CN114887111B

CN114887111B - Bioabsorbable composite hemostatic material and preparation method and application thereof

Info

Publication number: CN114887111B
Application number: CN202210313734.XA
Authority: CN
Inventors: 刘公岩; 陈茂; 稂时英; 向俊
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2022-03-28
Filing date: 2022-03-28
Publication date: 2023-07-04
Anticipated expiration: 2042-03-28
Also published as: CN114887111A

Abstract

The invention provides a bioabsorbable composite hemostatic material, a preparation method and application thereof. The invention provides a bioabsorbable composite hemostatic material, which is prepared from the following raw material components: the polyvinyl alcohol has a molecular weight ranging from 10000 to 50000Da, and the weight ratio of the polyvinyl alcohol to the gelatin to the tannic acid is 0.2 to 0.4:1 to 1.5:1. The composite hemostatic material provided by the invention has the advantages of simple preparation method, convenience in operation, small blood loss, high hemostatic speed, good antibacterial property, good biological absorbability and good adhesion with tissues, and has excellent universality.

Description

Bioabsorbable composite hemostatic material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of medical hemostatic materials, and particularly relates to a bioabsorbable composite hemostatic material, and a preparation method and application thereof.

Background

Clinically, uncontrolled bleeding caused by surgical means or vascular lesions presents great difficulties for clinical emergency treatment and wound treatment, and bleeding lacerations are not sufficiently treated to be easily invaded by external bacteria to cause further infection, serious persons even threaten the life health of patients, so that immediate closure of ruptured tissues has important clinical significance in surgical operations. At present, the traditional method for treating bleeding and opening hemostasis generally adopts medical dressings with certain hemostatic effects, such as bandages, gauze, gelatin sponges and the like, but the materials cannot effectively resist bacterial infection and other complications, have poor absorbability and often generate a large amount of medical wastes. And the high blood suction amount of the gauze can lead the blood loss of a patient to be more, the hemostatic time is longer, the hemostatic effect is to be further improved, and secondary injury can be brought to the patient when the dressing is removed. Therefore, development of a hemostatic material capable of improving the hemostatic effect of bleeding and laceration and reducing the wound infection probability and having low blood loss and high hemostatic speed is particularly important.

On the other hand, the existing wound dressing has poor antibacterial property, while some dressing adopts antibacterial substances, the adhesive property between the dressing and tissues is poor, and the better adhesive property not only can quicken the hemostasis speed and reduce the blood loss, but also can improve the hemostasis effect, and meanwhile, the wound dressing has better effect on wound healing and protection, so that research on the aspect is also urgently needed to be carried out.

Disclosure of Invention

The invention aims to solve the technical problems, and provides a bioabsorbable composite hemostatic material, and a preparation method and application thereof. The technical aim of the invention is to solve the problems of high blood loss and low hemostatic speed of the existing wound dressing such as gauze, the problems of poor bacteriostasis and poor biological absorbability of the existing wound dressing, and the problems of poor adhesion of the existing wound dressing and tissues.

Firstly, the invention provides a bioabsorbable composite hemostatic material, which is prepared from the following raw material components: the polyvinyl alcohol has a molecular weight ranging from 10000 to 50000Da, and the weight ratio of the polyvinyl alcohol to the gelatin to the tannic acid is 0.2 to 0.4:1 to 1.5:1.

The composite hemostatic material of the present invention has the design concept that the components with good biocompatibility are selected to form the raw materials of the hemostatic material, and the bioabsorbable raw materials are selected to enable the composite hemostatic material to have good biological absorbability, so the inventor tries to select three components of gelatin, polyphenol components and polymers containing polyhydroxy components with good biocompatibility to form the composite hemostatic material of the present invention. Under the design thought, the polyphenol component in the raw materials is combined with various hydrogen bond donors and acceptors, a hybrid network structure can be formed through abundant intermolecular hydrogen bonds, the polyphenol component can provide strong antibacterial performance for the material, and meanwhile, the strong oxidation resistance of the polyphenol component can play a great role in regulating inflammatory reaction in the wound healing stage. In addition, the interaction of the polyphenol component with the hydroxyl component should be able to provide the composite with a strong adhesion capability on wound tissue, while the amino component in the material is able to allow the composite to provide a further curing effect after adhesion.

The inventor firstly selects polyvinyl alcohol which is polyhydroxy polymer as one of the raw materials of hemostatic materials so as to meet the design requirement. However, the inventors found that the molecular weight of the polyvinyl alcohol has a significant effect on the hemostatic effect of the composite hemostatic material obtained by the present invention, and that the molecular weight range is only between 10000 and 50000Da, and that when the molecular weight of the polyvinyl alcohol exceeds 50000Da, as shown in the results of the studies of comparative examples 2 and 3 of the present invention, the hemostatic effect of the obtained hemostatic material is poor when the molecular weights of 78000Da and 140000Da are selected. And the effect is poor when the molecular weight is less than 10000 Da.

On the other hand, the present inventors studied the preparation of composite hemostatic materials with various compounds containing catechol components including tannic acid, gallic acid, dopamine, pyrogallic acid, protocatechuic acid, and the like, in order to meet the above-mentioned design requirements. As shown in comparative example 4, the inventors have conducted experiments with tannic acid and gallic acid, which are the most typical, and as a result, have found that a better hemostatic effect can be obtained only by selecting tannic acid, which is inferior to tannic acid when it is replaced with other catechol compounds such as gallic acid.

Therefore, the inventor finally determines the raw material formula, and simultaneously obtains the proportion range of the corresponding raw materials, so as to obtain the composite hemostatic material with less blood loss, high hemostatic speed, good antibacterial property, high biological absorbability and good adhesiveness with tissues, and provides a new thought for developing novel wound dressing.

Preferably, the molecular weight of the polyvinyl alcohol is 30000Da. In this molecular weight range, the resulting composite hemostatic material is best effective.

Preferably, the weight ratio of the polyvinyl alcohol to the gelatin to the tannic acid is 0.3:1:1. Under the proportion of the raw materials, the obtained composite hemostatic material has the best effect.

Further, the gelatin has a gel strength of 100 to 300g Bloom. Under the intensity range of the gel, the obtained composite hemostatic material has better effect.

Secondly, the invention provides a preparation method of the bioabsorbable composite hemostatic material, which comprises the following steps:

(1) Mixing polyvinyl alcohol and gelatin according to the weight ratio, preparing into an aqueous solution, heating and stirring to fully dissolve the aqueous solution, and obtaining a mixed solution;

(2) And (3) adding tannic acid into the mixed solution obtained in the step (1) according to the weight ratio, and continuously stirring at 60 ℃ to enable the tannic acid to self-assemble to obtain the composite hemostatic material.

Further, in the step (1), the heating temperature is 90 ℃, and the stirring and dissolving time is 1-2 h.

Further, the preparation method further comprises the step (3): and (3) carrying out vacuum drying on the composite hemostatic material obtained in the step (2), and grinding to obtain hemostatic powder.

Further, the vacuum drying conditions are as follows: drying in a vacuum oven at 60deg.C for 24 hr.

Third, the present invention also provides the use of the above-described bioabsorbable composite hemostatic material, including preparing the composite hemostatic material into a wound dressing for acute wound hemostasis. In addition, the application also comprises the preparation of the composite hemostatic material into an antibacterial dressing. The hemostatic material has good hemostatic effect, can be well used for hemostasis of acute wounds, and has good antibacterial property and tissue adhesiveness.

The beneficial effects of the invention are as follows:

the composite hemostatic material provided by the invention is a general dressing with biological absorbability and tissue adhesiveness, and tannic acid can better form a hybrid network structure through the combined action of non-covalent bonds (hydrogen bonds, pi-pi stacking and the like) and gelatin and polyvinyl alcohol in raw materials selected by the composite hemostatic material, so that a better hemostatic effect is achieved. The composite hemostatic material provided by the invention has the advantages of small blood loss, high hemostatic speed, good antibacterial property, high bioabsorbable property and good adhesion with tissues, and has excellent universality.

Drawings

Fig. 1 is SEM pictures of gelatin and example 1, wherein (a) is SEM picture of gelatin and (b) is SEM picture of example 1.

Fig. 2 is a frequency sweep rheological profile of gelatin and example 1, where (a) is the rheological profile of gelatin and (b) is the rheological profile of example 1.

FIG. 3 is the contact sterilization rate of the composite hemostatic material prepared in example 1; wherein: (a) is the contact sterilization rate of the composite material to staphylococcus aureus in 24 hours, (b) is the contact sterilization rate of the composite material to escherichia coli in 24 hours, and (c) is the contact sterilization rate to methoxy-resistant staphylococcus aureus in 24 hours.

FIG. 4 shows the shear bond strength (a) and the tensile bond strength (b) of the composite material prepared in example 1 to iron sheets, glass, PVC plastic and pigskin.

FIG. 5 is the residual mass fractions of the composite hemostatic material of example 1 at various times of protease treatment.

FIG. 6 shows the results of the tail-end hemostasis of mice with the composite materials and gauze prepared in example 1 and comparative examples 2, 3, and 4, and the blank control without the hemostasis treatment; wherein (a) is blood loss and (b) is blood loss time.

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the following detailed description of the present invention will be made with reference to the examples, which are given by way of illustration and explanation only, and are not intended to limit the present invention. Some non-essential modifications and adaptations of the invention according to the foregoing summary will still fall within the scope of the invention.

Example 1

A bioabsorbable composite hemostatic material is prepared from the following raw material components: the weight ratio of polyvinyl alcohol to gelatin to tannic acid is 0.3:1:1, wherein the gelatin has a gel strength of 100G blood (Shanghai Ala Biochemical technology Co., ltd., G108398, CAS: 9000-70-8), the molecular weight of the polyvinyl alcohol is 30000Da, and the preparation method of the composite hemostatic material comprises the following steps:

(1) Adding 3g of polyvinyl alcohol with the molecular weight of 3 ten thousand and 10g of gelatin powder into a flask filled with 50mL of deionized water at normal temperature, stirring and dissolving for 1h at the constant temperature of 90 ℃ to obtain a uniform mixed solution;

(2) Adding 10g of tannic acid into the uniform mixed solution in the step (1), keeping the temperature at 60 ℃ unchanged, and stirring until the tannic acid is self-assembled to obtain a composite hemostatic material;

(3) And (3) taking out the composite hemostatic material in the step (2), putting the composite hemostatic material into a vacuum drying oven, drying at 60 ℃ for 24 hours, taking out, and grinding to obtain the general composite hemostatic powder.

Example 2

A bioabsorbable composite hemostatic material is prepared from the following raw material components: the weight ratio of polyvinyl alcohol to gelatin to tannic acid is 0.2:1.5:1, wherein the gelatin has the adhesive strength of 300g blood (Sigema company), the molecular weight of the polyvinyl alcohol is 10000Da, and the preparation method of the composite hemostatic material comprises the following steps:

(1) 2g of polyvinyl alcohol with the molecular weight of 1 ten thousand and 15g of gelatin powder are added into a flask filled with 50mL of deionized water at normal temperature, and stirred and dissolved for 1.5h at the constant temperature of 90 ℃ to obtain a uniform mixed solution;

(2) And (3) adding 10g of tannic acid into the uniform mixed solution in the step (1), keeping the temperature at 60 ℃ unchanged, and stirring until the self-assembly is carried out to obtain the composite hemostatic material. The obtained composite hemostatic material is freeze-dried, and the FE-SEM is used for observation, so that the result also shows that the pore diameter of the composite hemostatic material is relatively reduced, and the number of pores is increased.

Example 3

A bioabsorbable composite hemostatic material is prepared from the following raw material components: the weight ratio of polyvinyl alcohol, gelatin and tannic acid is 0.4:1:1, wherein the gelatin has a gel strength of 240G Bloom (Shanghai Ala Biochemical technology Co., ltd., G108396, CAS: 9000-70-8), the molecular weight of the polyvinyl alcohol is 50000Da, and the preparation method of the composite hemostatic material comprises the following steps:

(1) Adding 4g of polyvinyl alcohol with the molecular weight of 5 ten thousand and 10g of gelatin powder into a flask filled with 50mL of deionized water at normal temperature, stirring and dissolving for 2 hours at the constant temperature of 90 ℃ to obtain a uniform mixed solution;

(2) And (3) adding 10g of tannic acid into the uniform mixed solution in the step (1), keeping the temperature at 60 ℃ unchanged, and stirring until the self-assembly is carried out to obtain the composite hemostatic material. The obtained composite hemostatic material is freeze-dried, and the FE-SEM is used for observation, so that the aperture of the composite hemostatic material is relatively reduced, and the number of the apertures is increased.

Comparative example 1

10g of gelatin (gel strength: 100g Bloom) powder was added to a flask containing 50mL of deionized water, and the mixture was stirred and dissolved at a constant temperature of 60 ℃ for 1 to 2 hours to obtain a uniform mixed solution, which was taken out after cooling and then observed with an FE-SEM as a control sample, and as shown in fig. 1 (a), it was found that the gelatin material had substantially no holes on the surface and had a large pore diameter.

The composite hemostatic material obtained in the step (2) of example 1 was freeze-dried, and observed by FE-SEM, and as shown in FIG. 1 (b), it was found that the composite hemostatic material had relatively small pore diameters and an increased number of pores.

Comparative example 2

Examination of polyvinyl alcohol molecular weight:

a preparation method of a hemostatic material, referring to example 1, is different in that polyvinyl alcohol with a molecular weight of 7.8 ten thousand is selected for preparation, and the specific steps are as follows:

(1) Adding 3g of polyvinyl alcohol with the molecular weight of 7.8 ten thousand and 10g of gelatin into a flask filled with 50mL of deionized water at normal temperature, stirring and dissolving for 1h at the constant temperature of 90 ℃ to obtain a uniform mixed solution;

(2) Adding 10g of tannic acid into the uniform mixed solution in the step (1), keeping the temperature at 60 ℃ unchanged, and stirring until the tannic acid is self-assembled to obtain the composite hemostatic material.

Comparative example 3

Examination of polyvinyl alcohol molecular weight:

a preparation method of a hemostatic material, referring to example 1, is different in that polyvinyl alcohol with a molecular weight of 14 ten thousand is selected for preparation, and the specific steps are as follows:

(1) 3g of polyvinyl alcohol with a molecular weight of 14 ten thousand and 10g of gelatin are added into a flask filled with 50mL of deionized water at normal temperature, and stirred and dissolved for 1h at a constant temperature of 90 ℃ to obtain a uniform mixed solution.

(3) And (3) taking out the composite material in the step (2), putting the composite material into a vacuum drying oven, drying at 60 ℃ for 24 hours, taking out the composite material, and grinding the composite material to obtain the general composite hemostatic powder.

Comparative example 4

Examination of catechol component-containing compounds:

a preparation method of hemostatic material, referring to example 1, is different in that tannic acid is replaced by gallic acid for preparation, and the specific steps are as follows:

(2) Adding 10g of gallic acid into the uniform mixed solution in the step (1), keeping the temperature at 60 ℃ unchanged, and stirring until the self-assembly is carried out to obtain a composite hemostatic material;

Experimental example 1

The composite hemostatic gel of example 1 and the gelatin of comparative example 1 were each taken and measured at 1 to 100 rad.s using a rotarheometer ^-1 Typical rheological behavior of the two colloids under the conditions of (2) is shown in figure 2. It can be seen that the composite hemostatic gel has better viscosity.

Experimental example 2

Cutting the composite hemostatic gel obtained in step (2) of example 1 and gelatin obtained in comparative example 1 into small pieces with a side length of 2cm and a thickness of 0.5cm, placing into a pore plate, and dripping 50uL of 10% above the material ⁷ CFU/mL bacterial liquid (bacterial liquid comprises staphylococcus aureus, escherichia coli and methicillin-resistant staphylococcus aureus, each single bacterial liquid is taken for respective experiments), and is respectively cultured at 37 ℃ for 3, 6, 9, 12 and 24 hours, then the bacterial liquid is taken out, surface bacteria are completely washed by sterile water, 20uL of bacterial suspension is taken out and is uniformly coated on a sterile culture medium flat plate, and then the bacterial liquid is placed in a constant temperature incubator for inversion culture at 37 ℃ for 24 hours. The living bacteria counting method is adopted for culture counting, and the dynamic bacteria inhibition rate is calculated, and the result is shown in figure 3, so that the bacteria inhibition effect of the composite hemostatic material is obviously higher than that of gelatin.

Experimental example 3

The composite hemostatic material prepared in example 1 was selected, and the shear adhesion and tensile adhesion strength of iron sheets, glass, PVC plastic and pigskin were examined. For the shear adhesion test, an adhesion sample having an adhesion area of 2.5cm wide and 1cm long was prepared, and the shear strength was determined by dividing the maximum force by the adhesion area at a constant tensile speed of 50mm/min, and the result was shown in fig. 4 (a). For the stretch-adhesion test, an adhesion sample having an adhesion area of 2.5cm wide and 2.5cm long was prepared, and the tensile strength was determined by dividing the maximum force by the adhesion area at a constant tensile speed of 50mm/min, and the result was shown in FIG. 4 (b). It can be seen that the composite hemostatic gel has good adhesion to various materials.

Experimental example 4

A mass (denoted as m 1) of the composite hemostatic material obtained in example 1 was weighed, immersed in a solution containing 3% of an acidic protease, oscillated at a speed of 100rpm at 37℃and the residual mass (denoted as m 2) of the material was measured after 24, 48, 72 and 168 hours. The remaining mass fraction was calculated as the ratio of m2 divided by m1, and the result is shown in fig. 5, it can be seen that the composite hemostatic material has good bioabsorbable properties.

Experimental example 5

The in vivo hemostatic potential of the composite material is evaluated by adopting a rat tail-breaking model, and male SD rats with weights of 230-250 g are selected. Prior to the experiment, animals were anesthetized by intraperitoneal injection of chloral hydrate (10%). The 50% length tail was then cut with a surgical cutting tool and allowed to dwell in air for 15 seconds to ensure continued blood loss. Next, hemostasis was performed with gauze, the composite material in example 1 and comparative examples 2 to 4, a blank control was not subjected to any hemostasis treatment, and the amount of bleeding and the hemostasis time of each group were quantitatively analyzed, and the results are shown in fig. 6. It can be seen that only the composite hemostatic material provided in the embodiment 1 of the present invention has the characteristics of small blood loss, fast hemostatic speed and short blood loss time, while the hemostatic materials obtained in other comparative examples have poor effects, the blood loss time of the embodiment 1 is less than 70s, and the blood loss amount is not more than 300mg.

The above experiments were performed with the composite hemostatic materials obtained in examples 2 and 3, and the obtained results were similar to those of the sample in example 1, and all showed better adhesion, bacteriostasis, bioabsorbable property and hemostatic performance, wherein the blood loss times of example 2 and example 3 were 100s and 108s, respectively, and the blood loss amounts were 390mg and 402mg, respectively, and it was seen that the hemostatic effect was slightly lower than that of example 1.

While specific embodiments of the invention have been described in detail in connection with the examples, it should not be construed as limiting the scope of protection of the patent. Various modifications and variations which may be made by those skilled in the art without the creative effort are within the scope of the patent described in the claims.

Claims

1. The bioabsorbable composite hemostatic material is characterized by comprising the following raw material components: polyvinyl alcohol, gelatin and tannic acid, wherein the molecular weight of the polyvinyl alcohol is Fan Wei and 30000Da, and the weight ratio of the polyvinyl alcohol to the gelatin to the tannic acid is 0.3:1:1.

2. The bioabsorbable composite hemostatic material of claim 1, wherein the gelatin has a gel strength of 100-300 g Bloom.

3. A method of preparing a bioabsorbable composite hemostatic material as claimed in claim 1 or claim 2, comprising the steps of:

(2) Adding tannic acid into the mixed solution obtained in the step (1) according to the weight ratio, and continuously stirring at 60 ℃ to enable the tannic acid to self-assemble to obtain the bioabsorbable composite hemostatic material.

4. A method according to claim 3, wherein the heating temperature in step (1) is 90 ℃, and the stirring and dissolving time is 1 to 2 hours.

5. The method of producing according to claim 3, further comprising the step (3): and (3) carrying out vacuum drying on the composite hemostatic material obtained in the step (2), and grinding to obtain hemostatic powder.

6. The method according to claim 5, wherein the vacuum drying conditions are: drying in a vacuum oven at 60deg.C for 24 hr.

7. Use of a bioabsorbable composite hemostatic material according to any of claims 1-2 or made by the method of any of claims 3-6, comprising preparing the composite hemostatic material into a wound dressing for acute wound hemostasis.

8. The use of claim 7, further comprising preparing the composite hemostatic material as an antimicrobial dressing.