Desenvolvimento e aplicações de biocerâmica

Self Setting Bone Cement Formulations Based on Egg shell Derived TetraCalcium Phosphate BioCeramics

Abstract

Tetra calcium phosphate; Egg shells; Bone cements; Hydroxyapatite; Biologically relevant ions

Egg shells have been used as a calcium source for synthesis of tetra calcium phosphate (ETTCP) by solid state reaction method. The cell parameters and cell volume of ETTCP measured by X-ray powder diffraction method were lower than the tetra calcium phosphate prepared using synthetic Ca(CO)3 (pure TTCP) for comparison. The vibration bands of ETTCP were also slightly different from the vibration bands of pure TTCP characterized by Fourier transformed infrared spectroscopy. ETTCP has been tried as a main component in a self setting bone cement to evaluate the advantages of the presence of the biologically relevant ions such as Mg2+, Sr2+, SiO2- 4, F-, K+ and Na+ ions in the cement properties. The setting time of the ETTCP derived cement was ~ 11 min compared to ~ 16 min of the pure TTCP derived cement. The amount of hydroxyapatite formed as the end product was about 12% higher for ETTCP derived cement than pure TTCP derived cement after 28 days of immersion in phosphate buffer solution as confirmed by phase analysis. Elemental analysis also indicates the presence of trace elements in minor concentration in ETTCP derived cement. Although both the cements showed similar compressive strength after 28 days, the initial strength of the ETTCP derived cement was remarkably higher during initial stages of the hardening reaction (24 h–7 days) compared to TTCP derived cement. Cell viability of L6 cells was higher and cell spreading was more for the ETTCP derived cement than pure TTCP derived cement. The present study has demonstrated the advantages of eggshell derived TTCP in bone cement formulations due to the presence of biologically relevant ions. This may help the clinician with brief surgical procedure by using faster setting cement as well as the patient to have quick recovery with a higher initial strength of cement.