Characterization, antimicrobial and cytotoxic activity of polymer blends based on chitosan and fish collagen.

This study aims to produce, characterize, and assess the antimicrobial activity and cytotoxicity of polymer blends based on chitosan (CT) and fish collagen (COL) produced by different precipitation methods. Polymer blends were obtained in alkaline (NaOH), saline (NaCl), and alkaline/saline (NaOH/NaCl) solutions with different CT:COL concentration ratios (20:80, 50:50, and 80:20). The polymer blends were characterized by various physicochemical methods and subsequently evaluated in terms of their in vitro antimicrobial and cytotoxicity activity. In this study, the degree of chitosan deacetylation was 82%. The total hydroxyproline and collagen content in the fish matrix was 47.56 mg. g-1 and 394.75 mg. g-1, respectively. The highest yield was 44% and was obtained for a CT:COL (80:20) blend prepared by precipitation in NaOH. High concentrations of hydroxyproline and collagen in the blends were observed when NaOH precipitation was used. Microbiological analysis revealed that the strains used in this work were sensitive to the biomaterial; this sensitivity was dose-dependent and increased with increasing chitosan concentration in the products. The biocompatibility test showed that the blends did not reduce the viability of fibroblast cells after 48 h of culture. An analysis of the microbiological activity of the all-polymer blends showed a decrease in the values of minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) for S. aureus and P. aeruginosa. The blends showed biocompatibility with NIH-3T3 murine fibroblast cells and demonstrated their potential for use in biomedical applications such as wound healing, implants, and scaffolds.

Synthesis and characterization of experimental endodontic sealers containing bioactive glasses particles of NbG or 45S5.

OBJECTIVE: This study evaluated the influence of adding bioactive glasses particles [Niobophosphate (NbG) or bioglass (45S5)] into endodontic cements in relation to physical, chemical and biological properties. METHODS: The following commercial cements were used as comparison: AH Plus (Dentsply), Endofill (Dentsply), MTA Fillapex (Angelus) and EndoSequence (BC Sealer, Brasseler). Setting time, radiopacity, flow rate, weight loss/variation, alkaline capacity (pH) at different time-intervals (24h/48h/7d/14d/28d), bioactivity (assessed under SEM/EDS, FTIR/ATR and XDR) and cell viability were measured. Data were analyzed by One-way ANOVA/Holm-Sidak post-test (α = 5%) (normal distribution) and Kruskal-Wallis/Students-Newman-Keuls post-test (α = 5%) (non-normal distribution). RESULTS: Bioactive endodontic experimental cements (containing NbG or 45S5) had high alkalinization capacity. The experimental cements presented high weight loss/variation (p < 0.001). 45S5 experimental cement did not present radiopacity (p < 0.001). AH Plus had the lowest cell cytotoxicity when compared to the other tested cements (p < 0.001). Regarding bioactivity, SEM/EDS analyses showed precipitates with high concentrations of Ca/P for 45S5 and NbG, as well as for MTA Fillapex and BC Sealer. AH plus and Endofill did not present bioactive precipitates. FTIR/ATR and XDR analyses found hydroxyapatite precursors for NbG, 45S5, MTA Fillapex and BC Sealer. SIGNIFICANCE: The incorporation of bioactive particles (NbG or 45S5) into endodontic cements had potential to neutralize acidic environments and induced formation of hydroxyapatite precursors. Clinically, these would produce a cement that is bactericidal and have the potential to improve tissue healing. The improved radiopacity and flowability would facilitate the visualization of the material in the radiograph and the filling of anatomical complexities during root canal obturation. As drawbacks, the excessive weight loss and post-setting cytotoxicity could result in clinical degradation of the cement and adjacent tissue irritation for the patient.

Anti-biofilm Action of Chenopodium ambrosioides Extract, Cytotoxic Potential and Effects on Acrylic Denture Surface.

Considering the challenge to control Candida-associated denture stomatitis, the search for antifungal substances derived from natural sources has become a trend in the literature. In this study the following effects of Chenopodium ambrosioides extract (CAE) were investigated: action against biofilms of Candida albicans, its cytotoxic potential, and changes caused in acrylic resin. The CAE was characterized by High Performance Liquid Chromatography (HPLC). The susceptibility of C. albicans to CAE was investigated by Minimum Inhibitory Concentration and Minimum Fungicidal Concentration (MIC and MFC) tests. Acrylic resin disks were fabricated, and C. albicans biofilms were developed on these for 48 h. Afterward the disks were immersed for 10 min in: PBS (Negative Control); 1% Sodium Hypochlorite (1% SH, Positive Control) or CAE at MIC or 5xMIC. The biofilms were investigated relative to counts and metabolic activity. The cytotoxic potential in keratinocytes and fibroblasts was verified by MTT test. Change in color and roughness of the acrylic resin was analyzed after 28 days of immersion in CAE. The data were analyzed by the ANOVA considering a 5% level of significance. The main compounds detected by HPLC were kaempferol and quercetin. Both MIC and MFC obtained the value of 0.25 mg/mL. The MIC was sufficient to significantly reduce the counts and activity of the biofilm cells (p < 0.0001), while 5xMIC resulted in almost complete eradication, similar to 1% SH. Keratinocytes and fibroblasts exposed to the MIC and 5xMIC presented cell viability similar to that of the Control Group (p > 0.05). No important changes in acrylic resin color and roughness were detected, even after 28 days. It could be concluded that the immersion of acrylic resin in C. ambrosioides extract in its minimum inhibitory concentration was effective for the reduction of C. albicans biofilms without any evidence of cytotoxic effects or changes in roughness and color of this substrate.

Punica granatum L. Leaf Extract Attenuates Lung Inflammation in Mice with Acute Lung Injury.

The hydroalcoholic extract of Punica granatum (pomegranate) leaves was previously demonstrated to be anti-inflammatory in a rat model of lipopolysaccharide- (LPS-) induced acute peritonitis. Here, we investigated the anti-inflammatory effects of the ethyl acetate fraction obtained from the pomegranate leaf hydroalcoholic extract (EAFPg) on the LPS-induced acute lung injury (ALI) mouse model. Male Swiss mice received either EAFPg at different doses or dexamethasone (per os) prior to LPS intranasal instillation. Vehicle-treated mice were used as controls. Animals were culled at 4 h after LPS challenge, and the bronchoalveolar lavage fluid (BALF) and lung samples were collected for analysis. EAFPg and kaempferol effects on NO and cytokine production by LPS-stimulated RAW 264.7 macrophages were also investigated. Pretreatment with EAFPg (100-300 mg/kg) markedly reduced cell accumulation (specially neutrophils) and collagen deposition in the lungs of ALI mice. The same animals presented with reduced lung and BALF TNF-α and IL-1ß expression in comparison with vehicle controls (p < 0.05). Additionally, incubation with either EAFPg or kaempferol (100 µg/ml) reduced NO production and cytokine gene expression in cultured LPS-treated RAW 264.7 macrophages. Overall, these results demonstrate that the prophylactic treatment with EAFPg attenuates acute lung inflammation. We suggest this fraction may be useful in treating ALI.

Efeito Antiproliferativo do Zoledronato em Linhagens Celulares Tumorais / Antiproliferative Effect of Zoledronate on Tumor Cell Lines / Efecto Antiproliferativo del Zoledronato en Linajes Celulares Tumorales

Introdução: Bisfosfonatos são fármacos utilizados para o tratamento de enfermidades ósseas, como a osteoporose e metástases ósseas, em razão do seu mecanismo de ação, que consiste na diminuição do processo de reabsorção do osso. Outros estudos verificaram que bisfosfonatos de alta potência, como o zoledronato, poderiam auxiliar no tratamento de outras enfermidades malignas por causa da promoção de um efeito antiproliferativo. Objetivo: Este estudo in vitro objetivou avaliar a atividade antiproliferativa de zoledronato em diferentes linhagens de células tumorais. Método: Nove linhagens humanas (U251; MCF7; NCI/ADR-RES; 786-0; NCI-H460; PC-3; OVCAR-3; HT29; K-562 e HaCaT) foram submetidas ao tratamento com as concentrações de 0,12; 1,2; 12 e 120 µM de zoledronato e tiveram sua atividade proliferativa avaliada após 48 horas, utilizando-se o corante sulforrodamina B. Resultados: Verificou-se que as concentrações de 12 µM e 120 µM de zoledronato foram eficazes para a redução em 50% e 100%, respectivamente, da proliferação das células 786-0 (carcinoma renal). A maior concentração de zoledronato (120 µM) promoveu um efeito citostático (redução da proliferação celular em 50%) para as células HaCaT (queratinócito humano não tumoral), HT-29 (carcinoma de cólon), NCI-ADR/ RES (adenocarcinoma de ovário com fenótipo de multirresistência) e NCI-H460 (carcinoma pulmonar). Conclusão: Esses resultados sugerem um promissor efeito auxiliar do zoledronato para o tratamento de alguns tipos de tumores; estudos complementares in vitro e in vivo são necessários para a validação dessa hipótese.

Introduction: Bisphosphonates are used in the treatment of bone diseases such as osteoporosis and bone metastases, because of their ability to inhibit bone resorption. There is evidence that high-potency bisphosphonates, such as zoledronate, are useful in the treatment of other malignancies because they have an antiproliferative effect. Objective:To evaluate the antiproliferative activity of zoledronate in different tumor cell lines. Method: This was an in vitro study in which nine human cell lines (U251, MCF7, NCI/ ADR-RES, 786-0, NCI-H460, PC-3, OVCAR-3, HT29, K-562, and HaCaT) were treated with of 0.12, 1.2, 12, and 120 µM of zoledronate, their proliferative activity being evaluated 48 h later with sulforhodamine B assay. Results: At the 12 µM and 120 µM doses, zoledronate effectively reduced the proliferation of 786-0 (renal carcinoma) cells by 50% and 100%, respectively. At the highest concentration (120 µM), zoledronate had a cytostatic effect (50% reduction in cell proliferation) on HaCaT (non-tumor human keratinocyte), HT-29 (colon carcinoma), NCI-ADR/ RES (multidrug-resistant ovarian adenocarcinoma), and NCI-H460 (lung carcinoma) cells. Conclusion: These results suggest a promising auxiliary effect of zoledronate for the treatment of some tumors. Further in vitro and in vivo studies are needed in order to test that hypothesis.

Introducción: Los bisfosfonatos son fármacos utilizados para el tratamiento de enfermedades óseas, como la osteoporosis y metástasis óseas debido a su mecanismo de acción, que consiste en la disminución del proceso de reabsorción del hueso. Otros estudios observaron que los bisfosfonatos de alta potencia, como el zoledronato, podrían ayudar en el tratamiento de otras enfermedades malignas debido a la promoción de un efecto antiproliferativo. Objetivo: Este estudio in vitro objetivó evaluar la actividad antiproliferativa de zoledronato en diferentes linajes de células tumorales. Método: Los nueve humano linajes (U251, MCF7, NCI / ADR-RES, 786-0, NCI-H460, PC-3, OVCAR-3, HT29, K-562 and HaCaT) se sometieron al tratamiento con las concentraciones de 0,12; 1,2; 12 y 120 µM de zoledronato y tuvieron su actividad proliferativa evaluada después de 48 horas utilizando el colorante sulforrodamina B. Resultados: Se comprobó que las concentraciones de 12 µM y 120 µM de zoledronato fueron efectivas para reducir en un 50% y un 100%, respectivamente, de la proliferación de las células 786-0 (carcinoma renal). La mayor concentración de zoledronato (120 µM) promovió un efecto citostático (reducción de la proliferación celular en un 50%) para las células HaCaT (queratinocito humano no tumoral), HT-29 (carcinoma de colon), NCI-ADR/RES (adenocarcinoma de ovário con fenótipo de multirresistencia) y NCI-H460 (carcinoma pulmonar). Conclusión: Estos resultados sugieren un prometedor efecto auxiliar del zoledronato para el tratamiento de algunos tumores; se requieren más estudios in vitro e in vivo para validar esta hipótesis

Chitosan-tripolyphosphate nanoparticles as Arrabidaea chica standardized extract carrier: synthesis, characterization, biocompatibility, and antiulcerogenic activity.

Natural products using plants have received considerable attention because of their potential to treat various diseases. Arrabidaea chica (Humb. & Bonpl.) B. Verlot is a native tropical American vine with healing properties employed in folk medicine for wound healing, inflammation, and gastrointestinal colic. Applying nanotechnology to plant extracts has revealed an advantageous strategy for herbal drugs considering the numerous features that nanostructured systems offer, including solubility, bioavailability, and pharmacological activity enhancement. The present study reports the preparation and characterization of chitosan-sodium tripolyphosphate nanoparticles (NPs) charged with A. chica standardized extract (AcE). Particle size and zeta potential were measured using a Zetasizer Nano ZS. The NP morphological characteristics were observed using scanning electron microscopy. Our studies indicated that the chitosan/sodium tripolyphosphate mass ratio of 5 and volume ratio of 10 were found to be the best condition to achieve the lowest NP sizes, with an average hydrodynamic diameter of 150±13 nm and a zeta potential of +45±2 mV. Particle size decreased with AcE addition (60±10.2 nm), suggesting an interaction between the extract's composition and polymers. The NP biocompatibility was evaluated using human skin fibroblasts. AcE-NP demonstrated capability of maintaining cell viability at the lowest concentrations tested, stimulating cell proliferation at higher concentrations. Antiulcerogenic activity of AcE-NP was also evaluated with an acute gastric ulcer experimental model induced by ethanol and indomethacin. NPs loaded with A. chica extract reduced the ulcerative lesion index using lower doses compared with the free extract, suggesting that extract encapsulation in chitosan NPs allowed for a dose reduction for a gastroprotective effect. The AcE encapsulation offers an approach for further application of the A. chica extract that could be considered a potential candidate for ulcer-healing pharmaceutical systems.