Biological ink spraying device

Abstract

The application discloses a kind of biological ink spraying devices, belong to medical instrument field, including shell, fluid input component, gas input piece, needle tube component and flow limiting block, shell is equipped with inner hole, fluid input component, gas input piece and needle tube component are all installed in shell, gas input piece is communicated with inner hole, needle tube component includes needle tube, needle tube is equipped with liquid flow channel, liquid flow channel is communicated with fluid input component, flow limiting block is installed in shell, flow limiting block is equipped with flow limiting portion, flow limiting block is equipped with through-hole, through-hole penetrates flow limiting portion, flow limiting portion is located in inner hole, needle tube tail end is located in through-hole, gas flow channel is formed between needle tube outer wall and through-hole inner wall, gas flow channel is communicated with inner hole, the cross-sectional area of gas flow channel is less than the cross-sectional area of inner hole, so that the gas input by gas input piece is accelerated to uniformly atomize the liquid output by needle tube.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a bio-ink spraying device. BACKGROUND

[0002] Large area skin wounds have now become a common clinical condition, which is often closely related to various emergencies or major chronic diseases, and has the characteristics of prolonged non-healing, seriously affecting the quality of life of patients, and more seriously, it may endanger life and cause huge social and economic losses at home and abroad. Cell spraying autologous transplantation is an innovative method for early treatment of large area deep second degree burn wounds, that is, using autologous epidermal derived cells (such as keratinocytes), the required number of cells only needs to come from a small donor site, after cell culture and passage or direct suspension in physiological saline or other biological materials, a bio-ink is prepared and uniformly sprayed on the wound, so that the cells proliferate and improve re-epithelialization. Compared with biological printing, this method has advantages in cost and can realize portable operation, especially in the early treatment of large area deep burn wounds, diabetic foot, skin ulcers and other chronic refractory wounds.

[0003] At present, there are some publicized atomizers or spraying systems based on the cell spraying autologous transplantation method. The publicized cell or drug spraying device (CN201711409096, CN202023309697, CN201810462736) adopts a piezoelectric printing nozzle, which is difficult to spray and print bio-ink with a viscosity greater than 6mPa·s, and under the intense oscillation of the ultrasonic transducer, the cell suspension has the risk of rapid heating, reducing the activity of the cells after spraying. The publicized cell suspension atomizer (CN202020240040) adopts a multi-mesh jet atomization method, which generally generates very large droplet sizes; in order to form an atomization effect, the driving hydraulic pressure of the cell suspension is very large, and the cell survival rate is relatively low, generally not higher than 80%; and it is difficult to atomize bio-ink with a viscosity greater than 6mPa·s. The publicized hydraulic cyclone atomization drug delivery device (CN202122889314, CN201910934672, CN201921645190) also has the defects of the above atomizers, and the activation rate of the cells after spraying is generally less than 80%, and it is difficult to achieve uniform spraying of high-viscosity bio-ink. SUMMARY

[0004] In order to overcome the deficiencies of the prior art, one of the purposes of the present application is to provide a bio-ink spraying device to improve the activity of cells after spraying, the cell differentiation efficiency and to realize the spraying of high-viscosity bio-ink.

[0005] One of the purposes of the present application is achieved by adopting the following technical solutions:

[0006] A bio-ink spraying device, comprising a housing, a fluid input assembly, a gas input, a needle tube assembly and a flow limiting block, the housing is provided with an inner hole, the fluid input assembly, the gas input and the needle tube assembly are all mounted on the housing, the gas input is communicated with the inner hole, the needle tube assembly comprises a needle tube, the needle tube is provided with a liquid flow channel, the liquid flow channel is communicated with the fluid input assembly, the flow limiting block is mounted on the housing, the flow limiting block is provided with a flow limiting part, the flow limiting block is provided with a through hole, the through hole penetrates through the flow limiting part, the flow limiting part is located in the inner hole, the needle tube tail end is located in the through hole, a gas flow channel is formed between the outer wall of the needle tube and the inner wall of the through hole, the gas flow channel is communicated with the inner hole, the cross-sectional area of the gas flow channel is smaller than that of the inner hole, so that the gas input by the gas input is accelerated to uniformly atomize the liquid output by the needle tube.

[0007] Further, the needle tube assembly is detachably mounted on the housing.

[0008] Further, the needle tube assembly comprises a positioning block and a needle tube, and the needle tube is fixedly connected with the positioning block.

[0009] Further, the needle tube is in interference fit with the positioning block.

[0010] Further, the positioning block comprises a body and a flange extending from the body, the housing comprises a first mounting part and a main body, the first mounting part is detachably connected with the main body, the positioning block extends into the main body, and the first mounting part abuts against the flange so that the positioning block is detachably mounted on the housing.

[0011] Further, the fluid input assembly comprises an input connector and an input tube mounted on the input connector, the input connector extends into the positioning block and is in threaded connection with the positioning block.

[0012] Further, the bio-ink spraying device further comprises a compression block, the compression block comprises a plug-in part and a compression part, the tail end of the input tube extends into the compression block, the plug-in part is located between the outer wall of the input tube and the inner wall of the input connector, the compression part abuts against the input connector and the positioning block, and the compression block enables the input tube to be in sealed connection with the needle tube.

[0013] Further, the flow limiting block is detachably mounted on the housing.

[0014] Further, the housing comprises a main body and a second mounting part, the second mounting part is detachably mounted on the main body, the flow limiting block is further provided with a base, the flow limiting part extends from the base, and the base comprises an abutting part, the abutting part abuts against the second mounting part so that the flow limiting block is mounted on the housing.

[0015] Further, the base is provided with a bottom end face, the needle tube is provided with a terminal end face, the second mounting portion is threadedly connected with the main body to adjust the distance between the terminal end face and the bottom end face.

[0016] Compared with the prior art, the bio-ink spraying device has the following advantages:

[0017] (1) The cross-sectional area of the gas flow channel is smaller than that of the inner hole, so that the gas input by the gas input member accelerates the uniform atomization of the liquid output by the needle tube. Through the above design, high-viscosity bio-ink can be uniformly sprayed;

[0018] (2) The needle tube assembly is detachably mounted in the housing, and when spraying bio-ink with different viscosities, the needle tube assembly can be conveniently replaced to correspond to needle tubes with different diameters;

[0019] (3) The flow limiting block is detachably mounted in the housing, and when spraying bio-ink with different viscosities, the flow limiting block can be conveniently replaced to adjust the cross-sectional area of the gas flow channel, so that the speed of gas ejection can be adjusted. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a perspective view of the bio-ink spraying device of the present application;

[0021] Figure 2 It is an exploded view of the bio-ink spraying device of the present application; Figure 1

[0022] It is a perspective view of the needle tube assembly of the bio-ink spraying device of the present application; Figure 3 Figure 2 It is a sectional view of the bio-ink spraying device of the present application;

[0023] Figure 4 Figure 1 It is an enlarged view of position A of the bio-ink spraying device of the present application;

[0024] Figure 5 It is an enlarged view of position B of the bio-ink spraying device of the present application; Figure 4

[0025] Figure 6 Figure 4

[0026] Figure 7(a) is a single-frame spray cone angle image during the spraying process of the bio-ink spraying device of the present application;

[0027] Figure 7(b) is a superimposed image of a large number of frames of the spray cone angle;

[0028] Figure 7(c) is an image after binarization of the spray angle image in Figure 7(b);

[0029] ​​​​​Figure 7(d) is a plot of the near-field cone angle θ1and the far-field cone angle θ2of the boundary in Figure 7(c) after least square fitting;

[0030] Figure 8 Figure 8 is a plot of the variation of θ1for different spray targets;

[0031] Figure 9 Figure 9 is a plot of the variation of θ2for different spray targets;

[0032] Figure 10(a) is a plot of the spray pattern of the bio-ink spray device for 1% (w / v) SA solution at an auxiliary air flow of 1.0 L / min;

[0033] Figure 10(b) is a plot of the spray pattern of the bio-ink spray device for 1% (w / v) SA solution at an auxiliary air flow of 1.5 L / min;

[0034] Figure 10(c) is a plot of the spray pattern of the bio-ink spray device for 1% (w / v) SA solution at an auxiliary air flow of 2.0 L / min;

[0035] Figure 10(d) is a plot of the spray pattern of the bio-ink spray device for 1% (w / v) SA solution at an auxiliary air flow of 5.0 L / min;

[0036] Figure 11 Figure 11 is a plot of the variation of the spray area of the bio-ink spray device of the present application at different spray heights;

[0037] Figure 12(a) is a plot of the spray pattern of the bio-ink spray device for a quantitative spray of 100 μL;

[0038] Figure 12(b) is a plot of the spray pattern of the bio-ink spray device for a quantitative spray of 500 μL;

[0039] Figure 12(c) is a plot of the droplet distribution of the viscous solution extruded using a 1 mL syringe needle;

[0040] Figure 13(a) is a plot of the effect of the bio-ink spray device for spraying 1 mL of 1% (w / v) SA on pig skin;

[0041] Figure 13(b) is a plot of the effect of the bio-ink spray device for spraying 2 mL of 1% (w / v) SA on pig skin;

[0042] Figure 13(c) is a plot of the effect of the bio-ink spray device for spraying 1 mL of normal saline on pig skin;

[0043] Figure 13(d) is a plot of the effect of the bio-ink spray device for spraying 2 mL of normal saline on pig skin;

[0044] Figure 14(a) is a plot of the effect of the bio-ink spray device for spraying 1 mL of 1% (w / v) SA on pig skin at a cell density of about 105 cells / mL solution after 4 hours of bio-ink jetting and 3D scanning and stitching of images;

[0045] Figure 14(b) is a 3D image of a solution with a cell density of about 10 5 cells / mL solution after 24 hours of bio-ink jetting and 3D scanning and stitching of images.

[0046] In the figure: 10, housing; 11, first mounting portion; 12, main body; 13, second mounting portion; 14, inner hole; 20, fluid input assembly; 21, input joint; 22, input pipe; 221, fluid input port; 30, pressing block; 31, plug-in portion; 32, pressing portion; 40, first sealing ring; 50, gas input piece; 60, needle tube assembly; 61, positioning block; 610, body; 611, flange; 612, positioning portion; 62, needle tube; 620, liquid flow channel; 621, end face; 70, flow limiting block; 71, flow limiting portion; 72, base; 720, bottom end face; 721, abutting portion; 73, through hole; 80, second sealing ring; 90, gas flow channel. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0048] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or can be present with another intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or can be present with another intervening element. When an element is referred to as being "disposed" on another element, it can be directly disposed on the other element or can be present with another intervening element. The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are for illustrative purposes only.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0050] As Figures 1 to 6The bio-ink spraying device of the present application is used for uniformly spraying high-viscosity bio-ink (cells or drugs).

[0051] The bio-ink spraying device comprises a housing 10, a fluid input assembly 20, a pressing block 30, a first sealing ring 40, a gas input piece 50, a needle tube assembly 60, a flow limiting block 70 and a second sealing ring 80.

[0052] The housing 10 comprises a first mounting part 11, a main body 12 and a second mounting part 13. The first mounting part 11 and the second mounting part 13 are respectively detachably mounted at both ends of the main body 12. The first mounting part 11 is provided with internal threads, the main body 12 is provided with external threads at both ends, and the second mounting part 13 is provided with internal threads. The first mounting part 11 is threadedly mounted at the upper end of the main body 12, and the second mounting part 13 is threadedly mounted at the lower end of the main body 12.

[0053] The fluid input assembly 20 comprises an input connector 21 and an input tube 22. The input connector 21 is provided with external threads, and the input tube 22 partially extends into the input connector 21 and is provided with a fluid input port 221.

[0054] The pressing block 30 comprises a plug-in part 31 and a pressing part 32, and the plug-in part 31 extends from the pressing part 32. The pressing block 30 is provided with a mounting hole which penetrates through the plug-in part 31 and the pressing part 32. The plug-in part 31 and the pressing part 32 are cylindrical, and the diameter of the plug-in part 31 is greater than that of the pressing part 32. The pressing part 32 is flat at the end away from the plug-in part 31.

[0055] The first sealing ring 40 is an annular sealing ring.

[0056] The gas input piece 50 is used for inputting gas into the housing 10.

[0057] The needle tube assembly 60 comprises a positioning block 61 and a needle tube 62. The positioning block 61 comprises a body 610, a flange 611 and a positioning part 612. The body 610 is cylindrical and hollow, and the inner wall of the body 610 is provided with internal threads. The flange 611 extends from the outer wall of the body 610 and is annular, and the flange 611 is used for fixing the positioning block 61. The positioning part 612 extends from the bottom of the body 610. The needle tube 62 is hollow and forms a liquid flow channel 620 inside. The end of the needle tube 62 is in interference fit with the positioning part 612, so that the needle tube 62 is fixed to the positioning block 61, and the positioning block 61 and the needle tube 62 form an integrated structure. When the bio-ink spraying device is used for different viscosity bio-ink, the needle tube assembly 60 can be conveniently replaced as a whole, and is suitable for different viscosity bio-ink. The end of the needle tube 62 is provided with an end face 621. The inner diameter of the needle tube 62 is 0.1-0.5 mm, the outer diameter is 1.5-2 times the inner diameter, and the length is 5-30 mm.

[0058] The flow limiting block 70 comprises a flow limiting part 71 and a base 72. The flow limiting part 71 extends from the base 72. The flow limiting block 70 is provided with a through hole 73 which penetrates the flow limiting part 71 and the base 72. The needle tube 62 extends into the through hole 73, and a gas flow channel 90 is formed between the outer wall of the needle tube 62 and the inner wall of the through hole 73. The needle tube 62 is coaxially arranged in the through hole of the flow limiting block 70, and the coaxiality is within the range of -0.05 to +0.05 mm. The outer diameter of the needle tube 62 is smaller than the inner diameter of the flow limiting block 70 by 0.2-1.0 mm. The end face 621 of the needle tube 62 does not exceed the bottom end face 720 of the flow limiting block 70, and the distance between them is limited to -0.5 to 0.5 mm. By adjusting the diameter of the through hole 73, the cross-sectional area of the gas flow channel 90 can be changed, so that the flow rate of the gas changes. The base 72 comprises a bottom end face 720 and a contact part 721. The contact part 721 is in contact with the second mounting part 13, so that the flow limiting block 70 is mounted on the shell 10.

[0059] During assembly of the bio-ink spraying device, the pressing block 30 is located in the positioning block 61 of the needle tube assembly 60, and the input pipe 22 partially extends into the input joint 21. The input joint 21 is threadedly connected with the positioning block 61. During the connection process, the input joint 21 is in contact with the pressing block 30, so that the input pipe 22 is in communication with the needle tube 62 and sealing is achieved. The first sealing ring 40 is sleeved on the positioning part 612 of the positioning block 61. The needle tube assembly 60 is placed in the main body 12, and the first mounting part 11 is threadedly connected with the main body 12. The flange 611 is clamped between the top of the main body 12 and the first mounting part 11, so that the needle tube assembly 60 is fixed on the shell 10. The gas input part 50 is mounted on the main body 12. The extension direction of the gas input part 50 is perpendicular to the extension direction of the main body 12. The second sealing ring 80 is sleeved on the end of the flow limiting part 71. The flow limiting part 71 of the flow limiting block 70 extends into the main body 12, and the gas flow channel 90 is formed between the outer wall of the needle tube 62 and the inner wall of the through hole 73. The second mounting part 13 is threadedly mounted on the end of the main body 12, so that the flow limiting block 70 is mounted on the shell 10. The input flow rate of the bio-ink of the spraying device is related to the viscosity coefficient of the bio-ink or the inner diameter of the needle tube 62, and can be selected to be 1-20 mL / min. The auxiliary air input flow rate of the spraying device is related to the inner diameter of the flow limiting block 70 or the viscosity coefficient of the bio-ink, and can be selected to be 1-10 L / min. The input flow rate of the bio-ink of the spraying device and the auxiliary air input flow rate are adjusted by setting the input flow rate of the bio-ink of the spraying device or the auxiliary air input flow rate parameter, so that bio-ink with different viscosities can be uniformly sprayed. The viscosity coefficient of the sprayed bio-ink is preferably 1-300 mPa·s.

[0060] When the bio-ink spraying device is used, the bio-ink is input from the fluid input port 221, enters the needle tube 62 through the input pipe 22, the gas enters from the gas input part 50, enters the gas flow channel 90 inside the main body 12, and the cross-sectional area of the gas flow channel 90 is much smaller than the cross-sectional area inside the main body 12, so that the gas flow rate is accelerated, the bio-ink sprayed from the needle tube 62 is atomized by the gas spray, uniform spraying is realized, and the activity of the cells after spraying and the cell differentiation efficiency are not affected. The spraying height of the bottom surface of the spraying device from the spraying surface is controlled to be 1-200 mm, preferably 5-100 mm. The input flow rate of the bio-ink of the spraying device, the spraying height, and the spraying area of the fixed-point spraying are controlled by setting the input flow rate of the bio-ink of the spraying device or the spraying height, wherein the spraying area of the fixed-point spraying is preferably 100-1500 mm 2 .

[0061] In the present application, the needle tube assembly 60 can be detachably installed in the shell, when spraying bio-ink with different viscosities, the needle tube assembly 60 can be conveniently replaced to correspond to needle tubes 62 with different diameters; the flow limiting block 70 can be detachably installed in the shell 10, when spraying bio-ink with different viscosities, the flow limiting block 70 can be conveniently replaced to adjust the cross-sectional area of the gas flow channel 90, so that the speed of the gas spray can be adjusted.

[0062] The use of the bio-ink spraying device will be described in detail below with different embodiments:

[0063] Example 1

[0064] During the spraying process of the bio-ink, within a certain spraying height range, the droplets are distributed in a conical shape in space, and the opening angle of the cone directly affects the spraying area. To evaluate the spraying area of the spraying device, the spraying process was photographed by a camera, and the spraying cone angle of the photographed spraying image was calculated in MATLAB software. A single frame image has a low signal-to-noise ratio and inaccurate boundaries, as shown in FIG. 7(a). The superimposed image of a large number of frames (7(b)) significantly improves the image signal-to-noise ratio. The image in FIG. 7(c) is obtained by binarizing the jet angle image shown in FIG. 7(b) using a local adaptive threshold segmentation method (LATSM). The boundaries in FIG. 7(c) are fitted using the least squares method to calculate the near-field cone angle θ1 and the far-field cone angle θ2 (FIG. 7(d)), respectively. The spraying objects are physiological saline, 0.4% (w / v), 0.6% (w / v), 0.8% (w / v), and 1% (w / v) sodium alginate (SA) solutions, respectively, and the viscosities of these spraying objects are tested by a viscometer, and the results are as follows: Figure 9

[0065]

[0066] ​The inner diameter of the needle 62 in the spraying device is set to 0.2–0.3 mm, the outer diameter to 0.4–0.8 mm, and the length to 5–20 mm. The inner diameter of the flow-limiting block 70 is set to 0.8–1.2 mm. The distance between the end face 621 of the needle 62 and the bottom face 72 of the flow-limiting block 70 is -0.2–0.2 mm. Auxiliary airflow Q A The flow rate Q of the object being sprayed should be controlled between 1 and 5 L / min. L When the spray rate was kept constant at 3 mL / min, the measured values ​​of θ1 and θ2 for different sprayed objects were as follows: Figure 8 and Figure 9 As shown. The spraying area of ​​the fixed-point spraying device can be further evaluated using formula (1):

[0067]

[0068] Where: h N h is the height of the breakpoint of the least squares fitted straight line from the outlet of the spraying device. F The height of the surface to be sprayed from the outlet of the spraying device.

[0069] Taking a 1% (w / v) SA coating target as an example, when the Q of the spraying device... L Control the flow rate at 2–4 mL / min, Q A The spraying conditions were as follows when the flow rates were set to 1.0, 1.5, 2.0, and 5.0 L / min respectively. Figure 10(a) , 10(b) As shown in Figures 10(c) and 10(d) (scale bar is 10mm); when the Q of the spraying device... A Controlled at 2-4 L / min, Q L When the spray rate is controlled between 0.2 and 4 mL / min, the spray area at different spray heights is as follows: Figure 11 As shown, H1, H2, H3, and H4 represent spraying heights of 25, 50, 75, and 100 mm, respectively. It is easy to see that the designed spraying device, under suitable spraying parameters, can achieve spraying heights ranging from 100 to 1200 mm. 2 The area of ​​the fixed-point spraying.

[0070] Example 2

[0071] To illustrate the spraying performance of the spraying equipment, 1% (w / v) SA was used as the spraying target, Q A Controlled at 2-3 L / min, Q LThe control was at 2-3 mL / min, the spraying height was set at 50-100 mm, and the spraying device was used to quantitatively spray 100 and 500 μL, respectively. The spraying states are shown in FIG. 12(a) and FIG. 12(b), respectively, in which the scale is 10 mm. In FIG. 12(c), the droplet distribution of the viscous solution extruded by a 1 mL syringe needle was used. Compared with the droplets extruded by the syringe, the size and distribution of the droplets sprayed by the spraying device were more uniform. When the capacity of the spraying device was 500 μL, the droplets could uniformly cover a certain area of the spraying surface.

[0072] Further, a certain area of pigskin was fixed on a plane with an angle of 45°, and then 1 mL and 2 mL of 1% (w / v) SA (FIG. 13(a) and FIG. 13(b)) and physiological saline (FIG. 13(c) and FIG. 13(d)) were sprayed on the pigskin by the spraying device. It can be seen that the droplets of the viscous SA solution can be more uniformly maintained on the surface of the pigskin than the physiological saline, and the droplets of the physiological saline have a very serious runoff problem.

[0073] Example Three

[0074] In order to further illustrate the spraying performance of the spraying device on the viscous bio-ink, a certain amount of human immortalized epidermal cells (HaCaT, China, COBIO-ER) was added to the 1% (w / v) SA solution prepared by using physiological saline to prepare a bio-ink with a cell density of about 10 5 cells / mL, and the bio-ink was used as the spraying object. A The control was at 2-3 L / min, L The control was at 2-3 mL / min, and the spraying height was set at 50-100 mm. The structure of the spraying device was the same as that in Example One. After the bio-ink was sprayed for 4 hours and 24 hours by using the spraying device, the samples after spraying were dyed by using a Calcein AM / PI kit (ref. C2015L, Beyotime Biotechnology, China), three-dimensional scanning imaging was performed by using a laser confocal microscope, and then 3D images were spliced by using Imaris software. It can be seen that, under the condition of using 1% (w / v) SA viscous solution as the carrier, the cells were in three-dimensional distribution within 4 hours of spraying (as shown in FIG. 14(a)), and after 24 hours of spraying, the cells all sank to the bottom of the container (as shown in FIG. 14(b)). It was observed that the cell suspension with physiological saline as the carrier generally sank to the bottom within half an hour. This also shows that the spraying device can avoid the problem of uneven spraying of cells caused by sinking of cells with low viscosity carriers within a short time in the process of spraying, printing or drug delivery.

[0075] The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but cannot be understood as the limitation of the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are equivalent modifications and evolutions of the above embodiments according to the essential technology of the present application, and these all belong to the protection scope of the present application.

Claims

1. A bio-ink spraying device, comprising a housing, characterized in that: The bio-ink spraying device further includes a fluid input component, a gas input component, a needle assembly, and a flow restrictor. The housing has an inner hole. The fluid input component, the gas input component, and the needle assembly are all mounted on the housing. The gas input component communicates with the inner hole. The needle assembly includes a needle tube with a hollow structure to form a liquid flow channel. The inner diameter of the needle tube is 0.1 to 0.5 mm. The needle tube has an outer diameter that is 1.5 to 2 times its inner diameter. The liquid flow channel is connected to the fluid input component. The flow limiting block is detachably installed on the housing. The flow limiting block has a flow limiting part and a through hole that penetrates the flow limiting part. The flow limiting part is located in the inner hole. The end of the needle tube is located in the through hole. The needle tube and the through hole of the flow limiting block are coaxially arranged. The outer diameter of the needle tube is 0.2 to 1.0 mm smaller than the inner diameter of the flow limiting block. A gas flow channel is formed between the outer wall of the needle tube and the inner wall of the through hole. The gas flow channel is connected to the inner hole. The cross-sectional area of ​​the gas flow channel is smaller than the cross-sectional area of ​​the inner hole, which accelerates the gas input by the gas input component and uniformly atomizes the liquid output by the needle tube.

2. The bio-ink spraying device according to claim 1, characterized in that: The needle assembly is detachably mounted to the housing.

3. The bio-ink spraying device according to claim 2, characterized in that: The needle assembly includes a positioning block and a needle tube, with the needle tube fixedly engaged with the positioning block.

4. The bio-ink spraying device according to claim 3, characterized in that: The needle tube is interference-fitted with the positioning block.

5. The bio-ink spraying device according to claim 3, characterized in that: The positioning block includes a body and a flange extending from the body. The housing includes a first mounting part and a main body. The first mounting part is detachably connected to the main body. The positioning block extends into the main body. The first mounting part abuts against the flange so that the positioning block is detachably mounted on the housing.

6. The bio-ink spraying device according to claim 5, characterized in that: The fluid input assembly includes an input connector and an input pipe installed on the input connector, the input connector extending into the positioning block and being threadedly connected to the positioning block.

7. The bio-ink spraying device according to claim 6, characterized in that: The bio-ink spraying device further includes a clamping block, which includes a plug and a clamping part. The end of the input tube extends into the clamping block. The plug is located between the outer wall of the input tube and the inner wall of the input connector. The clamping part abuts against the input connector and the positioning block. The clamping block seals the input tube with the needle tube.

8. The bio-ink spraying device according to claim 1, characterized in that: The housing includes a main body and a second mounting part, the second mounting part being detachably mounted on the main body. The current limiting block also has a base, the current limiting part extending from the base, the base including an abutting part, the abutting part abutting against the second mounting part to mount the current limiting block on the housing.

9. The bio-ink spraying device according to claim 8, characterized in that: The base has a bottom end face, the needle tube has an end face, and the second mounting part is threadedly connected to the main body to adjust the distance between the end face and the bottom end face.

Images