INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
TTCP-DCPA Based Calcium Phosphate Cements Containing Hybrid Microparticles as Drug Carriers,
Autor/es:
H. E. ROMEO Y M. A. FANOVICH,
Lugar:
Buzios, Brasil.
Reunión:
Simposio; BIOCERAMICS 21, XXI Simposio Internacional de Cerámicos en Medicina,; 2008
Resumen:
In recent years, considerable attention has been focused on the development of new
composite materials for application as drug delivery systems. In this field, calcium phosphate
cements (CPCs) are often employed as support to delivery of drugs, but their behavior has some
drawback related to the so-called burst effect. The aim of this work was to develop new CPCs
formulations from synthesized tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous
TTCP and drug-containing hybrid microparticles (DCHM). The main function of these DCHM is
providing nuclei of high concentration of drugs into the CPCs. The DCHM were synthesized via the
sol-gel method from a bridged precursor of the type (H3CO)3 Bridge (OCH3)3 and aspirin (AS)
as model drug. The inorganic polycondensation reached 89.5 % as calculated by 29Si NMR. The
analysis by small angle X-ray scattering (SAXS) reveled a short range structural ordering in the
DCHM at molecular level. Effective incorporation of AS inside the microspheres was detected by
FTIR spectroscopy. In vitro tests of DCHM according to ISO 10993-5 revealed non-cytotoxic
behavior. Four CPCs formulations containing 0, 1, 5 and 10 wt % of DCHM, were evaluated. The
presence of DCHM did not modify neither the degree of conversion to low-crystallinity HA nor the
measured setting times of the CPCs, however, the amount of incorporated microparticles
considerably affected the degree of porosity (macropores of 200 ìm) and interconnectivity of the
cement matrix.3CO)3 Bridge (OCH3)3 and aspirin (AS)
as model drug. The inorganic polycondensation reached 89.5 % as calculated by 29Si NMR. The
analysis by small angle X-ray scattering (SAXS) reveled a short range structural ordering in the
DCHM at molecular level. Effective incorporation of AS inside the microspheres was detected by
FTIR spectroscopy. In vitro tests of DCHM according to ISO 10993-5 revealed non-cytotoxic
behavior. Four CPCs formulations containing 0, 1, 5 and 10 wt % of DCHM, were evaluated. The
presence of DCHM did not modify neither the degree of conversion to low-crystallinity HA nor the
measured setting times of the CPCs, however, the amount of incorporated microparticles
considerably affected the degree of porosity (macropores of 200 ìm) and interconnectivity of the
cement matrix.29Si NMR. The
analysis by small angle X-ray scattering (SAXS) reveled a short range structural ordering in the
DCHM at molecular level. Effective incorporation of AS inside the microspheres was detected by
FTIR spectroscopy. In vitro tests of DCHM according to ISO 10993-5 revealed non-cytotoxic
behavior. Four CPCs formulations containing 0, 1, 5 and 10 wt % of DCHM, were evaluated. The
presence of DCHM did not modify neither the degree of conversion to low-crystallinity HA nor the
measured setting times of the CPCs, however, the amount of incorporated microparticles
considerably affected the degree of porosity (macropores of 200 ìm) and interconnectivity of the
cement matrix.ìm) and interconnectivity of the
cement matrix.