Antitumor activity of a hydrogel loaded with lipophilic bismuth nanoparticles on cervical, prostate, and colon human cancer cells.

The objective of this study was to analyze the antitumor activity of a hydrogel loaded with lipophilic bismuth nanoparticles on human cervical, prostate, and colon cancer cell lines. The effect of lipophilic bismuth nanoparticles on the viability of cancer cell lines (HeLa, DU145, and HCT-116) and non-cancer lung fibroblasts (HLF; LL 47[MaDo]) was determined with the MTT cell viability assay and compared with known antineoplastic drugs. The biocompatibility at an organismal level was verified in a murine model by histological examination. A lipophilic bismuth nanoparticle hydrogel at 50 µM time-dependently inhibited the growth of the three cancer cell lines, in a time-dependent way. A 1-hour exposure to 250 µM lipophilic bismuth nanoparticle hydrogel, inhibited the growth of the three cancer cell lines. The in-vitro efficacy of lipophilic bismuth nanoparticle was similar to the one of docetaxel and cisplatin, but without inhibiting the growth of non-cancer control cells. Histology confirmed the biocompatibility of lipophilic bismuth nanoparticles as there were no signs of cytotoxicity or tissue damage in any of the evaluated organs (kidney, liver, brain, cerebellum, heart, and jejunum). In conclusion, a lipophilic bismuth nanoparticle hydrogel is an innovative, low-cost alternative for the topical treatment of cervicouterine, prostate, and colon human cancers.

Hydroxyapatite decreases cytotoxicity of a glass ionomer cement by calcium fluoride uptake in vitro.

BACKGROUND: Glass ionomer cements (GICs) are widely used in dentistry because of their remineralizing and cariostatic potential induced by fluoride. In vitro studies have reported cell toxicity triggered by GICs; however, the influence of hydroxyapatite (HAp) must be considered. The aim of this study was to evaluate the effect of HAp in decreasing the cytotoxicity of the GIC 3M Vitrebond in vitro. METHODS: Samples of 3M Vitrebond (powder, liquid and light-cured) were incubated in Dulbecco's modified Eagle's medium-Ham's F12 (DMEM-F12) for 24 hours at 37°C. Subsequently, the light-cured medium was treated with 100 mg/mL of HAp overnight. Toxicity of conditioned media diluted 1:2, 1:4, 1:8 and 1:20 was analyzed on human gingival fibroblasts (HGFs) using light microscopy and the fluorometric microculture cytotoxicity assay. The amounts of calcium fluoride (CaF2) were determined by the alizarin red S method. RESULTS: The exposure of HGFs to light-cured induced cell death and morphological changes such as chromatin condensation, pyknotic nuclei and cytoplasmic modifications. Exposure to light-cured treated with HAp, significantly increased cell viability leading to mostly spindle-shaped cells (p<0.001). The concentration of CaF2 released by the light-cured was 200 ppm, although, in the light-cured/HAp conditioned medium, this quantity decreased to 88 ppm (p<0.01). CONCLUSIONS: These data suggest that HAp plays a protective role, decreasing the cytotoxic effect of 3M Vitrebond induced by CaF2.