Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
  • B01L3/502—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures
  • B01L3/5027—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip
  • B01L3/502761—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads or physically stretching molecules
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2200/00—Solutions for specific problems relating to chemical or physical laboratory apparatus
  • B01L2200/06—Fluid handling related problems
  • B01L2200/0647—Handling flowable solids, e.g. microscopic beads, cells, particles
  • B01L2200/0668—Trapping microscopic beads
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/06—Auxiliary integrated devices, integrated components
  • B01L2300/0627—Sensor or part of a sensor is integrated
  • B01L2300/0645—Electrodes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0848—Specific forms of parts of containers
  • B01L2300/0851—Bottom walls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0861—Configuration of multiple channels and/or chambers in a single devices
  • B01L2300/0864—Configuration of multiple channels and/or chambers in a single devices comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0861—Configuration of multiple channels and/or chambers in a single devices
  • B01L2300/0867—Multiple inlets and one sample wells, e.g. mixing, dilution
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2400/00—Moving or stopping fluids
  • B01L2400/08—Regulating or influencing the flow resistance
  • B01L2400/084—Passive control of flow resistance
  • B01L2400/086—Passive control of flow resistance using baffles or other fixed flow obstructions

Definitions

• TEER Transepithelial/transendothelial electrical resistance
• the patent US8454813B2 He describes a cell sorting device (cytometer). This device is not intended to characterize a biological object through measurements. The electrodes are positioned so that the created field forces the cell against the bottom of the well.
• the request for patent WO2022/084821A1 describes a DLD (deterministic lateral displacement) type particle sorting device.
• This device includes pillars serving each electrode.
• the combination of the DLD principle and electrophoresis allows, in particular, for an increase in the sorting throughput of the device.
• CTC cancer cell detection
• the aim of the invention is to provide a method for easily monitoring a biological object and/or its surrounding fluidic environment.
• the main microfluidic channel extends lengthwise along a longitudinal axis and has a constant cross-section over at least part of its length, the first central pillar and the second central pillar being positioned symmetrically on either side of said longitudinal axis.
• the trapping device has a third central pillar and a fourth central pillar positioned symmetrically on either side of said longitudinal axis, the third central pillar being located on the same side relative to the longitudinal axis as the first central pillar and the fourth central pillar on the same side as the second central pillar.
• the third central pillar carries a third electrode and the fourth central pillar carries a fourth electrode.
• central pillars of the trapping device are positioned along an arc of a circle.
• central pillars of the trapping device each have a circular cross-section.
• the first central pillar and the second central pillar each have a kidney-shaped cross-section.
• each lateral pillar has a triangular cross-section.
• each lateral pillar has a hemispherical shape.
• the support structure includes an intermediate layer made of a doped silicon-type material, this intermediate layer being configured to form each pillar.
• the intermediate layer includes a body constructed around said pillars, configured to be electrically insulating.
• the invention aims in particular to enable the measurement of electrical impedance through a biological object O.
• the biological object O is, for example, a cell aggregate.
• a cell aggregate is defined as the self-assembly of one or more cell types in three dimensions.
• Such a cell aggregate may be called, among other things, a spheroid, organoid, tumoroid, or neurosphere.
• This aggregate may also be an islet of Langerhans.
• the term "biological object,” referenced as O will be used generically to refer to such an aggregate, as this term is commonly used in the field of live cell culture.
• such a biological object O may, for example, have a diameter ranging from a few tens of micrometers to a few hundred micrometers.
• the microfluidic component of the invention includes a support.
• the support may have a multi-layered structure (see below in connection with the figure 5 ).
• the microfluidic component support includes a main microfluidic channel C_1.
• This channel advantageously has a rectangular cross-section. It extends straight along a designated longitudinal axis (X). It is designed to form a flow path for the biological object O to be analyzed. It therefore includes an inlet through which the biological object O is introduced, and an outlet.
• the component also includes a biological object trapping device, positioned inside the main microfluidic channel C_1, between its inlet and outlet.
• the trapping device comprises at least two first pillars, referred to as central pillars P_1, P_2, erected in the main microfluidic channel C_1, interposed in the fluidic flow.
• These central pillars P_1, P_2 are erected (in a transverse direction) in the main microfluidic channel and are positioned so as to block the biological object O when it is injected into the main microfluidic channel along the longitudinal axis (X).
• the two central pillars P_1, P_2 are positioned symmetrically, on either side of the longitudinal axis (X) of the main microfluidic channel C_1.
• the trapping device comprises four central pillars P_1, P_2. These four central pillars are also advantageously positioned symmetrically, two by two, on either side of the longitudinal axis (X) of the main microfluidic channel.
• the central pillars of the trapping device are positioned to form an arc.
• the arc is shaped to create a concave space to receive the biological object O as it flows from the inlet to the outlet of the main microfluidic channel C_1.
• the component can integrate into its support one or more lateral microfluidic channels C_20, C_30, each lateral channel having at least one junction zone Z_20, Z_30 with the main microfluidic channel C_1, through which it communicates with the main microfluidic channel C_1.
• lateral microfluidic channel, C_20 and C_30 is advantageously used to transport a culture medium suitable for the perfusion of the biological object O trapped by the trapping device.
• each junction zone, Z_20 and Z_30 is thus positioned opposite the trapping zone of the biological object O.
• the component comprises a series of one or more lateral pillars P_20, P_30 at each junction zone Z_20, Z_30 existing between a lateral microfluidic channel C_20, C_30 and the main microfluidic channel C_1.
• two series of one or more lateral pillars are present at each junction zone.
• the two series of one or more lateral pillars are positioned symmetrically with respect to the longitudinal axis (X).
• the first series may include five lateral pillars P_20 and the second series may include five lateral pillars P_30.
• the lateral pillars P_20 of the first series and the lateral pillars P_30 of the second series are positioned symmetrically with respect to the longitudinal axis (X).
• the lateral pillars are advantageously aligned along a direction parallel to the longitudinal axis (X).
• the component also incorporates several electrodes, used to perform impedance measurements across the biological object O when it is trapped by the trapping device.
• the electrodes are polarized and are therefore placed, in pairs, at distinct and opposite electrical potentials.
• Opposite electrical potentials mean that the two potentials have the same magnitude but opposite signs (one is positive and the other is negative).
• the positive electrical potential is set at +10 mV and the negative electrical potential at -10 mV.
• a sinusoidal potential is applied that oscillates between +10 and -10 mV.
• each central pillar P_1, P_2 of the trapping device is configured to form a separate electrode.
• lateral pillars P_20, P_30 are present, these are each configured to form a separate electrode.
• Each electrode of the component can be placed at a distinct electrical potential.
• each pillar is configured to form an electrode, it can be placed at a particular electrical potential.
• the microfluidic component is connected to a potentiostat, to which each electrode of the component is connected.
• the potentiostat is configured to regulate the electrical potential applied to each electrode.
• the potentiostat and the component thus form a complete measurement system for performing impedance measurements on the biological specimen.
• each electrical potential assigns to different field lines, thus allowing the characterization of the biological object O and/or its surrounding environment.
• the various impedance measurements taken between two pillars are data collected for analysis.
• a processing unit can be configured to analyze this measurement data and determine properties of the trapped biological object O and/or its surrounding environment.
• First configuration - Figure 3A This is the simplest configuration, allowing the biological object O to be trapped while measurements are taken as close as possible to it.
• This configuration incorporates only two central pillars, P_1 and P_2, placed at two distinct and opposite electrical potentials (+10mV and -10mV). They are positioned symmetrically with respect to the longitudinal axis.
• Second configuration - Figure 3B this is a configuration with only four central pillars, a first series of two central pillars P_1 located on the same side of the longitudinal axis (X) being at the same first electrical potential (by example +10mV), and a second series of two central pillars P_2 located on the other side of the longitudinal axis (X) at a second electrical potential (for example -10mV), opposite to that of the first electrical potential.
• Third configuration - Figure 3C Four central pillars P_1, P_2 in two series (as in the second configuration) and at least two lateral pillars P_20, P_30, a first lateral pillar P_20 at the level of the first junction zone Z_20 and a second lateral pillar P_30 at the level of the second junction zone Z_30.
• the two central pillars P_1 of the first series, located on the same side of the longitudinal axis (X), are at the same first electrical potential (for example +10mV)
• the two central pillars P_2 of the second series located on the other side of the longitudinal axis (X) are at the same second electrical potential (for example -10mV), opposite to that of the first electrical potential.
• the two lateral pillars P_20 and P_30 each have a distinct electrical potential, with the two potentials being opposite.
• Lateral pillar P_20 is at the same electrical potential (+10mV) as the central pillars P_1 of the first series.
• Lateral pillar P_30 is at the same electrical potential (-10mV) as the central pillars P_2 of the second series.
• Fourth configuration - 3D Figure It is identical to the third configuration, with several lateral pillars P_20, P_30 for each series. On the 3D figure Thus, five lateral pillars are used for each series of lateral pillars.
• the lateral pillars P_20 of the first series are all at the same electrical potential (for example, +10mV), and the lateral pillars P_30 of the second series are all at the same electrical potential (for example, -10mV), opposite to that applied to the pillars of the first series.
• the pillars (central and lateral) located on the same side of the longitudinal axis (X) are all at the same electrical potential, and the pillars located on the opposite side of the longitudinal axis (X) are at the opposite electrical potential.
• This configuration is identical to the fourth configuration ( 3D figure ), with the addition of the median pillar P_3 located in the axis of the longitudinal channel (X). This pillar is placed at a neutral electrical potential (0mV).
• the intermediate layer incorporating the pillars could be made of silicon and hollowed out at each pillar to allow for the metallic deposit. It would also be possible to deposit a metallic layer directly onto the surface of each pillar.
• the metal could be replaced by a metal oxide, a conductive material such as graphene, amorphous carbon (DLC), a material like indium oxide (ITO) or molybdenum disulfide ( MoS2 ), or any other biocompatible electrically conductive material.
• FIG. 5 Another advantageous and illustrated solution is figure 5 This involves creating the electrodes using a specific intermediate layer L_2 with conductive properties.
• this intermediate layer L_2 incorporates the component's pillars. It is, for instance, made of doped silicon.
• the intermediate silicon layer L_2 is N+ doped with arsenic. Its resistivity is given to be less than 3 mohm.cm.
• the electrical connections/tracks are, for example, made of platinum or gold.
• the intermediate layer L_2 is made of doped silicon, the entire intermediate layer L_2 has conductive properties, and therefore also the body of the support in which the main microfluidic channel C_1 and the lateral microfluidic channels C_20, C_30 are formed. However, it is also possible to make this volume electrically insulating and to make only the pillars of the structure conductive.
• the pillars have a suitable height, at most equal to the depth of the microfluidic channel and at least equal to half the largest dimension (e.g., its diameter) of the biological object O, in order to maintain effective trapping.
• the cylindrical central pillars have a cross-section of 100 ⁇ m in diameter.
• the height of the triangular cross-section of the lateral pillars is also 100 ⁇ m.
• the electrical connections are, for example, thin platinum lines, 50 ⁇ m wide.
• the central pillars are, for example, spaced 80 ⁇ m apart, and the lateral pillars are, for example, spaced 45 ⁇ m apart.
• Figure 4A This is the fourth configuration described above, in which the central pillars p_1, P_2 are chosen to be cylindrical and the lateral pillars p_20, P_30 to be semi-cylindrical in shape.
• the body of the intermediate layer L_2 is electrically isolated.
• the two central pillars P_1 and the lateral pillars P_20 are at the same electrical potential (+10mV) and on the other side of the longitudinal axis, the two other central pillars P_2 and the other lateral pillars P_30 are at the opposite electrical potential (-10mV).
• the impedance measurement at 1MHz is concentrated on a Z zone which typically corresponds to the zone where the biological object O is positioned when it is trapped in the component.
• Figure 4B This is also the fourth configuration described above, in which triangular-sectioned lateral pillars P_20 and P_30 are used. It can thus be seen that it is possible to focus the measurements on a zone Z that corresponds to the trapping zone of the biological object.
• Figure 4C We retain the same geometric and electrical configuration as that of the figure 3E All central pillars P_1, P_2 are placed at the same electrical potential (for example -10mV) and all lateral pillars P_20, P_30 are placed at the opposite electrical potential (+10mV). Numerical simulations show us that, in this In this configuration, impedance measurement will preferentially be performed on a zone Z corresponding to that occupied by the surrounding medium, excluding the area where the biological object is trapped. Such a current distribution is quite useful for performing reference measurements; for example, it will be possible to characterize the solution present in the surrounding medium, without the biological object O.
• Figure 4D This is the configuration with five central pillars ( figure 3F ), including a central pillar P_3 located on the longitudinal axis and at a neutral electrical potential.
• the two central pillars P_1 and the lateral pillars P_20 located on the same side of the longitudinal axis (X) are at the same electrical potential (+10mV), and the two other central pillars P_2 and the other lateral pillars P_30 located on the opposite side of the longitudinal axis (X) are at the opposite electrical potential (-10mV).
• the body of the intermediate layer L_2 is electrically isolated. In this configuration, it is possible to study a zone Z, which corresponds to the trapping zone of the biological object.
• Figure 4E This configuration involves changing the shape of two central pillars, P_1 and P_2 (one from each series), located closest to the longitudinal axis (X). These are shaped into a kidney-like form.
• the lateral pillars, P_20 and P_30 are chosen with a semi-cylindrical shape.
• the body of the intermediate layer, L_2 is electrically insulated. Electrically, the central pillars P_1 and lateral pillars P_20 are at the same potential (+10mV), while the central pillars P_2 and lateral pillars P_30 are at opposite potentials (-10mV).
• the solution of the invention thus makes it possible to fulfill the function of trapping the biological object O as well as the function of impedance measurement, by allowing one to get as close as possible to the trapped biological object O.
• connection configurations allow targeting, as desired, different areas of interest, including the biological object or its surrounding environment.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Dispersion Chemistry (AREA)
• Fluid Mechanics (AREA)
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• Physics & Mathematics (AREA)
• Hematology (AREA)
• Clinical Laboratory Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Apparatus Associated With Microorganisms And Enzymes (AREA)

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Citations (5)

• 2024
  • 2024-06-25 FR FR2406799A patent/FR3163733A1/fr active Pending
• 2025
  • 2025-06-02 EP EP25180174.2A patent/EP4674530A1/de active Pending

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Non-Patent Citations (2)

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