GOMES, D. S.; GOMES, DÉBORAH S.; DOS SANTOS GOMES, DÉBORAH.; http://lattes.cnpq.br/5559901782833359; GOMES, Déborah dos Santos.
Resumo:
Calcium phosphates have been extensively investigated for application in the
biomedical field due to their bioactivity and biocompatibility. However, the brittle
nature of these materials limits their application as scaffolds for tissue engineering.
This feature can be overcome by the use of hybrid materials. Thus, the objective of
this study was to produce nanofibrillary scaffolds of poly (lactic acid) / poly (ethylene
glycol) / calcium phosphate (PLA / PEG / CaP) by means of the solution blow
spinning technique (SBS). Calcium nitrate tetrahydrate and triethyl phosphate (TEP)
were used as inorganic precursors and a polyvinylpyrrolidone (PVP) polymer solution
was used as the guiding agent for the production of CaP nanofibers. The CaP
nanofibers were produced by SBS, Ca / P ratio equal to 1.67 and 1.1, and calcined at
1000 ° C. To produce the scaffolds, the CaP nanofibers were macerated and
dispersed in dimethyl carbonate solvent (DMC) and then PEG and PLA were added
to the solutions to be further subjected to the spinning process also by SBS. Final
concentrations of PEG in the scaffolds ranged from 20 to 30%. The nanofibers and
scaffolds produced were characterized by X-ray diffraction (XRD), thermogravimetry
(TG), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy
(SEM) and transmission (TEM) and bioactivity assay. From the obtained results it
was possible to note that for both Ca / P ratios there was formation of HAp as the
main phase. However, for Ca / P = 1.1, a small amount of calcium triphosphate (β-
TCP) was formed. The diffraction patterns and the thermogravimetric results
confirmed the formation of the organic / inorganic hybrid. The morphological analysis
of scaffolds showed that the addition of PEG made it possible to reduce defects in
their morphology. After bioactivity assays in PBS it was possible to observe a better
deposition of the apatite layer on the surface of CaP composite scaffolds with ratio =
1.1, over the 14 day test period. In conclusion, it was possible to obtain hybrid
scaffolds with randomly interconnected and highly porous structure with good
dispersion of the CaP load, in addition, scaffolds with higher CaP percentage indicate
better bioactivity to induce calcium mineralization for bone regeneration.