A vascular organ-on-a-chip that simulates human blood pressure

Abstract

This invention discloses a vascular organ-on-a-chip that simulates human blood pressure, comprising a substrate, a channel layer, a cell dynamic culture module, a solution mixing module, and a cell mechanical property measurement module. The cell dynamic culture module includes a first culture channel and a second culture channel, with a serpentine channel connecting the upstream of the first culture channel and the upstream of the second culture channel. The solution mixing module includes two oppositely arranged solution mixing channels, which are respectively connected to the first culture channel and the second culture channel. The cell mechanical property measurement module includes multiple measurement channels arranged side-by-side, with one end of each measurement channel connected to the other end of one solution mixing channel and the other end connected to the other end of another solution mixing channel. This invention simulates the human blood pressure environment within the vascular organ-on-a-chip, enabling simultaneous cell culture under parallel gradient pressure within the chip, and combining the vascular organ-on-a-chip with cell mechanical property measurement.

Description

Technical Field

[0001] This utility model relates to the field of biomedical device technology, and in particular to a vascular organ chip that simulates human blood pressure. Background Technology

[0002] In the human body, blood pressure at varying intensities significantly impacts vascular growth and regeneration. Endothelial cells (ECs) line the luminal surface of blood vessels, forming a direct interface with blood and the vascular basement membrane. They actively transport small molecules, macromolecules, and hormones within the vascular system, playing a crucial role in regulating blood pressure, coagulation, and angiogenesis. Researchers have investigated the effects of EC function on vasodilation, angiogenesis, lymphocyte adhesion, and migration—all of which are intricately linked to cellular biomechanical properties. Although existing studies have utilized EC mechanical properties to quantify cellular function, further in-depth exploration remains insufficient to elucidate the mechanisms by which different human blood pressure levels affect cellular physiology.

[0003] Currently, the assessment of cellular mechanical properties typically requires static cell culture in petri dishes or the use of animal models to simulate the vascular environment. However, the significant differences between the petri dish culture environment and in vivo conditions mean that statically cultured cells in the laboratory often cannot simulate the complex microenvironment within the human body, making it difficult to accurately reflect the physiological state of cells in vivo. Furthermore, the challenge of precisely controlling experimental parameters frequently compromises the reproducibility and reliability of experimental results. Animal models involve ethical and animal welfare considerations during experiments, and are characterized by long experimental cycles, high costs, significant inter-individual variability, and various confounding factors, making it difficult to meet the requirements for experimental efficiency and accuracy. In addition, existing methods for measuring cellular mechanical properties, including atomic force microscopy and optical tweezers, suffer from problems such as complex operation, invasiveness, single-point measurement, and low throughput, limiting the measurement accuracy and efficient analysis of cellular mechanical properties. Therefore, it is essential to develop a measurement technique that uses parallel gradient simulation of physiological and pathological conditions to elucidate the mechanistic influence of different blood pressure environments in the human body on cellular mechanical properties. Utility Model Content

[0004] In view of the shortcomings of existing technology, the purpose of this utility model is to provide a vascular organ chip that simulates human blood pressure.

[0005] To achieve the above objectives, the technical solution provided by an embodiment of this utility model is as follows:

[0006] A vascular organ-on-a-chip that simulates human blood pressure includes:

[0007] substrate;

[0008] A channel layer is disposed on the substrate, and a cell dynamic culture module, a solution mixing module and a cell mechanical property measurement module are disposed within the channel layer;

[0009] The cell dynamic culture module includes a first culture channel and a second culture channel arranged opposite to each other. The first culture channel is connected to a first injection port upstream and a first inlet / outlet downstream. The second culture channel is connected to a second injection port upstream and a second inlet / outlet downstream.

[0010] A serpentine channel connects the upstream of the first culture channel and the upstream of the second culture channel;

[0011] The solution mixing module includes two solution mixing channels arranged opposite each other. One end of each solution mixing channel is connected to the downstream of the first culture channel and the downstream of the second culture channel, respectively. Each solution mixing channel includes multiple mixing channels arranged side by side and connected in series.

[0012] The cell mechanical properties measurement module includes multiple measurement channels arranged side by side, with each measurement channel connected at both ends to the other end of the two solution mixing channels.

[0013] As a further improvement of this invention, the width of the first culture channel is smaller than the width of the second culture channel.

[0014] As a further improvement of this utility model, the width of the first culture channel is 540-660μm, the width of the second culture channel is 900-1100μm, and the height of both the first and second culture channels is 135-165μm.

[0015] As a further improvement of this utility model, the width of the serpentine channel is 40-50μm.

[0016] As a further improvement of this utility model, a U-shaped channel is connected end to end between adjacent mixing channels, and each mixing channel includes at least one hourglass channel.

[0017] As a further improvement of this utility model, the measurement channel includes a first transition channel, a micro-constraint channel, a recovery channel, a contraction channel, and a second transition channel that are connected in sequence. The first transition channel is connected to the other end of one of the solution mixing channels. The micro-constraint channel includes multiple micro-constraint segments, and a recovery segment is provided between two adjacent micro-constraint segments. The width of the contraction channel is smaller than the width of the recovery channel. The second transition channel is connected to the other end of the other solution mixing channel.

[0018] As a further improvement of this utility model, the width of the contraction channel is 5.4-6.6μm and the height is 18-22μm.

[0019] As a further improvement of this utility model, the recovery channel includes a straight channel and two curved channels respectively connected to both ends of the straight channel, and the two curved channels are arranged alternately.

[0020] As a further improvement of this utility model, a first outlet and a second outlet are respectively provided in the channel layer, wherein the other end of one of the solution mixing channels and one end of the measuring channel are connected to the first outlet, and the other end of the solution mixing channel and the other end of the measuring channel are connected to the second outlet.

[0021] The beneficial effects of this utility model are:

[0022] (1) Based on the principle of fluid diversion, through the design of chip microstructure, the stable pressure environment of high pressure / normal pressure and low pressure / normal pressure in the first culture channel and the second culture channel is precisely controlled to simulate the vascular microenvironment under different blood pressure in the human body.

[0023] (2) Based on the principles of microfluidics and fluid shielding, the chip functions are integrated. The vascular environment under different blood pressures in the human body is simulated in the vascular organ chip, and cells are cultured, processed and micro-constrained directly in the vascular organ chip to compare the differences in cell morphology and mechanical properties under high blood pressure / normal blood pressure and low blood pressure / normal blood pressure. This helps to explore the pathophysiological mechanisms of high blood pressure and low blood pressure, lays the foundation for developing more effective prevention and treatment strategies, and may guide the discovery of new biomarkers or diagnostic methods.

[0024] (3) High-throughput cell mechanical property measurement is achieved based on array-type micro-contraction channels. At the same time, the cell mechanical property measurement module is used in time-division multiplexing to measure the cell mechanical properties of the high blood pressure area / normal blood pressure area and the low blood pressure area / normal blood pressure area, which simplifies the operation process and improves experimental efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention;

[0027] Figure 2 This is a top view of a preferred embodiment of the present invention;

[0028] Figure 3This is a schematic diagram of the cell dynamic culture module, serpentine channel, and solution mixing module of a preferred embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of the measurement channel in a preferred embodiment of the present invention;

[0030] Figure 5 The preferred embodiment of this utility model shows a pressure simulation diagram of the cell dynamic culture module and solution mixing module of a vascular organ chip that simulates human blood pressure.

[0031] Figure 6 This image shows the experimental results of endothelial cell growth under simulated human blood pressure conditions within a vascular organ-on-a-chip according to a preferred embodiment of this utility model.

[0032] Figure 7 Simulation and experimental results of solution mixing effect of vascular organ chip according to preferred embodiment of this utility model;

[0033] Figure 8 The pressure and velocity simulation diagram of the cellular mechanical property measurement module of the vascular organ-on-a-chip according to a preferred embodiment of the present invention.

[0034] In the diagram: 1. Substrate; 2. Channel layer; 3. Cell dynamic culture module; 31. First culture channel; 32. Second culture channel; 33. First injection port; 34. First inlet / outlet; 35. Second injection port; 36. Second inlet / outlet; 37. Serpentine channel; 38. First outlet; 39. Second outlet; 4. Solution mixing module; 41. First solution mixing channel; 42. Second solution mixing channel; 43. Mixing channel; 431. Hourglass channel; 5. Cell mechanical property measurement module; 51. Measurement channel; 511. First transition channel; 512. Micro-constraint channel; 5121. Micro-constraint end; 5122. Recovery section; 513. Recovery channel; 5131. Straight channel; 5132. Curved channel; 514. Contraction channel; 515. Second transition channel. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0036] Please see Figures 1-4This application discloses a vascular organ-on-a-chip that simulates human blood pressure, including a substrate 1 and a channel layer 2. The channel layer 2 is disposed on the substrate 1, and a cell dynamic culture module 3, a solution mixing module 4, and a cell mechanical property measurement module 5 are disposed within the channel layer 2. The cell dynamic culture module 3 includes a first culture channel 31 and a second culture channel 32 disposed opposite to each other. The upstream of the first culture channel 31 is connected to a first injection port 33, and the downstream of the first culture channel 31 is connected to a first inlet / outlet 34. The upstream of the second culture channel 32 is connected to a second injection port 35, and the downstream of the second culture channel 32 is connected to a second inlet / outlet 36. A serpentine channel 37 connects the upstream of the first culture channel 31 and the upstream of the second culture channel 32. The solution mixing module 4 includes two solution mixing channels arranged opposite each other. One end of each solution mixing channel is connected to the downstream of the first culture channel 31 and the downstream of the second culture channel 32, respectively. That is, one end of one solution mixing channel is connected to the downstream of the first culture channel 31, and one end of the other solution mixing channel is connected to the downstream of the second culture channel 32. Each solution mixing channel includes multiple mixing channels arranged side by side and connected in series. The cell mechanical property measurement module 5 includes multiple measurement channels 51 arranged side by side. The two ends of each measurement channel 51 are connected to the other ends of the two solution mixing channels, that is, one end of the measurement channel 51 is connected to the other end of one solution mixing channel, and the other end of the measurement channel 51 is connected to the other end of the other solution mixing channel.

[0037] This invention integrates a cell dynamic culture module 3, a solution mixing channel 4, and a cell mechanical property measurement module 5 within a channel layer 2. It can simulate the human blood pressure environment within the chip, enabling parallel gradient pressure co-culture, processing, and measurement of cells in different channels. The cell dynamic culture module 3 utilizes parallel gradient pressure to dynamically irrigate cultured cells simultaneously. According to Poiseuille's law, fluid pressure difference is proportional to flow rate and flow resistance. The width of the serpentine channel 37 is smaller than the upstream width of the first culture channel 31 and the upstream width of the second culture channel 32. The reduced channel width increases flow resistance, resulting in a larger pressure drop. Thus, the serpentine channel 37 creates a pressure difference. Simultaneously, since multiple identical mixing channels are connected in series downstream of the first culture channel 31 and the second culture channel 32, the viscous resistance (i.e., the frictional resistance between the fluid and the channel wall) encountered by the fluid flowing through these mixing channels is much greater than that of the first culture channel 31 or the second culture channel 32, capturing most of the pressure difference. Therefore, there is almost no pressure difference in the upstream first culture channel 31 and the second culture channel 32, creating a constant blood pressure environment. The solution mixing channel 4 is connected to the cell dynamic culture module 3 and the cell mechanical property measurement module 5, respectively, and can regulate the overall pressure of the channel and perform the dual function of cell treatment; the cell mechanical property measurement module 5 can measure and analyze the mechanical properties of cells.

[0038] Please see Figure 1 Preferably, substrate 1 is a glass substrate. Preferably, channel layer 2 is a PDMS channel layer, which has low cost, good chemical properties, flexibility, and transparency. The cell dynamic culture module 3, solution mixing module 4, and cell mechanical property measurement module 5 within channel layer 2 can be fabricated using soft photolithography. Substrate 1 and channel layer 2 are irreversibly bonded together using oxygen plasma bonding technology.

[0039] Please see Figure 3 The first culture channel 31 and the second culture channel 32 are cell culture zones with different pressure environments. By creating parallel gradient pressures within the first culture channel 31 and the second culture channel 32 to dynamically irrigate cultured cells, the vascular environment of the human body under hypertension / normal blood pressure and hypotension / normal blood pressure is simulated. Preferably, the width of the first culture channel 31 is smaller than the width of the second culture channel 32. Preferably, the width of the first culture channel 31 is 540-660 μm, the width of the second culture channel 32 is 900-1100 μm, and the height of both the first culture channel 31 and the second culture channel 32 is 135-165 μm. More preferably, the width of the first culture channel 31 is 600 μm, the width of the second culture channel 32 is 1000 μm, and the height of both the first culture channel 31 and the second culture channel 32 is 150 μm. When simulating the human vascular environment under hypertension / normal blood pressure, the first culture channel 31 is the hypertension zone and the second culture channel 32 is the normal blood pressure zone; when simulating the human vascular environment under hypotension / normal blood pressure, the first culture channel 31 is the normal blood pressure zone and the second culture channel 32 is the hypotension zone.

[0040] The width of the serpentine channel 37 is preferably 40-50 μm, which enables more precise generation of the target pressure difference. More preferably, the width of the serpentine channel 37 is 45 μm.

[0041] One of the two solution mixing channels is designated as the first solution mixing channel 41, and the other as the second solution mixing channel 42. The first solution mixing channel 41 is connected in series downstream of the first culture channel 31, and the second solution mixing channel 42 is connected in series downstream of the second culture channel 32. Both the first solution mixing channel 41 and the second solution mixing channel 42 include multiple mixing channels 43 arranged side-by-side and connected in series. Preferably, adjacent mixing channels 43 are connected end-to-end by a U-shaped channel 44, and each mixing channel 43 includes at least one hourglass channel 431. The hourglass channel 431 has an hourglass structure, with the width at both ends greater than the width in the middle, which improves mixing efficiency, reduces cell damage, and allows for timely dispersal of clumps of cells within the channel. Preferably, each mixing channel 43 includes two hourglass channels 431.

[0042] Please see Figure 4The preferred measurement channel 51 includes a first transition channel 511, a micro-constraint channel 512, a recovery channel 513, a contraction channel 514, and a second transition channel 515 connected sequentially. The first transition channel 511 is connected to the other end of one of the solution mixing channels. The micro-constraint channel 512 includes multiple micro-constraint segments 5121, with a recovery segment 5122 disposed between adjacent micro-constraint segments 5121. The width of the contraction channel 514 is smaller than the width of the recovery channel 513. The second transition channel 515 is connected to the other end of another solution mixing channel. That is, the first transition channel 511 is connected to the other end of the first solution mixing channel 41, and the second transition channel 515 is connected to the other end of the second solution mixing channel 42. Cell elasticity, recovery capacity, and deformability are evaluated by measuring channel 51.

[0043] Preferably, the widths of the first transition channel 511, recovery channel 513, and second transition channel 515 are the same. The width of the micro-constraint segment 5121 is smaller than the width of the first transition channel 511. The width of the recovery segment 5122 is initially equal to the width of the micro-constraint segment 5121, gradually increases, and then gradually decreases until it is equal to the width of the micro-constraint segment 5121, facilitating cell deformation and recovery. Preferably, the recovery channel 513 includes a straight channel 5131 and two curved channels 5132 respectively connected to both ends of the straight channel 5131, with the two curved channels 5132 staggered. When a cell enters the recovery channel 513, the recovery channel 513 provides sufficient channel length to help the cell recover its deformation, while the curved channels 5132 reduce the channel depth, making it easier to adapt to the limited field of view of the camera. Preferably, the curved channels 5132 are U-shaped. The contraction channel 514 is a single contraction zone; when a cell passes through this contraction channel 514, the cell undergoes compression and deformation. The width of the contraction channel 514 is preferably 5.4-6.6 μm and the height is preferably 18-22 μm. More preferably, the width of the contraction channel 514 is 6 μm and the height is 20 μm.

[0044] The preferred channel layer 2 is provided with a first outlet 38 and a second outlet 39, respectively. The other end of one solution mixing channel and one end of the measuring channel 51 are both connected to the first outlet 38, and the other end of the solution mixing channel and the other end of the measuring channel 51 are both connected to the second outlet 39. Specifically, the other end of the first mixing channel 41 is connected to the first outlet 38, and the other end of the second mixing channel 42 is connected to the second outlet 39.

[0045] The first injection port 33, the first inlet / outlet 34, the second main inlet 35, the second inlet / outlet 36, the first outlet 38, and the second outlet 39 can all be drilled using a 0.5mm hole punch. All inlets are connected to 1ml disposable syringes using 0.6x0.9mm capillary tubes. A microfluidic pump is used to precisely control the fluid flow rate, and Luer plugs are used to close or open the inlets / outlets as needed. The specific experimental steps are as follows:

[0046] (1) Chip pretreatment. To avoid interference from external factors such as bacteria and fungi, the chips and consumables such as capillary tubes were soaked in alcohol and air-dried overnight before the experiment. The chips were sterilized with ultraviolet light for at least half an hour before the experiment, and all experimental operations must be performed in a clean bench.

[0047] (2) Microarray treatment before endothelial cell seeding. First, wash the channels three times with PBS. When simulating a human blood pressure environment under hypertension / normal blood pressure, after PBS washing, only open the first inlet 31 and the first inlet / outlet 34. Introduce FN (fibronectin) solution into the first culture channel 31 (hypertension zone) through the first inlet 31 to promote cell adhesion. Then, close the first inlet 31 and the first inlet / outlet 34, and open the second inlet 35 and the second inlet / outlet 36. Introduce FN solution into the second culture channel 32 (normal blood pressure zone) through the second inlet 35. Incubate in a CO2 incubator for 24-48 hours to increase cell adhesion. The procedure for simulating a human blood pressure environment under hypotension / normal blood pressure is the same as above. Human umbilical vein endothelial cells (HUVECS) are used in the experiment. Compared to directly using venous or arterial endothelial cells, HUVECS have stem cell potential and a longer passage number. For better experimental results, they need to be cultured for 4 to 7 generations before use.

[0048] (3) Cell seeding. Connect the microscope in the laminar flow hood to the computer screen in advance to observe the condition within the channel. When simulating the human blood pressure environment under hypertension / normal blood pressure, only open the first inlet 31 and the first inlet / outlet 34 to seed the centrifuged cells into 1×10⁻⁶ cells. 6 A cell suspension of cells / mL is slowly injected through the first injection port 31, and the cell density in the first culture channel 31 is observed. Subsequently, the first injection port 31 and the first inlet / outlet 34 are closed, and the second injection port 35 and the second inlet / outlet 36 are opened. The cell suspension is then slowly injected through the second injection port 35, and the cell density in the second culture channel 32 is observed. The operating procedure for simulating the human blood pressure environment under hypotension / normal blood pressure is the same as described above.

[0049] (4) Cellular trypsin treatment. When simulating the human blood pressure environment under hypertension / normal blood pressure, close the serpentine channel 37 to isolate the hypertension zone and the normal blood pressure zone. Close the second inlet 35 and the second inlet / outlet 36, and infuse trypsin through the first inlet 31 to detach the endothelial cells in the first culture channel 31 (hypertension zone). Simultaneously, inject culture medium through the first inlet / outlet 34 to terminate digestion. After mixing in the mixing channel, the cells enter the cell mechanical property measurement module 5. Similarly, close the first inlet 31 and the first inlet / outlet 34, and infuse trypsin through the second inlet 35 to detach the endothelial cells in the normal blood pressure zone. Simultaneously, introduce culture medium through the second inlet / outlet 36 to terminate digestion. After mixing in the mixing channel 43, the cells enter the measurement channel 51. The operating steps for simulating the human blood pressure environment under hypotension / normal blood pressure are the same as above.

[0050] (5) Cell measurement. The cell suspension mixed through the mixing channel 43 flows into the measurement channel 51 to measure the elastic modulus, recovery capacity and deformability of the cells.

[0051] Figure 5 This is a pressure simulation diagram of the cell dynamic culture module 3 and solution mixing module 4 of a vascular organ-on-a-chip to simulate human blood pressure. A 2D DXF file created in SOLIDWORKS is imported into COMSOL for simulation, with the channel height set to 150μm. Based on the simulation results, such as... Figure 5 As shown in (a), when the velocity is 24 μL / min, the pressure in the hypertension zone is 171.6 mmHg, and the pressure in the normal blood pressure zone is 94.8 mmHg, with shear forces of 2.1 dyn / cm. 2 0.67dyn / cm 2 It can simulate the vascular environment under high / normal blood pressure in the human body; such as Figure 5 As shown in (b), when the velocity is 13 μL / min, the pressure in the normal blood pressure zone is 91.8 mmHg, the pressure in the hypotension zone is 51.0 mmHg, and the shear force is 1.1 dyn / cm. 2 0.37dyn / cm 2This device can simulate the vascular environment under normal / low blood pressure in the human body. Before culturing cells within the chip, a pressure platform was built to test the pressure in the culture channels to prevent excessive deviation between the actual pressure environment and the simulation results. First, all channels were sealed with PBS solution, and then distilled water was injected into two culture channels respectively. Subsequently, the pressure sensor was adjusted to atmospheric pressure and zeroed. After preparation, the microfluidic pump was adjusted to the specified speed, and the experimental phenomena were observed. The experiment showed that within 0-2 hours, the pressure in the channel gradually rose to a stable range and fluctuated, and this stable state could be maintained for more than 24 hours. Specifically, when the speed was 24 μL / min, the chip simulated the human body's high / normal blood pressure environment, with the pressure in the high blood pressure area fluctuating between 165 and 168 mmHg, and the pressure in the normal blood pressure area fluctuating between 89 and 91 mmHg, which was in line with expectations. When the speed was 13 μL / min, the chip simulated the human body's normal / low blood pressure environment, with the pressure in the normal blood pressure area fluctuating between 88 and 90 mmHg, and the pressure in the low blood pressure area fluctuating between 50 and 52 mmHg, which was close to the predicted values.

[0052] Figure 6 This image shows the experimental results of endothelial cell growth under simulated human blood pressure conditions within a chip. To ensure experimental effectiveness, red ink and distilled water were pre-flushed into the chip for testing. To ensure cell growth within the specified pressure region, the entire channel was pre-sealed with PBS solution. Subsequently, the first injection port 31 and the first inlet / outlet 34 were opened, and red ink was injected through the first injection port 31. Figure 6 As shown in (a), the red ink will remain within the cell dynamic culture module 3 and will not enter the solution mixing module 4. Similarly, by opening only the second injection port 35 and the second inlet / outlet 36, red ink is injected through the second injection port 35 to achieve a similar experimental effect and realize the experimental expectations. After the chip conditions and cell conditions meet the requirements, the centrifuged cells are prepared into 1×10⁻⁶ cells. 6 Cell suspension at a concentration of [number] cells / mL was slowly introduced into the chip. The chip was then placed in a CO2 incubator and allowed to stand for 2 to 4 hours until the cells adhered. After 18 hours of dynamic culture in perfused medium, [further details omitted]. Figure 6 As shown in (b), the cells are arranged in a pebble-like shape and are tightly attached to the cell dynamic culture module 3.

[0053] Figure 7 Simulation and experimental results of solution mixing in a vascular organ-on-a-chip were presented. To verify the effectiveness of the mixing channel, concentration mixing simulations of the dilute substance transport module were performed using COMSOL fluid simulation software. The flow rates at the two inlets were set to 20 and 40 μl / min, and the concentrations were 1 and 0 mol / m³, respectively. 3 This simulates the flow mixing effect of trypsin and culture medium. The mixing effect is improved by introducing a U-shaped bend to alter the fluid motion state. Figure 7The simulation results for solution -(a) show that the two solutions converge at the Y-shaped outlet, then flow in a laminar flow state within the channel, gradually mixing after passing through multiple U-shaped bends, eventually achieving a uniform solution concentration before flowing out. The simulation effect of the improved hourglass-shaped mixing channel is as follows: Figure 7 -(b) Two hourglass channels 431 were added to the mixing channel 43 between the two U-shaped channels 44, which increased the contact area between the two solutions and significantly improved the mixing effect. Figure 7 -(c) Records the concentration change of the solution as it flows through the mixing channel. It shows that in the U-shaped bend structure, the concentration changes significantly when the solution reaches the position x = 9500 μm, but remains close to 0.5 mol / m³. 3 The solution only became homogeneous at the x = 4500 μm position. After changing the straight channel to an hourglass channel 431, the solution concentration at the x = 9500 μm position was close to 0.35 mol / m. 3 Furthermore, the concentration curve stabilized after x = 9000 μm, indicating that hourglass channel 431 significantly improved the mixing effect. To verify the functionality of the mixing region, red ink and distilled water were passed through to observe the final mixing effect of the solution, as shown in the attached figure. Figure 7 As shown in (d), red ink represents the culture medium, and distilled water represents trypsin. The results show that the two solutions merge at the Y-shaped confluence, and due to the low Reynolds number and the presence of U-shaped channel 44 and hourglass channel 431, the solutions are thoroughly mixed before entering the measurement channel 51. The experiment demonstrates that the hourglass structure of mixing channel 43 has excellent mixing performance and can be used for mixing various solutions, playing a crucial role in the construction of integrated chips.

[0054] Figure 8 This is a simulation diagram of pressure and velocity in module 5 of the cellular mechanical properties measurement module for the vascular organ-on-a-chip. The cellular mechanical properties module of the integrated chip was imported into COMSOL for fluid dynamics (CFD) simulation. This module contains eight parallel measurement channels 51. Each channel 51 is subdivided into three regions for evaluating cell elasticity, resilience, and deformability. Figure 8 As shown in (a), taking the simulated human blood pressure environment under hypertension / normal blood pressure as an example, the cells in the first culture channel 31, i.e., the hypertension zone, enter the micro-constraint channel 512 containing four consecutive contraction points from the first transition channel 511, undergoing four consecutive deformation and recovery cycles. Simulation calculations show that... Figure 8 As shown in (b), the pressure difference across this region is 323 Pa, sufficient for cells to pass through. Subsequently, entering recovery channel 513, the cell gradually transforms from an elongated shape to a circular shape; this region provides sufficient channel length to aid in the cell's recovery. Finally, the cell passes through contraction channel 514. Simulation calculations show that... Figure 8As shown in (b), the pressure difference across this region is 557 Pa. The cells undergo compression and deformation, ultimately exiting through the second transition channel 514 and being collected in the waste storage pool. The order in which cells from the second culture channel 32 (the conventional blood pressure zone) flow through the cell mechanical properties measurement module 5 is the reverse of that of the cells from the hypertension zone. Figure 8 -(c) Figure 8 As shown in (d), the cell enters the contraction channel 514 with a pressure difference of 557 Pa from the second transition channel 515, and after compression and deformation, it enters the recovery channel 513. After recovery, it enters the four continuously deformable micro-constraint channels 512 with a pressure difference of 323 Pa, experiencing four consecutive deformation and recovery cycles. Finally, the cell leaves through the first transition channel 511 and is collected in the waste storage pool.

[0055] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A vascular organ-on-a-chip that simulates human blood pressure, characterized in that, include: substrate; A channel layer is disposed on the substrate, and a cell dynamic culture module, a solution mixing module and a cell mechanical property measurement module are disposed within the channel layer; The cell dynamic culture module includes a first culture channel and a second culture channel arranged opposite to each other. The first culture channel is connected to a first injection port upstream and a first inlet / outlet downstream. The second culture channel is connected to a second injection port upstream and a second inlet / outlet downstream. A serpentine channel connects the upstream of the first culture channel and the upstream of the second culture channel; The solution mixing module includes two solution mixing channels arranged opposite each other. One end of each solution mixing channel is connected to the downstream of the first culture channel and the downstream of the second culture channel, respectively. Each solution mixing channel includes multiple mixing channels arranged side by side and connected in series. The cell mechanical properties measurement module includes multiple measurement channels arranged side by side, with each measurement channel connected at both ends to the other end of the two solution mixing channels.

2. The vascular organ chip simulating human blood pressure according to claim 1, characterized in that, The width of the first culture channel is smaller than the width of the second culture channel.

3. A vascular organ chip simulating human blood pressure according to claim 2, characterized in that, The width of the first culture channel is 540-660 μm, the width of the second culture channel is 900-1100 μm, and the height of both the first and second culture channels is 135-165 μm.

4. A vascular organ chip simulating human blood pressure according to claim 1, characterized in that, The width of the serpentine channel is 40-50 μm.

5. A vascular organ chip simulating human blood pressure according to claim 1, characterized in that, The adjacent mixing channels are connected end-to-end by a U-shaped channel, and each mixing channel includes at least one hourglass channel.

6. A vascular organ chip simulating human blood pressure according to claim 1, characterized in that, The measurement channel includes a first transition channel, a micro-constraint channel, a recovery channel, a contraction channel, and a second transition channel that are connected in sequence. The first transition channel is connected to the other end of one of the solution mixing channels. The micro-constraint channel includes multiple micro-constraint segments, and a recovery segment is provided between two adjacent micro-constraint segments. The width of the contraction channel is smaller than the width of the recovery channel. The second transition channel is connected to the other end of the other solution mixing channel.

7. A vascular organ chip simulating human blood pressure according to claim 6, characterized in that, The width of the contraction channel is 5.4-6.6 μm and the height is 18-22 μm.

8. A vascular organ-on-a-chip simulating human blood pressure according to claim 6, characterized in that, The recovery channel includes a straight channel and two curved channels respectively connected to both ends of the straight channel, with the two curved channels arranged alternately.

9. A vascular organ-on-a-chip simulating human blood pressure according to claim 1, characterized in that, The channel layer is provided with a first outlet and a second outlet respectively. One end of the solution mixing channel and one end of the measurement channel are both connected to the first outlet, and the other end of the solution mixing channel and the other end of the measurement channel are both connected to the second outlet.

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