Biocompatibility study of a hydroxyapatite-aiumina and silicon carbide composite scaffold for bone tissue engineering

To date, several scaffolds have been fabricated for application in bone tissue repair. However, there remains a need for synthesis of scaffolds with better mechanical properties, which can be applied to defects in weight-bearing bones. We constructed a composite ceramic bioscaffold of hydroxyapatite-alumina and silicon carbide [HA-Al2O3- SiC] to take advantage of the mechanical properties of this combination and show that it supports osteoblast-like cell attachment and growth. Ceramic composite microporous scaffolds were synthesized using an organic template [commercial polyurethane sponge with an open, interconnected microporosity]. Osteoblast-like cells [Saos-2] were then cultured on the scaffold and their growth pattern and viability were compared with those cultured in cell culture-treated flasks. Scanning electron microscopy [SEM] was used to assess cell attachment and migration. The fabricated scaffold shows fairly uniform pore morphologies. Cell growth and viability studies show that the scaffold is able to support osteoblast attachment and growth. However, SEM images indicated that the cells do not spread optimally on the scaffold surfaces. Our data suggest that that a ceramic hydroxyapatite-alumina and silicon carbide composite scaffold is a viable option for bone tissue repair. However, its surface properties should be optimized to maximise the attachment of osteoblasts

Fabrication of porous hydroxyapatite-gelatin composite scaffolds for bone tissue engineering

Engineering new bone tissue with cells and a synthetic extracellular matrix represents a new approach for the regeneration of mineralized tissues compared with the transplantation of bone [autografts or allografts]. in this study, to mimic the mineral and organic component of natural bone, hydroxapatite [HA] and gelatin [GEL] composite scaffolds were prepared. The raw materials were first compounded and the resulting composite were molded into cylindrical shape. Using solvent-casting method combined with freeze drying process, it is possible to produce scaffolds with mechanical and structural properties close to natural trabecular bone. Glutaraldehyde [GA] was used as cross linking agent. The chemical bonding and the microstructure were investigated by Fourier Transform Infra Red [FT-IR], Scanning Electron Microscopy [SEM] and Light microscopy. It was observed that the prepared scaffold has an open, interconnected porous structure with a pore size of 80-400 micro m, which is suitable for osteoblast cell proliferation. The mechanical properties of different weight fraction of HA [30, 40, and 50 wt%] was assessed and it was found that the GEL/HA with ratio of 50 wt% HA has the compressive modulus of10 Giga Pascal [GPa], the ultimate compressive stress of32 Mega Pascal [MPa] and the elongation of 3MPa similar to that of trabecular bone. The porosity and the apparent density of 50wt% HA scaffold were calculated and it was found that the addition of HA content can reduce the water absorption and the porosity. Since GA is cytotoxin, sodium bisulfite was used as GA discharger. The biological responses of scaffolds carried out by L929 fibroblast cell culture and it was observed that fibroblast cells partially proliferated and covered scaffold surface, 48h after seeding. these results demonstrate that the manufactured scaffolds are suitable candidate for trabecular bone tissue engineering

Fabrication of porous hydroxyapatite-gelatin scaffolds crosslinked by glutaraldehyde for bone tissue engineering

In this study, to mimic the mineral and organic components of natural bone, hydroxyapatite[HA] and gelatin[GEL] composite scaffolds were prepared using the solvent-casting method combined with a freeze drying process. Glutaraldehyde[GA] was used as a cross linking agent and sodium bisulfite was used as an excess GA discharger. Using this technique, it is possible to produce scaffolds with mechanical and structural properties close to those of the natural trabecular bone. The prepared scaffold has an open, interconnected porous structure. It was found that the GEL/HA ratio with a 50 wt% [weight percent] HA has the compressive modulus, the ultimate compressive stress and elongation similar to those for the trabecular bone. The chemical bonding and the microstructure of the composites were investigated by FT-IR [Fourier Transform Infra Red], SEM [Scanning Electron Microscopy] and Light microscopy, indicating the presence of bonds between Ca2[+] ions of HA and R-COO- ions of GEL in the HA-GEL composite scaffolds. It was found that the addition of HA content can reduce the water absorption and porosity of scaffold. The porosity and the apparent density of 50 wt% HA scaffold were also calculated. The biological responses of scaffolds were examined in L929 fibroblast cell culture, showed partially proliferation of cells around and on the composite surface