This study evaluates the cytotoxic and mutagenic effect of synthetic hydroxyapatite granules (source: School of Material and Mineral Resources Engineering, Universiti Sains Malaysia) in the bone marrow cells of mice. Mice are exposed to synthetic hydroxyapatite granules, the bone marrow cells are collected and observed for chromosome aberrations. No chromosome aberrations were noticed in the animals exposed to distilled water (negative control) and to the test substance, synthetic hydroxyapatite granules (treatment) groups. Chromosome aberrations were observed in the animals exposed to Mitomycin C (positive control group). There was no indication of cytotoxicity due to synthetic hydroxyapatite granules in the animals as revealed by the mitotic index. Hence, synthetic hydroxyapatite granules are considered non-mutagenic under the prevailing test conditions.
Bone Marrow Cells/*drug effects ; Bone Substitutes/*toxicity ; *Chromosome Aberrations ; Durapatite/*toxicity ; *Mutagenicity Tests

OBJECTIVEThe micronucleus test was applied to evaluate the genotoxicity of a new nanocomplex HA-PA66 root filling material in vitro.

METHODSThe dulbecco's modified eagle media(DMEM) extracts of the powder part and the mixture of the new nanomaterial were prepared separately. The V79 cell was used as the test cell and the mitomycin C(MMC) as the positive control. The MTT assay was employed in our study to evaluate the cytotoxic effect while the number of micronucleus was used as the criteria for the detection of genotoxocity.

RESULTSThe MTT values in test groups and negative group were not significantly different at different times (P > 0.05). The number of micronucleus in test groups (powder group: 6.1 +/- 1.1/1,000; complex group: 5.7 +/- 0.6/1,000) was similar to the negative control(5.3 +/- 0.8/1,000, P > 0.05), while they were significantly different to the positive control(123.9 +/- 8/1,000, P < 0.05).

CONCLUSIONThe new nanocomplex HA-PA66 root filling material showed no detectable cytotoxic and genotoxic effects in this study and was proved to be biocompatible.

Animals ; Biocompatible Materials ; toxicity ; Cricetinae ; Cricetulus ; Durapatite ; toxicity ; Micronucleus Tests ; methods ; Mutagenicity Tests ; methods ; Nanotechnology ; Nylons ; toxicity ; Root Canal Filling Materials ; toxicity

Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.
Apoptosis/drug effects ; Biocompatible Materials/*toxicity ; Bone Substitutes/*toxicity ; Cell Death/*drug effects ; Durapatite/*toxicity ; L Cells (Cell Line) ; *Prostheses and Implants

OBJECTIVEThis study aims to compare and determine a kind of nano-hydroxyapatite composite material with good antibacterial efficacy on Enterococcusfaecalis (E. faecalis) in vitro.

METHODSWe investigated the antimicrobial activity of four kinds of nano-hydroxyapatite composites, namely, silver/hydroxyapatite composite nanoparticles (Ag/nHA), yttrium/hydroxyapatite composite nanoparticles (Yi/nHA), cerium/hydroxyapatite composite nanoparticles (Ce/nHA), and hydroxyapatite nanoparticles (nHA), against E. faecalis in vitro using the agar diffusion and broth dilution method by measuring the growth inhibition zone and the minimum inhibitory concentration (MIC), respectively.

RESULTSThe agar diffusion test results showed that Ag/nHA displayed an obvious growth inhibition zone, whereas Yi/nHA, Ce/nHA, and nHA showed no influence on E. faecalis. The MIC value of Ag/nHA was 1.0 g.L-1, and the three other materials had no effect on E.faecalis even at the high concentration of 32.0 g.L-1.

CONCLUSIONAg/nHA display a potential antimicrobial efficacy to planktonic E.faecalis. Whereas, the three other kinds of nano-hydroxyapatite composites (Yi/nHA, Ce/nHA, nHA) show no influence.

Anti-Bacterial Agents ; pharmacology ; Anti-Infective Agents ; Durapatite ; pharmacology ; Enterococcus faecalis ; drug effects ; Microbial Sensitivity Tests ; Nanocomposites ; toxicity ; Silver

Porous nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite was developed by injection molding method. Uniformly distributed and interconnected pores with an average size of about 500 microm in matrix were obtained. The evaluation of biological safety of the porous composite including cell cytoxicity test, sensitivity test, pyrogen test, haemolysis test was carried out according to GB/T16886 and GB/T16175. The results showed that the porous n-HA/PA66 composite was of no cytotoxicity, no allergen and pyrogen reactions as well as no hemolytic effect.
Animals ; Bone Substitutes ; chemical synthesis ; toxicity ; Durapatite ; chemistry ; Guinea Pigs ; Implants, Experimental ; Materials Testing ; Mice ; Nanocomposites ; chemistry ; Nanoparticles ; chemistry ; Nylons ; chemistry ; Porosity ; Rabbits ; Tissue Engineering

The cuttlebones, harvested from cuttles, undergo the chemical reaction in high temperature and high pressure for a certain time. The products are qualitatively analysed, and spacial structure observation and cytocompatibility are tested. The results show that the chemical component of the cuttlebone is CaCO3 and the crystal type is aragonite. Cuttlebones undergo a hydro-thermal reaction, and thus transform into hydroxyapatite-that is, the cuttlebone-transformed hydroxyapatite(CBHA). The CBHA materials have the interconnected microporous network structures. Under the high magnification, CBHAs appear to have many micro-spheres, thus construct a new self-assembled nano-material system. The marrow stromal osteoblasts can adhere to and proliferate well on the surface of the CBHAs. These results show that CBHAs have good biocompatibility. Therefore, it can be a potential candidate scaffold for bone tissue engineering.
Animals ; Bone Substitutes ; chemical synthesis ; chemistry ; toxicity ; Cells, Cultured ; Durapatite ; chemical synthesis ; chemistry ; toxicity ; Materials Testing ; Osteoblasts ; cytology ; drug effects ; Rabbits ; Sepia ; anatomy & histology ; Spine ; anatomy & histology ; chemistry ; Tissue Engineering