Sterile preparation and injection device of autologous red blood cell drug-loaded blood gel

Abstract

The application relates to the technical field of orthopedic repair material preparation, and discloses a sterile preparation and injection device for autologous red blood cell drug-loaded blood gel, which comprises a cross bolt mixer, a multimodal injector combined with a composite syringe and a mixing flow channel, the cross bolt is internally integrated with a microfluidic mixing channel, a vertical shaft direction and a coronal shaft direction are respectively connected with a main injector and a drug-loaded injector, when the red blood cell-rich plasma enters the bolt, longitudinal shear force is generated through a spiral flow channel, so that bone morphogenetic protein suspension is vertically injected into a main flow channel through a one-way valve structure, equal ratio mixing of 4:1 is realized in the spiral channel, and the whole mixing process is completed in a closed system. The device has the advantages of realizing accurate and uniform mixing of the red blood cell-rich plasma and the drug in a sterile environment, reducing the risk of bacterial contamination, being capable of directly injecting and filling bone defects for the prepared blood gel, being excellent in biological safety and compatibility, and being low in preparation cost and simple in process.

Description

Technical Field

[0001] This invention relates to the field of orthopedic repair material preparation technology, specifically to a blood product processing and administration device, and in particular to a sterile preparation and injection device for autologous red blood cell drug-loaded blood gel. Background Technology

[0002] Bone defects are large-volume bone loss caused by trauma or surgery, leading to various complications such as nonunion, delayed healing, nonunion, and local functional impairment. The availability of bone-filling materials to fill these defects is a critical clinical need. Currently, bone-filling materials are mainly divided into natural and synthetic materials. Natural bone-filling materials include autologous bone grafts and allogeneic bone grafts. Autologous bone grafts require the removal of the patient's own bone tissue, such as the hip bone, limiting donor availability and causing significant trauma, thus restricting their application. Allogeneic bone grafts are taken from other people's bone tissue, posing risks such as immune rejection and pathogen transmission. The current clinical trend is to gradually replace natural bone-filling materials with synthetic materials. However, synthetic materials still have many shortcomings. Synthetic materials, such as metals, bioceramics, and bone cement, are all inorganic materials with poor biocompatibility. Implanting a foreign body can easily trigger immune rejection. Furthermore, synthetic materials can only passively fill bone defects and do not have the bone fusion-promoting effects similar to natural materials.

[0003] In response to the aforementioned technical challenges, autologous red blood cell-derived drug-loaded gel delivery systems have gained increasing attention in recent years. These autologous red blood cell gels, while possessing the ability to fill bone defects and promote bone repair, can also carry active drugs such as bone morphogenetic proteins, forming a gel delivery system with both filling and therapeutic functions. However, in existing blood gel preparation methods, the mixing process of red blood cell-rich plasma and drugs often employs open operations, making it difficult to achieve strictly aseptic conditions. Furthermore, manual mixing makes it difficult to ensure the uniform distribution of the drug within the gel, directly affecting the sustained-release effect and osteogenic activity of the drug-loaded gel. Therefore, there is an urgent need for a specialized instrument capable of precisely mixing autologous red blood cell gel and drugs in a closed, aseptic environment to address the contamination risks and uneven mixing problems inherent in existing preparation processes. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a novel blood gel preparation device that facilitates aseptic operation. After loading erythrocyte-rich plasma and drug, the device is dried internally under a vacuum at 37°C to form a blood gel, thereby reducing exposure to the environment. Simultaneously, it simplifies subsequent surgical implantation procedures. After debridement and fixation, the extensibility of the blood gel allows for direct injection, achieving complete filling of bone defect areas.

[0005] (a) The technical solution of the present invention.

[0006] Preferably, the multimodal syringe combining the composite syringe and the mixing channel has a total syringe capacity of 30ml and 5ml, respectively. The basic shape of the flow channel is a spiral surface, and the threads are made to connect with the needle hole surface after the surface is thickened. Blood is gradient centrifuged under aseptic conditions to obtain red blood cell-rich plasma, which is then mixed with a procoagulant component consisting of chitosan, thromboplastin, coagulation factor VIII, prothrombin complex, and human fibrinogen before being drawn into the syringe.

[0007] Preferably, 20 ml of erythrocyte-rich plasma and 5 ml of a mixture of procoagulant components and bone morphogenetic protein 2 are drawn separately and then pushed through a syringe at 25-45°C. The piston is pushed and pulled to allow the mixture to react in the flow channel of the cross bolt for 2-15 minutes.

[0008] Preferably, the cross bolt integrates a microfluidic mixing channel, with the main injector connected to the vertical axis and the drug-loaded injector to the coronal axis, respectively. When erythrocyte-rich plasma enters the bolt, longitudinal shear force is generated through the spiral channel, causing the bone morphogenetic protein suspension to be vertically injected into the main channel via a one-way valve structure. The bone morphogenetic protein suspension does not directly contact the gel upon entry but instead enters the opposing channels, achieving a 4:1 ratio of mixing within the spiral channel. The spiral channel incorporates a mixing enhancement structure, inducing secondary flow and repeated diversion to achieve uniform mixing. The entire mixing process is completed within a closed system, effectively reducing the risk of bacterial contamination.

[0009] (ii) Application method of the present invention.

[0010] A. Based on the patient's hemodynamic examination, after routine skin disinfection, blood is drawn by puncturing with a lancet. After blood appears in the tubing, the lancet is connected to the blood collection tube or syringe in the red blood cell-rich gel preparation kit of this invention. The amount of whole blood drawn is typically 8–50 ml, with 30 ml being commonly used, depending on the required red blood cell count and enrichment.

[0011] B. After collection, gently invert the blood collection tube several times to ensure the anticoagulant is thoroughly mixed with the blood and to prevent clotting. It is recommended that the ratio of anticoagulant volume to blood volume be 1:9 or 1:10. After mixing the blood and anticoagulant, take an appropriate amount (0.1 ml) of the mixed blood to determine the number of red blood cells, which will be used for comparison and monitoring in subsequent procedures.

[0012] C. Erythrocyte-rich plasma (ERCP) is prepared using density gradient centrifugation (DFC), where the erythrocyte sedimentation coefficient (ESC) is 1.096. The high-speed rotation of the centrifuge rotor via a coupling generates a relative centrifugal force (RCF) that effectively separates blood components with different ESCs from whole blood. In the two-stage centrifugation method, the relative centrifugal force (RCF) is 200g for the first centrifugation (5–10 min), and 400–700g for the second centrifugation (10 min). The high shear stress generated by the higher RCF may lead to excessive erythrocyte destruction, reducing the release of bioactive molecules such as TGF-β and VEGF from the ERCP.

[0013] D. Using the blood gel syringe described in this invention, draw 20 ml of quantitative erythrocyte-rich plasma, and gently invert it several times to ensure that the erythrocyte-rich plasma is in full contact with the adsorption rod.

[0014] E. Under sterile conditions, take 5 ml of the mixture of coagulation-promoting component and bone morphogenetic protein 2, and push it with a syringe at 25-45℃ to fully mix it with the 20 ml of plasma prepared in step D. Push and pull the piston to make it react in the flow channel of the cross bolt for 2-15 minutes. When the red blood cell-rich plasma enters the bolt, it is subjected to longitudinal shear force when it crosses the middle section of the annular pipe, causing the bone morphogenetic protein suspension in the lower cylinder to enter the opposite flow channel, achieving a fine mixing of equal proportion of 4:1.

[0015] F. After the coagulant and drug delivery system are completely mixed, push the 5ml syringe below to the maximum volume, then retract the blood gel adsorption syringe plunger. After retracting completely, separate the lower cross bolt structure from the blood gel syringe. Seal the syringe and place it in a vacuum dryer for gentle drying at 25-50℃. This step must be carried out in a completely sterile environment to avoid bacterial growth that could contaminate the blood gel.

[0016] G. After completing the required amount of filling material for one decompression procedure, collect 1 ml and store it at 22°C with shaking. Record the specific amount used during implantation. The FDA limits the storage time of erythrocyte-rich plasma to 5 days. However, after 120 minutes of preparation of the erythrocyte-rich blood gel described in this invention, the porosity of the erythrocytes significantly decreases; therefore, long-term storage is not recommended for use. If multiple bone tissue filling is required, simply increase the blood collection volume in step A and repeat steps D to F.

[0017] (III) The beneficial effects of the present invention.

[0018] (1) This invention adds a safer and more efficient new cross-linking coagulant to erythrocyte-rich plasma, enabling it to form a blood clot gel in vitro with mechanical strength, viscoelasticity, stability and durability that meet the requirements of bone filling materials. Compared with traditional preparation methods, the preparation cost is lower and the process is simpler.

[0019] (2) The present invention improves the preparation process of blood gel, the reaction conditions are mild, and the ratio of coagulant to plasma can be finely adjusted through the cross bolt structure, so that the performance of the prepared improved blood gel is controllable and adjustable. At the same time, by sealing the reaction system, the probability of potential bacterial contamination during the preparation process is significantly reduced, the risk of material implantation is reduced, and the biosafety and biocompatibility are better.

[0020] (3) The blood gel syringe of the present invention utilizes the good extensibility of blood gel, so that in addition to the traditional method of direct implantation into the bone defect area, it can also be directly injected after fixing the bone defect area to achieve complete filling of the defect area. This further expands the scope of application of blood gel, making it suitable for use as wound dressing and vaccine. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the method of using the autologous red blood cell gel preparation device of the present invention.

[0023] Figure 2 This is a cross-sectional view of the internal flow channel structure of the cross bolt mixer described in this invention.

[0024] Figure 3 This is a cross-sectional structural diagram of the cross bolt mixer described in this invention.

[0025] Figure 4 This is a schematic diagram of the overall structure of the cross bolt mixer described in this invention.

[0026] In the diagram: 100, Phillips head bolt; 110, first port; 111, Luer connector at the first port; 120, second port; 121, Luer connector at the second port; 130, third port; 131, Luer connector at the third port; 140, fourth port; 141, sealing cap at the fourth port; 200, main flow channel; 210, inlet section; 211, flow channel cross-section; 220, flow restriction section of the main flow channel; 230, spiral section. ; 240, Outlet section; 300, Branch channel; 310, Microporous plate section; 311, Microporous plate; 320, One-way valve structure; 321, Valve blade; 322, Limiting stent; 330, Branch channel flow limiting section; 340, Branch channel outlet section; 400, Mixing enhancement unit; 410, First mixing unit; 411, V-groove; 420, Second mixing unit; 421, Diverting column; 430, Third mixing unit. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use, are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] Furthermore, the use of terms such as "horizontal," "vertical," and "sag" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Example 1: Preparation of drug-loaded erythrocyte gel.

[0034] This embodiment details the specific process of using the cross-bolt mixer structure of the present invention to prepare drug-loaded erythrocyte gel.

[0035] First, such as Figure 2 As shown, a cross bolt 100 is prepared. This cross bolt has a cross-shaped four-way structure and is integrally injection molded from medical-grade PEEK material. Its four ports are as follows: the first port 110 is located on the left side and is used to connect to a 30ml main syringe containing red blood cell-rich plasma (PRP); the second port 120 is located on the right side and is used to connect to a blood gel collection syringe; the third port 130 is located on the lower side and is used to connect to a 5ml drug-loaded syringe containing a mixture containing bone morphogenetic protein 2 and procoagulant components; the fourth port 140 is located on the upper side and is a closed detection port, with a Luer connector sealing cap 141 at its end. Each port end is equipped with standard Luer connectors 111, 121, 131, and 141 for quick sealing connection.

[0036] The cross bolt has a main channel 200 and a branch channel 300 inside. The main channel 200 passes through the first port 110 and the second port 120, and its specific structure is as follows. Figure 2 , Figure 3 As shown: the inlet section 210 connects to the first port 110, with a gradually narrowing inner diameter to accelerate the fluid; the main flow channel limiting section 220 is located after the inlet section, with the flow channel cross-section reduced to 400μm×300μm, used to control the PRP flow rate; the spiral section 230 is located in the center of the cross bolt, with a 3-5 turn spiral rising structure, and the flow channel cross-section 211 is a rectangle with a width of 600μm and a depth of 400μm; the outlet section 240 connects to the second port 120, with a gradually widening inner diameter to facilitate gel outflow.

[0037] The tributary channel 300 connects the third port 130 to the middle section of the spiral segment 230 of the main channel, including: a microporous plate segment 310, which contains microporous plates 311 with micropore diameters of 200 μm, arranged in a 4×3 matrix, used to disperse the BMP-2 suspension into microjet streams; a one-way valve structure 320 located at the junction of the tributary channel and the main channel, consisting of two crescent-shaped silicone valve leaflets 321 and a limiting support 322, which is normally closed; a flow-limiting section 330 of the tributary channel located after the one-way valve, with the flow channel cross-section reduced to 300 μm × 300 μm, which, together with the microporous plate segment, controls the BMP-2 flow rate; and a tributary channel outlet segment 340 connecting the spiral segment 230 of the main channel to the fourth port 140, with an inner diameter of 1 mm, used for sampling and detection or venting.

[0038] The spiral section 230 is further provided with a mixing enhancement unit 400, including: a first mixing unit 410, located in the inlet region of the spiral section, with a V-shaped groove array on the inner wall of the flow channel, the grooves being 50 μm deep and spaced at 100 μm intervals; a second mixing unit 420, located downstream of the confluence of the branch channels, with an array of staggered flow-dividing columns 421 in the flow channel, the diameter of which is 100 μm and the height of which is 200 μm; and a third mixing unit 430, located in the outlet region of the spiral section, the flow channel exhibiting a wave-like undulation with an amplitude of 200 μm and a period of 1 mm.

[0039] During preparation, a 30ml syringe containing 20ml of PRP is connected to the first port 110, a 5ml syringe containing 5ml of BMP-2 suspension is connected to the third port 130, and a collection syringe is connected to the second port 120. Both syringes are injected simultaneously. The PRP is accelerated through the inlet section 210 and enters the spiral section 230; the BMP-2 suspension is dispersed into a fine jet through the microporous plate section 310, and under the shear force generated by the PRP flow, it pushes open the one-way valve leaflet 321 and is vertically injected into the main channel. The two fluids generate secondary flow under centrifugal force within the spiral section 230, and sequentially pass through the V-shaped grooves of the first mixing unit 410 to induce secondary flow, the flow-splitting columns of the second mixing unit 420 to force repeated flow splitting and merging, and the wavy undulations of the third mixing unit 430 to extend the mixing path, ultimately achieving molecular-level uniform mixing. The mixed fluid enters the collection syringe through the outlet section 240 and is allowed to stand at 37°C to crosslink and form a drug-loaded blood gel.

[0040] According to Hagen-Poiseuille's law, by optimizing the dimensions of the main flow restrictor section 220 and the tributary flow restrictor section 330, a precise flow ratio of 4:1 for PRP and BMP-2 suspension can be achieved under the same pressure differential.

[0041] The advantages of this invention are its simple structure, ease of use, reduced external contact during practical use, and guaranteed sterility. The addition of the blood gel adsorption rod simplifies the blood gel removal process, making it more convenient and sterile. The blood gel adsorption rod offers good maneuverability for the blood gel, allowing it to be directly placed in the intervertebral space, thus improving the work efficiency of the staff.

[0042] Example 2: Detection and degassing of drug-loaded erythrocyte gel.

[0043] This embodiment illustrates how to use the fourth port of the cross bolt to detect or vent fluid during the preparation process.

[0044] During the mixing process described in Example 1, the sealing cap 141 of the fourth port 140 remains closed. When it is necessary to detect the homogeneity or composition of the mixed fluid, the sealing cap can be opened, and detection devices such as pressure sensors or component analyzers can be connected to the fourth port via Luer connector 141. Since the branch channel outlet section 340 is directly connected to the main channel spiral section 230, the detection device can acquire samples of the mixed fluid in real time without interrupting the preparation process.

[0045] When air bubbles need to be expelled from the system, tilt the fourth port 140 upwards, open the sealing cap 141, and gently push the syringe to allow the fluid to flow slowly, causing the air bubbles to escape from the fourth port. After venting is complete, tighten the sealing cap again and continue the preparation process.

[0046] In addition, after preparation, cleaning fluid or disinfectant can be injected into the spiral section 230 through the fourth port to clean and maintain the internal flow channel and ensure sterility for reuse.

[0047] The advantages of this invention are its simple structure, ease of use, reduced external contact during practical use, and guaranteed sterility. The addition of the cross-screw mixer enables precise mixing and aseptic preparation of PRP and BMP-2, improving the quality and safety of the blood gel.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A sterile preparation and injection device for autologous red blood cell drug-loaded blood gel, characterized in that: The device includes a cross-shaped bolt mixer (100), a main syringe, a drug-loaded syringe, and a collection syringe. The cross-shaped bolt mixer (100) is a cross-shaped four-way structure, integrally injection molded from medical-grade PEEK material. Its four ports are a first port (110), a second port (120), a third port (130), and a fourth port (140), each with a standard Luer connector (111, 121, 131, 141). The first port (110) is used to connect to the main syringe, which contains erythrocyte-rich plasma. The second port (120) is used to connect to the collection syringe. The third port (130) is used to connect to the drug-loaded syringe, which contains a mixture containing bone morphogenetic protein 2 and a coagulation-promoting component. The fourth port (140) is used to connect to the main syringe. Port (140) is a closed detection port, and its end is provided with a Luer connector sealing cap (141); the cross bolt mixer (100) is provided with a main channel (200) and a branch channel (300) inside. The main channel (200) runs through the first port (110) and the second port (120). The branch channel (300) connects the third port (130) and the middle section of the spiral section (230) of the main channel (200). The cross bolt mixer (100) achieves precise 4:1 mixing of erythrocyte-rich plasma and a mixture containing bone morphogenetic protein 2 and coagulation-promoting components in a closed sterile environment through the cooperation of the main channel (200) and the branch channel (300). At the same time, the fourth port (140) can realize the functions of sampling and detection, exhaust and cleaning and maintenance of the internal flow channel.

2. The aseptic preparation and injection device for autologous red blood cell drug-loaded blood gel according to claim 1, characterized in that: The main channel (200) includes an inlet section (210), a main channel flow-limiting section (220), a spiral section (230), and an outlet section (240). The inlet section (210) is connected to the first port (110), and its inner diameter gradually narrows to accelerate the fluid. The main channel flow-limiting section (220) is located after the inlet section (210), and its cross-section is reduced to 400μm×300μm. The spiral section (230) is located in the center of the cross bolt mixer (100), and has a 3-5 spiral upward structure. Its cross-section is rectangular, with a width of 600μm and a depth of 400μm. The outlet section (240) is connected to the second port (120), and its inner diameter gradually widens to facilitate gel outflow. The spiral section (230), through the cooperation of the spiral structure and the mixing enhancement unit (400), enables the two fluids to generate secondary flow and repeated flow division, thereby achieving molecular-level uniform mixing.

3. The aseptic preparation and injection device for autologous red blood cell drug-loaded blood gel according to claim 1, characterized in that: The tributary channel (300) includes a microporous plate segment (310), a one-way valve structure (320), a tributary channel flow-limiting section (330), and a tributary channel outlet section (340); the microporous plate segment (310) contains a microporous plate (311) with micropores having a diameter of 200 μm and arranged in a 4×3 matrix; the one-way valve structure (320) is located at the intersection of the tributary channel (300) and the main channel (200), and consists of two crescent-shaped silicone valve leaflets (321) and a limiting support (32). 2) Composition, closed under normal conditions; the tributary flow-limiting section (330) is located after the one-way valve structure (320), and the flow channel cross-section is reduced to 300μm×300μm; the tributary outlet section (340) connects the spiral section (230) of the main channel (200) and the fourth port (140), with an inner diameter of 1mm; the one-way valve structure (320) can prevent the fluid in the main channel (200) from flowing back to the tributary (300), ensuring that the mixing process proceeds in one direction.

4. The aseptic preparation and injection device for autologous red blood cell drug-loaded blood gel according to claim 2, characterized in that: The spiral section (230) is equipped with a mixing enhancement unit (400), including a first mixing unit (410), a second mixing unit (420), and a third mixing unit (430). The first mixing unit (410) is located in the inlet region of the spiral section (230), and the inner wall of the flow channel is provided with an array of V-shaped grooves (411), with a groove depth of 50 μm and a spacing of 100 μm. The second mixing unit (420) is located downstream of the confluence of the branch channels (300), and the flow channel is provided with an array of staggered splitting columns (421), with a diameter of 100 μm and a height of 200 μm. The third mixing unit (430) is located in the outlet region of the spiral section (230), and the flow channel is undulating in a wave shape with an amplitude of 200 μm and a period of 1 mm.

5. The aseptic preparation and injection device for autologous red blood cell drug-loaded blood gel according to claim 1, characterized in that: The main syringe is a 30ml syringe containing 20ml of erythrocyte-rich plasma; the drug-loaded syringe is a 5ml syringe containing 5ml of a mixture containing bone morphogenetic protein 2 and a coagulation-promoting component.

6. The aseptic preparation and injection device for autologous red blood cell drug-loaded blood gel according to claim 1, characterized in that: The procoagulant component consists of chitosan, thromboplastin, coagulation factor VIII, prothrombin complex, and human fibrinogen.

7. A method for preparing autologous erythrocyte drug-loaded blood gel using the apparatus according to any one of claims 1-6, characterized in that: Includes the following steps: A. After routine disinfection of the patient's skin, use a blood collection needle to puncture and collect blood. The blood collection volume is 8-50ml. Connect the blood collection needle to the blood collection tube or syringe. After collection, repeatedly invert the blood collection tube to ensure that the anticoagulant is fully mixed with the blood. The ratio of anticoagulant volume to blood volume is 1:9 or 1:

10. B. Prepare erythrocyte-rich plasma using density gradient centrifugation. For the first centrifugation, the relative centrifugal force (RCF) is 200g, and the centrifugation time is 5–10 min. For the second centrifugation, the relative centrifugal force (RCF) is 400–700g, and the centrifugation time is 10 min. C. Connect the main syringe containing erythrocyte-rich plasma to the first port (110) of the cross-bolt mixer (100), connect the drug-loaded syringe containing a mixture of bone morphogenetic protein 2 and coagulation-promoting components to the third port (130), and connect the collection syringe to the second port (120). D. Simultaneously inject two syringes. The erythrocyte-rich plasma is accelerated through the inlet section (210) and enters the spiral section (230). The mixture containing bone morphogenetic protein 2 and coagulation-promoting components is dispersed into a microjet through the microporous plate section (310). Under the shear force generated by the flow of erythrocyte-rich plasma, it pushes open the one-way valve leaflet (321) and is vertically injected into the main channel (200). The two fluids are mixed in a 4:1 ratio in the spiral section (230). E. The mixed fluid enters the collection syringe through the outlet section (240) and is allowed to stand at 25-45℃ for 2-15 minutes to crosslink and form a drug-loaded blood gel; F. After sealing the collected syringes, place them in a vacuum dryer and dry them gently at 25-50℃. The entire process should be carried out in a sterile environment.

8. The preparation method according to claim 7, characterized in that: In step E, the mixed fluid is allowed to stand at 37°C for crosslinking.

9. The preparation method according to claim 7, characterized in that: In step F, after gentle drying, the drug-loaded blood gel is injected directly into the bone defect area using a syringe.

10. The aseptic preparation and injection device for autologous red blood cell drug-loaded blood gel according to claim 1, characterized in that: The fourth port (140) can be opened during the preparation process to remove air bubbles in the system, sample and test the uniformity or composition of the mixed fluid, and inject cleaning solution or disinfectant to clean and maintain the internal flow channel after preparation to ensure sterility for reuse.

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