Production and characterization of metal doped biphasic calcium phosphate/chitosan based bone scaffolds

Bone is a dynamic and composite structure with the ability to regenerate itself. However, in some cases where bone loss rates are high, this feature of the bone could be insufficient. In order to overcome such negative situations, interest in tissue engineering applications, which is a new approach as well as traditional treatment methods, is increasing day by day. With the development of technology, striking developments in tissue engineering have necessitated the use and development of noval materials which are biocompatible and have adequate properties for the production of scaffolds that support tissue-specific cell culture activities. The aim of this thesis study is the production and characterization of tissue scaffolds with optimum porosity, mechanical properties and bioactivity that would be enable bone tissue formation with tissue engineering strategy. Within the scope of the thesis, metal doped biphasic calcium phosphate (BCP)/chitosan-based scaffolds were produced by freeze-drying method. Lanthanum (La) and Samarium (Sm) were chosen as metal dopants, which are effective in bone tissue metabolism, although they are in trace amounts in the human body. In the first part of the study, pure BCP, La doped BCP and Sm doped BCP powders were synthesized by a two-step process involving a sol-gel and a sintering at 1200°C for 3 h. The chemical structure of all synthesized powders was confirmed by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS) analyzes. In the second part, the production of tissue scaffolds was produced by freeze drying method by adding the synthesized composite powders to chitosan. The microstructures of all produced composite scaffolds were examined by scanning electron microscopy (SEM). In the third part of the study, characterization were carried out. Within the scope of the thesis, the pore structures (size, shape, interconnectedness, etc.), degradation properties, swelling studies and mechanical properties of the scaffolds were examined and these properties were compared with each other. According to the results, it was observed that the pore structures of the scaffolds were within the observed limits. The mechanical properties of the scaffolds were improved by doping La and Sm. In order to determine the bioactivity properties of the tissue scaffolds, they were kept in stimulated body fluid (SBF) for specified periods. Surface characterizations and bioactivity analyzes were performed using XRD, SEM and EDS analysis. The results confirmed that the addition of La and Sm positively increased the bioactivity properties.