Effect of Lipophilic Bismuth Nanoparticles on Erythrocytes

Lipophilic bismuth dimercaptopropanol nanoparticles (BisBAL NPs) have a very important antimicrobial activity; however their effect on human cells or tissues has not been completely studied. Undesirable effects of bismuth include anemia which could result from suicidal erythrocyte death or eryptosis. The objective of this research was to determine the effect of bismuth dimercaptopropanol nanoparticles on blood cells. The nanoparticles are composed of 53 nm crystallites on average and have a spherical structure, agglomerating into clusters of small nanoparticles. Based on cell viability assays and optical microscopy, cytotoxicity on erythrocytes was observed after growing with 500 and 1000 µM of BisBAL NPs for 24 h. AM Calcein was retained inside erythrocytes when they were exposed to 100 µM (or lower concentrations) of BisBAL NPs for 24 h, suggesting the absence of damage in plasmatic membrane. Genotoxic assays revealed no damage to genomic DNA of blood cells after 24 h of exposition to BisBAL NPs. Finally, 100–1000 µM of bismuth nanoparticles promotes apoptosis between blood cells after 24 h of incubation. Hence BisBAL NPs at concentrations lower than 100 µM do not cause damage on blood cells; they could potentially be used by humans without affecting erythrocytes and leukocytes

Antimicrobial Effect of Lactobacillus reuteri on Cariogenic Bacteria Streptococcus gordonii, Streptococcus mutans,and Periodontal Diseases Actinomyces naeslundii and Tannerella forsythia

Lactic acid bacteria (LAB) are well known for their beneficial effects on human health in the intestine and immune system; however, there are few studies on the impact they can generate in oral health. The aim of this study was to test and compare in vitro antimicrobial activity of L. reuteri on pathogenic bacteria involved in the formation of dental caries: S. mutans, S. gordonii, and periodontal disease: A. naeslundii and T. forsythia. Also, we determined the growth kinetics of each bacterium involved in this study. Before determining the antimicrobial action of L. reuteri on cariogenic bacteria and periodontal disease, the behavior and cell development time of each pathogenic bacterium were studied. Once the conditions for good cell growth of each of selected pathogens were established according to their metabolic requirements, maximum exponential growth was determined, this being the reference point for analyzing the development or inhibition by LAB using the Kirby Bauer method. Chlorhexidine 0.12 % was positive control. L. reuteri was shown to have an inhibitory effect against S. mutans, followed by T. forsythia and S. gordonii, and a less significant effect against A. naeslundii. Regarding the effect shown by L. reuteri on the two major pathogens, we consider its potential use as a possible functional food in the prevention or treatment of oral diseases

In vitro evaluation of the antitumor effect of bismuth lipophilic nanoparticles (BisBAL NPs) on breast cancer cells

Aim: The objective of this study was to evaluate the antitumor activity of lipophilic bismuth nanoparticles (BisBAL NPs) on breast cancer cells. Materials and methods: The effect of varying concentrations of BisBAL NPs was evaluated on human MCF-7 breast cancer cells and on MCF-10A fibrocystic mammary epitheliocytes as noncancer control cells. Cell viability was evaluated with the MTT assay, plasma membrane integrity was analyzed with the calcein AM assay, genotoxicity with the comet assay, and apoptosis with the Annexin V/7-AAD assay. Results: BisBAL NPs were spherical in shape (average diameter, 28 nm) and agglomerated into dense electronic clusters. BisBAL NP induced a dose-dependent growth inhibition. Most importantly, growth inhibition was higher for MCF-7 cells than for MCF-10A cells. At 1 µM BisBAL NP, MCF-7 growth inhibition was 51%, while it was 11% for MCF-10A; at 25 µM BisBAL NP, the growth inhibition was 81% for MCF-7 and 24% for MCF-10A. With respect to mechanisms of action, a 24-hour exposure of 10 and 100 µM BisBAL NP caused loss of cell membrane integrity and fragmentation of tumor cell DNA. BisBAL NPs at 10 µM were genotoxic to and caused apoptosis of breast cancer cells. Conclusion: BisBAL NP-induced growth inhibition is dose dependent, and breast cancer cells are more vulnerable than noncancer breast cells. The mechanism of action of BisBAL NPs may include loss of plasma membrane integrity and a genotoxic effect on the genomic DNA of breast cancer cells. Keywords: antitumor activity, bismuth nanoparticles, breast cancer, chemotherapy, cytotoxicit

Antimicrobial potential of AH Plus supplemented with bismuth lipophilic nanoparticles on E. faecalis isolated from clinical isolates

The objective of this study was to determine the antimicrobial potential of AH plus supplemented with bismuth lipophilic nanoparticles (BisBAL NPs) on the growth of Enterococcus faecalis isolated from patients with endodontic infections. BisBAL NPs, synthesized with the colloidal method, were characterized, in its pure form or AH Plus-absorbed, by energy-dispersive X-ray spectroscopy and scanning electron microscopy (EDS-SEM). Antimicrobial activity was evaluated with disc diffusion assays, and antibiofilm activity with fluorescence microscopy. BisBAL NP-supplemented AH Plus had a 4.9 times higher antimicrobial activity than AH Plus alone ( p = 0.0001). In contrast to AH Plus alone, AH Plus supplemented with BisBAL NP inhibited E. faecalis biofilm formation. The sealing properties of AH plus were not modified by the incorporation of BisBAL NPs, which was demonstrated by a 12-day split-chamber leakage assay with daily inoculation, which was used to evaluate the possible filtration of E. faecalis . Finally, BisBAL NP-supplemented AH plus-BisBAL NPs was not cytotoxic for cultured human gingival fibroblasts. Their viability was 83.7% to 89.9% after a 24-h exposure to AH Plus containing 50 and 10 µM BisBAL NP, respectively. In conclusion, BisBAL NP-supplemented AH Plus constitutes an innovative nanomaterial to prevent re-infection in endodontic patients without cytotoxic effects

Cumulative antitumor effect of bismuth lipophilic nanoparticles and cetylpyridinium chloride in inhibiting the growth of lung cancer

Objective: To determine the combined antitumor effect of bismuth lipophilic nanoparticles (BisBAL NP) and cetylpyridinium chloride (CPC) on human lung tumor cells. Material and methods: The human lung tumor cells A549 were exposed to 1–100 µM BisBAL NP or CPC, either separately or in a 1:1 combination. Cell viability was measured with the PrestoBlue assay, the LIVE/DEAD assay, and fluorescence microscopy. The integrity and morphology of cellular microtubules were analyzed by immunofluorescence. Results: A 24-h exposure to 1 µM solutions reduced A549 growth with 21.5% for BisBAL NP, 70.5% for CPC, and 92.4% for the combination ( p < 0.0001), while a 50 µM BisBAL NP/CPC mixture inhibited cell growth with 99% ( p < 0.0001). BisBAL NP-curcumin conjugates were internalized within 30 min of exposure and could be traced within the nucleus of tumor cells within 2 h. BisBAL NP, but not CPC, interfered with microtubule organization, thus interrupting cell replication, similar to the action mechanism of docetaxel. Conclusion: The growth inhibition of A549 human tumor cells by BisBAL NP and CPC was cumulative as of 1 µM. The BisBAL NP/CPC combination may constitute an innovative and cost-effective alternative for treating human lung cancer

Evaluación de la biocompatibilidad de acrílico, Lucitone, Valplast y polipropileno, mediante la detección in situ de quimiocinas, citocinas proinflamatorias y células del sistema inmune

Tesis Univ. Granada. Departamento de Estomatología. Leída el 13 de mayo del 201

Green Synthesis of Silver Nanoparticles and Their Bactericidal and Antimycotic Activities against Oral Microbes

Nanotechnology is a new discipline with huge applications including medicine and pharmacology industries. Although several methods and reducing agents have been employed to synthesize silver nanoparticles, reactive chemicals promote toxicity and nondesired effects on the human and biological systems. The objective of this work was to synthesize silver nanoparticles from Glycyrrhiza glabra and Amphipterygium adstringens extracts and determine their bactericidal and antimycotic activities against Enterococcus faecalis and Candida albicans growth, respectively. 1 and 10 mM silver nitrate were mixed with an extract of Glycyrrhiza glabra and Amphipterygium adstringens. Green silver nanoparticles (AgNPs) were characterized by TEM, Vis-NIR, FTIR, fluorescence, DLS, TGA, and X-ray diffraction (XRD) analysis. Bactericidal and antimycotic activities of AgNPs were determined by Kirby and Bauer method and cell viability MTT assays. AgNPs showed a spherical shape and average size of 9 nm if prepared with Glycyrrhiza glabra extract and 3 nm if prepared with Amphipterygium adstringens extract. AgNPs inhibited the bacterial and fungal growth as was expected, without a significant cytotoxic effect on human epithelial cells. Altogether, these results strongly suggest that AgNPs could be an interesting option to control oral biofilms