172 results about "Cytotoxicity test" patented technology

The present invention includes devices, systems, and methods for assaying cells using cell-substrate impedance monitoring. In one aspect, the invention provides cell-substrate impedance monitoring devices that comprise electrode arrays on a nonconducting substrate, in which each of the arrays has an approximately uniform electrode resistance across the entire array. In another aspect, the invention provides cell-substrate monitoring systems comprising one or more cell-substrate monitoring devices comprising multiple wells each having an electrode array, an impedance analyzer, a device station that connects arrays of individual wells to the impedance analyzer, and software for controlling the device station and impedance analyzer. In another aspect, the invention provides cellular assays that use impedance monitoring to detect changes in cell behavior or state. In some preferred aspects, the assays are designed to investigate the affects of compounds on cells, such as cytotoxicity assays. In other preferred aspects, the assays are designed to investigate the compounds that effect IgE-mediated responses of cells to antigens.

The invention relates a biodegradable and absorbable natural polymer-based nano-fibrous membrane prepared by a freeze-drying method, and the application thereof. The natural polymer-based nano-fibrous membrane is prepared through the following steps of: dissolving natural polymer powder into a corresponding solvent so as to prepare an extremely-dilute solution with the concentration of 0.001-0.1wt %; after the natural polymer powder is completely dissolved in the solvent, transferring the obtained natural polymer solution into a liquid nitrogen refrigerating device, so that the natural polymer solution is rapidly frozen in a liquid nitrogen environment; then, carrying out freeze-drying treatment on the obtained product in a freeze drier for 12-48 hours to obtain natural polymer-based nano fibers; and carrying out cross-linking on the obtained natural polymer-based nano fibers by a corresponding cross-linking agent to obtain a natural polymer-based nano-fibrous membrane, and then carrying out MTT (methyl thiazolyl tetrazolium) cytotoxicity test and cell vaccination experiments on the natural polymer-based nano-fibrous membrane, with the obtained results showing that the obtained fibrous membrane has no toxicity but has excellent cell adhesion and proliferation properties. The natural polymer-based nano-fibrous membrane disclosed by the invention is simple in the operation process, easy to control and low in cost; and by using the nano-fibrous membrane disclosed by the invention, ultra-fine natural polymer-based nano fibers can be prepared continuously on a large scale.

The present invention provides a preparing method of a human hepatic progenitor cell which is amplified and cultivated in vitro, including: a. separating the human hepatic progenitor cell; b. co-cultivating a feeder cell and the human hepatic progenitor cell separated from the step a by a medium having no serum on an extracellular matrix containing human fibrin sealant or other analogues, obtaining a human hepatic progenitor cell colony by amplification. The human hepatic progenitor cell colony is easy to separate from the surface of human fibrin sealant by the simple gelatinolytic band process, purified or / and subcultured by further single cell preparation technology process such as enzymatic degradation etc. The human hepatic progenitor cell prepared by the method is hepatic progenitor cell treatment, including a cell transplantation and a bioartificial liver support system, providing excellent human hepatocyte source for cytotoxicity test platform in the drug screening, virus infection and drug screening platform etc.

The invention provides an in vitro amplification method for efficient and highly cytotoxic natural killer (NK) cells. Novel artificial antigen presenting cells 4-1BBL-mIL-21-aAPC, such as 4-1BBL-mIL-21-K562 cells and the like, are constructed through stably expressing 4-1BB ligands (4-1BBL) and membrane immobilized interleukin 21 (mIL-21) on the surfaces of cell membranes, and by using the novel artificial antigen presenting cells as feeder cells for amplification, the NK cells are directly amplified from peripheral blood lymphocytes. Flow cytometry, cytotoxicity test and the like suggest that the amplified cells NK have high purity and strong cytotoxicity and have obvious killing effect on tumor cells.

A 3-methoxy-flavone compound comprises 5,7-dihydroxy-8-(3,3-dimethyl diallyl)-3,3', 4'-trimethoxy flavone and 5, 7-2 dihydroxy-8- (3,3-dimethyl allyl)-3,4'-dimethoxy flavonoe. harmacological test results prove that: the 3-methoxy-flavone compound is an effective fatty acid synthase inhibitor, which shows the broad-spectrum anti-tumor effect in the cytotoxicity tests of various tumor cell lines and has strong tumor growth inhibiting effect on human prostate cancer cell LnCAP, human breast cancer cell ZR-75-1, human lung cancer cell NCI-H23 or human colon cancer cell HCT-116 when applied to human tumor transplant nude mice model tests. In addition, the 3-methoxy-flavone compound reveals no toxicity in mice acute toxicity tests, which then can be used as anti-tumor drug and is a new broad-spectrum anti-tumor drug with great development prospects.

The invention discloses a gene engineering cell and application thereof in NK (Nature Killer) cell proliferation, and provides an in vitro proliferation method of an NK cell with high efficiency and high cytotoxicity. A 4-1BB ligand (4-1BBL) and a membrane fixed interleukin 21 (mbIl-21) are stably expressed on the surface of a cell membrane by adopting a genetic engineering technology for constructing 4-1BBL-mbIl-21-gene engineering cells (4-1BBL-mbIl-21-Gene Engineering Cells, 4-1BBL-mbIl-21-GEC), such as 4-1BBL-mbIl-21-K562 cells, to be used as feeder cells for proliferation, and the NK cells are directly proliferated from peripheral blood monouclear cells, thus the operation is simpler and easier. Studies such as cell counting, flow cytometry and cytotoxicity tests indicate that high cell proliferation times, high NK cell purity, strong cytotoxicity and remarkable cancer cell killer effect are achieved.

The invention provides polypeptide. The structural formula of the polypeptide is as shown below (the structural formula is shown in the description). The invention further provides a polypeptide-siRNAinduction coassembly which is composed of polypeptide and siRNA. The invention further provides application of the polypeptide-siRNA induction coassembly to cell carrying. The invention further provides application of the polypeptide-siRNA induction coassembly to preparation of drugs for treating cervical cancer. After polypeptide and target siRNA are mixed and hatched for 5 minutes at the room temperature, stable and uniform nano particles can be formed. A cytotoxicity test proves that the coassembly nano particles have high biocompatibility, and the cytotoxicity and hemolysis toxicity of the coassembly nano particles are both low. A cell proliferation resistant test further verifies that the polypeptide-siRNA nano particles can effectively block a cervical cancer cell line HeLa in the G2 stage, so that growth of the cervical cancer line HeLa is hindered.

The invention discloses a method for testing in vitro cytotoxicity of cigarette smoke. The method is characterized by comprising the following steps of: 1) preparing a laboratory reagent; 2) performing cell inoculation culture; 3) performing cigarette smoke contamination; 4) dyeing with water-soluble tetrazolium-1 (WST-1); and 5) obtaining a result and analyzing. Compared with the prior art, the method is characterized in that a test step for washing cells for multiple times is eliminated in the whole test process, so that the method is easy and convenient to operate; a step of replacing a nutrient solution is not required during dyeing with the WST-1, and a diluted nutrient solution can be directly added for reacting; formazan produced by the WST-1 is water-soluble, so that a subsequent dissolution step is eliminated; and absorbance detection can be finished in 2 hours after WST-1 dyeing, so that the test period is shortened, and the method is quick in comparison with the conventional testing method. The measuring method is quick and convenient to operate, and also has the advantages of high sensitivity and stable result; and the method can be applied to smoke cytotoxicity test of multiple cell lines.

The invention discloses a two-photon fluorescent probe as well as a preparation method and application thereof. The two-photon fluorescent probe takes coumarin and rhodamine as a matrix. The structure of the two-photon fluorescent probe is described in the specification. Molecules of the two-photon fluorescent probe show relatively high selectivity and sensitivity in a system in which palladium ions (II) and other positive ions coexist. A cytotoxicity test shows that the two-photon fluorescent probe disclosed by the invention has hardly any toxic effect on cells, and a two-photon fluorescence microscopy imaging experiment shows that the two-photon fluorescent probe has good HeLa cell permeability and is applicable to detection of distribution of palladium ions (II) in cells.