RESUMEN
Calcium phosphate cements are of great interest for researchers and their applications in medical practice expanded. Nevertheless, they have a number of drawbacks including the insufficient level of mechanical properties and low degradation rate. Struvite (MgNH4PO4) -based cements, which grew in popularity in recent years, despite their neutral pH and acceptable mechanical performance, release undesirable NH4 + ions during their resorption. This issue could be avoided by replacement of ammonia ions in the cement liquid with sodium, however, such cements have a pH values of 9-10, leading to cytotoxicity. Thus, the main goal of this investigation is to optimize the composition of cements to achieve the combination of desirable properties: neutral pH, sufficient mechanical properties, and the absence of cytotoxicity, applying Na2HPO4-based cement liquid. For this purpose, cement powders precursors in the CaO-MgO-P2O5 system were synthesized by one-pot process in a wide composition range, and their properties were investigated. The optimal performance was observed for the cements with (Ca + Mg)/P ratio of 1.67, which are characterized by newberyite phase formation during setting reaction, pH values close to 7, sufficient compressive strength up to 22 ± 3 MPa (for 20 mol.% of Mg), dense microstructure and adequate matrix properties of the surface. This set of features make those materials promising candidates for medical applications.
Asunto(s)
Encéfalo/metabolismo , Calcio/deficiencia , Proteínas de Unión a Calmodulina/metabolismo , Proteínas del Citoesqueleto/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Fenómenos Fisiologicos de la Nutrición Prenatal , Animales , Encéfalo/embriología , Encéfalo/crecimiento & desarrollo , Calcio de la Dieta/metabolismo , Proteínas de Unión a Calmodulina/genética , Proteínas del Citoesqueleto/genética , Femenino , Masculino , Proteínas del Tejido Nervioso/genética , Embarazo , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKYRESUMEN
We studied the effect of drinking of low mineralized water containing 8 mg/liter Ca2+ on blood pressure and content of brain proteins in synaptosomes of SHR and WKY rats. Blood pressure increased in WKY rats, but not in SHR rats. In SHR rats, Ca2+ deficit reduced the content of GAP-43 protein and induced the appearance of its fragment GAP-43-3 in brain synaptosomes. In WKY rats, the content of this protein did not change, and its fragment GAP-43-3 was absent. No structural changes in BASP1 protein were found.