Fabrication of electrospun fibrous meshes and 3D porous titanium scaffolds for tissue engineering

Abstract

Tissue engineering is a multidisciplinary field that is rapidly emerging as a promising approach for tissue repair and regeneration. In this approach, scaffolds which allow cells to invade the construct and guide the cells grow into specific tissue play a pivotal role. Electrospinning has gained popularity recently as a simple and versatile method to produce fibrous structures with nano- to microscale dimensions. These electrospun fibers have been extensively applied to create nanofiber scaffolds for tissue engineering applications. Specifically for bone and cartilage tissue engineering, polymeric materials have some attractive properties such as the biodegradability. Ceramic scaffolds and implant coatings, such as hydroxyapatite and silica-based bioglass have also been considered as bone graft substitutes for bone repair because of their bioactivity and, in some cases, tunable resorbability. Besides tissue engineering scaffolds, for clinical application, especially for load-bearing artificial implants, metallic materials such as titanium are the most commonly used material. Osseointegration between bone and implants is very essential for implant success. To achieve better osseointegration between bone and the implant surface, three dimensional porous structures can provide enhanced fixation with bone by allowing tissue to grow into the pores. In this study, pre-3D electrospun polymer and ceramic scaffolds with peptide conjugation and 3D titanium scaffolds with different surface morphology were fabricated to testify the osteoblast and mensechymal stem cell attachment and differentiation. The overall goal of this thesis is to determine if the peptide functionalization of polymeric scaffolds and physical parameters of ceramic and metallic scaffold can promote osteoblast maturation and mesenchymal stem cell differentiation in vitro to achieve an optimal scaffold design for greater osseointegration. The results of the studies showed with functionalization of MSC- specific peptide, polymer scaffolds behaved with higher biocompatibility and MSC affinity. For the ceramic and metallic scaffolds, microstructures and nanostructures can synergistically promote osteoblast maturation and 3D micro-environment with micro-roughness is a promising design for osteoblast maturation and MSC differentiation in vitro compared to 2D surfaces.