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Información de la Tesis Doctoral

Development of nanomaterial based scaffolds for bone tissue regeneration

Sara López de Armentia Hernández

Dirigida por E. Paz, N. Dunne

02 de diciembre de 2022

Resumen:

Bone fractures and bone defects are often caused by traumatic injury, cancer or other diseases. When a defect appears, the spontaneous fracture healing process begins. However, sometimes bones defect cannot heal spontaneously. This situation occurs especially in large segmental bone defects when the defect reaches a critical size. In these cases, additional surgical interventions that help and allow bone healing are required. Autograft represents the gold standard for the treatment of critical-sized bone defects. However, significant problems are associated with its use, from donor-site morbidity to a limited amount of donor bone.

To avoid problems encountered when using conventional methods, researchers have made a significant effort to create 3D porous matrices, known as scaffolds. They are based on guided bone regeneration, the aim of which is bone regeneration and growth along the surface of the scaffold. Scaffolds have been manufactured by techniques like solvent casting, freeze-drying and salt leaching. However, the geometry, porosity and pore size are not controlled. This control can be achieved by Additive Manufacturing (AM) technologies. AM allows to imitate natural tissue or organs and to control the special arrangement among cells.

Graphene-based nanomaterials are promising candidates to be used as reinforcement for bone repair and regeneration applications due to the exceptional combination of excellent mechanical, thermal and electrical properties along with their proven antimicrobial and cell regeneration capabilities. Besides, nanocomposites with carbon nanomaterials have demonstrated to favour cell adhesion and proliferation on their surface and encourage bone growth.

However, to produce scaffolds reinforced with graphene-based nanomaterials by AM technologies, it is urgent to study the modification of available raw materials to adjust their properties to the needed for this purpose. Besides, in the case of photocurable polymers used in some AM technologies, the nanofillers used to modify their properties could also affect other parameters, like printability, polymerization, mechanical and/or biological performance.

The main objective of the doctoral thesis is to develop 3D bone scaffolds reinforced with Graphene-Based Nanomaterials (GBN) using Vat Photopolymerization techniques, i.e. stereolithography (SLA), that allow to obtain scaffolds with improved mechanical properties and high cell proliferation activity. To achieve it, some partial objectives are proposed:

  1. To define a procedure to prepare photocurable resins reinforced with GBN that allows to obtain structures by vat polymerization technologies.
  2. To study GBN effect on the thermal and UV polymerization process of acrylic photopolymer.
  3. To optimize the printing and post-printing processes of the GBN-reinforced resins to reach improvements in mechanical properties.
  4. To study the efficacy of reinforced photocurable resins in terms of cytotoxicity, cell proliferation and bone tissue regeneration.

This thesis has established solid foundations for manufacturing bone scaffolds with GBN by Vat photopolymerization additive manufacturing technologies, i.e. SLA, DLP, LCD, taking advantage of the good precision and easy sterilization offered by these technologies. 


Resumen divulgativo:

El objetivo principal de esta tesis doctoral es desarrollar andamios óseos tridimensionales reforzados con nanomateriales base grafeno (NBG) utilizando tecnologías de fabricación aditiva de fotopolimerización, como estereolitografía (SLA), que permita obtener andamios con propiedades mecánicas mejoradas y alta capacidad de proliferación celular. Esta tesis ha establecido unos cimientos sólidos para fabricar andamios óseos con NBG por tecnologías de fabricación aditiva basadas en fotopolimerización, aprovechando la buena precisión y la fácil esterilización que ofrecen dichas tecnologías. 


Descriptores: Cinética Química, Medidas de Propiedades Mecánicas, Materiales Compuestos, Cultivo Celular

Palabras clave: andamios óseos, estereolitografía, nanomateriales base grafeno, resina acrílica.

Cita:
S. López de Armentia (2022), Development of nanomaterial based scaffolds for bone tissue regeneration. Madrid (España).


Acceso a Repositorio público