Patent DE-102012003863-B3 (DE)
Title: Device, useful for determining effect of nanoparticle materials on living cells by measuring thermal power production of cells using chip-calorimeter, comprises flow measurement chamber, permanent magnet, pivot device, and thermopile
Inventor: MUEHLING MARTIN
IPC: C12Q1/00
Filed: 2012-02-22
Granted: 2013-03-07
Abstract: The device comprises: a flow measurement chamber having a measuring channel, a feed channel for supplying a thermal power, a magnetic bead sample prepared with a nanoparticle material brought in contact with living cells, a discharge channel for the bead sample and a transport liquid provided for transporting the bead sample; a permanent magnet (18) that is positioned on a surface of the flow measurement chamber and engages, with its magnetic field strength, into the flow measurement chamber; and a pivot device (20) holding the permanent magnet. The device comprises: a flow measurement chamber having a measuring channel, a feed channel for supplying a thermal power, a magnetic bead sample prepared with a nanoparticle material brought in contact with living cells, a discharge channel for the bead sample and a transport liquid provided for transporting the bead sample; a permanent magnet (18) that is positioned on a surface of the flow measurement chamber and engages, with its magnetic field strength, into the flow measurement chamber; a pivot device (20) holding the permanent magnet; and a thermopile (24, 25, 26, 27) that is present opposite to the permanent magnet and the flow measurement chamber. The apparatus is assigned to: a holding device (14) at which the flow measurement chamber is vertically suspended from the feed channel and/or the discharge channel; a pump unit, which is arranged downstream of the discharge channel and serves to a selective removal of the transport liquid; and a bead sample trap, which is connected to the pump unit and is stored into the bead sample. A heat output measurement in the chip-calorimeter is conduced to the bead sample magnetically fixed into the flow measurement chamber after decay of thermal disturbances triggered by a bead sample transport. The thermal power produced by the cells is converted to electrical signals. The thermopile is connected to an evaluation device via signal lines, and the electrical signals are transmitted to the evaluation device. The electrical signals in the evaluation device containing a computer are processed by a program-technical unit and technical and biological algorithms that reflect a reaction of the living cells to contact with a material of the nanoparticles on the basis of the measured thermal power produced by the cells. The chip-calorimeter is integrated in a thermostat to which the flow measurement chamber is thermally coupled and causes a partial thermo-static control of the transport liquid required for the transport. The supply channel and the discharge channel represent cannulas and are realized as steel capillaries. The pivoting device contains a spring that is attached between the permanent magnet and the holding device, a chord attached to the spring, and a magnet movable with the permanent magnet. The chord serves to deflect the spring present away from the surface of the flow measurement chamber. The bead sample trap comprises a filter magnet that filters out the bead sample from the transport liquid. A T-piece is mounted between the pump unit and the bead sample trap. A syringe is mounted at the branch line and guided with a cleaning liquid into the bead sample trap for cleaning the bead sample that is occupied with the cells or residual cells. A temperature sensor is mounted in a region of the holding device in contact with the feed channel. A funnel for filling the transport liquid with the bead sample is assigned to the feed channel. The transport liquid is water or a liquid culture medium. The magnetic bead sample for making measurements before the introduction of the feed channel consists of an unprepared magnetic bead, and a magnetic bead prepared with living cells to compare measurements with the magnetic bead sample contacted with nanoparticles. The living cells have a time-defined contact treatment with nanoparticles or not contact treatment with nanoparticles before the introduction of the flow measurement chamber, where an influence of the material of the nanoparticle on the living cells changes their metabolic heat output. The magnetic beads are composed of individual particles of paramagnetic iron oxide, and have a bead-like shape or drop-like shape of an agglomeration, which is surrounded by a protective layer made of starch, where the aggregation of polyethyleneimine is coated as a ligand that is strong unspecific anion exchanger. Independent claims are included for: (1) a chip-calorimeter to measure the thermal output of magnetic samples; and (2) a method for determining an effect of nanoparticle materials on living cells by measuring a thermal power output of the cells using an apparatus.