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Life (Basel, Switzerland) Jun 2021Research in fields studying cellular response to surface tension and mechanical forces necessitate cell culture tools with tunability of substrate stiffness. We created...
Research in fields studying cellular response to surface tension and mechanical forces necessitate cell culture tools with tunability of substrate stiffness. We created a scalable hydrogel dish design to facilitate scaffold-free formation of multiple spheroids in a single dish. Our novel design features inner and outer walls, allowing efficient media changes and downstream experiments. The design is easily scalable, accommodating varying numbers of microwells per plate. We report that non-adherent hydrogel stiffness affects spheroid morphology and compaction. We found that spheroid morphology and viability in our hydrogel dishes were comparable to commercially available Aggrewell™800 plates, with improved tunability of surface stiffness and imaging area. Device function was demonstrated with a migration assay using two investigational inhibitors against EMT. We successfully maintained primary-derived spheroids from murine and porcine lungs in the hydrogel dish. These features increase the ability to produce highly consistent cell aggregates for biological research.
PubMed: 34204955
DOI: 10.3390/life11060517 -
Organogenesis 2013Stem cells in vivo are housed within a functional microenvironment termed the "stem cell niche." As the niche components can modulate stem cell behaviors like... (Review)
Review
Stem cells in vivo are housed within a functional microenvironment termed the "stem cell niche." As the niche components can modulate stem cell behaviors like proliferation, migration and differentiation, evaluating these components would be important to determine the most optimal platform for their maintenance or differentiation. In this review, we have discussed methods and technologies that have aided in the development of high throughput screening assays for stem cell research, including enabling technologies such as the well-established multiwell/microwell plates and robotic spotting, and emerging technologies like microfluidics, micro-contact printing and lithography. We also discuss the studies that utilized high throughput screening platform to investigate stem cell response to extracellular matrix, topography, biomaterials and stiffness gradients in the stem cell niche. The combination of the aforementioned techniques could lay the foundation for new perspectives in further development of high throughput technology and stem cell research.
Topics: Animals; Cell Differentiation; Cells, Cultured; Extracellular Matrix; High-Throughput Screening Assays; Humans; Mice; Rats; Stem Cell Niche; Stem Cell Research; Stem Cells
PubMed: 23899508
DOI: 10.4161/org.25425 -
Annals of Plastic Surgery Oct 2019Biofilms represent a complex milieu of matrix-enclosed microorganisms, which can significantly contribute to the pathology of chronic wounds. In this study, we compare... (Comparative Study)
Comparative Study Review
BACKGROUND
Biofilms represent a complex milieu of matrix-enclosed microorganisms, which can significantly contribute to the pathology of chronic wounds. In this study, we compare the activity of 3 commercial antimicrobial wound care solutions, Vashe (HOCl based), PhaseOne (HOCl based), and Sulfamylon (mafenide acetate), for their in vitro activity against bacterial and fungal biofilms.
METHODS
Reference and clinical isolates of 6 Gram-negative bacterial species (36 total strains), 3 Gram-positive bacteria (21 strains), and 3 Candida species (9 strains) were used to create biofilms. Various working concentrations of the 3 antiseptic agents were incubated with the biofilms in microwell plates; they were monitored from 1 minute to 24 hours to compare bacterial and fungal viability through colony forming unit analysis.
RESULTS
Vashe and PhaseOne displayed excellent bactericidal and fungicidal activity, whereas Sulfamylon demonstrated minimal activity against the biofilms tested. With the exception of Candida albicans, all biofilms were eliminated at either 1 or 10 minutes using Vashe and PhaseOne solutions. In most cases, mafenide was unable to eliminate both bacterial and fungal biofilms, even with 24 hours of treatment.
CONCLUSIONS
Biofilms represent a major clinical challenge, with no clear consensus for treatment of chronic wounds or prosthetic devices. Our results suggest that hypochlorous acid-based wound solutions such as Vashe and PhaseOne are more efficacious than mafenide in eliminating bacterial and fungal biofilms. Further studies are necessary to investigate and compare the in vivo efficacy of these products in clinical care.
Topics: Administration, Topical; Anti-Infective Agents; Antifungal Agents; Biofilms; Chronic Disease; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Sensitivity and Specificity; Solutions; Wounds and Injuries
PubMed: 31524733
DOI: 10.1097/SAP.0000000000001996 -
Applied and Environmental Microbiology May 2022The capacity to defluorinate polyfluorinated organic compounds is a rare phenotype in microbes but is increasingly considered important for maintaining the environment....
The capacity to defluorinate polyfluorinated organic compounds is a rare phenotype in microbes but is increasingly considered important for maintaining the environment. New discoveries will be greatly facilitated by the ability to screen many natural and engineered microbes in a combinatorial manner against large numbers of fluorinated compounds simultaneously. Here, we describe a low-volume, high-throughput screening method to determine defluorination capacity of microbes and their enzymes. The method is based on selective binding of fluoride to a lanthanum chelate complex that gives a purple-colored product. It was miniaturized to determine biodefluorination in 96-well microtiter plates by visual inspection or robotic handling and spectrophotometry. Chemicals commonly used in microbiological studies were examined to define usable buffers and reagents. Base-catalyzed, purified enzyme and whole-cell defluorination reactions were demonstrated with fluoroatrazine and showed correspondence between the microtiter assay and a fluoride electrode. For discovering new defluorination reactions and mechanisms, a chemical library of 63 fluorinated compounds was screened with Pseudomonas putida F1 in microtiter well plates. These data were also calibrated against a fluoride electrode. Our new method revealed 21 new compounds undergoing defluorination. A compound with four fluorine substituents, 4-fluorobenzotrifluoride, was shown to undergo defluorination to the greatest extent. The mechanism of its defluorination was studied to reveal a latent microbial propensity to defluorinate trifluoromethylphenyl groups, a moiety that is commonly incorporated into numerous pharmaceutical and agricultural chemicals. Thousands of organofluorine chemicals are known, and a number are considered to be persistent and toxic environmental pollutants. Environmental bioremediation methods are avidly being sought, but few bacteria biodegrade fluorinated chemicals. To find new organofluoride biodegradation, a rapid screening method was developed. The method is versatile, monitoring chemical, enzymatic, and whole-cell biodegradation. Biodegradation of organofluorine compounds invariably releases fluoride anions, which was sensitively detected. Our method uncovered 21 new microbial defluorination reactions. A general mechanism was delineated for the biodegradation of trifluoromethylphenyl groups that are increasingly being used in drugs and pesticides.
Topics: Biodegradation, Environmental; Fluorides; Fluorine; Pseudomonas putida
PubMed: 35435713
DOI: 10.1128/aem.00288-22 -
RSC Advances May 2024Single use plasticware (SUP) in scientific, diagnostic, and academic laboratories makes a significant contribution to plastic waste generation worldwide. Polystyrene...
Single use plasticware (SUP) in scientific, diagnostic, and academic laboratories makes a significant contribution to plastic waste generation worldwide. Polystyrene (PS) microwell plates form a part of this waste. These plates are the backbone of high throughput colorimetric measurements in academic, research, and healthcare settings for detection/quantification of wide-ranging analytes including proteins, carbohydrates, nucleic acids, and enzyme activity. Polystyrene (PS) microwell plates serve as a platform for holding samples and reagents, where mixing initiates chemical reaction(s), and the ensuing color changes are quantified using a microplate reader. However, these plates are rarely reused or recycled, contributing to the staggering amounts of plastic waste generated in scientific laboratories. Here, we are reporting the fabrication of cellulose acetate (CA) microwell plates as a greener alternative to non-biodegradable PS plates and we demonstrate their application in colorimetric assays. These easy to fabricate, lighter weight, customizable, and environmentally friendly plates were fabricated in 96- and 384-well formats and made water impermeable through chemical treatment. The plates were tested in three different colorimetric analyses: (i) bicinchoninic acid assay (BCA) for protein quantification; (ii) chymotrypsin (CT) activity assay; and (iii) alkaline phosphatase (AP) activity assay. Color intensities were quantified using a freely available smartphone application, Spotxel® Reader (Sicasys Software GmbH). To benchmark the performance of this platform, the same assays were performed in commercial PS plates too and quantified using a UV/Vis microplate reader. The two systems yielded comparable linear correlation coefficients, LOD and LOQ values, thereby validating the CA plate-cell phone based analytical method. The CA microwell plates, coupled with smart phone optical data capture, provide greener, accessible, and scalable tools for all laboratory settings and are particularly well-suited for resource- and infrastructure-limited environments.
PubMed: 38741966
DOI: 10.1039/d4ra01317d -
Frontiers in Toxicology 2022The methods outlined here are part of a series of papers designed specifically for genotoxicity assessment of nanomaterials (NM). Common Considerations such as NM...
The methods outlined here are part of a series of papers designed specifically for genotoxicity assessment of nanomaterials (NM). Common Considerations such as NM characterization, sample preparation and dose selection, relevant to all genotoxicity assays, are found in an accompanying paper. The present paper describes methods for evaluation of mutagenicity in the mammalian (mouse) () gene occurring in L5178Y mouse lymphoma (ML) cells and in the designated gene in human lymphoblastoid TK6 cells. Mutations change the functional genotype from TK to TK, detectable as cells surviving on media selective for the lack of thymidine kinase (TK) function. Unlike cells with TK enzyme function, the TK cells are unable to integrate the toxic selection agent, allowing these cells to survive as rare mutant colonies. The ML assay has been shown to detect a broad spectrum of genetic damage, including both small scale (point) mutations and chromosomal alterations. This assay is a widely used mammalian cell gene mutation assay for regulatory purposes and is included in the core battery of genotoxicity tests for regulatory decision-making. The TK6 assay is an assay using a human cell line derived similarly via mutagenic manipulations and optimal selection. Details are provided on the materials required, cell culture methods, selection of test chemical concentrations, cytotoxicity, treatment time, mutation expression, cloning, and data calculation and interpretation. The methods describe the microwell plate version of the assays without metabolic activation.
PubMed: 35757197
DOI: 10.3389/ftox.2022.864753 -
In Vivo (Athens, Greece) 2020In order to investigate the combination effect of anticancer drugs and X-ray irradiation on neurotoxic side-effects (neurotoxicity), a method that provides homogeneously...
BACKGROUND
In order to investigate the combination effect of anticancer drugs and X-ray irradiation on neurotoxic side-effects (neurotoxicity), a method that provides homogeneously X-ray-irradiated cells was newly established.
MATERIALS AND METHODS
PC12 cell suspension was irradiated by X-ray (0.5 Gy) in serum-supplemented medium, immediately inoculated into 96-microwell plates and incubated overnight. The medium was replaced with fresh serum-depleted medium containing 50 ng/ml nerve growth factor to induce differentiation toward nerve-like cells with characteristic neurites according to the overlay method without changing the medium. The differentiated cells were treated by anticancer drugs as well as antioxidants, oxaliplatin or bortezomib, and the viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method.
RESULTS
Antioxidants and anticancer drugs were cytotoxic to differentiating PC12 cells. Combination of anticancer drugs and X-ray irradiation slightly reduced cell viability.
CONCLUSION
The present 'population irradiation method' may be useful for the investigation of the combination effect of X-ray irradiation and any pharmaceutical drug.
Topics: Animals; Antineoplastic Agents; Apoptosis; Biomarkers; Cell Line, Tumor; Cell Survival; Disease Models, Animal; Immunohistochemistry; Mice; Nervous System; Phosphorylation; Radiation, Ionizing; Signal Transduction; X-Rays
PubMed: 32354886
DOI: 10.21873/invivo.11869 -
Medicina (Kaunas, Lithuania) Oct 2023Ceritinib (CER) is a potent drug of the third-generation tyrosine kinase inhibitor class. CER has been approved for the treatment of patients with non-small-cell lung...
Development of Two Novel One-Step and Green Microwell Spectrophotometric Methods for High-Throughput Determination of Ceritinib, a Potent Drug for Treatment of Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer.
Ceritinib (CER) is a potent drug of the third-generation tyrosine kinase inhibitor class. CER has been approved for the treatment of patients with non-small-cell lung cancer (NSCLC) harboring the anaplastic lymphoma kinase (ALK) mutation gene. In the literature, there is no green and high-throughput analytical method for the quantitation of CER in its dosage form (Zykadia capsules). This study describes, for the first time, the development and validation of two novel one-step and green microwell spectrophotometric methods (MW-SPMs) for the high-throughput quantitation of CER in Zykadia capsules. These two methods were based on an formation of colored derivatives upon the reaction of CER with two different benzoquinone reagents via two different mechanisms. These reagents were -benzoquinone (OBQ) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and their reactions proceeded via condensation and charge transfer reactions, respectively. The reactions were carried out in 96-well transparent plates, and the absorbances of the colored reaction products were measured with an absorbance microplate reader at 540 and 460 nm for reactions with OBQ and DDQ, respectively. The optimum conditions of reactions were established, their molar ratios were determined, and reaction mechanisms were postulated. Under the refined optimum reaction conditions, procedures of MW-SPMs were established and validated according to the guidelines of the International Council on Harmonization. The limits of quantitation were 6.5 and 10.2 µg/well for methods involving reactions with OBQ and DDQ, respectively. Both methods were applied with great reliability to the determination of CER content in Zykadia capsules and their drug uniformity. Greenness of the MW-SPMs was evaluated using three different metric tools, and the results proved that the two methods fulfil the requirements of green analytical approaches. In addition, the simultaneous handling of a large number of samples with microvolumes in the proposed methods gave them the advantage of a high-throughput analysis. : The two methods are valuable tools for rapid routine application in pharmaceutical quality control units for the quantitation of CER.
Topics: Humans; Carcinoma, Non-Small-Cell Lung; Lung Neoplasms; Anaplastic Lymphoma Kinase; Reproducibility of Results; Benzoquinones; Indicators and Reagents
PubMed: 37893531
DOI: 10.3390/medicina59101813 -
RSC Advances Oct 2022Herein, we report a sensitive and selective enzyme-linked aptamer-based sandwich assay (ELASA) to detect lactate dehydrogenase (LDH), which is an attractive biomarker...
Herein, we report a sensitive and selective enzyme-linked aptamer-based sandwich assay (ELASA) to detect lactate dehydrogenase (LDH), which is an attractive biomarker for malaria diagnosis and antimalarial medication. We performed the sandwich assay with a single aptamer sequence, called 2008s, owing to the structural properties of the LDH tetramer instead of using a conventional sandwich assay with two different aptamers (or antibodies) for capturing and probing a target molecule. First, the biotinylated LDH aptamer was linked with immobilized streptavidin on a microwell plate for binding flexibility, and then LDH was bound to the aptamer. Next, a horseradish peroxidase-conjugated aptamer of the same sequence was used to analyze LDH quantitatively. Using this approach, the limit of detection (LOD) of LDH with the naked eye was 100 ng mL, and the LOD and limit of quantification from the absorbance measurements were 34.9 ng mL and 95.5 ng mL, respectively, based on LDH spiked blood samples. Our proposed method selectively binds LDH, not human lactate dehydrogenase. Therefore, this method may be a valuable tool for diagnosing, monitoring, and quarantining malaria cases easily and rapidly.
PubMed: 36320752
DOI: 10.1039/d2ra03796c -
Frontiers in Microbiology 2022In order to exploit the microbes present in the environment for their beneficial resources, effective selection and isolation of microbes from environmental samples is...
In order to exploit the microbes present in the environment for their beneficial resources, effective selection and isolation of microbes from environmental samples is essential. In this study, we fabricated a gel-filled microwell array device using resin for microbial culture. The device has an integrated sealing mechanism that enables high-density isolation based on the culture of microorganisms; the device is easily manageable, facilitating observation using bright-field microscopy. This low-cost device made from polymethyl methacrylate (PMMA)/polyethylene terephthalate (PET) has 900 microwells (600 μm × 600 μm × 700 μm) filled with a microbial culture gel medium in glass slide-sized plates. It also has grooves for maintaining the moisture content in the micro-gel. The partition wall between the wells has a highly hydrophobic coating to inhibit microbial migration to neighboring wells and to prevent exchange of liquid substances. After being hermetically sealed, the device can maintain moisture in the agarose gels for 7 days. In the bacterial culture experiment using this device, environmental bacteria were isolated and cultured in individual wells after 3 days. Moreover, the isolated bacteria were then picked up from wells and re-cultured. This device is effective for the first screening of microorganisms from marine environmental samples.
PubMed: 36590440
DOI: 10.3389/fmicb.2022.1031439