Showing 2 results for Cytotoxicity
V. Dave, R. Kotian, P. Madhyastha, K. Boaz, P. Rao, B.p. Charitha,
Volume 16, Issue 4 (12-2019)
Abstract
The aim of the present study is to assess the hardness, corrosion, and cytotoxicity of a commercially available cobalt-chromium (Co-Cr) alloy before and after simulated heat treatments at porcelain firing temperature. Five Co-Cr samples were fabricated using lost wax casting procedure. Heat treatments were carried out at 650°C, 750°C, 850°C, and 950°C. Vickers hardness was measured for as-cast and heat treated samples. The corrosion test was carried out separately in 0.1 N NaCl, 1% citric acid and artificial saliva at room temperature using potentiodynamic polarization technique. Gingival tissue biopsy of patients was taken and cultured to measure the cell viability by MTT colorimetric assay. Lowest hardness was observed at 650°C. 0.1 N NaCl and 1% citric acid corrosion medium showed a similar trend of corrosion rate. The least corrosion rate was found in artificial saliva. Firing temperature has an impact on the physical, chemical and biological properties of Co-Cr alloy in long-term clinical use.
Ebrahim Zabihi, Roghayeh Pourbagher, Seyedali Seyedmajidi,
Volume 19, Issue 4 (12-2022)
Abstract
The optimization of biomaterials biodegradation rate similar to tissue regeneration, is one of the main
goals in the field of tissue engineering. However, the necessity to assess their possible toxicity is always considered.
The aim of this study was cytotoxicity and genotoxicity evaluation of fluorapatite/bioactive glass (FA/BG)
nanocomposite foams with two various weight ratios to determine the optimal composition. Nanocomposite foams
were made by gel-casting method with FA and BG as precursors in two weight ratios (A and B). Nanocomposite
foam extracts (CFEX) were prepared by shaking 100 mg/mL of each foam in a complete culture medium for 72 h in
a shaker incubator at 120 rpm/37ºC. Saos-II cells were exposed to different concentrations of CFEXs for 24 and
48 h and then cytotoxicity and genotoxicity were evaluated by MTT and comet assay, respectively. Based on the MTT
assay results after 24 h exposure, CFEX A at concentrations ≥75% and CFEX B at concentrations ≥50% had a
cytotoxic effect, while after 48 h, both CFEXs showed similar cytotoxicity at concentrations ≥25%. According to the
result of the comet assay, DNA damage increased with the increase of CFEXs concentration and exposure time.
Both CFEXs showed significantly higher comet tails elongation scores at concentrations ≥50% and ≥25% after 24
and 48 h exposure, respectively. Both composite foams could be considered as a non-toxic candidate for tissue
engineering at concentrations <25% which was less than FA50%/BG50% composite. Therefore, the composite with
equal FA/BG proportion has priority if similar results are obtained in in vivo complementary experiments.
