CN113908329B

CN113908329B - Implantable hydrogel dressing and preparation method thereof

Info

Publication number: CN113908329B
Application number: CN202111150587.0A
Authority: CN
Inventors: 孙陆军; 曹瑾; 潘璟弘; 潘海江
Original assignee: Horizon International Beijing Medical Devices Co ltd
Current assignee: Horizon International Beijing Medical Devices Co ltd
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2022-07-08
Anticipated expiration: 2041-09-29
Also published as: CN113908329A

Abstract

The invention discloses an implantable hydrogel dressing and a preparation method thereof. The dressing comprises the following components in percentage by mass: hydroxybutyl chitosan: 0.1% -10%; gel enhancer: 0.1-10%; water: and (4) the balance. The preparation method comprises the following steps: (1) respectively weighing hydroxybutyl chitosan, a gel reinforcing agent and other auxiliary materials according to the mass percentage, mixing, adding water, and dissolving for 1-48 hours at a certain temperature; (2) intermittent slow stirring is carried out during the dissolving period, and a certain stirring speed and stirring time are controlled to ensure that the dissolution is complete; (3) and then the subsequent filtration sterilization or moist heat sterilization is carried out to obtain sterile solution, namely the implantable hydrogel dressing. According to the invention, by selecting a proper gel reinforcing agent, the prepared implantable hydrogel dressing has a certain strength after being solidified at body temperature, and is not easy to be scattered by touch during use and operation; can meet the requirements of filtration sterilization or damp-heat sterilization, and is particularly suitable for being used as a surface deep tissue or an in-vivo implanted dressing.

Description

Implantable hydrogel dressing and preparation method thereof

Technical Field

The invention belongs to the technical field of medicine and health, and particularly relates to a reinforced implantable hydrogel dressing capable of being sterilized by heat and moisture and a preparation method thereof.

Background

Chitosan is a natural high-molecular polycation polysaccharide, has the advantages of good biocompatibility, no immunogenicity, no toxic or side effect and good biological safety, also has various effects of stopping bleeding, easing pain, resisting bacteria, resisting infection and the like, can promote wound healing, is easy to prepare into a membrane, and has good performance for preparing various dressings. The chitosan-based materials have been developed over decades, through the first and second generation materials, and have been developed to the third stage.

The first generation of chitosan materials are chitin extracted from shells of crustaceans such as shrimp, crab, etc. and chitosan obtained by further deacetylation. Chitin is insoluble in common solvents, chitosan is soluble in partial dilute acid solution, but neither is soluble in neutral aqueous solution. The second generation of chitosan material is prepared by grafting soluble groups on the molecules of chitin or chitosan to make them become water-soluble materials, and the representative materials are derivatives such as carboxymethyl chitin and carboxymethyl chitosan. The material solves the problem that the first generation chitosan material is insoluble in water, solves the problem that the acidic solution of the first generation chitosan material can not enter the body for use in the medical field, and greatly expands the application of the chitosan material in the human body.

The third generation of chitosan material is made into intelligent chitosan biomaterial by grafting intelligent groups on chitin or chitosan molecules, and comprises temperature sensitive intelligent material, pH sensitive biomaterial, pressure sensitive biomaterial, magnetic sensitive biomaterial and the like. Among them, chitosan materials obtained by grafting hydroxybutyl groups are widely used due to their excellent temperature sensitivity. The hydroxybutyl chitosan material not only solves the problem of water insolubility of the first generation of biological materials, but also has the temperature sensitivity.

Up to now, there are hundreds of chitosan products registered by the national food and drug administration for nursing burns, scalds, surgical incisions and the like, most of which use a first-generation chitosan material as a base material, the preparation method of the chitosan material is relatively simple and has low cost, but the chitosan material can only be dissolved in a partial acid solution and cannot be used in vivo, so the application range of the chitosan material is limited.

The product using the second generation chitosan material as the basic material is less than ten, the material overcomes the defect that the first generation material is insoluble in water, can be dissolved in a wide pH value range, has good biocompatibility, can be used in a human body, but the solution of the material has fluidity after being applied to the human body, and cannot stay in a diseased part for a long time to play a role.

The product taking the third generation chitosan as the basic material only has a product of temperature-sensitive hydroxybutyl chitosan wound dressing at present. The product is temperature sensitive, i.e. the product is in solution state at low temperature (below its gel temperature), and can be transformed into a gel state which can not flow after being heated up gradually and being higher than its gel temperature, for example, after reaching the body temperature of 37 ℃. This property allows the material to be immobilized and to function for a long period of time after it is applied to the affected area.

The temperature-sensitive hydroxybutyl chitosan wound dressing has good fluidity at low temperature, can be used on wound surfaces in almost any shape, including plane type, wrinkle type, gap type and the like, is changed into non-flowing gel after being used and is attached to the wound surfaces, and cannot be lost due to change of body positions, so that the long-term treatment effect is achieved, and the problems that the material such as second-generation carboxymethyl chitosan has high fluidity and is easy to leave the wound surface parts needing barriers are solved. Therefore, the hydroxybutyl chitosan material has good wound healing promotion and hemostasis performance.

Patent application publication No. CN 102276756 a and patent application publication No. CN 101284884 a both disclose methods for preparing hydroxybutyl chitosan, but no further preparation is available as a product for clinical use.

Patent application with publication number CN 109646393A discloses a temperature-sensitive gel for body surface wound repair, which comprises the raw material components of auxiliary materials such as hydroxybutyl chitosan, glycerol or propylene glycol and water, but is only used for body surface wound repair, and does not consider whether the formula is suitable for deep body surface or in vivo.

When the hydroxybutyl chitosan solution is implanted into a body as a dressing, the hydroxybutyl chitosan solution can flow at low temperature and is solidified into white gel at body temperature, but the white gel has low strength, is easy to break under the action of extremely small external force and cannot be gathered together again, so that the use strength is greatly reduced. This situation has led to formulations of this type that are not truly clinically useful.

In addition, the hydroxybutyl chitosan solution needs to be subjected to filtration sterilization or moist heat sterilization in the preparation process, and different problems also exist. In moist heat sterilization, the sterilization parameters are typically 121 ℃, 15 minutes or 121 ℃, 30 minutes, at which temperature hydroxybutyl chitosan solute in solution will aggregate out and be irreversible, i.e. not resolubilizable by standing at low temperatures. This results in sterilization being able to be carried out only by means of filter sterilization. In the filtration sterilization, if the temperature of the solution is controlled to be slightly increased, the molecules in the solution are aggregated, so that gel is generated, and the filtration speed is very slow and even difficult to perform. In addition, in the process of using filtration sterilization, not only the process control in the production is required to be particularly strict and the aseptic operation process is added, but also the sterility guarantee level of the final product can only reach 10^-3Cannot achieve the conventional sterile product 10^-6Sterility Assurance Level (SAL) requirements.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide a moisture and heat sterilizable reinforced implantable hydrogel dressing for deep wound surface on body surface or in vivo, the solution of which has a certain strength after being solidified at body temperature and is not easily shattered by touch during the operation; and the problem that the hydroxybutyl chitosan material cannot be filtered due to precipitation caused by temperature fluctuation or cannot be sterilized by moist heat due to gel precipitation is avoided.

It is another object of the present invention to provide a method for preparing the above implantable hydrogel dressing.

Through intensive research, the invention finds that the reason for causing the gel breakage or aggregation precipitation of the hydroxybutyl chitosan is that at body temperature or high temperature, the hydrophobic groups of the hydroxybutyl chitosan in the solution are exposed, and the hydroxybutyl chitosan generates repulsion action with strongly polar ions dissociated from substances such as sodium chloride in the solution, so that the hydrophobic parts are aggregated, namely the hydroxybutyl chitosan molecules are aggregated, and therefore, the strongly polar ionic osmotic pressure regulator commonly used in pharmacopoeia such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, potassium nitrate, sodium sulfate and the like cannot be used for being compatible with the hydroxybutyl chitosan preparation under the conventional conditions. The polar group-containing substance with relatively low polarity but capable of being dissolved in water, such as hydroxyl or amino, and the like, is dissolved and compatible with the hydroxybutyl chitosan, the solution is body fluid at low temperature, and is converted into non-flowing gel at body temperature, the gel can not be scattered under external force at the moment, and has higher strength, the substance not only has the function of osmotic pressure regulation, but also improves and enhances the strength of the gel, the gel enhancer is polyalcohol substances containing three or more hydroxyl groups, such as glycerol, mannitol, sorbitol, and the like, and oligosaccharides containing 2-12 monosaccharide units, and the gel enhancer comprises but not limited to: sucrose, lactose, maltose, trehalose, cellobiose, gentiobiose, raffinose, xylothreose, cyclodextrin, or the like.

The technical scheme of the invention is as follows:

an implantable hydrogel dressing, characterized in that the dressing comprises the following mass components:

hydroxybutyl chitosan: 0.1% -10%;

gel enhancer: 0.1-10%;

water: the balance;

the gel enhancer is a polyalcohol substance containing three or more hydroxyl groups or oligosaccharide containing 2-12 monosaccharide units.

The polyol materials include, but are not limited to: glycerol, mannitol, sorbitol, or the like.

Such oligosaccharides include, but are not limited to: sucrose, lactose, maltose, trehalose, cellobiose, gentiobiose, raffinose, xylothreose, cyclodextrin, or the like.

Further, the dressing also comprises other auxiliary materials: 0.1-10%; the other auxiliary materials include but are not limited to the following substances, such as cosolvent, stabilizer, bacteriostatic agent, antioxidant, acid-base regulator, surfactant and the like, and specifically include various amino acids or polymers, sucrose fatty acid ester, sorbitan oleate, polysorbate, sodium dodecyl sulfate, polyoxyethylene castor oil, gelatin, agar, polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, inorganic acid, inorganic base, organic acid, organic base and the like.

Further, preferred dressings comprise the following mass components:

hydroxybutyl chitosan: 1% -5%;

gel enhancer: 0.5% -5%;

and (3) other auxiliary materials: 0.5-3%;

water: and (4) the balance.

Because the implantable hydrogel dressing has unique temperature sensitivity, the composition solution is in a flowable liquid state at low temperature (such as 2-8 ℃) and is solidified into hydrogel with certain strength at body temperature, the obtained composition solution has high viscosity at low temperature and is not in a flowable liquid state due to the fact that the stirring speed is high and the continuous stirring time is long by adopting a conventional dissolution stirring mode without control, the temperature sensitivity of a final product is not obvious, and the convenience and the effect in clinical use are greatly influenced.

Accordingly, the method for preparing the implantable hydrogel dressing of the present invention comprises the following steps:

(1) respectively weighing hydroxybutyl chitosan, a gel reinforcing agent and other auxiliary materials according to the mass percentage, mixing, adding water, and dissolving for 1-48 hours at a certain temperature; (2) intermittent slow stirring is carried out during the dissolving period, and a certain stirring speed and stirring time are controlled to ensure that the dissolution is complete; (3) and then the subsequent filtration sterilization or moist heat sterilization is carried out to obtain sterile solution, namely the implantable hydrogel dressing.

The certain temperature is 0-15 ℃, preferably 0-10 ℃.

The intermittent slow stirring speed is 0-100rpm, preferably 0-50 rpm.

The intermittent slow stirring time is 0 to 2 hours, preferably 0 to 1 hour.

The invention has the advantages that:

1. by selecting a proper gel reinforcing agent, the prepared implantable hydrogel dressing has good temperature sensitivity, good fluidity at low temperature (such as 2-8 ℃), certain strength after being solidified at body temperature, and difficult shattering caused by touch during use and operation, and meets the clinical application requirements.

2. The implantable hydrogel dressing can meet the requirements of further filtration sterilization or damp-heat sterilization after the solution is prepared, and the problems that the materials are separated out due to temperature fluctuation to cause the materials to be incapable of being filtered or agglomerated after the damp-heat sterilization and the like are solved.

3. The implantable hydrogel dressing can be used for nursing various wounds on the superficial layer of the body surface and is more suitable for deep tissues of the body surface or implantation in vivo. Can be used for deep burn nursing, deep wound packing and hemostasis, tissue adhesion prevention after in vivo implantation or placement, in vivo hemostasis and the like.

4. The implantable hydrogel dressing can be used as a drug carrier for deep tissues or in vivo implantation after being mixed with drugs such as growth factors for promoting healing, platelet-rich plasma, analgesic drugs, anti-inflammatory drugs and the like.

Drawings

FIG. 1 is a graph showing the gel temperature test of the product of example 1.

FIG. 2 is a graph comparing the gel state of the sample of example 2 and the sample of comparative example 1 at 2 ℃ to 8 ℃.

FIG. 3 is a graph showing a comparison of the gel state of the sample of example 2 and the sample of comparative example 1 after the temperature is raised to 37 ℃.

Fig. 4 is a graph comparing the gel state of the sample of example 2 and the sample of comparative example 1 after being manually thrown by human hands.

FIG. 5 is a graph comparing the shear viscosity of the sample of example 3 and the sample of comparative example 2.

Detailed Description

The invention is explained in further detail below by means of specific embodiments with reference to the drawings.

Example 1:

hydroxybutyl chitosan: 2 percent;

glycerol: 2 percent;

water: 96 percent.

Respectively weighing hydroxybutyl chitosan and glycerol according to the proportion, mixing, adding water, preserving heat and dissolving at the temperature of 3-8 ℃, intermittently stirring at the rotating speed of 10rpm for 1 hour, completely dissolving after 24 hours, filtering and sterilizing, and aseptically packaging to obtain an aseptic solution.

Example 2:

hydroxybutyl chitosan: 3 percent;

sorbitol: 5 percent;

water: 92 percent.

Weighing hydroxybutyl chitosan and sorbitol according to the proportion, mixing, adding water, preserving heat and dissolving at the temperature of 5-10 ℃, intermittently stirring at the rotating speed of 20rpm for 20 minutes for total stirring time, preserving heat for 48 hours, filtering, sterilizing and packaging aseptically to obtain an aseptic solution.

Example 3:

hydroxybutyl chitosan: 5 percent;

mannitol: 4.8 percent;

water: 90.2 percent.

Weighing hydroxybutyl chitosan and sorbitol according to the proportion, mixing, adding water, preserving heat and dissolving at the temperature of 5-15 ℃, intermittently stirring at the rotating speed of 80rpm for 30 minutes in total stirring time, preserving heat for 48 hours, filtering, sterilizing and packaging to obtain the sterile solution.

Example 4:

hydroxybutyl chitosan: 5 percent;

beta-cyclodextrin: 2.0 percent;

polyethylene glycol 400: 0.5 percent;

water: 92.5 percent.

Respectively weighing hydroxybutyl chitosan, beta-cyclodextrin and polyethylene glycol according to the proportion, mixing, adding water, dissolving at the temperature of 0-5 ℃, intermittently stirring at the rotating speed of 100rpm for 5 minutes, keeping the temperature for 48 hours, filtering, sterilizing and packaging aseptically to obtain an aseptic solution.

Example 5:

hydroxybutyl chitosan: 3 percent;

cellobiose: 5 percent;

water: 92 percent.

Respectively weighing hydroxybutyl chitosan and cellobiose according to the proportion, mixing, adding water, preserving heat and dissolving at the temperature of 5-10 ℃, intermittently stirring at the rotating speed of 20rpm, keeping the temperature for 20 minutes totally, preserving heat for 48 hours, packaging by a subsequent pre-filling and sealing syringe, and performing damp-heat sterilization to obtain the sterile solution.

Example 6: osmotic pressure test

The solutions of examples 1 to 5 were subjected to an osmolarity test using an osmolarity tester model SMC 30D, and the test results were: 302mOSmol/kg, 311mOSmol/kg, 316mOSmol/kg, 292mOSmol/kg, 285 mOSmol/kg. The osmotic pressure requirements of the implant products are met, namely 270 mOSmol/kg-350 mOSmol/kg.

Example 7: solubility test

Weighing a certain mass of hydroxybutyl chitosan, deducting water content, dissolving in pure water at different temperatures, and stirring properly; after 48 hours, a uniform portion of the solution was taken, dried at 105 ℃ and constant weight, and the dissolved concentration was calculated. As can be seen from the data in Table 1, the hydroxybutyl chitosan was soluble at 4 ℃ and 10 ℃ both at a concentration of greater than 10%, whereas it was soluble at 15 ℃ at 1.66%. While temperatures above 20 ℃ are slightly or poorly soluble. These data also further support the selection of the dissolution temperature in examples 1-5.

TABLE 1 solubility data for hydroxybutyl chitosan

Serial number	Temperature/. degree.C	Maximum dissolved concentration	Solubility in water
				1	4	＞10%	Is easy to dissolve
2	10	＞10%	Is easy to dissolve
				3	15	1.662%	Soluble in water
4	20	0.264%	Slightly soluble
				5	30	0.003%	Is difficult to dissolve

Example 8: gel temperature test

The solution of example 1 was subjected to a gel temperature test using a rheometer, where the intersection of the storage modulus (G') and the dissipation modulus (G ") is the gel temperature, as shown in fig. 1. As can be seen from the figure, the gel temperature of the sample is 15.9 ℃, meets the requirement of gel below the body temperature, and can be used as a deep tissue or an in-vivo implantation dressing.

Example 9: gel State and gel Strength comparison test

The sample (No. 1) of example 2 and the sample (No. 2) of comparative example 1, which is prepared from 0.9% sodium chloride solution and has a hydroxybutyl chitosan concentration of 3wt%, were subjected to different temperature conditions and gel strength tests, and a clinical application method was simulated, in which each solution was stabilized at 2-8 ℃ for 20 minutes or more, and then taken out and placed in a temperature environment of 37 + -1 ℃ to be converted into a non-flowing gel. And crushing the gels into a relatively cracked gel state by external force respectively, collecting and placing the gel state on a test platform of a rheometer, and testing the gel strength at 37 +/-0.2 ℃. The results are shown in table 2, and the sample states are shown in fig. 2 to 4.

As can be seen from the data in the table, the strength value of the sample prepared by using the formula in the patent is 293.9Pa after the temperature is raised and the sample is not scattered after being forcibly thrown, so that the strength is very high; the sample prepared by the conventional ionic osmotic pressure regulator has the strength of only 8.4Pa after being gelled by heating, is easy to break after being thrown by hands, and is still in a broken state after being kept warm for more than 30 minutes. This data also confirms that the formulation of this patent is significantly superior to samples prepared from conventional ionic osmolytes and can be used clinically, which is not of practical clinical significance.

The samples of example 1 and examples 3-5 were tested for gel strength of 205.3Pa, 562.5Pa, 530.8Pa and 316.7Pa, respectively.

TABLE 2 gel State and gel Strength Properties of the samples of example 2 and of comparative example 1

Example 10:

the shear viscosity test was performed on the sample prepared in example 3 (labeled 1 in fig. 5) and comparative example 2 (labeled 2 in fig. 5) obtained using the same formulation but prepared by dissolving the sample at 5-15 c with constant stirring at 150rpm for 48 hours, and the results are shown in fig. 5. Sample 1 is a typical newtonian fluid over the range of shear rates tested, while sample 2 is a non-newtonian fluid. At a shear rate of 1s^-1The shear viscosity of sample 2 was 9 times that of sample 1. The sample 1 at 4 ℃ has good fluidity, while the sample 2 has high viscosity and poor fluidity, almost loses the temperature sensitivity and has reduced clinical use value, thereby proving that the sample 1 has good fluidity and the sample 2 has high viscosity and poor fluidity, and the clinical use value is reduced by apparent visual observationThe dissolving temperature, the stirring speed and the stirring time in the preparation process are clear to have great influence on the product performance.

Example 11:

to confirm the deep wound repair effect of the sample prepared in example 3 of the present invention, animal experiments were performed. Rats not using medical materials were selected as a control group, rats treated with the samples prepared in example 3 of the present invention were selected as a test group, and the wound surface of the animal model was a circle having a diameter of 2 cm. Through observation, the following results are found: wound area of control group rat is 0.8cm after 10 days of operation²Left and right; the area of the wound surface of the test group is 0.2cm²On the other hand, the animal index is normal. The wound area of the control rat is 0.2cm after 21 days of operation²On the left and right, the rat wound surface of the test group healed completely. Therefore, the prepared sample has good deep wound repair effect.

Finally, it should be noted that: the above embodiments are only intended to illustrate the technical solution of the present invention and not to limit the same, and a person of ordinary skill in the art can make modifications or equivalents to the specific embodiments of the present invention with reference to the above embodiments, and any modifications or equivalents without departing from the spirit and scope of the present invention are within the scope of the claims of the present invention.

Claims

1. A method of making an implantable hydrogel dressing comprising the steps of:

(1) the method comprises the following steps of: hydroxybutyl chitosan: 0.1% -10%, gel enhancer: 0.1-10%, water: respectively weighing the rest, namely respectively weighing hydroxybutyl chitosan and a gel reinforcing agent, mixing, adding water, and dissolving for 1-48 hours at the temperature of 0-15 ℃; the gel enhancer is a polyalcohol substance containing three or more hydroxyl groups or oligosaccharide containing 2-12 monosaccharide units; (2) intermittent slow stirring is carried out during the dissolving period, and the stirring speed of 10-100rpm and the stirring time of 5 minutes-2 hours are controlled to ensure that the dissolution is complete; (3) and then the subsequent filtration sterilization or moist heat sterilization is carried out to obtain sterile solution, namely the implantable hydrogel dressing.

2. The method of preparing an implantable hydrogel dressing according to claim 1, wherein step (1) further comprises the following additional excipients: 0.1 to 10 percent.

3. A method of making an implantable hydrogel dressing according to claim 1 wherein said temperature is in the range of 0 ℃ to 10 ℃.

4. The method of making an implantable hydrogel dressing according to claim 1 wherein the intermittent slow agitation is at a speed of 10 to 50 rpm.

5. A method of making an implantable hydrogel dressing according to claim 1 wherein the intermittent slow agitation is for a period of time in the range of 5 minutes to 1 hour.

6. A method of making an implantable hydrogel dressing according to claim 1 wherein the polyol is glycerol, mannitol or sorbitol.

7. The method of claim 1, wherein the oligosaccharide comprises sucrose, lactose, maltose, trehalose, cellobiose, gentiobiose, raffinose, xylothreose, or cyclodextrin.

8. The method of claim 2, wherein the other excipients comprise a solubilizing agent, a stabilizing agent, a bacteriostatic agent, an antioxidant, an acid-base modifier, and a surfactant.