Papers by Author: S.S. Silva

Abstract: In this study, it is shown that it is possible to develop 3D-porous bilayer hydroxyapatite/chitosan scaffolds by means of combining a sintering and a freeze-drying technique. Scanning electron microscopy (SEM/EDS) studies revealed that the scaffolds possess a well-defined orientation and anisotropic porosity, with pore size ranging between 50-350 µm. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) patterns evidenced the formation of crystalline hydroxyapatite. Moreover, the compression tests revealed that these scaffolds have adequate mechanical properties for being used in tissue engineering of osteochondral defects.

Abstract: In this paper we report a new type of cross-linked porous structure based on a chitosansoy protein blend system developed by means of combining a sol-gel process with the freeze-drying technique. The final structure was investigated by Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), contact angle measurements and the morphology by scanning electron microscopy (SEM). The water uptake capability and the weight loss were measured up to 14 days and their mechanical properties were assessed with compression tests. Results showed that the addition of tetraethyl orthosilicate (TEOS) to the chitosan-soy protein blend system provide specific interactions at the interface between the two polymers allowing to tailor the size and distribution as well as the degradation rate of the hybrids. Finally, TEOS incorporation induces an increase of the surface energy that influences the final physicochemical properties of the materials.