CN115487345B

CN115487345B - Hemostatic hydrogel and hemostatic sponge based on silk fibroin, and preparation methods and applications thereof

Info

Publication number: CN115487345B
Application number: CN202211007835.0A
Authority: CN
Inventors: 刘文广; 卞欣雨
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2022-08-22
Filing date: 2022-08-22
Publication date: 2024-03-12
Anticipated expiration: 2042-08-22
Also published as: CN115487345A

Abstract

The invention provides a silk fibroin-based hemostatic hydrogel and hemostatic sponge, and a preparation method and application thereof, wherein lauroyl arginine ethyl ester hydrochloride and silk fibroin are added into deionized water and stirred to be fully dissolved, so as to obtain a mixed solution; sucking the mixed solution by using a syringe, placing the mixed solution at 40-45 ℃ to gel the mixed solution for 70-90s, and taking out the mixed solution to obtain the silk fibroin-based hemostatic hydrogel, and pushing the hydrogel into a wound by using the syringe to achieve the purpose of in-situ gelling hemostasis. The silk fibroin-based hemostatic hydrogel and hemostatic sponge have good antibacterial property and biodegradability, and can be used for hemostasis of incompressible wounds.

Description

Hemostatic hydrogel and hemostatic sponge based on silk fibroin, and preparation methods and applications thereof

Technical Field

The invention relates to the technical field of biomedical materials, in particular to a silk fibroin-based hemostatic hydrogel and hemostatic sponge, and a preparation method and application thereof.

Background

Bleeding is a major cause of death in battlefields and hospitals, and death or injury due to bleeding can be greatly reduced by timely appropriate intervention. However, the traditional gauze compression or operation suturing method is long in time consumption and low in efficiency, and especially, rapid hemostasis of internal bleeding tissues such as incompressible trunk, liver and the like is difficult to achieve. Therefore, there is a need for a hemostatic agent that is effective in treating such incompressible wound bleeding. In response to this problem, various hemostatic materials have been developed. For example, XStat is composed of a plurality of compressed cellulose sponges, which can rapidly expand and exert pressure on the wound to control bleeding. But because the sponge is not degradable, more time is required to remove the material. Many injectable sponges have also been developed, but these materials lack blood guidance due to uniform internal pores, poor interconnectivity. These materials also fail to activate the endogenous coagulation pathway and lack anti-infective properties against bacterial infections. Thus, there is an urgent need to develop a class of antimicrobial, biodegradable hemostatic materials for the treatment of incompressible wounds.

Silk Fibroin (SF) is a natural polymer extracted from cocoons, its excellent mechanical properties, controlled biodegradation and biocompatibility, making it potential for biomedical materials. Under the induction of some conditions, SF solution can generate beta-sheet structure, such as shearing force, pH, high temperature, etc., so that SF is gelled to form hydrogel materialAnd (5) material. However, such a process greatly limits the formation and application of SF materials by requiring tens of minutes to more than an hour, slow gel time. Lauroyl arginine ethyl ester hydrochloride (LAE), an amino acid type surfactant, is one of FDA approved food additives, and has been demonstrated to have good biocompatibility and antibacterial properties, and to be metabolized and degraded to CO in vivo ₂ And urea. The gelation time of SF under the induction of LAE is greatly shortened to be even within 1 min. This LAE-induced in situ rapid gelation mechanism was first used to prepare injectable antimicrobial biodegradable hemostatic hydrogels to treat incompressible hemorrhages. The amphiphilicity of the LAE surfactant and the rapid increase in viscosity during gelation were also used to trap air bubbles to produce SF-LAE sponges with asymmetric porosity, with large and small pores created in the upper and lower parts of the sponge, respectively. The macropores of the sponge help drain blood, while the dense pores can prevent blood from flowing out to close incompressible wounds. The LAE-induced SF rapid gelation method and the hydrogel and the asymmetric sponge prepared by the method are expected to provide new possibility for treating non-compression hemorrhage in emergency.

Disclosure of Invention

The invention overcomes the defects in the prior art, and provides a silk fibroin-based hemostatic hydrogel and hemostatic sponge, as well as preparation methods and applications thereof.

The aim of the invention is achieved by the following technical scheme.

A hemostatic hydrogel based on silk fibroin and a preparation method thereof are carried out according to the following steps:

step 1, adding lauroyl arginine ethyl ester hydrochloride and silk fibroin into deionized water, stirring to fully dissolve the lauroyl arginine ethyl ester hydrochloride and the silk fibroin, and obtaining a mixed solution, wherein the concentration of the lauroyl arginine ethyl ester hydrochloride in the obtained mixed solution is 5-15wt% and the concentration of the silk fibroin is 5-20wt%;

and 2, sucking the mixed solution prepared in the step 1 by using a syringe, placing the mixed solution at 40-45 ℃ to gel the mixed solution for 70-90 seconds, and taking out the mixed solution to obtain the silk fibroin-based hemostatic hydrogel, and pushing the hydrogel into a wound by using the syringe to achieve the purpose of in-situ gelling hemostasis.

In step 1, the concentration of lauroyl arginine ethyl ester hydrochloride in the obtained mixed solution was 15wt%, and the concentration of silk fibroin was 20wt%.

In step 2, the constant temperature was 42℃and the mixed solution gelation time was 80s.

The storage modulus of silk fibroin-based hemostatic hydrogels was 222kPa.

A hemostatic sponge based on silk fibroin and a preparation method thereof are carried out according to the following steps:

step 1, adding lauroyl arginine ethyl ester hydrochloride and silk fibroin into deionized water, stirring to fully dissolve the lauroyl arginine ethyl ester hydrochloride and the silk fibroin, and obtaining a mixed solution, wherein the concentration of the silk fibroin in the obtained mixed solution is 5-10wt% and the concentration of the lauroyl arginine ethyl ester hydrochloride is 7.5-15wt%;

step 2, mixing the mixed solution prepared in the step 1 by vortex to generate a large number of bubbles in the mixed solution, heating the mixed solution while vortex mixing at a temperature of 60-90 ℃ for 90-120s, and rapidly gelling the silk fibroin induced by lauroyl arginine ethyl ester hydrochloride in the heating process, wherein a large number of bubbles are fixed in the hydrogel, so that the SF-LAE porous hydrogel with asymmetric pores is finally obtained under the action of gravity and buoyancy;

and 3, freeze-drying the SF-LAE porous hydrogel with the asymmetric pores prepared in the step 2 to obtain the silk fibroin-based hemostatic sponge.

In step 1, the concentration of silk fibroin in the obtained mixed solution was 5wt%, and the concentration of lauroyl arginine ethyl ester hydrochloride was 7.5wt%.

In step 2, the heating temperature was 90℃and the heating time was 105s.

In step 3, the freeze-drying time is 2-3 days, 24 hours per day.

The compression strength of the hemostatic sponge based on the silk fibroin after water absorption is 35-37kPa, and the porosity of the hemostatic sponge based on the silk fibroin is 84-92%.

The beneficial effects of the invention are as follows: the invention shortens the time required by gelation of Silk Fibroin (SF) solution, and two types of hemostatic agents are prepared: the first type of hemostatic is an instant hydrogel hemostatic, which can induce rapid gelation of Silk Fibroin (SF) solution based on lauroyl arginine ethyl ester hydrochloride (LAE), and firstly, a hemostatic hydrogel SF-LAE-H material which can be immediately gelled in situ after being mixed is designed; the second type of hemostatic agent is hemostatic sponge material, which is obtained by vortex mixing LAE and SF solution, heating the mixed solution to induce rapid gelation of silk fibroin, fixing a large number of bubbles in rapidly gelled hydrogel, and further lyophilizing to obtain SF-LAE-S hemostatic sponge with high liquid absorption rate and asymmetric pores; the porous structure connected with each other can quickly absorb blood, enrich blood cells and accelerate hemostasis; the silk fibroin-based hemostatic hydrogel and hemostatic sponge have good antibacterial property and biodegradability, and can be used for hemostasis of incompressible wounds.

Drawings

FIG. 1 is a graph of the shear modulus G', G "of SF-LAE-H hydrogels over time.

FIG. 2 is an infrared spectrum of SF-LAE-H hydrogel.

FIG. 3 is a schematic of SF-LAE-H as a gel in vivo hemostatic results, wherein (a) a rat liver penetration model is shown; (b) Hemostatic effect photographs of blank group (1) and SF-LAE-H group (2); yellow arrows indicate bleeding sites; (c, d) blood loss and hemostasis time in rat liver penetration models for blank, gauze and SF-LAR-H groups; data are expressed as mean ± standard deviation. Significant differences were detected by one-way ANOVA. n=5, P <0.01, P <0.001.

FIG. 4 is a photograph of the macroscopic morphology of SF-LAE-S sponge.

FIG. 5 is a scanning electron micrograph of SF-LAE-S sponge and commercial gelatin sponge Gel-S at 200, 300, 2000 magnification, respectively.

FIG. 6 is a graph of the results of the porosity of Gel-S, pure silk fibroin lyophilized sponge PSF-S, SF-LAE-S sponge, data expressed as mean.+ -. Standard deviation. Significant differences were detected by one-way ANOVA, n=4, P <0.001 and ns: no significance was observed.

FIG. 7 is a Fourier infrared spectrum of SF-LAE-S sponge.

FIG. 8 is a graph showing the results of the liquid absorption rate of SF-LAE-S sponge versus time for deionized water, phosphate Buffered Saline (PBS) solution, and anticoagulated rabbit whole blood.

FIG. 9 is a graph showing the results of compressive stress-strain tests of Gel-S degree SF-LAE-S sponge, wherein A is a graph showing the results of compressive stress-strain of Gel-S degree SF-LAE-S sponge after water absorption and blood absorption, and B is a photograph (B) showing the longitudinal and transverse compression of SF-LAE-S after water absorption;

fig. 10 is a bar graph of the results of relative activity testing of bacteria after co-culture with SF-LAE-S, where data are expressed as mean ± standard deviation, significant differences are detected by one-way ANOVA with n=4, P <0.001 and ns, no significance.

FIG. 11 is a graph of results of in vivo hemostasis test of SF-LAE-S sponge, (a) a schematic of hemostasis of a rabbit liver penetration injury model, (b, c) blood loss and hemostasis time of 1-blank, 2-gauze and 3-SF-LAE-S in a rabbit liver penetration injury model, and the data are expressed as mean.+ -. Standard deviation. Significant differences were detected by one-way ANOV a for (b, c) n=5, P <0.05, P <0.01, P <0.001 and ns: no significance; (d) Photographs of the hemostatic processes of the blank, gauze and SF-LAE-S in the rabbit liver perforation wound model.

FIG. 12 is a bar graph of the results of cell activity testing of SF-LAE-S, PSF-S sponge.

FIG. 13 is a flow chart of the preparation process of the present invention.

Detailed Description

The technical scheme of the invention is further described by specific examples.

Example 1

The hemostatic hydrogel based on silk fibroin is prepared by deionized water respectively into a solution with SF concentration of 20% and LAE concentration of 15%, the solution is sucked by a syringe and then is injected into a bleeding wound for in-situ gelation and hemostasis after 80s in a constant temperature oven at 42 ℃.

Example 2

The hemostatic hydrogel based on silk fibroin is prepared by deionized water respectively, and mixed solution with SF concentration of 15% and LAE concentration of 15% is filled into a 42 ℃ incubator for 80s after being sucked by a syringe and injected into a bleeding wound for in-situ gelation hemostasis.

Example 3

The hemostatic sponge based on silk fibroin is prepared by deionized water respectively, and the mixed solution with SF concentration of 5% and LAE concentration of 7.5% is heated for about 105s while generating bubbles by vortex, so that porous gel is rapidly formed. The gel was then freeze-dried to give SF5-LAE7.5-S porous sponge and loaded into a syringe.

Example 4

The hemostatic sponge based on silk fibroin is prepared by respectively preparing a solution with SF concentration of 10% and LAE concentration of 7.5% after mixing by deionized water, and heating the solution for about 105s while generating bubbles by vortex to quickly form porous gel. The gel was then freeze-dried to give SF10-LAE7.5-S porous sponge.

Example 5

The hemostatic sponge based on silk fibroin is prepared by respectively preparing a solution with SF concentration of 20% and LAE concentration of 15% after mixing by deionized water, and heating the solution for about 105s while generating bubbles by vortex to quickly form porous gel. The gel was then freeze-dried to give SF20-LAE15-S porous sponge.

Comparative example 1

The solution with SF concentration of 10% is prepared by deionized water, the solution is heated for about 105s while generating bubbles by vortex, and the solution is not formed into hydrogel after heating is stopped, and is still in a solution state. And freeze-drying the obtained solution to obtain the PSF-S sponge, wherein the sponge has low porosity, poor liquid absorption capability and no good hemostatic capability.

Characterization of SF-LAE-H hydrogels:

(1) Rheological property testing was performed on SF-LAE-H: from the change in storage modulus and loss modulus over time (FIG. 1), G 'and G' start to intersect in a relatively short time, indicating ultra-rapid formation of hydrogels. And the storage modulus of the hydrogel can reach 222kPa at the highest.

(2) Infrared spectroscopic testing was performed on SF-LAE-H: 1626-1628cm ^-1 (amide I) is due to the beta sheet conformation, as shown in FIG. 2, SF-LAE-H is at 1628cm ^-1 There is shown a distinct peak, attributed to the beta sheet, indicating the formation of a physical cross-linked network and successful induction of SF by LAE.

(3) In vivo hemostatic Capacity test on SF-LAE-H hydrogel: as shown in fig. 3, the SF-LAE-H precursor solution solidifies in time after injection into the wound, eventually achieving complete hemostasis. Furthermore, by recording blood loss and hemostatic time, the hemostatic performance of SF-LAE-H was further assessed and gauze was used as a control group. The blood loss of the blank group, the gauze group and the SF-LAE-H group is 2.45 g, 2.11 g and 0.30 g respectively; the trend of the hemostasis time change is similar, namely 383 seconds, 345 seconds and 34 seconds, and obviously the SF-LAE-H has the least blood loss and the best hemostasis effect. This indicates that the material can stop bleeding by physical blockage and is a potential hemostatic material.

(4) Antibacterial property test of SF-LAE-H hydrogel: the antibacterial properties of SF-LAE-H hydrogels were evaluated using a bacterial co-culture method. In the experiment, two gram-negative bacteria such as escherichia coli and staphylococcus aureus and gram-positive bacteria are adopted for the experiment. The antibacterial properties of the sponge were evaluated by the relative activities of bacteria after co-culture with the sponge, and the results are shown in fig. 10, in which SF-LAE-H hydrogels show much higher antibacterial activity than other groups, indicating excellent antibacterial effects. Characterization of SF-LAE-S sponge:

(1) Due to buoyancy and gravity, more large bubbles move upward, fewer small bubbles stay in the lower part of the hydrogel, thus forming an asymmetric hydrogel with loose upper part and dense lower part, and the porous hydrogel is further freeze-dried to obtain the SF-LAE-S sponge with asymmetric pores, and the macroscopic morphology of the SF-LAE-S sponge is shown in FIG. 4. The microscopic morphology of SF-LAE-S was imaged by Scanning Electron Microscopy (SEM). As shown in FIG. 5, the pores in the upper portion of SF-LAE-S are larger and sparse, while the pores in the lower portion are smaller and dense. In addition, at 2000 times magnification, the micropores formed by freeze-drying can be seen throughout the sponge network. These micropores are formed by water crystals inside the hydrogel and are small in size. These micropores of different sizes help to form a hierarchical porous structure providing excellent liquid absorption capacity. In contrast, commercial gelatin sponge Gel-S has very few, though large, pores, which are detrimental to capillary action and water absorption. The non-piled pores of the SF-LAE-S sponge can lead the macropores at the upper end to drain blood, and the dense pores at the lower end can prevent the blood from losing. Meanwhile, comparing the porosity of the sponge in FIG. 6, the SF-LAE-S sponge has a higher porosity.

(2) Infrared spectroscopy was performed on SF-LAE-S sponge: 1626-1628cm ^-1 (amide I) is due to beta sheet conformation, as shown in FIG. 7, SF-LAE-S is at 1628cm ^-1 There is shown a distinct peak, attributed to the beta sheet, indicating the formation of a physical cross-linked network and successful induction of SF by LAE.

(3) Liquid absorption Capacity test on SF-LAE-S sponge: the ultra-fast liquid absorption capacity is crucial to realizing rapid hemostasis, the liquid absorption rate of SF-LAE-S sponge in water, PBS and anticoagulated rabbit whole blood is evaluated, and a medical hemostatic sponge (Gel-S) is selected as a control group. The initial weight of the SF-LAE sponge in the dry state is first tested, then the weighed dry state sponge is respectively immersed in the three liquids, the sponge is taken out at different time points, the superfluous liquid adsorbed on the surface is wiped off by a wet tissue, and the mass of the sponge is weighed again to calculate the liquid absorption capacity. As shown in FIG. 8, the absorption kinetics of SF5-LAE7.5-S sponge is shown to be the greatest in 100S for all of water (1923%), PBS (1734%), and blood (2898%), wherein the absorption rate for blood is the fastest, indicating that SF5-LAE7.5 sponge has the ability to absorb water and blood instantaneously, and Gel-S sponge has difficulty in absorbing water and blood.

(4) Mechanical testing of SF-LAE-S sponge: the compression stress-strain curve of SF-LAE sponge after water absorption and anticoagulation of rabbit whole blood was tested, using a Legend 2344 electronic force measuring machine, at room temperature, gel-S as control group. The sponge is cut into cylinders with the diameter of 11mm and the height of 0.5cm, and the cylinders are respectively put into deionized water and anticoagulated rabbit whole blood to reach equilibrium waiting test. The compression rate of the tensile machine was adjusted to 10mm/min, and the sample was tested. The sponge is respectively immersed into water and anticoagulated rabbit whole blood, and is measured after balance stabilization. As a result, as shown in FIG. 9, SF-LAE-S exhibited good mechanical stability and mechanical strength (54 kPa) after absorbing water and blood. Whereas Gel-S impregnated with water and blood has a poor strength. In the compression display diagram, the SF-LAE-S sponge is lightly pressed by hands, so that the original shape of the sponge can be quickly recovered, and the good rebound performance of the SF-LAE-S sponge is proved.

(5) Antibacterial property test was performed on SF-LAE-S sponge: the antibacterial properties of SF-LAE-S sponges were evaluated using a bacterial co-culture method. In the experiment, two gram-negative bacteria such as escherichia coli and staphylococcus aureus and gram-positive bacteria are adopted for the experiment. The antibacterial properties of the sponge were evaluated by the relative activities of bacteria after co-culture of the sponge, and as shown in FIG. 10, SF-LAE-S showed much higher antibacterial activity than the other groups, indicating excellent antibacterial effects.

(6) In vivo hemostatic Capacity test on SF-LAE-S sponge: the prepared sponge material was loaded into a syringe having a diameter of 11mm, and the upper end was exposed to the outside so that the macropores first contacted the wound to drain blood, and the dense portion blocked the wound to prevent blood from overflowing. SF-LAE-S in vivo hemostatic performance was evaluated in a rabbit liver penetration injury model by recording hemostatic time and blood loss. For the rabbit liver penetrating wound model, a perforation of 14mm in diameter was made in the rabbit liver and the sponge was pushed into the wound with a syringe, unpressurized, until no blood was allowed to flow out (fig. 11 a). After 145 seconds of treatment with gauze, blood continued to bleed from the liver lobes of the rabbits, while the bleeding of the SF-LAE-S group stopped completely. Bleeding times for the control, gauze and SF-LAE-S groups were 20.9 minutes, 8.4 minutes and 2.4 minutes, respectively; the blood loss of the control, gauze and SF-LAES groups was 27.0g, 7.3g and 2.9g, respectively (FIGS. 11b, c). From a quantitative point of view, the total blood loss and blood loss time were significantly lower in the SF-LAE-S group than in the other groups, indicating its great potential as a hemostatic material.

(7) Is the cytotoxicity result of SF-LAE-H, SF-LAE-S sponge on mouse fibroblast (L929). Soaking prepared SF-LAE-H, SF-LAE-S sponge in culture medium for 24 hr, respectively, and mixing L929 cells at a ratio of 2×10 ⁴ The concentration of cells/well was inoculated into 96-well plates, cultured for 24 hours, the above SF-LAE-S sponge extract was added to each well, co-cultured for 1 day, then 20. Mu.L of 5mg/mL of 3- (4, 5-dimethylthiazole-2) -2, 5-diphenyltetrazolium bromide (MTT) solution and 180. Mu.L of fresh medium were added to each well, cultured for 4 hours, N' -dimethyl sulfoxide (DMSO) was added, shaking was performed in a microplate reader for 3 minutes, and absorbance at 570nm was measured, and cell viability was calculated by the ratio of absorbance using cells without sponge as a control group. When the MTT was used to quantitatively determine the cell viability, the results are shown in FIG. 12, and it can be seen that the SF-LAE-H, SF-LAE-S sponge cell viability was more than 90% compared with the control group, indicating that the hydrogel and sponge have better cell compatibility.

According to the invention, the preparation of hemostatic hydrogel and hemostatic sponge can be realized by adjusting the technological parameters, and the test shows that the hemostatic hydrogel and the hemostatic sponge have basically consistent performance with the invention. The foregoing has described exemplary embodiments of the invention, it being understood that any simple variations, modifications, or other equivalent arrangements which would not unduly obscure the invention may be made by those skilled in the art without departing from the spirit of the invention.

Claims

1. The preparation method of the silk fibroin-based hemostatic hydrogel is characterized by comprising the following steps: the method comprises the following steps of:

and 2, sucking the mixed solution prepared in the step 1 by using a syringe, and placing the mixed solution at 40-45 ℃ to gel the mixed solution for 70-90 seconds, and taking out the gel to obtain the silk fibroin-based hemostatic hydrogel.

2. The method for preparing a silk fibroin-based hemostatic hydrogel according to claim 1, wherein: in step 1, the concentration of lauroyl arginine ethyl ester hydrochloride in the obtained mixed solution was 15wt%, and the concentration of silk fibroin was 20wt%.

3. The method for preparing a silk fibroin-based hemostatic hydrogel according to claim 1, wherein: in step 2, the constant temperature was 42℃and the mixed solution gelation time was 80s.

4. A silk fibroin-based hemostatic hydrogel prepared by the method of preparing a silk fibroin-based hemostatic hydrogel according to any one of claims 1-3, wherein: the storage modulus of silk fibroin-based hemostatic hydrogels was 222kPa.

5. The preparation method of the silk fibroin-based hemostatic sponge is characterized by comprising the following steps of: the method comprises the following steps of:

step 2, mixing the mixed solution prepared in the step 1 by vortex to generate a large amount of bubbles in the mixed solution, heating the mixed solution while vortex mixing at a temperature of 60-90 ℃ for 90-120s, and rapidly gelling the silk fibroin induced by lauroyl arginine ethyl ester hydrochloride in the heating process to fix the bubbles in the hydrogel, so as to obtain SF-LAE porous hydrogel with asymmetric pores due to the action of gravity and buoyancy;

6. The method for preparing a silk fibroin-based hemostatic sponge according to claim 5, wherein: in step 1, the concentration of silk fibroin in the obtained mixed solution was 5wt%, and the concentration of lauroyl arginine ethyl ester hydrochloride was 7.5wt%.

7. The method for preparing a silk fibroin-based hemostatic sponge according to claim 5, wherein: in step 2, the heating temperature was 90℃and the heating time was 105s.

8. The method for preparing a silk fibroin-based hemostatic sponge according to claim 5, wherein: in step 3, the lyophilization time is 2 to 3 days.

9. A silk fibroin-based hemostatic sponge prepared by the method of any one of claims 5-8, wherein: the compression strength of the hemostatic sponge based on the silk fibroin after water absorption is 35-37kPa, and the porosity of the hemostatic sponge based on the silk fibroin is 84-92%.

10. Use of a silk fibroin-based hemostatic hydrogel according to any one of claims 1-4 in biological materials.

11. Use of a silk fibroin-based hemostatic sponge according to any one of claims 5-9 in biological material.