Higher Percentage Of Viable Cells Research Articles

Effects of octenidine applied alone or mixed with sodium hypochlorite on eukaryotic cells.

To assess the effects of octenidine dihydrochloride (OCT) on eukaryotic cells and the cytotoxicity of OCT associated with sodium hypochlorite - NaOCl (NaOCl/OCT). L929 fibroblasts and human osteoblast-like cells (Saos-2) were exposed to 0.1% OCT, 2% CHX, 2.5% NaOCl, 5.25% NaOCl and mixtures of 5.25% NaOCl and 0.1% OCT (NaOCl/OCT) at 90:10, 80:20 and 50:50 ratios. Cell viability was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red (NR) assays; type of cell death, by flow cytometry; cytoskeleton, by actin and α-tubulin fluorescence; and alkaline phosphatase (ALP) activity, by thymolphthalein release. The data were analysed by two-way ANOVA and Bonferroni tests (α=0.05). MTT and NR assays revealed that 0.1% OCT had the lowest cytotoxicity (P<0.05), followed by 2% CHX (P<0.05). The 2.5% NaOCl, NaOCl/OCT 80:20 and NaOCl/OCT 50:50 solutions had intermediate cytotoxicity. NaOCl 5.25% and NaOCl/OCT 90:10 had the highest cytotoxicity (P<0.05). The OCT group had a higher percentage of viable cells than the NaOCl and CHX groups (P<0.05), and induced apoptosis at higher doses. The cytoskeleton alterations were observed at 0.12%, 0.6% and 2.02% for the NaOCl, CHX and OCT groups, respectively. The solutions did not induce ALP activity. Octenidine dihydrochloride was less cytotoxic, induced apoptosis at higher doses, caused few changes in the cytoskeleton and did not induce alkaline phosphatase activity. In addition, octenidine dihydrochloride reduced the cytotoxicity of 5.25% NaOCl when combined at 20 and 50%.

Effect of addition titanium dioxide nanoparticles as acrylic resin denture base filler on cytotoxicity

Denture base material should have a good level of biocompatibility. Acrylic resin is frequently used as a denture base material, however it has a disadvantage of producing residual monomer. Residual monomer is known to have a cytotoxicity effect. Titanium dioxide (TiO2) nanoparticles are used as fillers due to their biocompatibility and ability to enhance the mechanical properties of acrylic resin. The addition of the material to acrylic resin could affect the amount of residual monomer. The aim of this study was to examine the effect of the addition of TiO2 nanoparticles as acrylic resin denture base filler on the cytotoxicity in fibroblast cells. The samples consisted of 24 heat cured acrylic resins in disc shape (5 mm in diameter and 2 mm in thickness), divided into 4 groups (n = 6): three groups given treatment with0.5%, 1%, 2% TiO2, respectively and one control group. Cell viability was measured with MTT assay. The results were tested with one way ANOVA with 95% confidence level followed by LSD post hoc test. The results showed that the highest percentage of cell viability was found in the treatment group of 0.5% TiO2 with value of 91.83 ± 1.75%, while the lowest value was seen in the treatment group of 2% TiO2 with value of 79.38 ± 3.34%. Significant differences were shown between the treatment groups of 0.5% and 2% TiO2, as well as between the control and treatment group with 2% TiO2. The conclusions of this research are the addition of TiO2 nanoparticles as acrylic resin denture base filler has an effect on cytotoxicity; the addition of 0.5% TiO2 nanoparticles filler results in lower cytotoxicity on fibroblast cells compared to the addition of 1% and 2% TiO2.

Fabrication Of Gold Nanoparticles In Absence Of Surfactant As In Vitro Carrier Of Plasmid DNA.

PurposeThis work aimed to synthesize surfactant-free AuNPs for targeted delivery of plasmid DNA encoded p53 gene and to avoid conventional production method of Gold nanoparticles (AuNPs) which may adversely affect the final shape, diversity, and size due to accumulation of the formulated surfactant – gold complex to the surface.MethodsThe AuNPs were fabricated using seeded-growth method with L-Cystine methyl ester hydrochloride as capping agent, then loaded with plasmid DNA encoded p53 gene. The resultant AuNPs and AuNPs-p53 complex were evaluated for physical characteristics and morphology. Confirmation of complex formation was performed using gel electrophoresis. Furthermore, the efficient delivery and cytotoxicity behavior of the encoded gene were examined on both healthy lung cells (WI38) and cancerous lung cells (A549).ResultsL-cysteine methyl ester hydrochloride AuNPs showed acceptable physical characteristics (30 nm, +36.9 mv, and spherical morphology). P53 attachment to AuNPs was confirmed by gel electrophoresis. The RT-PCR proved the overexpression of p53 by the fabricated AuNPs-p53 complex. The high percentage of cell viability in normal lung cell line (WI 38) proved the safety of L-cysteine methyl ester functionalized AuNPs. Additionally, the apoptotic effect due to expression of p53 gene loaded on AuNPs was only prominent in lung cancer cell line (A549), revealing selectivity and targeting efficiency of anticancer AuNPs-p53 complex.ConclusionAuNPs can be considered as a potential delivery system for effective transfection of plasmid DNA which can be used for successful treatment of cancer.

Human Osteoblast Cell Behaviour on Titanium Discs Treated with Argon Plasma.

(1) Background. Titanium is characterized by its biocompatibility and resistance to stress and fatigue. Treatment with argon plasma may favour growth of human osteoblasts with respect to cell adhesion and proliferation. The aim of this study was to analyse the behaviour of human osteoblasts (MG-63) on Grade IV and V titanium possessing a sand-blasted, acid-etched (SLA) surface. SLA is a widely used surface treatment to create micro- and macroretentions to enhance osteoconductive properties on the surface. (2) Methods. One group of each grade of titanium was decontaminated with argon plasma and compared. On each disc, 20 × 104 cells were cultivated for morphological analysis, study of cell viability (regarding a negative control [100% viability]) and mitochondrial energy balance. (3) Results. At 24 h titanium treated with SLA showed a higher percentage of cell viability (47.3 ± 8.1%) compared to titanium IV treated with argon plasma, which presented a percentage of 79.1 ± 1.1%. Grade V titanium treated with argon plasma presented a higher viability percentage 91.3 ± 3.0% whereas nontreated Grade V titanium presented 53.3 ± 4.0%. Cells cultivated on the surfaces with an argon-plasma treatment were enlarged in comparison to non-treated discs. The cells with smaller circularity with a greater spread and spindle shape were the ones cultivated on the Grade V titanium surface. Cells seeded on treated titanium IV and titanium V, treated or not, showed higher mitochondrial activity over nontreated titanium IV. (4) Conclusions. Cells cultivated on those Grade V titanium discs that were decontaminated with argon plasma presented higher levels of cell adhesion and proliferation, lower mitochondrial damage and a higher mean cell area compared to those not decontaminated with argon plasma.

Viability of fibroblast cells on the clove (Syzygium aromaticum) leaves ethanol extract

Introduction: Various active compounds of herbal plants that are known to accelerate the wound healing process are flavonoids, tannins, and saponins. One amongst them is clove (Syzygium aromaticum), with the leaves as the most common part to be used as herbal medicine due to the antibacterial, anti-inflammatory, and antioxidant properties. However, the use of the biocompatibility of clove leaves as herbal medicine is still unknown. Therefore, this study was aimed to determine the cytotoxicity effects of clove leaves ethanol extract on the fibroblast cells and safe dosage (IC50) for medicinal use. Methods: Phytochemical tests using the Farnsworth method and viability test was performed using the laboratory experimental with post-test only control group design. The samples were divided into seven concentrations; 500, 250, 125, 62.5, 31.25, 15.63, and 7.81 μg/ml, with three repetitions (triplo) towards the fibroblast cells. Viability test was performed using MTS assay. Results: Based on the results obtained from one-way ANOVA statistical test, there was a significant difference between the percentage of cell viability and each concentration (α ≤ 0.05), with IC50 value of 344.814 μg/ml. Conclusion: Clove (Syzygium aromaticum) leaves ethanol extract showed a high percentage of cell viability at the concentrations below the IC50 value.Keywords: Clove leaves, cytotoxicity, fibroblast cell, MTS assay, periodontal diseases, viability.

Fluid flow in a Porous Scaffold for Microtia by Lattice Boltzmann Method

The birth deformity of ear, known as microtia, varies from a minimal deformed ear to the absence of auricular tissue or anotia. This malformation has been treated by reconstructing the external ear, mainly by autogenous rib cartilage in auricular repair. The fabrication of the ear framework is a prolonged reconstructive procedure and depends of the surgeon’s skill. In order to avoid these inconveniences and reduce surgery time, it was proposed in a previous work to use implants made with biocompatible materials. One of these is a scaffold made by fused deposition modeling using PLA based in the three-dimensional geometry of the ear cartilage. The aim of this work is to evaluate the feasibility of this scaffold to perform cell culture in a perfusion biorreactor by estimating the flow transport characteristics in porous media using a scaffold with the porous geometry of the human auricular cartilage for microtia. Flow and heat transfer through the scaffold were simulated by the lattice Boltzmann method, and permeability and shear stress distribution were obtained at different Reynolds numbers. The permeability values of the scaffold achieved are in the order of magnitude of scaffolds used for cell culture. Linear dependencies between maximum shear stress and Reynolds number, and between maximum shear stress and permeability were obtained. The values of shear stress achieved correspond to high percentage of cell viability. The scaffolds for microtia treatment with the proposed filling pattern select is appropriate for cell culture in a perfusion bioreactor with characteristics similar to those described herein.

Microstructure characterization of biocompatible heterojunction hydrogen titanate-Ag2O nanocomposites for superior visible light photocatalysis and antibacterial activity

Hydrogen trititanate (H2Ti3O7·2H2O) and hydrogen trititanate/Ag2O hybrid nanocomposites (NCs) with novel structure have been synthesized by a simple solvothermal route followed by Na+/H+ ion-exchange. Growths of hydrogen trititanate with nanofiber (HTNF) and nanotube (HTNT) morphologies and hydrogen trititanate-Ag2O (HTFAG and HTTAG) nanocomposites have been tailored by controlling the solvent media. Detailed microstructure characterization of all these samples have been carried out by Rietveld refinement of XRD data and analyzing FESEM/HRTEM micrographs and FTIR spectra. Band gap energies of all these semiconducting samples are obtained from UV–Vis absorption spectra. Both HTFAG and HTTAG NCs exhibit enhanced photocatalytic degradation of organic pollutant (Congo red dye) under visible light, in comparison to HTNF and HTNT respectively due to the formation of a heterojunction between H2Ti3O7·2H2O and Ag2O, which is supported by photoluminescence spectroscopy. HTFAG and HTTAG NCs also show superior antibacterial activity against both gram-negative (Escherichia coli) and gram-positive (Bacillus subtilis) bacteria compared to their pure counterparts. MTT assay reflects a sufficiently high percentage of cell viability and confirms the significant cytocompatibility of all the samples.

Synthesis, antimicrobial activity and high cell viability of copper derivatives of 2-thiouracil, purine-6-thione and 2,4,6-trimercaptotriazine

Reactions of copper(II) acetate with 2-thiouracil (tucH2) and triphenyl phosphine (1:1:1 or 1:1:2 molar ratios) in methanol-acetonitrile/chloroform mixture yielded a light brown N,S-bridged dinuclear CuI complex, [Cu(PPh3)2(µ-N,S-tucH)Cu(PPh3)2Cl] 1, incorporating uninegative 2-thiouracilate. X-ray crystallography has shown that the crystals of complex 1 comprise a two component twin system and belong to the space group Ia. The major component 1a is about 77% and the minor component 1b is about 23%. One Cu is four-coordinate tetrahedral with center {CuP2SCl} and the other Cu is three-coordinate distorted trigonal planar with {CuP2N} center. Crystal data: 1, formula, C76H63ClCu2N2OP4S; space group: Ia; monoclinic, a, 22.2638(9); b, 11.8050(4); c, 27.4455(10) Å; β, 113.358(5); R, 4.80%;173(2) K. The antimicrobial activities of dinuclear 1 as well as that of the previously reported 2-thiouracil, 2,4,6-trimercaptotriazine (tmtH3) and purine-6-thione (purSH2) complexes, [CuCl(κ1-S-tucH2)(PPh3)2] 2, [Cu2Br2(μ-S-tucH2)2(PPh3)2] 3, [Cu(tmtH2)(PPh3)2] 4, [Cu3Br2(k1-N,k1-S,µ-S-tmtH2)(PPh3)6] 5 and [Cu(k1-N,k1-S-purSH)(PPh3)2] 6, have been screened against gram negative, Escherichia coli (MTCC 119) and Shigella flexneri (MTCC 1457), gram positive, Enterococcus faecalis (MTCC 439) and Staphylococcus aureus (MTCC 740) microorganism. High percentage of cell viability (96–97%) is observed in some cases.

Direct-Contact Cytotoxicity Evaluation of CoCrFeNi-Based Multi-Principal Element Alloys.

Transition metal multi-principal element alloys (MPEAs) are novel alloys that may offer enhanced surface and mechanical properties compared with commercial metallic alloys. However, their biocompatibility has not been investigated. In this study, three CoCrFeNi-based MPEAs were fabricated, and the in vitro cytotoxicity was evaluated in direct contact with fibroblasts for 168 h. The cell viability and cell number were assessed at 24, 96, and 168 h using LIVE/DEAD assay and alamarBlue assay, respectively. All MPEA sample wells had a high percentage of viable cells at each time point. The two quaternary MPEAs demonstrated a similar cell response to stainless steel control with the alamarBlue assay, while the quinary MPEA with Mn had a lower cell number after 168 h. Fibroblasts cultured with the MPEA samples demonstrated a consistent elongated morphology, while those cultured with the Ni control samples demonstrated changes in cell morphology after 24 h. No significant surface corrosion was observed on the MPEAs or stainless steel samples following the cell culture, while the Ni control samples had extensive corrosion. The cell growth and viability results demonstrate the cytocompatibility of the MPEAs. The biocompatibility of MPEAs should be investigated further to determine if MPEAs may be utilized in orthopedic implants and other biomedical applications.

Persistent presence of outer membrane epitopes during short- and long-term starvation of five Legionella pneumophila strains

BackgroundLegionella pneumophila, the causative agent of Legionnaire’s disease, may enter a viable but non-culturable (VBNC) state triggered by environmental stress conditions. Specific outer-membrane epitopes of L. pneumophila are used in many diagnostic applications and some of them are linked to important virulence-related factors or endotoxins. However, it is not clear how the presence and status of these epitopes are influenced by environmental stress conditions. In this study, changes of outer membrane epitopes for monoclonal antibodies (mAb) from the Dresden panel and the major outer membrane protein MOMP were analysed for five L. pneumophila strains during short- and long-term starvation in ultrapure water.ResultsWith ELISA and single cell immuno-fluorescence analysis, we could show that for most of the investigated mAb-strain combinations the total number of mAb-stained Legionella cells stayed constant for up to 400 days. Especially the epitopes of mAb 3/1, 8/5, 26/1 and 20/1, which are specific for L. pneumophila serogroup 1 subtypes, and the mAb 9/1, specific for serogroup 6, showed long-term persistence. For most mAb- stained cells, a high percentage of viable cells was observed at least until 118 days of starvation. At the same time, we observed a reduction of the fluorescence intensity of the stained cells during starvation indicating a loss of epitopes from the cell surface. However, most of the epitopes, including the virulence-associated mAb 3/1 epitope were still present with high fluorescence intensity after 400 days of starvation in up to 50% of the starved L. pneumophila population.ConclusionsThe results demonstrate the continuous presence of outer membrane epitopes of L. pneumophila during short-term and long-term starvation. Thus, culture-independent mAb-based diagnostic and detection tools, such as immuno-magnetic separation and microarray techniques are applicable for both L. pneumophila in the culturable and the VBNC state even after long-term starvation but nevertheless require careful testing before application. However, the mere presence of those epitopes is not necessarily an indication of viability or infectivity.

In Vitro Comparative Study of Oxygen Plasma Treated Poly(Lactic⁻Co⁻Glycolic) (PLGA) Membranes and Supported Nanostructured Oxides for Guided Bone Regeneration Processes.

(1) Background: The use of physical barriers to prevent the invasion of gingival and connective tissue cells into bone cavities during the healing process is called guided bone regeneration. The objective of this in-vitro study was to compare the growth of human osteoblasts on Poly(Lactic–co–Glycolic) (PLGA) membranes modified with oxygen plasma and Hydroxyapatite (HA), silicon dioxide (SiO2), and titanium dioxide (TiO2) composite nanoparticles, respectively. (2) Methods: All the membranes received a common treatment with oxygen plasma and were subsequently treated with HA nanostructured coatings (n = 10), SiO2 (n = 10) and TiO2 (n = 10), respectively and a PLGA control membrane (n = 10). The assays were performed using the human osteoblast line MG-63 acquired from the Center for Scientific Instrumentation (CIC) from the University of Granada. The cell adhesion and the viability of the osteoblasts were analyzed by means of light-field microphotographs of each condition with the inverted microscope Axio Observer A1 (Carl Zeiss). For the determination of the mitochondrial energy balance, the MitoProbe™ JC-1 Assay Kit was employed. For the determination of cell growth and the morphology of adherent osteoblasts, two techniques were employed: staining with phalloidin-TRITC and staining with DAPI. (3) Results: The modified membranes that show osteoblasts with a morphology more similar to the control osteoblasts follow the order: PLGA/PO2/HA > PLGA/PO2/SiO2 > PLGA/PO2/TiO2 > PLGA (p < 0.05). When analysing the cell viability, a higher percentage of viable cells bound to the membranes was observed as follows: PLGA/PO2/SiO2 > PLGA/PO2/HA > PLGA/PO2/TiO2 > PLGA (p < 0.05), with a better energy balance of the cells adhered to the membranes PLGA/PO2/HA and PLGA/PO2/SiO2. (4) Conclusion: The membrane in which osteoblasts show characteristics more similar to the control osteoblasts is the PLGA/PO2/HA, followed by the PLGA/PO2/SiO2.

Bioactivity of novel functionally structured titanium-ceramic composites in contact with human osteoblasts.

The aim of this study was to analyze the osteogenic cell behavior on the surface of novel functionally graded titanium-based composites containing bioactive ceramics. Titanium grade V discs (8 × 3 mm) embedding gradual content of hydroxyapatite (TiAlV-HA) or beta-tricalcium phosphate (TiAlV-βTCP) were produced by hot-pressing technique. Titanium-ceramic composite discs and Ti grade V (control group) were placed in contact with human osteoblast culture assays. The morphology and adhesion of osteoblasts were inspected by field emission guns scanning electron microscopy (FEGSEM) while cell viability was assessed by fluorometric method. Alkaline phosphatase (ALP) activity and fluorescent microscopic analyses were used to evaluate mineralization on the test and control discs. FEGSEM images showed cells adhered to Ti6Al4V-ceramic and Ti6Al4V surfaces over a period of 24 h, and therefore, an intense proliferation of osteoblasts and spreading cells was noticed for 7 days. Cell viability increased with time on all the surfaces although TiAlV-βTCP revealed significant higher percentage of cell viability than that recorded for TiAlV-HA (p < 0.01). TiAlV-βTCP also showed the highest hydrophilic character. ALP levels increased on the Ti6Al4V-ceramic surfaces when compared to the control group. Also, a qualitative analysis of mineralization evidenced an increase in mineral content on TiAlV-HA or TiAlV-βTCP groups. Novel functionally graded composites based on Ti grade V and hydroxyapatite or βTCP showed a higher bioactivity in presence of osteoblasts than that recorded on Ti grade V. Also, such functionally graded materials can prevent risks of failures by detachment of bioactive ceramic materials during implant placement. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1923-1931, 2018.

Cytotoxicity of gypsum-based biomaterial for direct pulp capping using stem cells from human exfoliated deciduous teeth.

Aim:The aim of this study was to evaluate the cytotoxicity effects of experimental gypsum-based biomaterial prepared with various concentrations of chitosan (Gyp-CHT).Materials and Methods:The study was performed using cell viability assay for mitochondrial dehydrogenase activity in stem cells from human exfoliated deciduous teeth (SHED), after 1, 2, and 3 days of exposure to the biomaterial extracts of varying concentrations. Differences in mean cell viability values were assessed by one-way analysis of variance, followed by Dunnett T3 post hoc test for multiple comparisons (P < 0.05).Results:The cell viability to Gyp-CHT in low extract concentrations was statistically similar to that of the control and different from that of high extract concentrations. Gyp-5% CHT showed the highest percentage of cell viability with 110.92%, 108.56%, and 109.11%. The cell viability showed a tendency toward increment with low extract concentration and no constant effect of CHT on cell viability toward higher or lower.Conclusions:Gyp-CHT biomaterial has no cytotoxic effects on the cultured SHED.

Photopolymerization of cell-laden gelatin methacryloyl hydrogels using a dental curing light for regenerative dentistry

Photopolymerized hydrogels, such as gelatin methacryloyl (GelMA), have desirable biological and mechanical characteristics for a range of tissue engineering applications. ObjectiveThis study aimed to optimize a new method to photopolymerize GelMA using a dental curing light (DL). MethodsLithium acylphosphinate photo-initiator (LAP, 0.05, 0.067, 0.1% w/v) was evaluated for its ability to polymerize GelMA hydrogel precursors (10% w/v) encapsulated with odontoblast-like cells (OD21). Different irradiances (1650, 2300 and 3700mW/cm2) and photo-curing times (5–20s) were tested, and compared against the parameters typically used in UV light photopolymerization (45mW/cm2, 0.1% w/v Irgacure 2959 as photoinitiator). Physical and mechanical properties of the photopolymerized GelMA hydrogels were determined. Cell viability was assessed using a live and dead assay kit. ResultsComparing DL and UV polymerization methods, the DL method photopolymerized GelMA precursor faster and presented larger pore size than the UV polymerization method. The live and dead assay showed more than 80% of cells were viable when hydrogels were photopolymerized with the different DL irradiances. However, the cell viability decreased when the exposure time was increased to 20s using the 1650mW/cm2 intensity, and when the LAP concentration was increased from 0.05 to 0.1%. Both DL and UV photocrosslinked hydrogels supported a high percentage of cell viability and enabled fabrication of micropatterns using a photolithography microfabrication technique. SignificanceThe proposed method to photopolymerize GelMA cell-laden hydrogels using a dental curing light is effective and represents an important step towards the establishment of chair-side procedures in regenerative dentistry.

Effect of sterilization processes on the properties of a silane hybrid coating applied to Ti6Al4V alloy

Abstract

A novel multicolor flow-cytometry application for quantitative detection of receptors on vascular smooth muscle cells.

There is a need to develop new techniques for quantitative measurement of receptors expression on particular vasculature cells types. Here, we describe and demonstrate a novel method to measure quantitatively and simultaneously the expression of endothelin B receptor (ETB) on vascular smooth muscle cells (VSMC). We isolated cells from male rat tissues such as: brain pial, brain intraparenchymal and retina vessels. To analyze solid tissues, a single-cell suspension was prepared by a combined mechanic and enzymatic process. The cells were stained with Fixable Viability Dye, followed by fixation, permeabilization and antibodies staining. The expression of ETB receptors on VSMC was measured by flow-cytometry and visualized by fluorescence microscopy. We obtained a high percentage of viable cells 87.6% ± 1.5% pial; 84.6% ± 4.3% parenchymal and 90.6% ± 4% retina after isolation of single cells. We performed a quantitative measurement of ETB receptor expression on VSMC and we identified two subpopulations of VSMC based on their expression of smooth muscle cells marker SM22α. The results obtained from pial vessels are statistically significant (38.4% ± 4% vs 9.8% ± 3.32%) between the two subpopulations of VSMC. The results obtained from intraparenchymal and retina vessels were not statistically significant. By specific gating on two subpopulations, we were able to quantify the expression of ETB receptors. The two subpopulation expressed the same level of ETB receptor (p = 0.45; p = 0.3; p = 0.42) in pial, parenchymal and retina vessels, respectively. We applied our method to the animals after induction of subarachnoid hemorrhage (SAH). There was statistically significant expression of ETB receptor (p = 0.02) on VSMC between sham 61.4% ± 4% and SAH 77.4% ± 4% rats pial vessels. The presented technique is able to quantitatively and selectively measure the level of protein expression on VSMC. The entire technique is optimized for rat tissue; however the protocol can also be adapted for other species.

Cytotoxic Effect of the Combination of Gemcitabine and Atorvastatin Loaded in Nanoparticle on the MCF-7 Breast Cancer Cells and HFS Human Foreskin Cells

Background: The combination of anticancer drugs in nanoparticles has great potential as a promising strategy to maximize drug efficacies. Gemcitabine (GEM), a nucleoside analogue, and atorvastatin (ATV), a cholesterol lowering agent, have shown anticancer effect with some limitations. Objective: The study aimed to evaluate antitumor activity of the combination therapy of GEM and ATV encapsulated in nanodroplets of microemulsion (ME) formulation in MCF-7 breast cancer cells and healthy HFS human foreskin cells. Method: The physical characterization of drug formulas has been studied by the transmission electron microscope (TEM). The cytotoxicity and efficacy of the formulation were examined by 3(4,5-dimethylthiazole-2-yl)-2,5-diphyneltetrazolium bromide (MTT) assay, light microscopy, and ApopNexin apoptosis detection kit. Results: It has been found that the IC50, inhibitory concentration at which 50 percent of the cells inhibited, for the combination of GEM and ATV at 1:2 ratio, respectively, in the ME (GEM/2ATVME) with a droplet diameter of 4.81±0.86 nm, subjected into the MCF-7 cells for 24h, was similar to the combination of GEM and ATV at 1:1 ratio, respectively, in water (GEM/ATV). According to the FITC/PI assay, 5 µM of GEM/2ATV-ME was less toxic on the HFS cells as higher percentages of viable cells (85.15%) were detected when compared to the GEM/ATV that caused reduction in the percentages of the viable cells (66.45%). Conclusion: Formulating GEM with ATV in ME has improved the therapeutic anticancer potential of both drugs while reducing their side effects on the normal cells.

Simplified conditions for storing and cryopreservation of dental pulp stem cells

ObjectivesThis study aimed to simplify the collection, isolation and cryopreservation procedure of human dental pulp stem cells (DPSCs) to ease the establishment of dental stem cell banking. DesignExtracted third molars were collected and stored either in growth medium or in gentamicin-saline (480μg/ml) for 6, 9 or 12h. DPSCs were isolated and subjected to cryopreservation by a controlled-rate or rapid freezing method in 5 or 10% DMSO. Flow cytometry and growth pattern of DPSCs before and after cryopreservation were conducted. ResultsRate of contamination by which the extracted teeth were stored in control and gentamicin-saline were 9.1% (N=33) and 2.3% (N=43), respectively. Successful cell isolation rate of teeth preserved in gentamicin-saline at 6h (92.9%) was comparable to those of growth media group (90.3%). At 9 and 12h, the rates dropped significantly to 75% and 54%, respectively. Cryopreservation by controlled-rate freezing either in 5 or 10% DMSO resulted in a significantly higher percentage of viable cells than by rapid freezing. Cells conserved by controlled-rate freezing in 5% DMSO showed a pattern of growth similar to control unfrozen cells; 10% DMSO significantly deteriorated the growth pattern of the cells. After thawing, DPSCs conserved by controlled-rate freezing still expressed stemness characteristics, although hematopoietic stem cell markers were slightly increased. ConclusionGentamicin-saline was effective in preserving human teeth for DPSC isolation. Controlled-rate freezing in 5% DMSO gave the highest rate of cell viability. This study simplifies the storage conditions and proposes a simple method for cryopreservation of DPSCs.

In Vitro and in Vivo Study of Poly(Lactic⁻co⁻Glycolic) (PLGA) Membranes Treated with Oxygen Plasma and Coated with Nanostructured Hydroxyapatite Ultrathin Films for Guided Bone Regeneration Processes.

The novelty of this study is the addition of an ultrathin layer of nanostructured hydroxyapatite (HA) on oxygen plasma modified poly(lactic–co–glycolic) (PLGA) membranes (PO2) in order to evaluate the efficiency of this novel material in bone regeneration. Methods: Two groups of regenerative membranes were prepared: PLGA (control) and PLGA/PO2/HA (experimental). These membranes were subjected to cell cultures and then used to cover bone defects prepared on the skulls of eight experimental rabbits. Results: Cell morphology and adhesion of the osteoblasts to the membranes showed that the osteoblasts bound to PLGA were smaller and with a lower number of adhered cells than the osteoblasts bound to the PLGA/PO2/HA membrane (p < 0.05). The PLGA/PO2/HA membrane had a higher percentage of viable cells bound than the control membrane (p < 0.05). Both micro-CT and histological evaluation confirmed that PLGA/PO2/HA membranes enhance bone regeneration. A statistically significant difference in the percentage of osteoid area in relation to the total area between both groups was found. Conclusions: The incorporation of nanometric layers of nanostructured HA into PLGA membranes modified with PO2 might be considered for the regeneration of bone defects. PLGA/PO2/HA membranes promote higher osteosynthetic activity, new bone formation, and mineralisation than the PLGA control group.

Expression of cross-tolerance to a wide range of conditions in a human lung cancer cell line after adaptation to nitric oxide.

Previously, we have shown that A549, a human lung adenocarcinoma, can be adapted to nitric oxide (NO●). NO● is a nitrogen-based free radical that is synthesized by a family of enzymes known as nitric oxide synthases. NO● has been shown to be overexpressed in patient populations of different cancers. In addition, it has been observed that patients who express high levels of nitric oxide synthases tend to have poorer clinical outcomes than those with low levels of expression. The original cell line A549 (parent) and the adapted A549-HNO (high nitric oxide) cell line serve as a useful model system to investigate the role of NO● in tumor progression and prognosis. We have previously shown that the A549-HNO-adapted cells grow aggressively when compared to A549-parent cells. Furthermore, we have shown that the A549-HNO-adapted cells exhibit a higher percentage of cell viability when exposed to ultraviolet and X-ray radiation than the A549-parent cells. Cancer patients who develop resistance to one treatment often become resistant to other previously unencountered forms of treatment. This phenomenon is known as cross-tolerance. To determine whether NO● is a potential cross-tolerance causing agent, we have expanded our research by conducting parallel studies to a variety of other agents and conditions beyond radiation and ultraviolet exposure. We exposed both cell lines to varying levels of chemotherapeutic drugs (taxol and doxorubicin), temperature, pH, calcium chloride, cadmium chloride, copper chloride, sodium chloride, ferrous chloride, and sodium-R-lipoic acid. Our results show that the A549-HNO cells exhibit greater viability than the A549-parent cells when exposed to each of the various conditions. Therefore, NO● is one potential driving force that can make tumor cells exhibit cross-tolerance.