Developing a Porous Material to use as a Bone Scaffold

Introduction: Bone scaffolds are used to repair bone defects caused by cancer, surgery, periodontitis, osteoporosis and its related fractures. The current use of autograft and allograft bone replacement methods has various limitations forcing the direction of new research into synthetic bone substitutes. Development of these materials also provides us with knowledge of osteoconductive materials which can be applied in the development of prosthetic coating materials leading to efficient integration of the appliance in situ. Objectives: To synthesise a bioactive, biocompatible and porous scaffold material with sufficient mechanical properties. Pore sizes of between 100 and 300µm are essential for bone formation (1). Methods: Two biocompatible materials were used for this study. An alginate polymer matrix (which has FDA approval for use as a wound dressing) was reinforced with a bioactive glass powder filler component. A freeze drying technique was used to achieve porosity. X- ray microtomography (XMT), Scanning Electron Microscopy (SEM) and associated computer analysis software (TomView, Drishti) were employed to assess pore architecture. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X- ray Diffraction (XRD) were used to analyse the chemical structure and potential bioactivity of the material produced. Compression testing was completed using Instron 5567 equipment. Results: The data collected showed evidence that the novel material produced had an appropriate pore size for osteoconduction (average =109.80±39.81µm and maximum= 308.87µm). The bioactive glass had an amorphous structure, favourable for bioactivity, further confirmed by SBF studies. Conclusion: Statistical analysis (Student's t test) of compression data confirms the glass filler significantly (P<0.05) increased the collapse yield of the scaffolds compared with pure alginate scaffolds fabricated in the same way. Cell culture studies are planned for future study into bioactivity. 1. Mohan N, Nair P, D. Novel Porous, Polysaccharide Scaffolds for Tissue Engineering Applications. Trends Biomater Artif Organs. 2005;18(2).