3D Printing of Nanoreinforced Pectin-Based Hydrogels with Tunable Flow Properties for Bone Regeneration

• Autor(a) principal: Sabino, Diogo Rodrigues Francisco
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/91471
• topic: hydrogel; scaffold; 3D printing; laponite; methacrylated-pectin; polysaccharide; Domínio/Área Científica::Engenharia e Tecnologia::Nanotecnologia

Hydrogels have proved to be highly attractive biocompatible materials which can be used for tissue engineering applications. Among the hydrogels, Polysaccharides due to their superior mechanical properties, stability, and resemblance of the native extracellular bone matrix (ECM) are appealing to use as cell-based regenerative therapy. To impart complex 3-dimensional architectural features, printing methodology is a versatile approach due to its capability to fabricate customizable scaffolds. Pectin stands out since its solubility can be more easily modulated compared with the other natural polymers. One of the big burdens in this regard is that the lack of multifunctional printable materials which can resemble ECM of bone tissue. In order to make pectin printable for bone tissue engineering, nanosilicates can be used to modify the flow behavior of pectin. Moreover, nanosilicates provide osteogenic properties, mechanical reinforcement, and triggering of cell phenomena, making up for the absence of such properties in polysaccharides. Here, we hypothesized that the incorporation of laponite (LAP) nanosilicates within methacrylated-pectin (PEMA) enhance the shape fidelity and mechanical properties. Therefore, pectin was modified through a methacrylation process creating a UV-crosslinkable methacrylated-pectin (PEMA) hydrogel. Polymer concentration was kept unchanged while laponite amount was tuned in order to study its influence on disc-shaped scaffolds and to define a printability window. Using an extrusion-based process, the compositions of PEMA/LAP were printed and their printability properties quantified and a detailed study on the rheological properties of the PEMA/LAP hydrogels was conducted. Remarkably, elastic modulus in the range of 8-48 kPa were obtained, which is ideal to promote osteogenesis. Rheological properties, as well as mechanical properties, confirmed the existence of a saturation limit for LAP, from which scaffolds properties deteriorate. This nanocomposite platform highlights the potential of printed PEMA/LAP for bone tissue engineering, proposing a 3D-printable, low cost, tunable, biocompatible and highly promising alternative in this field.