Measuring device for mechanical properties of 3D cell tissue

Abstract

The invention discloses a device for measuring mechanical properties of 3D cell tissues. The device comprises a base platform, a movable sliding block, a special beam structure and a base platform fixing beam, the special beam structure comprises an upper rigid end, a deformation section and a lower rigid end; wherein the upper rigid end and the lower rigid end are respectively inserted and fixedly connected with the deformation section; the base platform and the base platform fixing beam are integrally manufactured or connected in an inserted mode. The base platform is provided with a sliding groove and connected with the movable sliding block through the sliding groove. The movable sliding block is provided with a hole site, and the lower rigid end is inserted into the hole site to be connected with the movable sliding block. According to the method, the mechanical change attribute of the three-dimensional tissue in the deformation process can be measured, the mechanical change of the three-dimensional tissue can be measured, and quantitative mechanical research plays a promoting role in revealing a mechanism in vitality.

Description

Technical Field

[0001] The present invention relates to the field of cell mechanics technology, and in particular to a device for measuring the mechanical properties of 3D cell tissues. Background Art

[0002] As a key element in fully understanding the healthy behavior of life, the mechanical properties of cells are extremely important in terms of measurement, adjustment, and estimation. However, existing domestic and foreign instruments can measure the mechanical properties of single cells in different ways, such as atomic force microscopy (AFM), which uses laser reflection on the needle tip to characterize strain, and can measure Young's modulus in conjunction with the mechanical sensing of the needle tip. Another example is the use of optical tweezers technology: the strain is observed through the extrusion deformation of the optical tweezers, and the Young's modulus is obtained by combining the stress generated by the optical potential trap. However, these instruments start at millions, which is not conducive to promotion. In addition, most devices measure the force of a single cell in two dimensions, rather than considering the mechanical properties of the entire cell group as a whole. Measuring the cell layer force as a whole is similar to the real environment of the human body, and can better provide relevant 3D data, providing more accurate data for understanding cell mechanics and tissue mechanics.

[0003] Existing technology devices mostly use an integral double cantilever beam setting and use 502 glue to stick the tissue, which obviously changes the mechanical properties of biological tissue and cannot truly reflect the mechanical properties. In addition, biological materials are generally soft materials with small Young's modulus and poor resistance to deformation. If you want to measure the mechanical properties of tissue using a cantilever beam, you must produce a large deformation, which will inevitably destroy the tissue structure. Therefore, the measured tissue mechanics is very inaccurate and has irreversible damage to the structure. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a device for measuring the mechanical properties of 3D cell tissues, which solves the problem that traditional devices cause large deformation of three-dimensional tissues, and also overcomes the problem that the mechanical properties during the measurement process cannot be measured.

[0005] Technical solution: The device for measuring the mechanical properties of 3D cell tissues described in the present invention comprises a base platform, a movable slider, a special beam structure, and a base platform fixed beam; the special beam structure comprises: an upper rigid end, a deformation section, and a lower rigid end; wherein the upper rigid end and the lower rigid end are respectively inserted and fixedly connected with the deformation section; the base platform and the base platform fixed beam are integrally manufactured or inserted and connected; the base platform is provided with a slide groove, which is connected to the movable slider through the slide groove; the movable slider is provided with a hole, and the lower rigid end is connected to the movable slider by inserting into the hole.

[0006] Furthermore, the deformation section is a metal wire.

[0007] Furthermore, the rigid section is made of a hard material.

[0008] Furthermore, the three-dimensional tissue or the three-dimensional tissue carrier is adhered to the base platform fixed beam and the special beam structure respectively, and a mechanical analysis is performed on the three-dimensional tissue or the three-dimensional tissue carrier.

[0009] Furthermore, the mechanical analysis of the three-dimensional tissue or three-dimensional tissue carrier is performed on the special beam structure, which is as follows: the special beam structure is a three-times hyperstatic structure, and the force along the beam direction of the deformable beam is 0, so the force and bending moment perpendicular to the beam direction are solved.

[0010] Furthermore, the force perpendicular to the beam direction, that is, the concentrated force on the three-dimensional tissue or the three-dimensional tissue carrier, is solved by the displacement method of unconstrained displacement. The formula is as follows:

[0011] Given the deflection equation for the beam

[0012]

[0013] Among them, C and D are integration constants given by constraint information;

[0014] Since the upper constraint is released, there is a normal force F at the upper end. 三维组织 and bending moment M. And the displacement constraint at the upper end is

[0015] d 梁上部 =d1-d2

[0016] θ 梁上端 =0

[0017] Combining the above deflection formula and displacement constraint, we can get

[0018]

[0019] Wherein E is the Young's modulus of the metal wire; I is the section moment of inertia; EI is the bending stiffness of the section; l is the length of the metal wire, d1 is the displacement length of the lower part of the metal wire connected to the moving slider; d2 is the displacement length of the upper part of the metal wire connected to the three-dimensional tissue.

[0020] Furthermore, the bending moment formula is as follows:

[0021]

[0022] Wherein E is the Young's modulus of the metal wire; I is the section moment of inertia; EI is the bending stiffness of the section; l is the length of the metal wire, d1 is the displacement length of the lower part of the metal wire connected to the moving slider; d2 is the displacement length of the upper part of the metal wire connected to the three-dimensional tissue.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: it changes the method of roughly applying loads in existing equipment, can improve the problem of large deformation of existing equipment, and change irregular large deformation into regular tensile deformation, ensuring that the structure is not damaged and the accuracy of the measurement data is guaranteed; it can measure the mechanical change properties of three-dimensional tissues during deformation, and can measure the mechanical changes of three-dimensional tissues. Such quantitative mechanical research has a promoting effect on revealing the mechanisms in life mechanics. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the device of the present invention;

[0025] Figure 2 is a mechanical schematic diagram of a 3D cell layer force loading and measurement device of the present invention;

[0026] Figure 3 It is a schematic diagram of the structure of the movable slider of the present invention;

[0027] Figure 4 It is the finite element modeling node diagram of the present invention;

[0028] Figure 5 It is the finite element modeling result diagram of the present invention;

[0029] Figure 6 It is the finite element node displacement data diagram of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0031] like Figure 1-Figure 3 As shown, an embodiment of the present invention provides a device for measuring the mechanical properties of 3D cell tissues, including a base platform, a movable slider, a special beam structure, and a base platform fixed beam; the special beam structure includes: an upper rigid end, a deformation section, and a lower rigid end; wherein the upper rigid end and the lower rigid end are respectively inserted and fixedly connected with the deformation section; the base platform and the base platform fixed beam are integrally manufactured or inserted and connected; the base platform is provided with a slide groove, which is connected to the movable slider through the slide groove; the movable slider is provided with a hole, and the lower rigid end is connected to the movable slider by inserting into the hole.

[0032] The deformable segment is a metal wire. The rigid segment is made of a hard material. The three-dimensional tissue or three-dimensional tissue carrier is adhered to the base platform fixed beam and the special beam structure respectively, and a mechanical analysis is performed on the three-dimensional tissue or three-dimensional tissue carrier. The mechanical analysis of the three-dimensional tissue or three-dimensional tissue carrier is the mechanical analysis of the special beam structure, which is as follows: the special beam structure is a three-times hyperstatic structure, and the force along the beam direction of the deformable beam is 0, then the force and bending moment perpendicular to the beam direction are solved.

[0033] Among them, the force perpendicular to the beam direction, that is, the concentrated force on the three-dimensional tissue or the three-dimensional tissue carrier, is solved by the displacement method of releasing constraints. The formula is as follows:

[0034] Given the deflection equation for the beam

[0035]

[0036] Among them, C and D are integration constants given by constraint information;

[0037] Since the upper constraint is released, there is a normal force F at the upper end. 三维组织 and bending moment M. And the displacement constraint at the upper end is

[0038] d 梁上部 =d1-d2

[0039] θ 梁上端 =0

[0040] Combining the above deflection formula and displacement constraint, we can get

[0041]

[0042] Wherein E is the Young's modulus of the metal wire; I is the section moment of inertia; EI is the bending stiffness of the section; l is the length of the metal wire, d1 is the displacement length of the lower part of the metal wire connected to the moving slider; d2 is the displacement length of the upper part of the metal wire connected to the three-dimensional tissue.

[0043] Furthermore, the bending moment formula is as follows:

[0044]

[0045] Where E is the Young's modulus of the wire; I is the moment of inertia of the section; EI is the bending stiffness of the section; l is the length of the wire, d1 is the displacement length of the lower part of the wire connected to the moving slider; d2 is the displacement length of the upper part of the wire connected to the three-dimensional tissue. Figure 4 As shown, the performance of the device is verified by the finite element method: the overall special beam structure is the same as the actual one, but only the stress and deformation part on the left is simulated. The displacement d1 is applied to the lower side, and the upper side has a collagen constraint, so the upper end displacement is d2. The finite element beam unit material properties are given here:

[0046] Beam structure material property table

[0047]

[0048] The displacement results of modeling and analysis using the APDL method in Ansys, as well as the specific displacement values ​​of each node are given (the displacement of the device structure only moves along the x direction, and the movement in the y direction can be ignored)

[0049] like Figure 4-Figure 6 As shown, the displacement graph results and displacement data results are given to verify the device of the present invention and its inherent mechanical principles. Figure 5 As shown, the first node and the 23rd node are the two displacement data points d1 and d2 required for the present invention. That is, d1 = d2 = -5.000e-3, d 23 =d2=-3.393e-3.

[0050] At this time, the required two-point displacement is brought into the mechanical formula measured by the patented device:

[0051]

[0052] Because the K value of the spring can be determined by the finite element method itself, the spring force can be directly calculated

[0053] F 弹簧 =K*d2=3*10 5 *3.393*10 -3 =1.0140*10 -6 #

[0054]

[0055] Therefore, the present invention can better meet the requirements reflected by the actual situation.

Claims

1. A device for measuring the mechanical properties of 3D cell tissues, characterized in that: It includes a base platform, a movable slider, a special beam structure, and a fixed beam of the base platform; the special beam structure includes: an upper rigid end, a deformation section, and a lower rigid end; wherein, the upper rigid end and the lower rigid end are respectively inserted and fixedly connected with the deformation section; the base platform and the fixed beam of the base platform are integrally manufactured or inserted and connected; the base platform is provided with a slide groove, which is connected to the movable slider through the slide groove; the movable slider is provided with a hole, and the lower rigid end is connected to the movable slider by inserting into the hole.

2. A device for measuring 3D cell tissue mechanical properties according to claim 1, characterized in that: The deformation section is a metal wire.

3. The device for measuring the mechanical properties of 3D cell tissue according to claim 1, characterized in that: The rigid section is made of a hard material.

4. The device for measuring the mechanical properties of 3D cell tissue according to claim 1, characterized in that: The three-dimensional tissue or the three-dimensional tissue carrier is adhered to the base platform fixed beam and the special beam structure respectively, and a mechanical analysis is performed on the three-dimensional tissue or the three-dimensional tissue carrier.

5. The device for measuring the mechanical properties of 3D cell tissue according to claim 4, characterized in that: The mechanical analysis of the three-dimensional tissue or three-dimensional tissue carrier is the mechanical analysis of the special beam structure, which is as follows: the special beam structure is a three-times hyperstatic structure, and the force along the beam direction of the deformable beam is 0, so the force and bending moment perpendicular to the beam direction are solved.

6. The device for measuring the mechanical properties of 3D cell tissue according to claim 5, characterized in that: The force perpendicular to the beam direction is the concentrated force on the three-dimensional tissue or the three-dimensional tissue carrier. The force on the three-dimensional tissue is solved by the displacement method of releasing the constraints. The formula is as follows: Given the deflection equation for the beam Among them, C and D are integration constants given by constraint information; Since the upper constraint is released, there is a normal force F at the upper end. 三维组织 and bending moment M. And the displacement constraint at the upper end is d 梁上部 =d1-d2 i 梁上端 =0 Combining the above deflection formula and displacement constraint, we can get Wherein E is the Young's modulus of the metal wire; I is the section moment of inertia; EI is the bending stiffness of the section; l is the length of the metal wire, d1 is the displacement length of the lower part of the metal wire connected to the moving slider; d2 is the displacement length of the upper part of the metal wire connected to the three-dimensional tissue.

7. The device for measuring the mechanical properties of 3D cell tissues according to claim 5, characterized in that: The bending moment formula is as follows: Wherein E is the Young's modulus of the metal wire; I is the section moment of inertia; EI is the bending stiffness of the section; l is the length of the metal wire, d1 is the displacement length of the lower part of the metal wire connected to the moving slider; d2 is the displacement length of the upper part of the metal wire connected to the three-dimensional tissue.

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