Biocompatibility and biofunctionality evaluations of metallic scaffolds for bone tissue engineering
Bone grafting has been widely and successfully used in biomedical fields. Current methods of bone grafting that have been used in medical fields are autografting, allografting, and xenografting but there is a limitation of using those bone grafts due to disease transmission, host rejection and other problems. Use of synthetic bone grafting is another alternative method to solve those issues. Various types of materials such as metals, ceramic, and polymer have been used as synthetic bone graft. Polyurethane is commonly used in bone tissue engineering applications because it has excellent biocompatibility. However, polyurethane has lack of bioactive group and it not biostable when it contacts with living tissue that cause device failure in long term implants. The objective of this thesis was to enhance the mechanical properties of polyurethane. A metallic coating on polyurethane was fabricated to enhance its mechanical properties. Compression test was performed on polyurethane coated samples and effect of stress, strain and the average ultimate strength of the Nb coated, Mg coated and plain polyurethane samples were evaluated. Stress, strain and the average ultimate strength of Nb coated sample was improved significantly whiles stress, strain and the ultimate strength of Mg coated sample did not improve much based on applied coating conditions. Cytotoxicity evaluations of coated samples were conducted using direct and indirect tests. Cells proliferated well with Nb and Mg coated polyurethane samples and the coatings were biocompatible. Moreover, biofunctionality of coated samples were evaluated by performing cell proliferation. Cell proliferation, cell ahhesion and cell morphology of MC-3T3 osteoblasts cells line were observed for 1 day, 4 days and 7 days. The proliferation of cells decreased with coated samples as compared to polyurethane. Optimization of cell culture media is needed to enhance cell proliferation on coated samples.
Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering