A liquid hemostatic foam for non-compressible bleeding

Abstract

This invention discloses a liquid hemostatic foam for non-compressible bleeding, belonging to the field of hemostatic materials technology. It comprises: a foaming solution; the foaming solution includes: gelatin, silk fibroin, and transition metal ions; the transition metal ions include: Ca... 2+ Fe 2+ The liquid hemostatic foam is made by foaming a foaming solution; the foaming is achieved using a foaming device and the Tessari method. This sprayable liquid foam hemostatic material is suitable for various emergency rescue situations, adaptable to complex wounds and injuries that cannot be compressed. Current research on this material is still in its early stages, with no relevant research in China; therefore, this project is highly innovative. Unlike traditional powders, sponges, or tourniquets, the amount of liquid foam used can be adjusted according to the injured area, effectively expanding and sealing the bleeding site for treatment. Simultaneously, the liquid foam can be easily removed from the wound without affecting further treatment of the patient, meeting clinical treatment needs.

Description

Technical Field

[0001] This invention relates to the field of hemostatic materials technology, and more particularly to a liquid hemostatic foam for non-compressible bleeding. Background Technology

[0002] In clinical settings such as trauma care and surgery, non-compressible bleeding (e.g., intra-abdominal hemorrhage, visceral hemorrhage, and massive arterial hemorrhage) is a key factor leading to patient death. This type of bleeding is characterized by deep wounds, irregular wound shapes, rapid bleeding rates, and difficulty in controlling it through external pressure. This places extremely high demands on the rapid response capability, wound adaptability, biosafety, and subsequent compatibility of hemostatic materials. Traditional hemostatic materials, such as sponge-based materials including natural and synthetic polymer sponges, work by absorbing blood and expanding to form a physical barrier. However, sponge-based materials have a fixed shape and cannot adapt to the complex cavities and irregular wound surfaces of the abdominal cavity and internal organs, making it difficult to achieve comprehensive hemostasis. Furthermore, the high mechanical strength of sponges after absorbing water and expanding leads to tight adhesion to wound tissue, which can easily cause traction damage during subsequent removal, resulting in secondary bleeding, increased patient suffering, and greater treatment difficulty. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a liquid hemostatic foam for non-compressible bleeding; it can solve the problem that sponge-like materials have a fixed shape and cannot adapt to the fitting requirements of complex cavities such as the abdominal cavity and internal organs and irregular wounds.

[0004] Technical solution: To solve the above-mentioned technical problems, according to one aspect of the present invention, more specifically, a liquid hemostatic foam for non-compressible bleeding, comprising: a foaming solution; The foaming solution includes: gelatin, silk fibroin, and transition metal ions; The transition metal ions include: Ca 2+ Fe 2+ ; The liquid hemostatic foam is made by foaming with a foaming solution; The foaming is achieved using a foaming device and the Tessari method.

[0005] Furthermore, the foaming solution is prepared by dissolving gelatin and silk fibroin powder in water, stirring to prepare a precursor solution, then adding transition metal ions to the precursor solution, and continuing to stir to obtain the foaming solution.

[0006] Furthermore, the foaming device consists of two 20ml polyethylene syringes, the tips of which are connected by a silicone tube. One polyethylene syringe is loaded with foaming solution, and the other polyethylene syringe is loaded with air. By repeatedly pushing and pulling the polyethylene syringes, injectable liquid hemostatic foam is generated.

[0007] Furthermore, the volume ratio of the foaming solution to air is 1:10 to 1:2.

[0008] Furthermore, the polyethylene syringe is repeatedly pushed and pulled 30 times.

[0009] Furthermore, the liquid hemostatic foam is used for non-compressible bleeding, including: intra-abdominal bleeding, visceral bleeding, and major arterial bleeding.

[0010] Furthermore, the liquid hemostatic foam is applied in emergency rescue, battlefield, and first aid scenarios.

[0011] Furthermore, the gelatin and the silk fibroin powder are dissolved in water, the stirring temperature is 60°C, and the stirring time is 1 hour; the transition metal ions are added to the precursor solution, and the stirring time is continued for 30 minutes.

[0012] Beneficial Effects: Sprayable liquid foam hemostatic material is suitable for various emergency rescue situations, adapting to complex wounds and injuries that cannot be compressed. Current research on this material is still in its early stages, with no relevant research in China, thus this project is highly innovative. Unlike traditional powders, sponges, or tourniquets, liquid foam can be used in adjusted amounts according to the injured area, effectively expanding and sealing the bleeding site for treatment. Simultaneously, liquid foam can be easily removed from the wound without affecting further treatment of the patient, meeting clinical treatment needs and offering significant advantages by avoiding secondary harm to the patient from additional removal procedures. The raw materials used in the liquid foam hemostatic material are all biocompatible and human-friendly, and the resulting product has extremely high commercialization potential, filling a current market gap. Attached Figure Description

[0013] Figure 1 This is a roadmap for liquid hemostatic foam technology. Detailed Implementation

[0014] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] Example 1. Preparation of liquid hemostatic foam Different concentrations of gelatin and silk fibroin powder were dissolved in water and stirred at 60°C for 1 hour to prepare a precursor solution. Then, different transition metal ions were added to the precursor solution, and stirring was continued for 30 minutes to obtain a foaming solution.

[0016] 2. Preparation of foaming equipment and trial of foaming formula: The foaming apparatus consists of two 20ml polyethylene syringes, their tips connected by a silicone tube. One syringe is filled with foaming solution, and the other with air. Multiple sampling points were set with a foaming solution:air ratio between 1:10 and 1:2. By repeatedly pushing and pulling the syringes 30 times, the foaming solution and gas were continuously circulated within the tubes, generating injectable liquid foam for further investigation.

[0017] 3. Characterization experiment of liquid hemostasis foam 3.1 Characterization of hemostatic foam The composition and structure of the material were determined using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). FTIR spectroscopy was performed using a Thermo Fisher 6700 FTIR spectrometer at wavelengths of 4000-600 cm⁻¹, with one sample taken after every 16 scans. NMR spectroscopy was performed using a Bruker 400 MHz liquid NMR spectrometer, with a scan range of 0-10 PPM. 3.2 Characterization of material rheological properties Rheological testing was used to characterize some mechanical properties of the material in its linear viscoelastic state. The testing instrument was a DHR-2 rheometer. The storage modulus G' and loss modulus G” of the material were measured by dynamic frequency scanning within the angular frequency range of 0.1-100 rad / s and at a fixed strain of 1%. The viscoelastic region of the material was determined by strain scanning test. The parallel plates used had a geometric diameter of 25 mm and a gap of 1 mm between the two plates.

[0018] 3.3 Observation of the microscopic morphology of foam A small amount of spray-formed foam was placed on a glass slide and allowed to stand for a few minutes. Images were then captured at 100x and 400x magnification using an inverted microscope. The bubble size distribution was analyzed using ImageJ. At least 10 images were analyzed for each foam formulation. Rat heparinized blood was diluted 10-fold in saline, and a drop of blood was mixed with the foam on a glass slide. A coverslip was then placed on the sample. Blood cell adsorption was observed by imaging at 100x magnification.

[0019] 3.4 Material Biosafety Performance Testing L929 cells in the logarithmic growth phase were seeded into 96-well plates at a density of 5 x 10³ cells per well, with six replicates per group. After 24 hours of cell culture and adherence, the culture medium was aspirated and discarded. Extracts were added according to the group, and the cells were cultured for the specified time. The supernatant was then removed, and CCK-8 assay reagent was added. After incubation, absorbance was measured at 450 nm using a microplate reader. Live / Dead staining was used to further assess membrane cytotoxicity. The culture medium was aspirated from the wells, and the cells were washed with PBS. Cells were stained using a Live / Dead Viability / Cytotoxicity Kit (Invitrogen, Molecular Probes, Eugene, OR), and cell morphology was observed and recorded under an inverted fluorescence microscope.

[0020] 3.5 In vitro coagulation test of materials Two healthy SD rats were used, and 10 ml of blood was collected from the abdominal aorta. Heparin was used for anticoagulation. The blood was injected into 50 ml EP tubes, and then 5 ml of liquid foam was sprayed onto each tube. After the foam expanded and came into contact with the blood, the EP tubes were inverted to observe whether the foam could coagulate the blood and prevent the blood from falling off due to gravity.

[0021] 3.6 Material Hemolysis Test Two healthy SD rats were used, and 10 ml of blood was collected from the abdominal aorta. The blood was anticoagulated with heparin and diluted with physiological saline. Separately, 1 ml of each of the different formulations was mixed with 10 ml of physiological saline and incubated at 37 ℃ for 30 min. Then, 0.2 ml of diluted rat blood was added to each formulation, and the mixture was gently shaken and incubated at 37 ℃ for 60 min. For the positive control, 0.2 mL of diluted rabbit whole blood was added to 10 mL of 1% NaHCO3 solution and gently shaken to ensure complete hemolysis. For the negative control, 0.2 mL of diluted rabbit blood was added to 10 mL of physiological saline. All tubes were centrifuged (750 rpm, 5 min), and the supernatant was used to measure the optical density (OD) at a wavelength of 545 nm using a spectrophotometer. The OD value for each group was the average of the measurements from three tubes in each group, and the hemolysis percentage was calculated using the following formula: Hemolysis percentage % = (Sample OD value - Negative control OD value) / (Positive control OD value - Negative control OD value) × 100%.

[0022] 4. Materials for animal experiments All the following animal experiments were conducted in accordance with scientific research guidelines and were subject to relevant ethical oversight.

[0023] 4.1 Rat liver resection hemostasis model Two groups of rats (n=6) were randomly selected. After anesthesia with 10% chloral hydrate, the abdomen was opened to fully expose the liver. Filter paper was placed under the right lower lobe, and liver tissue was removed from the lower edge of the right lower lobe using tissue scissors (wound size: 2.0 cm × 0.5 cm). The wound size was recorded with a ruler. After tissue bleeding, liquid hemostatic foam was immediately sprayed onto the wound, and the hemostasis time was recorded. After complete hemostasis, the filter paper was removed, and the blood loss was calculated. The wound was kept open, and the foam dissipation time was recorded. The wound was then sutured, and the rats were housed in separate cages. Seven days later, the weight changes, feeding, and excretion of one group of rats were observed. The abdomen was opened again to observe the residual material at the hemostasis site, the recovery of damaged tissue, and whether there was adhesion or other lesions in nearby tissues and organs. A certain amount of blood was taken from the abdominal aorta of the rats for blood biochemistry and metabolic analysis. The right lower lobe of the liver and other abnormal tissues (heart, spleen, lungs, and kidneys) were removed, prepared into pathological sections, stained, and observed for thrombosis, inflammatory reactions, and toxicity analysis. Fourteen days later, the other group of rats underwent the same treatment.

[0024] 4.2 Rat femoral artery puncture injury model Two groups of rats (n=6) were randomly selected. After anesthetizing with 10% chloral hydrate, the right groin area of ​​the lower limb was exposed. The right femoral artery was cut open and separated. Filter paper was placed under the lower side of the right hind limb, and the femoral artery was pierced with a 26G needle. Immediately after bleeding, liquid hemostatic foam was sprayed onto the wound, and the hemostasis time was recorded. After complete hemostasis, the filter paper was removed, and the blood loss was calculated. The wound was kept open, and the foam dissipation time was recorded. The wound was then sutured, and the rats were housed separately in their respective groups. Seven days later, the weight changes, food intake, and excretion of one group of rats were observed. The recovery status of the right hind limb was determined using a gait analyzer. Pathological sections of the femoral artery and surrounding tissues were prepared, and the inflammatory response and recovery status were observed. Fourteen days later, the other group of rats underwent the same treatment.

[0025] 4.3 Porcine clavicle artery massive hemorrhage model Three Bama miniature pigs, weighing approximately 30 kg and raised normally, were used in each group and fasted for at least 12 hours prior to surgery. After anesthesia, 2% isoflurane was continuously administered via mechanical ventilation to maintain the anesthesia. An incision was made to expose the right femoral artery and femoral vein. A 6F-caliber tip catheter was placed in the femoral artery to monitor mean arterial pressure (MAP) and in the femoral vein for fluid replacement / resuscitation. A 4.5 cm skin incision was made above the left superficial pectoralis major muscle cranially, approximately 5 cm parallel to the sternum. The pectoralis major muscle was separated to expose the subclavian artery, and surrounding tissue was transcribed. A transverse section of the subclavian artery was created at the mid-axillary line using surgical scissors. Liquid hemostatic foam was sprayed onto the bleeding site after 30 seconds of free bleeding, and hemostasis was observed. Complete hemostasis was considered achieved when no significant blood oozing was observed at the foam edge or around the tissue. For wounds that did not hemostasis within 2 minutes, artificial hemostasis was achieved through methods such as cauterization. A gauze packing group served as a control.

[0026] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A liquid hemostatic foam for treating non-compressible bleeding, characterized in that, include: Foaming solution; The foaming solution includes: gelatin, silk fibroin, and transition metal ions; The transition metal ions include: Ca 2+ Fe 2+ ; The liquid hemostatic foam is made by foaming with a foaming solution; The foaming is achieved using a foaming device and the Tessari method.

2. The liquid hemostatic foam for non-compressible bleeding according to claim 1, characterized in that: The foaming solution is prepared by dissolving gelatin and silk fibroin powder in water, stirring to prepare a precursor solution, then adding transition metal ions to the precursor solution, and continuing to stir to obtain the foaming solution.

3. The liquid hemostatic foam for non-compressible bleeding according to claim 1, characterized in that: The foaming device consists of two 20ml polyethylene syringes, the tips of which are connected by a silicone tube. One polyethylene syringe is loaded with foaming solution, and the other polyethylene syringe is loaded with air. By repeatedly pushing and pulling the polyethylene syringes, injectable liquid hemostatic foam is generated.

4. A liquid hemostatic foam for non-compressible bleeding according to claim 3, characterized in that: The volume ratio of the foaming solution to air is 1:10 to 1:

2.

5. A liquid hemostatic foam for non-compressible bleeding according to claim 3, characterized in that: The polyethylene syringe is pushed and pulled 30 times.

6. A liquid hemostatic foam for non-compressible bleeding according to claim 1, characterized in that: The liquid hemostatic foam is used for non-compressible bleeding, including: intra-abdominal bleeding, visceral bleeding, and major arterial bleeding.

7. A liquid hemostatic foam for non-compressible bleeding according to claim 1, characterized in that: The liquid hemostatic foam is used in emergency rescue, battlefield, and first aid scenarios.

8. A liquid hemostatic foam for non-compressible bleeding according to claim 2, characterized in that: The gelatin and the silk fibroin powder are dissolved in water, and the stirring temperature is 60°C for 1 hour; the transition metal ions are added to the precursor solution, and the stirring time is continued for 30 minutes.

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