Antimicrobial and antitumor activities of an alginate-based membrane loaded with bismuth nanoparticles and cetylpyridinium chloride.

OBJECTIVE: To evaluate the antitumor and antimicrobial properties of an alginate-based membrane (ABM) loaded with bismuth lipophilic nanoparticles (BisBAL NPs) and cetylpyridinium chloride (CPC) on clinically isolated bacteria and a pancreatic cancer cell line. MATERIAL AND METHODS: The BisBAL NP-CPC ABM was characterized using optical and scanning electron microscopy (SEM). The antimicrobial potential was measured using the disk-diffusion assay, and antibiofilm activity was determined through the live/dead assay and fluorescence microscopy. The antitumor activity was analyzed on the pancreatic cell line (Panc 03.27) using the MTT assay and live/dead assay with fluorescence microscopy. RESULTS: After a 24-h exposure (37°C, aerobic conditions), 5 µM BisBAL NP reduced the growth of K. pneumoniae by 77.9%, while 2.5 µM BisBAL NP inhibited the growth of Salmonella, E. faecalis and E. faecium by 82.9%, 82.6%, and 78%, respectively (p < 0.0001). The BisBAL NPs-CPC ABM (at a ratio of 10:1; 500 and 50 µM, respectively) inhibited the growth of all isolated bacteria, producing inhibition halos of 9.5, 11.2, 7, and 10.3 mm for K. pneumoniae, Salmonella, E. faecalis, and E. faecium, respectively, in contrast to the 6.5, 9.5, 8.5, and 9.8 mm obtained with 100 µM ceftriaxone (p < 0.0001). The BisBAL NPs-CPC ABM also reduced bacterial biofilms, with 81.4%, 74.5%, 97.1%, and 79.5% inhibition for K. pneumoniae, E. faecium, E. faecalis, and Salmonella, respectively. Furthermore, the BisBAL NPs-CPC ABM decreased Panc 03.27 cell growth by 76%, compared to 18% for drug-free ABM. GEM-ABM reduced tumoral growth by 73%. The live/dead assay confirmed that BisBAL NPs-CPC-ABM and GEM-ABM were cytotoxic for the turmoral Panc 03.27 cells. CONCLUSION: An alginate-based membrane loaded with BisBAL NP and CPC exhibits dual antimicrobial and antitumoral efficacy. Therefore, it could be applied in cancer treatment and to diminish the occurrence of surgical site infections.

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.

Cetylpyridinium chloride inhibits human breast tumor cells growth in a no-selective way.

OBJECTIVE: Analyze the antitumor capacity of cetylpyridinium chloride (CPC) on human breast tumor cells, and the possible action mechanism. MATERIAL AND METHODS: The human breast tumor cells MCF-7 and no-tumor breast cells MCF-10A were exposed to CPC under various condition (concentration and duration). Cell viability was measured with MTT assay, the LIVE/DEAD assay, and fluorescence microscopy. Membrane permeability after CPC exposure was evaluated by Calcein AM assay, mitochondrial morphology with a MitoView staining, and genotoxicity with the comet assay and fluorescence microscopy. RESULTS: CPC was cytotoxic to both MCF-7 and MCF-10A as of a 24-h exposure to 0.1 µM. Cytotoxicity was dose-dependent and reached 91% for MCF-7 and 78% for MCF-10A after a 24-h exposure to 100 µM CPC, which outperformed the positive control doxorubicin in effectiveness and selectivity. The LD50 of CPC on was 6 µM for MCF-7 and 8 µM for MCF-10A, yielding a selectivity index of 1.41. A time response analysis revealed 64% dead cells after only 5 min of exposure to 100 µM CPC. With respect to the action mechanisms, the comet assay did not reveal genome fragmentation. On the other hand, membrane damage was dose-dependent and may also affect mitochondrial morphology. CONCLUSION: Cetylpyridinium chloride inhibits MCF-7 cell growing in a non-selective way as of 5 min of exposure. The action mechanism of CPC on tumor cells involves cell membrane damage without change neither mitochondrial morphology nor genotoxicity.

Bismuth Lipophilic Nanoparticles (BisBAL NP) Inhibit the Growth of Tumor Cells in a Mouse Melanoma Model.

AIM: The objective of this study was to analyze the antitumor effect of BisBAL NP in a mouse melanoma model. MATERIALS AND METHODS: The antitumor activity of BisBAL NP on murine B16-F10 melanoma cells was determined both in vitro (PrestoBlue cell viability assay and Live/Dead fluorescence) and in vivo, in a mouse model, with the following 15-day treatments: BisBAL NP, negative control (PBS), and cell-death control (docetaxel; DTX). Mouse survival and weight, as well as the tumor volume, were recorded daily during the in vivo study. RESULTS: BisBAL NP were homogeneous in size (mean diameter, 14.7 nm) and bismuth content. In vitro, 0.1 mg/mL BisBAL NP inhibited B16-F10 cell growth stronger (88%) than 0.1 mg/mL DTX (82%) (*p<0.0001). In vivo, tumors in mice treated with BisBAL NP (50 mg/kg/day) or DTX (10 mg/kg/day) were 76% and 85% smaller than the tumors of negative control mice (*p<0.0001). The average weight of mice was 18.1 g and no statistically significant difference was detected among groups during the study. Alopecia was only observed in all DTX-treated mice. The survival rate was 100% for the control and BisBAL NP groups, but one DTX- treated mouse died at the end of the treatment period. The histopathological analysis revealed that exposure to BisBAL NP was cytotoxic for tumor tissue only, without affecting the liver or kidney. CONCLUSION: BisBAL NP decreased the tumor growing in a mouse melanoma model without secondary effects, constituting an innovative low-cost alternative to treat melanoma.

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.

Antimicrobial Effect of Calcium Hydroxide Combined with Electrolyzed Superoxidized Solution at Neutral pH on Enterococcus faecalis Growth.

OBJECTIVE: To evaluate the effect of the combination of calcium hydroxide (Ca(OH)2) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals. METHODS: Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH)2, OxOral®, and OxOral® plus Ca(OH)2. RESULTS: A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH)2 treatment from 4.4 ± 0.074 log10 CFU/mL to 0.0 ± 0.001 log10 CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083). CONCLUSION: The combination of OxOral® and Ca(OH)2 provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy.

Antimicrobial potential of bismuth lipophilic nanoparticles embedded into chitosan-based membrane.

The objective of this work was to analyze the antimicrobial and antibiofilm activities of bismuth lipophilic nanoparticles (BisBAL NPs) incorporated into chitosan-based membranes. Chitosan-based membranes were homogeneously embedded with BisBAL NPs, confirming the bismuth presence by scanning electron microscopy. The tensile strength of chitosan-based membrane alone or with BisBAL NPs showed similar results as elongation, suggesting that BisBAL NP addition did not affect membrane mechanical properties. Chitosan-based membranes complemented with 100 µM of BisBAL NPs caused a complete inhibition of biofilm formation and a 90-98% growth inhibition of six different oral pathogens. Cytotoxicity studies revealed that 80% of human gingival fibroblasts were viable after a 24-h exposure to the chitosan-based membrane with 100 µM of BisBAL NPs and collagen. Altogether, we conclude that the biological properties of chitosan-based membranes supplemented with BisBAL NPs could be a very interesting option for tissue regeneration.

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.

Terapia farmacológica y avances terapéuticos en xerostomía e hiposalivación / Pharmacological therapy and therapeutic advancesin xerostomy and hyposalivation

La saliva juega un rol determinante en el mantenimiento y función de los tejidos orales, donde un decremento en los niveles del flujo salival conllevan a una hiposalivación o hiposialia, trayendo consigo una serie de características que propician un ambiente ideal para la instalaciónde microorganismos oportunistas y condiciones nocivas para la saludoral y sistémica de los pacientes. Hoy en día existen múltiples causas que conllevan a una hiposialia, entre ellas el síndrome de Sjõgren, la radioterapia de haz externo, entre otras, los cuales se han puesto a prueba mediante sialogogos farmacológicos como pilocarpina, cevimelina, betanecoly carbacolina, además de alternativas terapéuticas para revertir los signos obtenidos por la hiposalivación y mitigar los síntomas de xerostomía. El objetivo del presente es realizar una revisión de literatura sobre el tratamiento farmacológico en hiposalivación y xerostomía ensíndrome de Sjõgren y radioterapia de haz externo.

Saliva plays a determinant role in the maintenance and function of oral tissues, where a decrease in salivary flow levels leads to hyposalivation or hyposialia, bringing with it a series of characteristics that provide anideal environment for the installation of opportunistic microorganisms and conditions harmful to the oral and systemic health of patients.Today there are many causes that lead to hyposialia, including Sjögren’ssyndrome, external beam radiotherapy, among others, which have beentested by pharmacological sialogogs such as pilocarpine, cevimelin, betanecol and carbacoline, in addition to therapeutic alternativesto reverse the signs obtained by hyposalivation and to mitigate the symptoms of xerostomia. The objective of the present is to make a reviewof the literature on the pharmacological treatment in hyposalivation and xerostomia in Sjögren’s syndrome and external beam radiotherapy.

Antimicrobial and antibiofilm activities of MTA supplemented with bismuth lipophilic nanoparticles.

The objective of this work was to determine the antimicrobial and antibiofilm properties of mineral trioxide aggregate (MTA) supplemented with bismuth lipophilic nanoparticles (BisBAL NPs). The antimicrobial activity of the composite MTA-BisBAL NPs was determined by the disk diffusion assay, while antibiofilm activity was analyzed by fluorescence microscopy. The cytotoxicity of MTA-BisBAL NPs was determined on human gingival fibroblasts by optical microscopy and crystal violet staining. MTA-BisBAL NPs inhibited the growth of Enterococcus faecalis, Escherichia coli, and Candida albicans and also detached the biofilm of fluorescent E. faecalis after 24 h of treatment. The addition of BisBAL nanoparticles did not significantly modify the physical properties of MTA, and cytotoxicity was not observed when MTA-BisBAL NPs was added on human gingival fibroblasts. Altogether these results suggest that BisBAL nanoparticles provide antimicrobial and antibiofilm activities to MTA while it retained their biophysical properties without cause side effects on human gingival fibroblasts.

Matriz dérmica acelular en cirugía mucogingival / Acellular dermal matrix in mucogingival surgery

La recesión gingival y los defectos periodontales son una condiciónque afectan a la gran parte de la población joven y adulta, éstospueden ocurrir sin ningún tipo de síntoma pero pueden dar lugar ala preocupación estética del paciente, hipersensibilidad, dificultad enla higiene oral o provocar la pérdida del diente. El injerto de matriz dérmica acelular ha sido utilizado como un sustituto para los injertos subepiteliales conectivos autógenos en cirugías mucogingivales, es obtenido asépticamente de la piel de un humano donador y ha mostrado resultados clínicos favorables en el área de periodoncia. El objetivo de este estudio es revisar la literatura sobre las características, usos, ventajas y avances de la matriz dérmica acelular, así como conocer sus beneficios en los procedimientos de cirugías mucogingivales, como la preservación y aumento de reborde...

Cytokines: monitors of disease severity for the clinic.

BACKGROUND: Cytokines communicate between the cells of the immune system and its targets to maintain homeostasis after injury or pathogenic events. They are involved in almost any pathological situation imaginable. OBJECTIVE: To verify the importance of cytokines as biomarkers in current preclinical (aetiopathogenic, development of new therapies) and clinical studies (diagnosis, disease severity, prognosis and response to therapy). METHOD/RESULTS: A Medline search with the query 'cytokine' AND 'biomarker' AND a variable for a variety of biomedical fields, followed by deeper-level searches, demonstrated the immense popularity of cytokines as biomarkers in almost any biomedical field. CONCLUSION: As cytokines are not disease-specific they do not serve as single diagnostic biomarkers. The strength of the cytokines resides in monitoring disease severity, prognosis and response to treatment.

Alteraciones vasculares con el suministro de ácido glucurónico a ratas / Vascular lesions because of glucuronic acid in rats

Después de haber observado que los pacientes diabéticos tienen elevadas las concentraciones plasmáticas de bilirrubina conjugada y de ácido glucurónico y conociendo que éste forma parte de la estructura química de los glucosaminoglicanos (ácido hialurónico, heparina y condroitín), que a su vez forman parte de la estructura de los capilares, vasos de mayor calibre y tejido conectivo, planteamos la hipótesis de que las elevaciones de las concentraciones de ácido glucurónico originan la elevación de los niveles de glucosaminoglicanos, y de que éstos intervienen en forma fundamental en las lesiones vasculares que presentan como complicación crónica los pacientes con diabetes mellitus. Se trató a 10 ratas Wistar con ácido glucurónico (30 mg) en 50 ml de agua para beberlo ad livitum por tiempo sin definir. A los 60 días, todas las ratas estaban ciegas y no respondían a estímulos luminosos. Estudios de oftalmoscopia, anatomopatológicos del ojo y riñón y de microscopia electrónica del riñón confirmaron la presencia de lesiones vasculares con formación de edema, congestión de vasos, microaneurismas y hemorragias, y en todos los estudios se encontró engrosamiento de membrana basal. Se concluye que el ácido glucurónico suministrado oralmente a ratas es capaz de reproducir las lesiones vasculares que como complicación crónica presenta las personas con diabetes mellitus