Publicação
Three dimensional cell-scaffold constructs for application in bone tissue engineering
| Resumo: | Bone is a dynamic tissue with an amazing capacity of self-repair. However, when the defect reaches a critical size bone loses this capacity and medical intervention is needed. Bone is the second most transplanted tissue in the world and there is a huge need for bone grafts and substitutes and therefore leading to a decrease in bone banks donors. Scaffolds are of great importance for tissue engineering and orthopedic implants since they provide biological anchorage for the surrounding bony tissue via the ingrowth of tissue into pores. The pores of scaffolds have direct implications on their biofunctionality. Thus, a porous structure is critical for cell nutrition, proliferation, cell migration, and formation of newly vascularized tissue. Scaffold’s mechanical properties should also match that of bone in order to prevent stress shielding which is one of the main causes for implant’s failure. In this study, three-dimensional porous scaffolds with maximized mechanical strength capable for load-bearing applications and with elastic modulus near of the bone were produced. The porous scaffolds were made of: i) Ti6Al4V, ii) ZrO2 and iii) PEEK. Their microstructures were characterized by mean of performing SEM and Micro CT analyses. To assess the chemical composition of the scaffolds, XPS analysis was performed. The crystallographic phase of ZrO2 was investigated by XRD. Mechanical compressive tests were performed in order to evaluate the elastic modulus and compressive stress. Their efficacy as scaffold material for bone regeneration applications was evaluated in vitro by seeding SaOS-2 cells onto the scaffolds. The viability, proliferation and differentiation of SaOS-2 cells was analyzed. The cellular viability was assessed by Alamar blue test at day 1, day 3, day 7 and day 14. For the study of cell proliferation, DNA quantification was performed for the same time points. To assess the differentiation of SaOS-2 cells, alkaline phosphatase was qualitatively and quantitatively evaluated by performing the ALP quantification and staining with Fast violet B. Mechanical results showed an elastic modulus near of the bone which can minimize the phenomenon of stress shielding. The in vitro results revealed cytocompatibility with no cell alterations or death of SaOS-2 seeded on scaffolds surfaces. The proposed scaffolds showed great potential in vitro to be used in bone tissue engineering scaffolding applications. |
|---|---|
| Autores principais: | Pereira, Helena Filipa Ribeiro da Silva |
| Assunto: | Ti6Al4V ZrO2 PEEK Mechanical properties In vitro assays Propriedades mecânicas Testes in vitro Engenharia e Tecnologia::Engenharia dos Materiais |
| Ano: | 2017 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Bone is a dynamic tissue with an amazing capacity of self-repair. However, when the defect reaches a critical size bone loses this capacity and medical intervention is needed. Bone is the second most transplanted tissue in the world and there is a huge need for bone grafts and substitutes and therefore leading to a decrease in bone banks donors. Scaffolds are of great importance for tissue engineering and orthopedic implants since they provide biological anchorage for the surrounding bony tissue via the ingrowth of tissue into pores. The pores of scaffolds have direct implications on their biofunctionality. Thus, a porous structure is critical for cell nutrition, proliferation, cell migration, and formation of newly vascularized tissue. Scaffold’s mechanical properties should also match that of bone in order to prevent stress shielding which is one of the main causes for implant’s failure. In this study, three-dimensional porous scaffolds with maximized mechanical strength capable for load-bearing applications and with elastic modulus near of the bone were produced. The porous scaffolds were made of: i) Ti6Al4V, ii) ZrO2 and iii) PEEK. Their microstructures were characterized by mean of performing SEM and Micro CT analyses. To assess the chemical composition of the scaffolds, XPS analysis was performed. The crystallographic phase of ZrO2 was investigated by XRD. Mechanical compressive tests were performed in order to evaluate the elastic modulus and compressive stress. Their efficacy as scaffold material for bone regeneration applications was evaluated in vitro by seeding SaOS-2 cells onto the scaffolds. The viability, proliferation and differentiation of SaOS-2 cells was analyzed. The cellular viability was assessed by Alamar blue test at day 1, day 3, day 7 and day 14. For the study of cell proliferation, DNA quantification was performed for the same time points. To assess the differentiation of SaOS-2 cells, alkaline phosphatase was qualitatively and quantitatively evaluated by performing the ALP quantification and staining with Fast violet B. Mechanical results showed an elastic modulus near of the bone which can minimize the phenomenon of stress shielding. The in vitro results revealed cytocompatibility with no cell alterations or death of SaOS-2 seeded on scaffolds surfaces. The proposed scaffolds showed great potential in vitro to be used in bone tissue engineering scaffolding applications. |
|---|