Highly porous bio-glass scaffolds fabricated by polyurethane template method with hydrothermal treatment for tissue engineering uses

Bioglass scaffolds, which contain a significant percentage of porosity for tissue engineering purposes, have low strength. For increasing the strength and efficiency of such structures for use in tissue engineering, fabrication of hierarchical meso/macro-porous bioglass scaffolds, developing their mechanical strength by hydrothermal treatment and adjusting pH method, and achieving the appropriate mesopore size for loading large biomolecules, were considered in this study.

Mesoporous bioglass (MBG) powders were synthesized using cetyltrimethylammonium bromide as a surfactant, with different amounts of calcium sources to obtain the appropriate size of the mesoporous scaffolds. Then MBG scaffolds were fabricated by a polyurethane foam templating method, and for increasing scaffold strength hydrothermal treatment (90 °C, for 5 days) and adjustment pH (pH=9) method was used to obtain hierarchical meso/macro-porous structures. The sample characterization was done by Simultaneous thermal analysis, Fourier transform infrared spectroscopy, Field Emission Scanning electron microscopy, small and wide-angle X-ray powder diffractions, transmission electron microscopy, and analysis of nitrogen adsorption-desorption isotherm. The mechanical strength of scaffolds was also determined.

The MBG scaffolds based on 80.28 (wt.) % SiO2- 17.89 (wt.) % CaO- 1.81 (wt.) % P2O5 presented interconnected large pores and pores in the range of 100-150 μm and 6-18 nm, respectively and 0.4 MPa compressive strength. 

The total pore volume and specific surface area were obtained from the Brunauer-Emmett-Teller theory, 0.709 cm3 g-1 and 213.83 m2 g-1, respectively. These findings could be considered in bone-cartilage tissue engineering.