Multifunctional soft materials: synthesis and applications
- Autores: Josué Muñoz Galindo
- Directores de la Tesis: Sonia Merino Guijarro (dir. tes.), Maria Antonia Herrero Chamorro (codir. tes.)
- Lectura: En la Universidad de Castilla-La Mancha ( España ) en 2022
- Idioma: inglés
- Tribunal Calificador de la Tesis: Félix Rodríguez Iglesias (presid.), Ana Sánchez-Migallón Bermejo (secret.), Amparo Ruiz Carretero (voc.)
- Programa de doctorado: Programa de Doctorado en Química Sostenible por la Universidad de Castilla-La Mancha; la Universidad de Extremadura; la Universidad Jaume I de Castellón; la Universitat de València (Estudi General) y la Universitat Politècnica de València
- Materias:
- Enlaces
- Tesis en acceso abierto en: RUIdeRA
- Resumen
The development of new materials in the field of medicine to regenerate artificial organs has grown in recent years to solve many health problems related to transplants or tissue regeneration. This thesis pretends to delve into the field of new scaffolds for cell culture and tissue engineering.
The first chapter provides an overview of hydrogels and nanomaterials. In the field of new scaffolds, hydrogels have been chosen since they are presented as very promising materials for applications in tissue engineering and regenerative medicine. Their flexibility and biocompatibility make them the best candidates for this purpose, mimicking the extracellular matrix and providing an ideal environment for growing and proliferating cells. Nanomaterials such as graphene in small amounts provide an ideal environment for growing neurons due to their fantastic electrical properties. Besides, magnetic iron nanoparticles allow us to prepare magnetic responsive hydrogels also taking advantage of their good properties for biomedical applications. Therefore, the combination between hydrogels and these nanomaterials gives rise to adequate scaffolds for tissue engineering and cell culture applications.
Sometimes 3D systems present problems related to cell adhesion since cells do not have specific receptors for chemical compounds of the hydrogel network. Therefore, to solve this issue, some scaffolds have been designed with different approaches to attach biological molecules or growth factors to a hydrogel matrix.
Taking into account this purpose, chapter 2 is based on the preparation of novel hydrogels with a sulfonated derivative monomer. The capacity of the sulfonate group to interact with proteins and growth factors provides the opportunity for its use as a monomer in a polymer network, studying their capability for cell culture. Besides, the role of nanomaterials such as graphene and magnetic nanoparticles is analysed. Studies with cells confirm the role of the sulfonate group in cell viability.
Likewise, the modification of graphene layers with sulfonic groups provides a different approach for cell culture studies, considering the appropriate properties of graphene and the capacity of the sulfonate group to coordinate growth factors. Thus, chapter 3 is focused on the functionalisation of graphene with a sulfonic derivative and its incorporation into a hydrogel network.
The binding of different types of cells has been established with peptide sequences covalently linked to the hydrogel network, such as the RGD peptide. Thus, chapter 4 is focused on the functionalisation of the RGD sequence with acrylate moieties for its inclusion in the hydrogel network. Cell viability studies revealed the positive influence of the peptide in the network and its incorporation.
The following, chapter 5, is focused on the preparation of a novel physically crosslinked hydrogel with an inherent blue emission due to an Aggregation-Induced Emission (AIE) process when excited under UV light. For this purpose, a penyltriazine compound has been used for the first time as a monomer in a hydrogel network. Polymer formation and intermolecular H-bonds arising from triazine moieties operate as AIE mechanisms. The combination of soft materials and AIE properties expands the applications of these materials. As a proof of concept, two luminescent dyes have been incorporated into the hydrogel to produce a white-light-emitting material.
It is important to highlight that in all chapters, an exhaustive study of the swelling capacity and mechanical properties of the hydrogels is presented, in order to adequate them for their final application. Thus, Young’s Modulus has been analysed to study the elasticity of the materials, or viscoelastic behaviour. These important parameters should be considered for cell spreading and cell differentiation. Besides, an adequate mesh size of hydrogels should be obtained for the incorporation of cells inside. The control of the pore size was performed by SEM microscopy measurements. Additionally, FTIR spectroscopy or TGA analysis have been widely used to check the inclusion of the molecules in the polymeric network of the hydrogels and the behaviour of the modified systems. SQUID analysis has been also used to measure the magnetization of magnetic hydrogels.
Therefore, a wide range of hydrogels with tunable properties have been designed and fully characterised. These non-cytotoxic hydrogels show potential application in the field of tissue engineering.
Finally, a soft responsive 3D scaffold based on Liquid Crystals is presented in chapter 6. The development of LC polymer materials has recently attracted too much attention due to the great potential of photoreversible optical molecules to control a wide variety of physical, chemical, and mechanical material properties in response to light. Azobenzene is the most promising chemical for photoreversible polymers. They have shown a great potential for a variety of cell control applications being able to reproduce well features of a dynamic 3D extracellular environment and provide controlled input of mechanical stimuli to living cells. A visible light-responsive liquid crystalline polymer material doped with fluorinated azobenzene is presented. Their surface topography is easily tuneable using mild illumination and temperature conditions, showing also potential application in the field of tissue engineering.
