Real-time Cell Analysis Assay Research Articles

Evaluation of three alternative methods to the plaque reduction neutralizing assay for measuring neutralizing antibodies to dengue virus serotype 2

BackgroundDengue is a global public health challenge which requires accurate diagnostic methods for surveillance and control. The gold standard for detecting dengue neutralizing antibodies (nAbs) is the plaque reduction neutralization test (PRNT), which is both labor-intensive and time-consuming. This study aims to evaluate three alternative approaches, namely, the MTT-based (or (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) microneutralization assay, the xCELLigence real-time cell analysis (RTCA), and the immuno-plaque assay-focus reduction neutralization test (iPA-FRNT).MethodsTwenty-two residual serum samples were tested for DENV-2 nAbs using all four assays at three neutralization endpoints of 50%, 70% and 90% inhibition in virus growth. For each neutralization endpoint, results were compared using linear regression and correlation analyses. Test performance characteristics were further obtained for iPA-FRNT using 38 additional serum samples.ResultsPositive correlation of DENV-2 neutralization titers for the MTT-based microneutralization assay and the PRNT assay was only observed at the neutralization endpoint of 50% (r = 0.690). In contrast, at all three neutralization end points, a linear trend and positive correlation of DENV-2 neutralization titers for the xCELLigence RTCA and the PRNT assays were observed, yielding strong or very strong correlation (r = 0.829 to 0.967). This was similarly observed for the iPA-FRNT assay (r = 0.821 to 0.916), which also offered the added advantage of measuring neutralizing titers to non-plaque forming viruses.ConclusionThe xCELLigence RTCA and iPA-FRNT assays could serve as suitable alternatives to PRNT for dengue serological testing. The decision to adopt these methods may depend on the laboratory setting, and the utility of additional applications offered by these technologies.

Rapid discrimination between clinical Clostridioides difficile infection and colonization by quantitative detection of TcdB toxin using a real-time cell analysis system.

It is important to accurately discriminate between clinical Clostridioides difficile infection (CDI) and colonization (CDC) for effective antimicrobial treatment. In this study, 37 stool samples were collected from 17 CDC and 20 CDI cases, and each sample were tested in parallel through the real-time cell analysis (RTCA) system, real-time PCR assay (PCR), and enzyme-linked immunosorbent assay (ELISA). RTCA-measured functional and toxical C. difficile toxin B (TcdB) concentrations in the CDI group (302.58 ± 119.15 ng/mL) were significantly higher than those in the CDC group (18.15 ± 11.81 ng/mL) (p = 0.0008). Conversely, ELISA results revealed no significant disparities in TcdB concentrations between the CDC (26.21 ± 3.57 ng/mL) and the CDI group (17.07 ± 3.10 ng/mL) (p = 0.064). PCR results indicated no significant differences in tcdB gene copies between the CDC (774.54 ± 357.89 copies/μL) and the CDI group (4,667.69 ± 3,069.87 copies/μL) (p = 0.407). Additionally, the functional and toxical TcdB concentrations secreted from C. difficile isolates were measured by the RTCA. The results from the CDC (490.00 ± 133.29 ng/mL) and the CDI group (439.82 ± 114.66 ng/mL) showed no significant difference (p = 0.448). Notably, RTCA-measured functional and toxical TcdB concentration was significantly decreased when mixed with pooled CDC samples supernatant (p = 0.030). This study explored the novel application of the RTCA assay in effectively discerning clinical CDI from CDC cases.

Aquaporin 9 is involved in CRC metastasis through DVL2-dependent Wnt/β-catenin signaling activation.

Aquaporin 9 (AQP9) is permeable to water or other small molecules, and plays an important role in various cancers. We previously found that AQP9 was related to the efficacy of chemotherapy in patients with colorectal cancer (CRC). This study aimed to identify the role and regulatory mechanism of AQP9 in CRC metastasis. The clinical significance of AQP9 was analysed by using bioinformatics and tissue microarray. Transcriptome sequencing, Dual-Luciferase Reporter Assay, Biacore, and co-immunoprecipitation were employed to demonstrate the regulatory mechanism of AQP9 in CRC. The relationship between AQP9 and CRC metastasis was verified in vitro and in vivo by using real-time cell analysis assay, high content screening, and liver metastasis models of nude mice. We found that AQP9 was highly expressed in metastatic CRC. AQP9 overexpression reduced cell roundness and enhanced cell motility in CRC. We further showed that AQP9 interacted with Dishevelled 2 (DVL2) via the C-terminal SVIM motif, resulting in DVL2 stabilization and theWnt/β-catenin pathway activation. Additionally, we identified the E3 ligase neural precursor cell expressed developmentally downregulated 4-like (NEDD4L) as a modulator regulating the ubiquitination and degradation of AQP9. Collectively, our study revealed the important role of AQP9 in regulating DVL2 stabilization and Wnt/β-catenin signaling to promote CRC metastasis. Targeting the NEDD4L-AQP9-DVL2 axis might have therapeutic usefulness in metastatic CRC treatment.

Tribulus terrestris L. extract ameliorates atherosclerosis by inhibition of vascular smooth muscle cell proliferation in ApoE−/− mice and A7r5 cells via suppression of Akt/MEK/ERK signaling

Ethnopharmacological relevanceAtherosclerosis (AS) is one of major threatens of death worldwide, and vascular smooth muscle cell (VSMC) proliferation is an important characteristic in the progression of AS. Tribulus terrestris L. is a well-known Chinese Materia Medica for treating skin pruritus, vertigo and cardiovascular diseases in traditional Chinese medicine. However, its anti-AS activity and inhibition effect on VSMC proliferation are not fully elucidated. AimsWe hypothesize that the furostanol saponins enriched extract (FSEE) of T. terrestris L. presents anti-AS effect by inhibition of VSMC proliferation. The molecular action mechanism underlying the anti-VSMC proliferation effect of FSEE is also investigated. Materials and methodsApolipoprotein-E deficient (ApoE−/−) mice and rat thoracic smooth muscle cell A7r5 were employed as the in vivo and in vitro models respectively to evaluate the anti- AS and VSMC proliferation effects of FSEE. In ApoE−/− mice, the amounts of total cholesterol, triglyceride, low density lipoprotein and high density lipoprotein in serum were measured by commercially available kits. The size of atherosclerotic plaque was observed by hematoxylin & eosin staining. The protein expressions of α-smooth muscle actin (α-SMA) and osteopontin (OPN) in the plaque were examined by immunohistochemistry. In A7r5 cells, the cell viability and proliferation were tested by MTT and Real Time Cell Analysis assays. The cell migration was evaluated by wound healing assay. Propidium iodide staining followed by flow cytometry was used to analyze the cell cycle progression. The expression of intracellular total and phosphorylated proteins including protein kinase B (Akt) and mitogen-activated protein kinases (MAPKs), such as mitogen-activated extracellular signal-regulated kinase (MEK), extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), were detected by western blotting analysis. ResultsFSEE significantly reduced the area of atherosclerotic plaque in high-fat diet-fed ApoE−/− mice. And FSEE increased the protein expression level of α-SMA and decreased the level of OPN in atherosclerotic plaque, which revealed the inhibition of VSMC phenotype switching and proliferation. In A7r5 cells, FSEE suppressed fetal bovine serum (FBS) or oxidized low density lipoprotein (oxLDL)-triggered VSMC proliferation and migration in a concentration dependent manner. FSEE protected against the elevation of cell numbers in S phase induced by FBS or oxLDL and the reduction of cell numbers in G0/G1 phase induced by oxLDL. Moreover, the phosphorylation of Akt and MAPKs including MEK, ERK and JNK could be facilitated by FBS or oxLDL, while co-treatment of FSEE attenuated the phosphorylation of Akt induced by oxLDL as well as the phosphorylation of MEK and ERK induced by FBS. In addition, (25R)-terrestrinin B (JL-6), which was the main ingredient of FSEE, and its potential active pharmaceutical ingredients tigogenin (Tigo) and hecogenin (Heco) also significantly attenuated FBS or oxLDL-induced VSMC proliferation in A7r5 cells. ConclusionFSEE presents potent anti- AS and VSMC proliferation activities and the underlying mechanism is likely to the suppression of Akt/MEK/ERK signaling. The active components of FSEE are JL-6 and its potential active pharmaceutical ingredients Tigo and Heco. So, FSEE and its active compounds may be potential therapeutic drug candidates for AS.

Effects of platelet-rich fibrin on osteogenic differentiation of Schneiderian membrane derived mesenchymal stem cells and bone formation in maxillary sinus

BackgroundThe existence of mesenchymal stem cells (MSCs) in Schneiderian membrane has not been determined. The aim of this study is to investigate whether there are MSCs in Schneiderian membrane, and the effect of platelet-rich fibrin (PRF) on osteogenic differentiation of these cells and on new bone formation in maxillary sinus after maxillary sinus floor elevation.MethodsSchneiderian membrane derived mesenchymal stem cells (SM-MSCs) were isolated from rabbit maxillary sinus. Cells were identified by flow cytometry and multipotential differentiation. Real-time cell analysis assay, fluorescence staining, transwell assay, and wound healing assay were used to determine the effects of PRF stimulation on cell proliferation and migration. The osteogenic differentiation ability of cells stimulated by PRF or osteoinductive medium was evaluated by alkaline phosphatase staining, alizarin red staining, PCR and Western blot. Equivalent volume Bio-oss and the mixture of Bio-oss and PRF were used as bone graft materials for maxillary sinus floor elevation. Micro-CT, bone double-staining, HE staining, Masson staining, and toluidine blue staining were used to evaluate the osteogenic effect in 8 and 12 weeks after surgery.ResultsThe cell surface markers were positive for expression of CD90, CD105, and negative for expression of CD34, CD45. SM-MSCs had the ability of osteogenic, adipogenic and chondrogenic differentiation. PRF could stimulate proliferation, migration and osteogenic differentiation of SM-MSCs, which was achieved by up-regulating ERK 1/2 signaling pathway. PRF could accelerate the formation of new bone in maxillary sinus and increase the amount of new bone formation.ConclusionsMSCs existed in Schneiderian membrane, and PRF stimulation could promote cell proliferation, migration and osteogenic differentiation. The application of PRF in maxillary sinus floor elevation could accelerate bone healing and increase the quantity and quality of new bone. PRF, as autologous graft materials, might offer a promising strategy for the clinical bone formation during MSFE procedure.Graphical abstract6kDexyoSUyN5j1q7bTF377Video .

Standardized two-step testing of antibody activity in COVID-19 convalescent plasma

SummaryThe COVID-19 pandemic revealed an urgent need for rapid profiling of neutralizing antibody responses and development of antibody therapeutics. The current Food and Drug Administration-approved serological tests do not measure antibody-mediated viral neutralization, and there is a need for standardized quantitative neutralization assays. We report a high-throughput two-step profiling approach for identifying neutralizing convalescent plasma. Screening and downselection for serum antibody binding to the receptor-binding domain are followed by quantitative neutralization testing using a chimeric vesicular stomatitis virus expressing spike protein of SARS-CoV-2 in a real-time cell analysis assay. This approach enables a predictive screening process for identifying plasma units that neutralize SARS-CoV-2. To calibrate antibody neutralizing activity in serum from convalescent plasma donors, we introduce a neutralizing antibody standard reagent composed of two human antibodies that neutralize SARS-CoV strains, including SARS-CoV-2 variants of concern. Our results provide a framework for establishing a standardized assessment of antibody-based interventions against COVID-19.

Challenges in Coopted Hydrophilic and Lipophilic Herbal Bioactives in the Same Nanostructured Carriers for Effective Bioavailability and Anti-Inflammatory Action.

There is ongoing research on various herbal bioactives and delivery systems which indicates that both lipid nanocarriers and herbal medicines will be fine tunned and integrated for future bio-medical applications. The current study was undertaken to systematically develop NLC-DSG-yam extract for the improved efficacy of herbal Diosgenin (DSG) in the management of anti-inflammatory disorders. NLCs were characterized regarding the mean size of the particles, morphological characteristics, physical stability in time, thermal behaviour, and entrapment efficiency of the herbal bioactive. Encapsulation efficiency and in vitro antioxidant activity measured the differences between the individual and dual co-loaded-NLC, the co-loaded one assuring a prolonged controlled release of DSG and a more emphasized ability of capturing short-life reactive oxygen species (ROS). NLCs safety properties were monitored following the in vitro MTS ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction assay) and RTCA (Real-Time Cell Analysis) assays. Concentrations less than 50 μg/mL showed no cytotoxic effects during in vitro cytotoxicity assays. Besides, the NLC-DSG-yam extract revealed a great anti-inflammatory effect, as the production of pro-inflammatory cytokines (TNF-alpha, IL-6) was significantly inhibited at 50 μg/mL NLC (e.g., 98.2% ± 1.07 inhibition of TNF-α, while for IL-6 the inhibition percentage was of 62% ± 1.07). Concluding, using appropriate lipid nanocarriers, the most desirable properties of herbal bioactives could be improved.

ANTIPROLIFERATIVE ACTIVITY OF PYRROLIDINE DERIVATIVES COMPOUND IN COLON CANCER CELLS

Objective: Anti-cancer drug research plays an important role for chemotherapeutic treatments in various types of cancer. Pyrolidine derived compounds have been reported by many researchers to be a potent anti-cancer compound. It is aimed to investigate the effects of pyrolidine-derived compounds that are thought to be new drug candidates with antiproliferative activity on DLD-1 and CCD-18CO cell lines. Material and Methods: The antiproliferative activity of the pyrrolidine-derived compound was determined for 24 hours at different concentrations (25-100 µM) on DLD-1 (human colon cancer) and CCD-18CO (normal colon fibroblast) cell lines by comparing MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5 Diphenyltetrazolium bromide) and RTCA (real-time cell analysis) assays. The significance of the differences between data sets in the MTT assay was analyzed statistically by ANOVA with SPSS 20.0 program for DLD-1 and CCD-18CO cell lines. Results: It has been determined that pyrrolidine-derived compounds reduce the number of DLD-1 cancer cells according to negative control with the MTT method and suppress the DLD-1 cell according to the RTCA assay results. Thus, the compounds have been shown to inhibit cell proliferation and have antiproliferative activity. Conclusion: Pyrrolidine-derived compounds will be the first step for antiproliferative activity studies in DLD-1 cancer cells and will guide the next studies.

Antioxidant and cytotoxic activity studies of sulfur containing glycine imine derivatives MCF-7 and DLD-1 cell lines

Objective: To investigate the antioxidant and cytotoxic activities of sulfur-containing glycine imine derivatives MCF-7 (human breast adenocarcinoma) and DLD-1 (colorectal adenocarcinoma) cell lines. Methods: This study examined the antioxidant activities (25-200 µM) of sulfur-containing glycine imine derivatives via the DPPH, metal chelating and reduction methods. Furthermore the cytotoxic activity of MCF-7, MCF-12A (normal breast epithelial) and DLD-1, CCD-18CO (normal colon fibroblast) were examined with MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) and RTCA (Real-time Cell Analysis) assays. Results: The antioxidant assay of the metal chelating activity showed significant results (71, 77 and 40% respectively) as compared to knowing synthetic antioxidant (trolox; 95.45, EDTA; 97.06 %). Reducing activity was found to be very low compared to the standard compounds.Compounds were shown to be moderated by DPPH (2,2-Diphenyl-1-picrylhydrazyl) activity, and the IC50 value ranged from 91 to 150. The IC50 values (100 µM) of the MTT and RTCA analyses were similar. Conclusion: The study showed that the compounds had selective and significant antioxidant activities, and we also found that they had cytotoxic effects on MCF-7 and DLD-1 cells.

Toxicity of abrasive nanoparticles (SiO2, CeO2, and Al2O3) on Aliivibrio fischeri and human bronchial epithelial cells (16HBE14o-)

SiO2, CeO2, and Al2O3 nanoparticles (NPs) are used as abrasive particles in chemical and mechanical planarization (CMP), a key process in semiconductor fabrication. The CMP process generates high volumes of effluents containing abrasive NPs. Since no regulations are available limiting the release of these NPs, there are concerns about their potential environmental and health risks. This study investigates four industry relevant model CMP slurries including colloidal silica (c-SiO2), fumed silica (f-SiO2), cerium oxide (CeO2), and aluminum oxide (Al2O3) for their inhibition on bioluminescence activity of the marine bacterium, Aliivibrio fischeri. Additionally, the cytotoxicity of the slurries on human bronchial epithelial cells (16HBE14o-) was evaluated using a novel impedance-based real-time cell analysis (RTCA) system. The results showed that f-SiO2 and CeO2 slurries had no acute toxicity on A. fischeri at concentrations up to 1136 and 909 mg/L, respectively. A concentration of 1364 mg/L of c-SiO2 and Al2O3 led to 37.6% and 28.4% inhibition on microbial activity after 30 min of exposure. High concentrations of c-SiO2 and f-SiO2 slurries (250 and 500 mg/L) led to cell death in the RTCA assay. This study further demonstrated that the toxicity of the model CMP slurries was due to the abrasive NPs but not to other additives in the slurry. In contrast, CeO2 and Al2O3 slurries were not inhibitory or only showed limited inhibitory effect on the viability and proliferation of 16HBE14o- cells after 24 h of exposure. These results indicate that the abrasive NPs used in CMP are not likely to cause acute environmental and health risks at environmentally relevant concentrations.

Standardized Two-Step Testing of Antibody Activity in COVID-19 Convalescent Plasma

The COVID-19 pandemic revealed an urgent need for rapid profiling of neutralizing antibody responses and development of antibody therapeutics. The current Food and Drug Administration-approved serological tests do not measure antibody-mediated viral neutralization, and there is a need for standardized quantitative neutralization assays. We report a high-throughput two-step profiling approach for identifying neutralizing convalescent plasma. Screening and down-selection for serum antibody binding to the receptor-binding domain are followed by quantitative neutralization testing using a chimeric vesicular stomatitis virus expressing spike protein of SARS-CoV-2 in a real-time cell analysis assay. This approach enables a predictive screening process for identifying plasma units that neutralize SARS-CoV-2. To calibrate antibody neutralizing activity in serum from convalescent plasma donors, we introduce a neutralizing antibody standard reagent composed of two human antibodies that neutralize SARS-CoV strains, including SARS-CoV-2 variants of concern. Our results provide a framework for establishing a standardized assessment of antibody-based interventions against COVID-19. Funding Information: This work was supported by the National Institute of Health (NIH) National Center for Advancing Translational Sciences (NCATS) grant 3UL1TR002243-04S4, Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), the Hays Foundation COVID-19 Research Fund (to I.T.), Defense Advanced Research Projects Agency (DARPA) grant HR0011-18-2-0001, U.S. N.I.H. contract 75N93019C00074, the Dolly Parton COVID-19 Research Fund at Vanderbilt, and a grant from Fast Grants, Mercatus Center, George Mason University. Declaration of Interests: I.T. reports grants from NIH/NIAID, during the conduct of the study, and has served as a consultant for Nashville Biosciences and Horizon Therapeutics. J. D. C., L.J.S., and M.R.D. report grants from NIH/NCATS, during the conduct of the study. T.W.R. reports grants from NIH/NCATS, during the conduct of the study; personal fees from Cumberland Pharmaceuticals, Inc, personal fees from Sanofi Pharma, and personal fees from Cytovale, outside the submitted work. T.G.S. reports grants from NIH, during the conduct of the study. W.H.S. reports grants from NCATS of the NIH, during the conduct of the study. M.S.D. is a consultant for Inbios, Vir Biotechnology, Fortress Biotech, and Carnival Corporation and on the Scientific Advisory Boards of Moderna an Immunome. The Diamond laboratory has received funding support in sponsored research agreements from Moderna, Vir Biotechnology and Emergent BioSolutions. J.E.C. has served as a consultant for Luna Biologics, is a member of the Scientific Advisory Board of Meissa Vaccines and is Founder of IDBiologics. The Crowe laboratory at Vanderbilt University Medical Center has received sponsored research agreements from Takeda Vaccines, IDBiologics and AstraZeneca and grants from NIH, and DARPA during the conduct of the study. Vanderbilt University has applied for patents related to antibodies described in this paper. All other authors declare no competing interests. Ethics Approval Statement: The studies were approved by the Vanderbilt University Medical Center Institutional Review Board, and samples were collected after written informed consent was obtained by research personnel.

Mitochondria-targeted triphenylphosphonium-based compounds do not affect estrogen receptor α.

BackgroundTargeting negatively charged mitochondria is often achieved using triphenylphosphonium (TPP) cations. These cationic vehicles may possess biological activity, and a docking study indicates that TPP-moieties may act as modulators of signaling through the estrogen receptor α (ERα). Moreover, in vivo and in vitro experiments revealed the estrogen-like effects of TPP-based compounds. Here, we tested the hypothesis that TPP-based compounds regulate the activity of ERα.MethodsWe used ERa-positive and ERα-negative human breast adenocarcinoma cell lines (MCF-7 and MDA-MB-231, respectively). Cell proliferation was measured using a resazurin cell growth assay and a real-time cell analyzer assay. Cell cycle progression was analyzed using flow cytometry. Real-time PCR was used to assess mRNA expression of endogenous estrogen-responsive genes. Luciferase activity was measured to evaluate transcription driven by estrogen-responsive promoters in cells transfected with an estrogen response element (ERE)3-luciferase expression vector.ResultsThe TPP-based molecules SkQ1 and C12TPP, as well as the rhodamine-based SkQR1, did not increase the proliferation or alter the cell cycle progression of MCF-7 cells. In contrast, 17β estradiol increased the proliferation of MCF-7 cells and the proportion of cells in the S/G2/M-phases of the cell cycle. TPP-based compounds did not affect the induction of transcription of an ERE-luciferase expression vector in vitro, and SkQ1 did not alter the levels of expression of estrogen-dependent genes encoding GREB1, TFF1, COX6, and IGFBP4.ConclusionTPP-based compounds do not possess properties typical of ERα agonists.

5-AZA treatment induces cytotoxicity and in vitro expression of immunogenic NY-ESO-1 antigen in non-small lung cancer cell NCI-H1975

Abstract Background Lung cancer is a major threat to the world and 80% of the reported cases belong to non-small cell lung cancers. Epigenetic modifications are common in lung cancers but can be reversible by using demethylating agents such as 5-AZA. Through our present study, we hypothesized that treatment with 5-AZA may induce the apoptosis and expression of immunogenic NY-ESO-1 antigen in NCI-H1975 cells. Apoptotic cell death would help to release the induced NY-ESO-1 protein which in turn could trigger T cells mediated immune responses. Methods NCI-H1975 cells were treated with incrementing concentrations (1 to 10µM) of 5-AZA. Cytotoxicity was measured using real-time cell analyzer assay (RTCA). Apoptosis and cell cycle analysis were measured by flow cytometry and western blot. A proteomic profiling was carried out using label-free mass spectrometry. Bisulfite sequencing was performed for NY-ESO-1 gene and expression at mRNA and protein level was analyzed using qRT-PCR, cellular ELISA. Results RTCA data revealed that 5-AZA treatment reduced cell proliferation at 120 h which was opted for comparative study. Flow cytometry showed an induction of apoptosis and a cell-cycle arrest at Sub-G0 phase. Western blot analysis confirmed the induction of apoptotic marker proteins such as cleaved Caspase3, Caspase8, PARP and BAX. We also observed that 31 proteins responsible for the induction of apoptosis were upregulated and 18 proteins linked to cell proliferation and metastasis were down-regulated. Bisulfite sequencing revealed demethylation of the promoter of NY-ESO-1 gene and showed an induced expression of NY-ESO-1 protein and mRNA levels. Conclusion Our study shows that 5-AZA cytotoxic effect would induce the expression of the immunogenic NY-ESO-1 antigen leading to activation of T cells mediated immune response. Our data infers the potential use of 5-AZA for lung cancer treatment. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Synthesis of Chiral Penicillamine-Coated Gold Nanoparticles and Effect on PC12 Cells for the Treatment of Alzheimer’s Disease

Recently, nano-scaled chirality has attained significant attraction from various research areas depending on its fundamental significance in the matter of living and nature. In this work, we designed and fabricated d-/l-Pe-Au nanoparticles (Chiral Penicillamine-modified Gold NPs), system for the treatment of Alzheimer’s disease. RTCA (real-time cell analysis) assay was performed using rat PC12 (Pheochromocytoma) cells to investigate the capable cytotoxicity of d-/l-Pe-Au nanoparticles. At any point of given time, with increase in the concentration of d-Pe-Au nanoparticles, we observed a significant decrease in the cell index, which suggests that the cytotoxic effect on the PC12 cells depends on the concentration. We believe that the results obtained may be significant for other chiral nanoparticles in the treatment of the disease called Alzheimer’s and also has an extensive utilization in the studies and applications based on NPs.

Comparison of Cytotoxicity Evaluation of Anticancer Drugs between Real-Time Cell Analysis and CCK-8 Method.

Critical cytotoxicity evaluation of pharmaceuticals is necessary for the clinical practice of chemotherapy. To quantitatively evaluate cell viability, currently there are two main types of sensitive methods including real-time cell analysis (RTCA) and CCK-8 assay, in which RTCA records electrochemical signal changes around an incubated cell, whereas CCK-8 is based on the colorimetric method. Despite the different detection principles adopted for the cytotoxicity assessment, the comparison of the two methods in terms of the application scope is lacking. In this study, comparison studies were conducted between the RTCA and CCK-8 assays using anticancer drugs including doxorubicin hydrochloride, curcumin, irinotecan (CPT-11), taxol, and oxaliplatin, which are classified into two groups of drug molecules in the absence and presence of additives. The cytotoxicity evaluation of these drugs on cancer cells revealed that the physicochemical properties of drug formulations such as optical and electrochemical properties are closely linked with the readout of cytotoxic methods. The experimental results suggested that the preselection of cytotoxic assay is critical for the quantitative measurement of cytotoxicity of anticancer drugs, which is of clinical importance for their therapeutic usage.

Positive impact of Platelet-rich plasma and Platelet-rich fibrin on viability, migration and proliferation of osteoblasts and fibroblasts treated with zoledronic acid

Bisphosphonates are frequently used for the antiresorptive treatment in bone metastasis diseases or for osteoporosis. A side effect of this therapy is osteonecrosis of the jaw. This inhibits osteoclast function, but osteoblasts and fibroblasts are also negatively affected in terms of impaired proliferation. Additive local treatment with platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) promotes adhesion, proliferation and migration of cells due to high concentrations of growth factors like PDGF, TGF and IGF. The aim of the study was to investigate the effect of PRP or PRF on proliferation, migration and viability of osteoblasts and oral fibroblasts, treated with zoledronic acid (ZA). ZA treated fibroblasts and osteoblasts were exposed to PRP/PRF. Cell proliferation, migration and viability were measured using the real-time cell-analyzer assay (RTCA), the scratch assay and the MTT assay. There was a significant increase in closure of the scratch area by PRP/PRF treated osteoblasts (PRP = 40.6%, PRF = 100.0%, NC = 0.0%) as well as fibroblasts (PRP = 100.0%, PRF = 100.0%, NC = 12.7%) in comparison to the group of negative control (all p ≤ 0.05). Furthermore, the negative effect of ZA on cell migration was generally reduced in both cell lines using PRP/PRF. The viability and proliferation of cells decreased after exposure to ZA, whereas we observed an enhancement of cell viability within 24 hours by application of PRP/PRF in ZA treated cells. The negative effect of ZA on cell proliferation was especially reduced when using PRF. The use of PRF/PRP improves the behavior of ZA-treated cells, but PRF appears to have an advantage in comparison to PRP. This study demonstrates that treatment with PRF/PRP may have positive effects in the therapy of Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ).

Real-time assessment of platinum sensitivity of primary culture from a patient with ovarian cancer with extensive metastasis and the platinum sensitivity enhancing effect by metformin.

The aim of the present study was to perform a rapid evaluation of the efficiency of commonly used platinum-based chemotherapy regimens for patients with ovarian cancer with extensive metastases using an in vitro method combined with culturing primary cells and real-time monitoring, and to further explore the enhanced effect of metformin on susceptibility of ovarian cancer cells to platinum-based chemotherapy. The primary omental metastatic (OM) cells were isolated from the omentum metastasis of a surgical patient with stage IIIc ovarian carcinoma. Drug sensitivity was evaluated using the xCELLigence system, and screening of the most effective platinum chemotherapy was performed through analysis of cell susceptibility to cisplatin, carboplatin, nedaplatin and paclitaxel or docetaxel alone or in combination. At the same time, this system was used to determine whether metformin was able to increase the sensitivity of cancer cells to platinum chemotherapy. The results revealed that nedaplatin exhibited the most marked cytotoxic effect on the OM cells, followed by those of carboplatin and cisplatin. The addition of docetaxel enhanced the cytotoxic effect, and the combination of platinum and paclitaxel also enhanced the effect. Metformin rapidly increased the sensitivity of cells to platinum-based chemotherapy, and this effect was dose-dependent. The sensitivity of OM cells to different platinum-based regimens was varied. The effect of metformin on chemotherapeutic sensitization of cancer cells is clear in vitro, and the real-time cell analyzer assay has the potential to assist in determining individualized drug regimens for patients with metastatic ovarian cancer.

Isolation of phytoconstituents and evaluation of biological potentials of Berberis hispanica from Algeria

The aim of this study was to isolate the phytoconstituents and evaluate the biological activities of Berberis hispanica. Three phenolic compounds (tamarixetin, caffeic acid and rutin) were isolated from B. hispanica. The structures of the pure compounds were elucidated by spectroscopic and mass-spectrometric analyses, including 1D-, 2D-NMR, and HPLC-TOF/MS. In addition, antimicrobial, anti-oxidant and anti-proliferative effects of the extracts, some fractions and isolated compounds were evaluated. The extracts of B. hispanica were evaluated against six bacterial strains and exhibited the highest activity against Klebsiella pneumonia (15 mm at 100 mg/mL). Fraction T36 (IC50<5 μg/mL) from the n-butanol extract displayed higher radical scavenging activity than butylated hydroxytoluene. The isolated compounds were evaluated for their antiproliferative effects against human cervical adenocarcinoma (HeLa) cell line by real time cell analyzer assay and tamarixetin exhibited the remarkable effect (IC50<50 μg/mL) on HeLa cells. This study supports the documented medicinal effects of B. hispanica.
 Video Clip of Methodology:
 Antiproliferative Assay: 4 min 31 sec Click to watch

Robust real-time cell analysis method for determining viral infectious titers during development of a viral vaccine production process

The classical cell-culture methods, such as cell culture infectious dose 50% (CCID50) assays, are time-consuming, end-point assays currently used during the development of a viral vaccine production process to measure viral infectious titers. However, they are not suitable for handling the large number of tests required for high-throughput and large-scale screening analyses. Impedance-based bio-sensing techniques used in real-time cell analysis (RTCA) to assess cell layer biological status in vitro, provide real-time data. In this proof-of-concept study, we assessed the correlation between the results from CCID50 and RTCA assays and compared time and costs using monovalent and tetravalent chimeric yellow fever dengue (CYD) vaccine strains. For the RTCA assay, Vero cells were infected with the CYD sample and real-time impedance was recorded, using the dimensionless cell index (CI). The CI peaked just after infection and decreased as the viral cytopathic effect occurred in a dose-dependent manner. The time to the median CI (CITmed) was correlated with viral titers determined by CCID50 over a range of about 4–5log10 CCID50/ml. This in-house RTCA virus-titration assay was shown to be a robust method for determining real-time viral infectious titers, and could be an alternative to the classical CCID50 assay during the development of viral vaccine production process.

Simultaneous detection and characterization of toxigenic Clostridium difficile directly from clinical stool specimens.

We employed a multiplex polymerase chain reaction (PCR) coupled with capillary electrophoresis (mPCR-CE) targeting six Clostridium difficile genes, including tpi, tcdA, tcdB, cdtA, cdtB, and a deletion in tcdC for simultaneous detection and characterization of toxigenic C. difficile directly from fecal specimens. The mPCR-CE had a limit of detection of 10 colony-forming units per reaction with no cross-reactions with other related bacterial genes. Clinical validation was performed on 354 consecutively collected stool specimens from patients with suspected C. difficile infection and 45 isolates. The results were compared with a reference standard combined with BD MAX Cdiff, real-time cell analysis assay (RTCA), and mPCR-CE. The toxigenic C. difficile species were detected in 36 isolates and 45 stool specimens by the mPCR-CE, which provided a positive rate of 20.3% (81/399). The mPCR-CE had a specificity of 97.2% and a sensitivity of 96.0%, which was higher than RTCA (x2 = 5.67, P = 0.017) but lower than BD MAX Cdiff (P = 0.245). Among the 45 strains, 44 (97.8%) were determined as nonribotype 027 by the mPCR-CE, which was fully agreed with PCR ribotyping. Even though ribotypes 017 (n = 8, 17.8%), 001 (n = 6, 13.3%), and 012 (n = 7, 15.6%) were predominant in this region, ribotype 027 was an important genotype monitored routinely. The mPCR-CE provided an alternative diagnosis tool for the simultaneous detection of toxigenic C. difficile in stool and potentially differentiated between RT027 and non-RT027.