to fabricate tissue scaffolds, nanotechnology based methods such as electrospinning have demonstrated to play a relevant role in mimicking the properties of proteins fibers of the extracellular matrices.
The aim of this thesis is focused on the fabrication of protein based nanofibers (i.e. gelatin and collagen) to prepare artificial scaffolds with high biocompatibility using the electrospinning technique, mainly based on the use of electric force.
Firstly, the work was concentrated on the study of the effect of the operational and chemical parameters controlling the electrospinning process on the morphology and size of the obtained nanofibers. As a result, the optimal process parameters to obtain nanofibers of predefined properties were established. The results show that variations in the operational parameters (voltage, flow rate and distance between needle and collector) into the stable work range have not significant influence on the properties of electrospun nanofibers. By contrast, it was demonstrate that the solution parameters (polymer type, concentration, etc.) as well as the collector conductivity have a significant effect on the electrospinning process determining the final properties of the nanofibers.
Secondly, the study was concentrated in the search of alternative solvents able to keep the integrity of the proteins, that is, avoiding the denaturation and degradation of the polymer chains. With this objective, a comprehensive research about the fabrication of electrospun nanofibers at room temperature from mixtures of gelatin/acetic acid/water benign system was carried out. The electrospinnability limits of this system were established and the results were modeled from a complete analysis of the rheological system properties, in order to allow the prediction of the final fiber properties based on the solution composition.
Alternatively, a ternary mixture of PBS/Water/Ethanol was proposed as a new benign solvent for the electrospinning of three different gelatin materials. In this case, the effect of the type of gelatin on the electrospinninability and morphology of the nanofibers has also been studied based on their different origin and extraction process.
Thirdly, the stability of the electrospun nanofibers was addressed taking into account its importance regarding a potential application in tissue engineering as a scaffold. In this work, several application methods of glutaraldehyde as crosslinker were analyzed along as their influence on the morphology and size of electrospun fibers. In addition, a direct method of stabilization has been proposed based on the incorporation of low amounts of glutaraldehyde in the spinning solution offering the possibility to obtain stable nanofibers directly without the need of a post-spinning treatment.
Finally, with the purpose of increasing the mechanical properties of the nanofibers scaffolds, composite biomaterials were designed based on the deposition of proteins nanofibers over the surface of a synthetic biomaterial such as polyurethane. In this case, collagen nanofibers were fabricated by electrospinning and deposited onto different end-group-modified polyurethanes.
The morphology and distribution of the nanofibers was studied taking into account the chemistry of the biomaterial. Also the effect of the nanolayer of fibers on the final properties of the polyurethanes was analyzed.
