CN115931700A

CN115931700A - Flat plate flow cavity experiment system

Info

Publication number: CN115931700A
Application number: CN202211637113.3A
Authority: CN
Inventors: 王进
Original assignee: Jiangsu Biosurf Biotech Co Ltd
Current assignee: Jiangsu Biosurf Biotech Co Ltd
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2023-04-07
Also published as: CN111896459B; CN111896459A

Abstract

A high-flux medical degradable metal corrosion characteristic flat plate flow cavity experiment system adopts a parallel multi-group form, namely liquid output by a pump source enters a corresponding high-flux flow cavity through more than one flow channel, the shape of the buffer area at the inlet of the high-flux flow cavity is an isosceles triangle, the long side of the triangle is twice of the short side, and the top angle is chamfered to form an arc shape; the transition area of the inlet buffer area and the experimental sample and the transition area of the outlet buffer area and the experimental sample; more than one experimental sample groove is arranged on the bottom plate in parallel along the radial flow direction; the sampling equipment of the microscopic imaging system group observes and records the change condition of the experimental sample through quartz glass; the experimental sample observation zone of the flow chamber developed a uniform shear stress. The shearing force applied to the experimental sample area of the system is the physiological shearing force of the aorta, the shearing force in the experimental sample area is uniformly distributed, and the experiment of various materials is efficiently completed under the same in-vitro simulated in-vivo fluid dynamic environment.

Description

Flat plate flow cavity experiment system

Technical Field

The invention relates to biomedical material experimental equipment, in particular to the field of biomedical magnesium-based metal material surface modification technology experimental equipment.

Background

In the cardiovascular field, when the blood vessel is diseased and causes stenosis, the most common and effective method at present is stent implantation. In order to avoid a series of complications caused by the fact that the stent is a foreign object and is implanted into a body, particularly, late thrombus is caused by the long-term existence of the stent, it is important to find a material which can provide corresponding mechanical support to restore blood flow during pathological changes and gradually disappear along with the healing of blood vessels. Medical metal materials such as magnesium-based vascular stents are widely concerned due to excellent mechanical properties and biocompatibility, but the degradation rate of the medical metal materials is too high to become the biggest obstacle in application of the medical metal materials, and through development of more than ten years, a plurality of modified alloy materials are applied to the degradable metal stents to improve corrosion resistance.

At present, the corrosion behavior of the medical degradable metal material is researched by mostly adopting a static corrosion mode of soaking a sample in a simulation medium, which is far away from the real blood flowing environment, and the time and the labor are consumed by adopting animal experiments to research the in-vivo degradation behavior of the medical degradable metal. The flow chamber and the bioreactor can be used for simulating in-vivo fluid environments, and are used for researching the influence of fluid shearing force on various cells at present, for example, a Chinese patent with the application number of 201710215686.X discloses a Z-shaped simple parallel flat plate flow chamber which is used for researching the change rules of the shape, the adhesion, the function and the like of the cells under the action of the fluid shearing force. But the flow cavity platform for detecting the corrosion performance of the medical metal material has few reports, the number of experimental samples capable of being detected at one time is small, high-throughput parallelism detection cannot be realized, the time cost is high, and the efficiency is low.

Disclosure of Invention

In view of the above defects of the prior art, the invention aims to provide a flat plate flow cavity system for detecting the corrosion behavior of medical degradable metals at high flux, and research the corresponding degradation behavior to efficiently complete experiments of various materials under the same in-vitro simulated in-vivo fluid dynamic environment.

The invention is realized by the following means:

a high-throughput experiment system for a medical degradable metal corrosion characteristic flat plate flow cavity is used for observing and recording the degradation process of a medical degradable metal sample in the flow cavity in situ and consists of the flow cavity connected with a pump source for providing fluid shearing force and a fluid flow recovery and collection system. The flow cavity adopts a parallel multi-group form, namely, liquid output by a pump source enters the corresponding high-flux flow cavity through more than one channel, and an experimental sample observation area of the flow cavity forms uniform shear stress to form a complete flow cavity; the shape of the arrangement of the inlet buffer zone of the high-flux flow cavity is an isosceles triangle, the long side of the triangle is twice of the short side, and the vertex angle is chamfered to form an arc shape; an inlet buffer and test sample transition zone 19 and an outlet buffer and test sample transition zone 20; more than one experimental sample groove 18 is arranged on the bottom plate in parallel along the radial flow direction; the sampling equipment of the microscopic imaging system group 4 observes and records the change condition of the experimental sample through the quartz glass 7; a sealing ring is placed in a sealing ring groove 16 of the bottom plate, quartz glass is pressed on the sealing ring, a cover plate is pressed on the quartz glass, and the quartz glass is just placed in a quartz glass groove 17; the screw is used for penetrating through the threaded hole 14 of the bottom plate and the circular hole 15 of the cover plate to be fixed to form a complete flow cavity, and the experimental sample observation area of the flow cavity forms uniform shearing stress.

The pump set 1 provides fluid flow for the whole system, the flow of the pump is controlled in the preferred range of 0-1000ml/min, the number of the flow cavities and the pump heads matched with the flow cavities are increased, the pump set and the corresponding number of the liquid collecting devices form a circulating flow system, and a microscopic imaging system connected with a display is used for observing the change condition of an experimental sample in the flow cavities to form a high-flux detection platform.

The pump source comprises 1-8 peristaltic pumps/injection pumps which are connected in parallel, each pump is provided with 4-8 channels, the flow rate of the pump is controlled in an optimal range of 0-1000ml/min, and 4-64 fluid can be simultaneously output to enter the flow cavity.

The quantity of flow chamber is confirmed according to the quantity of laboratory sample, can place a plurality of laboratory samples in same flow chamber, and when the fluid flow of pump is unchangeable, can increase flow chamber quantity, provides more laboratory sample and places the space, detects simultaneously, reaches the purpose that the high flux detected.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

(1) The flat plate flow cavity provided by the invention has a simple structure, is easy to process, and can determine the shape and the number of the internal experimental sample grooves according to requirements.

(2) The flat plate flow cavity system for detecting the corrosion behavior of the medical degradable metal at high flux realizes high flux research, and provides a new way for simultaneously researching the degradation behavior of various medical metal materials under the action of physiological shearing force.

(3) The flat plate flow cavity system for detecting the medical degradable metal corrosion behavior at high flux provided by the invention has the advantages that the fluid shearing force can be adjusted by the pump, the shearing force conditions of different parts of a human body can be simulated, the system not only can be used for researching the degradation behavior of a medical metal material, but also can be used for evaluating the influence of different coatings on the metal surface under the action of the fluid shearing force, and even can be used for researching the drug release and the like of the surface coating.

Drawings

FIG. 1 is a flat plate flow chamber system for high throughput testing of medical degradable metal corrosion behavior according to one embodiment of the invention;

FIG. 2 is a schematic assembly view of a flat plate flow chamber structure according to one embodiment of the present invention;

FIG. 3 is a top view of a flat plate flow chamber according to an embodiment of the present invention;

FIG. 4 is a longitudinal cross-sectional configuration view of a flat plate flow chamber according to an embodiment of the present invention;

FIG. 5 is a top view of a flat plate flow chamber bottom plate structure according to an embodiment of the invention.

Reference numerals:

1 pump package, 2 high flux flow chamber group, 3 collection device group, 4 microscopic imaging device group, 5 bottom plates, 6 sealing rings, 7 quartz glass, 8 apron, 9 entrances, 10 exports, 11 observation windows, 12 entry buffers, 13 export buffers, 14 bottom plate screw holes, 15 apron circular ports, 16 sealing ring grooves, 17 quartz glass grooves, 18 experimental sample grooves, 19 entry buffers and experimental sample transition zones, 20 export buffers and experimental sample transition zones, 21 even shear force district, 22 experimental samples.

Detailed Description

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in figure 1, the system of the invention consists of a pump set 1 for providing fluid shearing force, a high-flux flow cavity set 2, a microscopic imaging system set 4 connected with a display and a fluid collecting device set 3 connected with a liquid outlet of the high-flux flow cavity. The pump set can provide a fluid flow rate in the preferred range of 0-1000ml/min, with the number of pump heads matching the number of flow chambers.

2-5, the high flux flow chamber comprises a bottom plate 5, a sealing ring 6, quartz glass 7 and a cover plate 8; a circular inlet 9 and a circular outlet 10 are arranged on the bottom plate, and the inlet and the outlet are symmetrically arranged; the inlet buffer area 12 is arranged in an isosceles triangle shape, the long side of the triangle is twice of the short side, and the vertex angle is chamfered to form an arc shape; an inlet buffer and test sample transition zone 19 and an outlet buffer and test sample transition zone 20; the experimental sample is placed in the experimental sample groove 18, and the experimental sample in the experimental sample area can be observed through the quartz glass 7 through the observation window 11; a sealing ring is placed in a sealing ring groove 16 of the bottom plate, quartz glass is pressed on the sealing ring, a cover plate is pressed on the quartz glass, and the quartz glass is just placed in a quartz glass groove 17; screws penetrate through the threaded holes 14 of the bottom plate and the circular holes 15 of the cover plate to be fixed to form a complete flow cavity, and an experimental sample observation area of the flow cavity forms uniform shearing stress.

As shown in fig. 2 and 4, the fluid enters from the inlet 9, and becomes moderate under the buffering action of the inlet buffer zone 12; when the fluid enters the area where the experimental sample is located through the inlet buffer area and the experimental sample transition area 19, the shearing force becomes uniform, the fluid flows through the surface of the experimental sample, and all the experimental samples are subjected to the same shearing force action in the uniform shearing force area 21; then passes through the outlet buffer zone and the experimental sample transition zone 20, reaches the outlet buffer zone 13, and flows out through the outlet 10.

As shown in fig. 2, a sealing ring groove 16 is formed on the bottom plate, a sealing ring 6 is placed in the sealing groove, the thickness of the sealing ring is slightly larger than the depth of the sealing groove, and the quartz glass 7 presses the sealing ring and extrudes the sealing ring until the quartz glass is tightly attached to the upper surface of the bottom plate; the cover plate is provided with a quartz glass groove, the cover plate covers the quartz glass, the screw penetrates through the cover plate and the bottom plate, the screw is screwed, the cover plate is pressed by the screw to transmit force to the quartz glass, the quartz glass can extrude the sealing ring until the quartz glass is tightly attached to the upper surface of the bottom plate after being pressed, the sealing performance is ensured, and the flow cavity is assembled.

The processing and manufacturing materials of the flow cavity bottom plate and the cover plate comprise Polycarbonate (PC), polyethylene (PE) or polymethyl methacrylate (PMMA).

As shown in FIG. 4, the shearing force of the uniform shearing force zone 21 is controlled by the flow rate, and is related to the cross-sectional dimension of the uniform shearing force zone of the parallel flat flow chamber through which the fluid passes and the dynamic property of the fluid, the cross-section formed by the upper and lower parallel plates of the flow chamber is rectangular, and the cross-section is calculated according to a specific shearing force calculation formula

Obtaining the required value, wherein tau is the shearing stress, and determining the cavity width w and the height h of the uniform shearing force area of the flow cavity, the dynamic viscosity eta of the fluid and the flow rate Q of the fluid. In the flow chamber designed in this embodiment, once a certain fluid is selected, the amount of shear force is controlled by the flow rate, and the required shear force can be obtained according to the requirement.

As shown in fig. 5, the uniform shearing force zone 21 of the bottom plate is provided with the experimental sample grooves, the length, width and height of the experimental sample grooves of the bottom plate of the flow chamber in this embodiment are 20 × 10 × 2mm, according to different requirements, experimental sample grooves of different sizes, such as 20 × 10 × 1mm, 10 × 10 × 2mm, 10 × 10 × 1mm and the like, can be provided, and the experimental sample grooves of other sizes are not listed one by one; the number of the experimental sample grooves on the bottom plate can be set according to different test requirements, and the number of the experimental sample grooves marked by the embodiment is 7, and the experimental sample grooves are arranged in a single row; the experimental sample grooves can also be arranged in a uniform shearing force area in two rows, three rows, four rows or even more, so that more experimental samples can be placed in one flow cavity, and a high-throughput experiment can be carried out; simple modifications and variations of this embodiment according to the invention are possible and still fall within the scope of the solution according to the invention.

As shown in fig. 2 and fig. 3, the cover plate is hollow in the middle, and can penetrate through the quartz glass below as an observation window 11 to observe the change of the experimental sample under the action of fluid shearing force, the flow cavity is arranged below the lens of the microscopic imaging device 4 to observe the corrosion condition of the experimental sample in real time, and observe and record the whole corrosion process of the medical metal under the action of physiological shearing force.

As shown in fig. 1, four flow chambers are used in the present embodiment, four medical metal materials, such as magnesium-based intravascular stent materials, are respectively placed in the four flow chambers, and 7 experimental samples are placed in each flow chamber; the adopted pump has four pump heads and 4 liquid collecting bottles; connecting the pump, the flow chamber and the liquid collecting bottle into a circulating system by using a silicone tube so as to simulate an in vivo blood circulating system; the flow cavity is arranged below the lens of the microimaging device, the whole process that metal corrodes under the action of fluid shear force provided by the flow cavity can be recorded, and the corrosion change of four medical metal materials under the action of the same shear force is observed; and each material in the same flow cavity is provided with a plurality of experimental samples, and the experimental samples can be taken out at different time points for other detection. The more experiment sample grooves are designed in the flow cavity, the more experiment samples are placed, and more samples can be detected simultaneously; and the number of the flow cavities and the number of the corresponding pump heads are increased, so that high-flux detection is realized.

In the embodiment, simulated body fluid SBF, phosphate buffered saline PBS and DMEM cell culture medium are used as in-vitro simulated fluids to simulate the fluid environment in blood vessels, and the fluids have similar properties to blood and are lower in cost compared with the blood.

The medical metal begins to corrode in the circulatory system described above, corrosion products are in the circulating fluid, and the fluid collection device is used to collect fluid containing degradation products for later analysis of the composition.

Claims

1. A flat-plate flow chamber experiment system is characterized by consisting of a flow chamber connected with a pump source for providing fluid shearing force and a liquid flow recovery and collection system.

2. The flat panel flow chamber assay system of claim 1, wherein:

the pump source comprises an injection pump, and the injection pump outputs fluid into the flow cavity;

the liquid outlet of the flow cavity is connected with the liquid flow recovery and collection system, and the liquid flow recovery and collection system collects the fluid for later-stage component analysis;

the pump, the flow cavity and the liquid flow recovery and collection system are connected into a circulating system.

3. The flat panel flow cell assay system of claim 2 wherein the amount of shear is controlled by the amount of flow, the shear being calculated by the formula

Wherein tau is the shearing stress, w and h are the cavity width and height of the uniform shearing force area of the flow cavity respectively, eta is the dynamic viscosity of the fluid, and Q is the flow rate of the fluid.

4. The flat panel flow cell assay system of claim 3 wherein the flow cell is provided with an experimental sample viewing area.

5. The flat plate flow chamber experimental system of claim 4, wherein said flow chamber comprises a bottom plate, a sealing ring, quartz glass and a cover plate, the bottom plate comprises a uniform shearing force area, the test sample grooves are opened in the uniform shearing force area, the number of the test sample grooves can be set to be single row, double row, three rows, four rows or more according to different experimental requirements, the test sample observation area has an observation window, and the test sample in the area where the test sample is located is observed through the quartz glass.

6. The flat panel flow cell assay system of claim 5, wherein fluid enters the flow cell at the inlet, passes through the inlet buffer zone, the transition zone between the inlet buffer zone and the test sample, the uniform shear force zone, the transition zone between the outlet buffer zone and the test sample, and the outlet buffer zone, and exits the flow cell through the outlet.

7. The flat panel flow cell assay system of claim 6 wherein the flow cell is positioned under the lens of a microimaging device.

8. Use of the flat flow cell assay system of claims 1-7 for studying the degradation behavior of medical grade metallic materials.

9. Use of the flat panel flow cell assay system of claims 1-7 to evaluate the effect of a coating on the shear forces of a fluid.

10. Use of the flat panel flow chamber assay system of claim 9 to evaluate the effect of a coating on the shear force of a fluid, wherein the coating is a surface coating.

11. Use of the flat panel flow chamber assay system of claims 1-7 for studying drug release from a surface coating.

12. Use of the flat panel flow chamber assay system according to claims 8-9 and 11 wherein the shear conditions at different parts of the human body can be simulated by pump adjustment.