tetracycline and calcium-phosphate--dibasic--dihydrate

Calcium phosphate cements have the advantage that they can be prepared as a paste that sets in a few minutes and can be easily adapted to the shape of the bone defect, which facilitates its clinical application. In this research, six formulations of brushite (dicalcium phosphate dihydrated) cement were obtained and the effect of the addition of sodium alginate was analyzed, such as its capacity as a tetracycline release system. The samples that contain sodium alginate set in 4 or 5 min and showed a high percentage of injectability (93%). The cements exhibit compression resistance values between 1.6 and 2.6 MPa. The drug was released in a range between 12.6 and 13.2% after 7 days. The antimicrobial activity of all the cements containing antibiotics was proven. All samples reached values of cell viability above 70 percent. We also observed that the addition of the sodium alginate and tetracycline improved the cell viability.

Topics: 3T3-L1 Cells; Alginates; Animals; Anti-Bacterial Agents; Biocompatible Materials; Bone Cements; Bone Regeneration; Calcium Phosphates; Cell Proliferation; Cell Survival; Compressive Strength; Hydrogen-Ion Concentration; Mice; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Pressure; Stress, Mechanical; Tetracycline; Time Factors; Tissue Engineering; X-Ray Diffraction

The aim of this study was to investigate the adsorption and desorption kinetics of antibiotics to microporous bioceramics fabricated by a novel low temperature 3D powder direct printing process. The adsorption of vancomycin, ofloxacin and tetracycline onto hydroxyapatite, brushite and monetite showed a linear correlation with the drug concentration in the immersion solution, whereas a non-linear relationship was found between the immersion time and the amount of adsorbed drug. Differences in the total amount of adsorbed drugs were correlated to the specific surface areas of the matrices, which varied between 2.4-13.1 m(2)/g. Normalised drug loadings were found to be in the range of 1.5-1.8 mg/m(2) for vancomycin and ofloxacin, whereas higher loads of up to 5-7 mg/m(2) were obtained for tetracycline. Vancomycin and ofloxacin were rapidly released into PBS buffer within 1-2 days, while tetracycline showed a much slower release rate of approximately 25% after 5 days of immersion. Additional polymer impregnation of the drug loaded matrix with PLA/PGA polymer solutions enabled the release kinetics to be delayed such that sustained release was achieved in polymer ceramic biocomposites.

Topics: Adsorption; Anti-Bacterial Agents; Biocompatible Materials; Calcium Phosphates; Chemistry, Pharmaceutical; Drug Carriers; Drug Compounding; Drug Implants; Durapatite; Kinetics; Models, Chemical; Ofloxacin; Polyesters; Polyglycolic Acid; Porosity; Powders; Solubility; Surface Properties; Technology, Pharmaceutical; Temperature; Tetracycline; Vancomycin