Synthesis and cytotoxicity evaluation of granular magnesium substituted beta-tricalcium phosphate

Objective: The aim of this study was to produce dense granules of tricalcium phosphate (β-TCP) and magnesium (Mg) substituted β-TCP, also known as β-TCMP (Mg/Ca=0.15 mol), in order to evaluate the impact of Mg incorporation on the physicochemical parameters and in vitro biocompatibility of this novel material. Material and Methods: The materials were characterized using X-ray diffraction (XRD), infrared spectroscopy (FTIR), electron microscopy and inductively coupled plasma (ICP). Biocompatibility was assayed according to ISO 10993-12:2007 and 7405:2008, by two different tests of cell survival and integrity (XTT and CVDE). Results: The XRD profile presented the main peaks of β-TCP (JCPDS 090169) and β-TCMP (JCPDS 130404). The characteristic absorption bands of TCP were also identified by FTIR. The ICP results of β-TCMP granules extract showed a precipitation of calcium and release of Mg into the culture medium. Regarding the cytotoxicity assays, β-TCMP dense granules did not significantly affect the mitochondrial activity and relative cell density in relation to β-TCP dense granules, despite the release of Mg from granules into the cell culture medium. Conclusion: β-TCMP granules were successfully produced and were able to release Mg into media without cytotoxicity, indicating the suitability of this promising material for further biological studies on its adequacy for bone therapy.

Comparison of the antiviral activity and toxicity of a protein magnesium ammonium phospholinoleate anhydride polymer with other antiviral drugs

1. SB-73, a magnesium ammonium phospholinoleate anhydride aggregate, exhibited antiviral action in vitro in the concentration range of 50 to 100 µg/ml against herpes simplex type 1, stomatitis vesicular virus, adenovirus type 5, and in vivo in the dose range of 0.7 to 1.3 mg/Kg against canine parvovirus distemper virus. 2. The lethal dose (LD50) was 2.71 ñ 1.55 g/Kg body weight in mice inoculated intraperitoneally. Oral ingestion of the aggregate up to 30 g/Kg body weight by mice had no lethal effects during the 14 days of observation. 3. In in vitro cytotoxicity experiments with fibroblasts (V-79 Chinese hamster cell line), no toxic effects were observed with SB-73 concentrations (120 µg/ml) having antiviral activity. 4. In a cellular proliferation experimental using hamster V-79 cells, we observed 72% proliferation after treatment of the cells with a high concentration (500 µg/ml) of SB-73. 5. Compound SB-73 showed no genotoxicity for human lymphocytes at concentrations of 100 µg/ml. 6. When the cytoxicity and genotoxicity of SB-73 wee compared with those of acyclovir, idoxuridine and AZT at 500µg/ml concentration the compound was found to have effects similar to those of acyclovir