Pre-potting injection gel preparation and application thereof

Abstract

The invention belongs to the technical field of biomedical materials, and discloses a pre-potting injection gel preparation and application thereof. The pre-potting injection gel preparation provided by the invention is a gel particle preparation which is prepared by mixing micron-sized gel particles formed by crushing prefabricated gel with a carrier solution, defoaming, and then filling into a pre-potting injection instrument for preservation. The prefabricated gel block is prepared by mixing an aldehyde-terminated multi-arm polyethylene glycol solution and a multi-amino compound solution in equal volume. The pre-potting injection gel preparation provided by the invention can meet clinical application requirements in the aspects of soft tissue filling, radiotherapy isolation protection, vascular embolism and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a pre-filled injection gel preparation and application thereof. Background Art

[0002] In situ injectable gel preparations are typically multi-component solution preparations that, when injected into the body, gel under physiological conditions. Their advantage lies in their ability to form gel blocks in situ within the body, better adapting to complex physiological environments and irregular tissue shapes, and closely adhering to surrounding tissues. In drug delivery applications, they can achieve precise drug release at specific locations. However, in situ injectable gel preparations also have some shortcomings. Their gelation process primarily relies on chemical reactions between multi-component solutions, such as redox reactions and Schiff base reactions. This chemical reaction process can be affected by a variety of factors in the body, such as temperature, pH, and fluid dilution. This makes it difficult to precisely control the gelation time and extent during actual clinical use, posing a significant challenge to both doctors performing surgical operations and patients. Furthermore, in clinical use, in situ gels typically require on-site preparation or complex operating procedures, making them inconvenient for medical staff to operate during emergency treatments or when operating space and time are limited.

[0003] Pre-filled injectable gel preparations typically come pre-filled with gel particles in a syringe, allowing the physician to inject directly. Compared to in situ injectable gel preparations, they are easier and quicker to use, requiring no on-site preparation, reducing the number of steps and contamination risks. Furthermore, because the gel particles undergo chemical reactions during the preparation process, their physical and chemical properties are relatively stable and less affected by environmental factors within the body. Common pre-filled gel preparations, such as cross-linked sodium hyaluronate gel preparations, use commonly used cross-linking agents such as divinyl sulfone, 1,4-butanediol diglycidyl ether, and epichlorohydrin. Because these chemical cross-linking agents are generally highly toxic, additional dialysis, extraction, and leaching procedures are required after gel preparation to remove the cross-linking agent, keeping the cross-linking agent residue below a certain limit and reducing the toxicity of the gel preparation. This is exemplified by related sodium hyaluronate gel patents such as CN 102731801B. The process involves numerous steps and is relatively complex.

[0004] Polyethylene glycol and its derivatives (PEG) are biomaterials with promising commercial development potential due to their excellent biocompatibility, easily regulated molecular weight, narrow molecular weight distribution, and excellent batch-to-batch stability. PEG has terminal hydroxyl groups, which can be easily modified through chemical reactions to form carboxyl, amino, or sulfhydryl groups. Furthermore, with the growing popularity of minimally invasive surgery, injectable hydrogel technology offers high clinical value due to its ease of use and minimal risk to patients, while minimizing harm to patients.

[0005] The application of aldehyde-terminated multi-arm polyethylene glycol is mostly presented in the form of in situ injectable gel preparations, and it has not yet been found to be used in the form of pre-filled gel particle preparations. In addition, the limitation of the application of pre-filled gel preparations in the existing technology is mainly that the dispersibility and stability of the gel particles are difficult to maintain during sterilization and storage. Summary of the Invention

[0006] The purpose of the present invention is to make up for the deficiencies of the existing technology and disclose a pre-filled injectable gel preparation and its application, which can meet the clinical application requirements of soft tissue filling, radiotherapy isolation protection, vascular embolism and the like.

[0007] In a first aspect, the present invention provides a prefilled injectable gel preparation, which is a gel particle preparation comprising micron-sized gel particles formed by crushing a prefabricated gel, mixing the particles with a carrier solution, degassing the mixture, and then filling the mixture into a prefilled injectable device for storage. The prefabricated gel block is prepared by mixing equal volumes of an aldehyde-terminated multi-arm polyethylene glycol solution and a polyamino compound solution, wherein the aldehyde-terminated multi-arm polyethylene glycol solution is prepared by mixing the aldehyde-terminated multi-arm polyethylene glycol with a phosphate buffer solution, and the pH of the prepared aldehyde-terminated multi-arm polyethylene glycol solution is 3 to 6; the polyamino compound solution is prepared by mixing a polyamino compound with an alkaline solution, and the pH of the prepared polyamino compound solution is 7 to 9; and the particle size of the gel particles ranges from 30 to 800 microns.

[0008] The carrier solution comprises at least a mixture of linear polyethylene glycol and a neutral solvent, wherein the neutral solvent is purified water or a neutral buffer solution. As another embodiment of the present application, the carrier solution further comprises glycerol. The pH of the carrier solution is 6.5 to 7.5, and the molecular weight of the linear polyethylene glycol is 500 to 100,000 Da. The concentration of the linear polyethylene glycol in the prepared carrier solution is 1% to 60% w / w, where w / w represents the mass of the solute / the total mass of the solution.

[0009] As a preferred embodiment of the present application, the neutral buffer solution is selected from physiological saline or phosphate buffer, with a pH of 6.5 to 7.5, more preferably a phosphate buffer with a pH of 7.4.

[0010] As a preferred embodiment of the present application, in the aldehyde-terminated multi-arm polyethylene glycol, the aldehyde groups and the multi-arm polyethylene glycol can be connected by ester bonds, amide bonds, ether bonds, urethane bonds, imine bonds or urea bonds, the number of arms of the aldehyde-terminated multi-arm polyethylene glycol is 4 to 8, the molecular weight is not less than 2000 Da, and the aldehyde groups are selected from one or more of aromatic aldehydes and alkyl aldehydes. As a more preferred embodiment of the present application, in order to make the gel particles have development properties, the aldehyde-terminated multi-arm polyethylene glycol is further modified to iodinated aldehyde-terminated multi-arm polyethylene glycol, wherein at least one arm of the multi-arm polyethylene glycol is terminated by an aldehyde group, and at least one arm is terminated by an iodine-substituted phenyl group; the aldehyde group or iodine-substituted phenyl group is connected to the multi-arm polyethylene glycol by an ester bond, amide bond, ether bond, urethane bond, imine bond or urea bond.

[0011] As a preferred embodiment of the present application, the polyamino compound is composed of one or more of polylysine, polyethyleneimine, chitosan, and gelatin.

[0012] As a preferred embodiment of the present application, the aldehyde-terminated multi-arm polyethylene glycol solution is an aldehyde-terminated eight-arm polyethylene glycol solution 8-PEG-CHO with a mass fraction of 10% to 20%, the solvent is a 0.02M phosphate solution, and the pH is 3.81; the molecular weight of the aldehyde-terminated eight-arm polyethylene glycol is 20KDa, and the structural formula is as follows:

[0013]

[0014] The polyamino compound solution is a polylysine (ε-poly-lysine, ε-PL) solution with a mass fraction of 0.65% to 30%, the solvent is a 0.05M sodium hydroxide aqueous solution, and the pH is 7.36; wherein the polylysine has the structural formula shown below and a molecular weight of 3600 to 4300 Da;

[0015]

[0016] Further preferably, the mass fraction of aldehyde-terminated eight-arm polyethylene glycol in the aldehyde-terminated eight-arm polyethylene glycol solution is 20%, the mass fraction of ε-PL in the polylysine solution is 30%, the carrier solution is 20% PEG20K / PBS7.4, and the mass ratio of gel particles to carrier is 1:10.

[0017] As a preferred embodiment of the present application, based on the prefilled injectable gel preparation provided in the first aspect, the prefilled injectable gel preparation is further sterilized. Further preferably, the sterilization treatment can be irradiation sterilization treatment or high temperature and high pressure sterilization treatment.

[0018] Preferably, the fragmentation treatment includes, but is not limited to, chopping the gel with a knife or wire; or grinding in a ball mill, homogenizer, blender, or mortar and pestle; or passing the hydrogel through meshes of different particle sizes by mechanical gravity or compressed gas positive pressure, collecting the fragments, and then passing them through the same mesh or another mesh, repeatedly crushing the gel with positive pressure until the desired size is reached.

[0019] In a second aspect, the present invention also provides the use of the pre-filled injection gel preparation in the preparation of soft tissue filling hydrogels, tissue isolation and protection hydrogels, and vascular embolization hydrogels.

[0020] It should be noted that the percentages (%) and mass fractions involved in the present invention refer to the proportion of the corresponding components in the total solution mass.

[0021] Beneficial effects: The prefilled injectable gel preparation provided by the present application can regulate the degradation time and swelling degree of the gel through the component formula and the carrier solution, and the selected carrier solution can achieve the gel particles prepared by the present application to be stored in the solvent system and maintain good dispersion without aggregation and adhesion after sterilization, thereby reducing the injection resistance of the gel particles. On the other hand, the prefilled injectable gel preparation provided by the present invention can be used as a soft tissue filling hydrogel, a tissue isolation and protection hydrogel, and a vascular embolization hydrogel. When the gel particles in the prefilled injectable gel preparation are injected into the tissue, chemical adhesion and aggregation can occur, thereby reducing the migration of the gel particles and making the in situ filling effect more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a photo of the gel particles of Comparative Example 1 in Test Example 1 after being left to stand for 24 hours;

[0023] Figure 2 This is a photo of the gel particles of Comparative Example 1 in Test Example 1 after being treated with high temperature and high pressure;

[0024] Figure 3 This is a photo of the gel blocks in Test Example 2 after incubation in different carrier solutions at 37°C for 24 hours;

[0025] Figure 4 This is a photo of some gel blocks in Test Example 3 after being treated with high temperature and high pressure.

[0026] Figure 5 The degradation of the gel in different carriers in Test Example 4;

[0027] Figure 6 Actual photos of the gel self-healing test process in Test Example 5;

[0028] Figure 7 This is a photo of the sample status of Example 21 in Test Example 6;

[0029] Figure 8 This is a photo of the sample status of Example 22 in Test Example 6;

[0030] Figure 9 This is a photo of the samples prepared in Comparative Examples 11 and 12 in Test Example 6 after 24 hours;

[0031] Figure 10 This is a photo of the sample prepared in Comparative Example 13 after 24 hours. DETAILED DESCRIPTION

[0032] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. In the following examples, various processes and methods not described in detail are conventional methods well known in the art.

[0033] The present invention is further described in detail below with reference to specific examples and data. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0034] The PEG6K involved in the following examples and comparative examples all represent linear polyethylene glycol with a molecular weight of 6000Da, and the 6000Da linear polyethylene glycol in the following examples and comparative examples are all purchased from Aladdin; PEG20K represents a linear polyethylene glycol with a molecular weight of 20000Da, and the 20000Da linear polyethylene glycol used in the following examples and comparative examples are all purchased from Aladdin.

[0035] The structural formula of the aldehyde-terminated eight-arm polyethylene glycol, 8-PEG-CHO, involved in the following examples and comparative examples is as follows:

[0036]

[0037] Preparation materials of 8-arm PEG-CHO: 8-arm PEG, i.e., 8-arm Poly(ethylene glycol)(HG)[8-armPEG-OH(HG)], with a molecular weight Mn of 20k, was purchased from Xiamen Sinobond Biotechnology, with a product number of 06021800112. Preparation process: According to the synthesis process of benzaldehyde-terminated four-arm polyethylene glycol reported in Section 2.1 of the open document Adv Healthc Mater. 2016 Nov; 5(21): 2813-2822. doi: 10.1002 / adhm.201600720. Epub 2016 Sep 26., 8-arm polyethylene glycol (8-arm-PEG-CHO) terminated with benzaldehyde was prepared by replacing 4-arm PEG in the preparation raw material with 8-arm PEG. The rest of the preparation conditions were exactly the same as those in the above document. The prepared 8-arm-PEG-CHO was used as the raw material of polyethylene glycol derivatives in the following experiments of this application.

[0038] The structural formula of polylysine involved in the following examples and comparative examples is shown below. It was purchased from Aladdin Reagent and has a molecular weight of 3600 to 4300 Da.

[0039]

[0040] Comparative Example 1

[0041] Step S1, preparing component A and component B: preparing a 10% aldehyde-terminated eight-arm polyethylene glycol solution (8-PEG-CHO, 20KDa) in a 0.02M phosphate solution at a pH of 3.81 as component A; preparing a 0.65% polylysine (ε-poly-lysine, ε-PL) solution in a 0.05M sodium hydroxide aqueous solution at a pH of 7.36 as component B;

[0042] Step S2, preparing gel blocks: mixing component A and component B in an equal volume ratio, and letting them stand for 4 hours until component A and component B form gel blocks.

[0043] Step S3, preparing gel particles: grinding the hydrogel blocks with a blender to obtain coarse gel particles, then sieving the coarse gel particles through a 100-300 micron sieve to collect gel particles of 100-300 microns.

[0044] Step S4, filling the gel particles into a vial and sealing the vial to obtain the sample of Comparative Example 1.

[0045] Comparative Example 2

[0046] The only difference between Comparative Example 2 and Comparative Example 1 is that step S4 further includes the steps of: mixing the gel particles with purified water, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Comparative Example 2.

[0047] Comparative Example 3

[0048] The only difference between Comparative Example 3 and Comparative Example 1 is that step S4 further includes the step of mixing the gel particles with PBS 7.4, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Comparative Example 3; PBS 7.4 refers to a phosphate buffer solution with a pH of 7.4. The specific preparation steps of PBS 7.4 are as follows: 8 g of sodium chloride, 0.2 g of potassium chloride, 0.2 g of potassium dihydrogen phosphate, and 2.9 g of sodium dihydrogen phosphate 12 hydrate are weighed, 1 L of purified water is added, and after complete dissolution, a phosphate buffer solution with a pH of 7.4 is obtained.

[0049] Comparative Example 4

[0050] The only difference between Comparative Example 4 and Comparative Example 1 is that step S4 further includes the following steps: mixing the gel particles with 0.9% NaCl, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Comparative Example 4; the specific preparation steps of 0.9% NaCl are: weighing 0.9 g of NaCl, adding 100 g of purified water, and completely dissolving it to obtain a 0.9% NaCl solution.

[0051] Comparative Example 5

[0052] The only difference between Comparative Example 5 and Comparative Example 1 is that step S4 further includes the steps of: mixing the gel particles with 2.6% glycerol, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Comparative Example 5; the specific preparation steps of 2.6% glycerol are: using purified water as a solvent to prepare a 2.6% glycerol aqueous solution.

[0053] Example 1

[0054] The only difference between Example 1 and Comparative Example 1 is that step S4 further includes the steps of mixing the gel particles with a 20% PEG6K / purified water solution, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Example 1; the specific preparation steps of the 20% PEG 6K / purified water solution are: using purified water as a solvent to prepare a 20% mass fraction of PEG6K / purified water solution.

[0055] Example 2

[0056] The only difference between Example 2 and Comparative Example 1 is that step S4 further includes the steps of: mixing the gel particles with a 20% PEG6K / PBS7.4 solution, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Example 2; the specific preparation steps of the 20% PEG 6K / PBS7.4 solution are: using PBS7.4 as a solvent to prepare a PEG6K / PBS7.4 solution with a mass fraction of 20%.

[0057] Example 3

[0058] The only difference between Example 3 and Comparative Example 1 is that step S4 further includes the steps of: mixing the gel particles with a 20% PEG6K / PBS7.4 / glycerol solution, wherein the mass fraction of the gel particles is 60%, and then filling and sealing to obtain the sample of Example 3; the specific preparation steps of the 20% PEG6K / PBS7.4 / glycerol solution are: mixing PBS7.4 and glycerol in a mass ratio of 1:1 to a uniform solution, and using this uniform solution as a solvent to prepare a PEG6K solution with a mass fraction of 20%.

[0059] Test Example 1: Effects of different carriers on the storage and dispersibility of gel particles

[0060] After the gel particle sample of Comparative Example 1 was left at room temperature for 24 hours, it was observed that Figure 1 As shown, the gel particles self-heal to form gel blocks and return to their original state. This is due to the reversibility of the Schiff base chemical bond. The gel particles formed by mechanical cutting and other methods can reversibly recover to the shape of the initial gel block after a period of self-repair. Therefore, the reversible healing reaction of the gel particles in Comparative Example 1 is not conducive to the long-term stable storage of the product. When the gel particles in Comparative Example 1 are provided in the form of a pre-filled syringe, there is a risk that it is difficult to use by push injection in clinical practice. However, if the gel particles are injected into the tissue, the healing reaction of the gel particles is conducive to the tissue anchoring of the gel particles, reducing the risk of particle migration.

[0061] The sealed sample of Comparative Example 1 was immediately sterilized at high temperature and high pressure, that is, at 121°C and 0.1 MPa for 30 minutes. Figure 2 As shown in the figure, before sterilization, the sample was in the state of gel particles. After the sterilization was completed and the sample was allowed to stand at room temperature, the sample changed from colorless and transparent gel particles to whitish and sticky gel blocks. This shows that high temperature and high pressure treatment, on the one hand, will accelerate the Schiff base reaction between gel particles; on the other hand, it will cause a certain degree of dehydration of the gel particles.

[0062] The gel particles were mixed with the above-mentioned different carriers, wherein the mass fraction of the gel particles was 60%, canned and sealed, and subjected to high temperature and high pressure treatment (121°C, 30 min). After the treatment was completed and the sample cooled to room temperature, the effects of different carriers on the gel particles were observed. The results are shown in Table 1.

[0063] Table 1: Effects of different carrier solutions on gel particles

[0064] carrier Sample status after high temperature and high pressure treatment Comparative Example 1 No carrier Gel particle agglomeration Comparative Example 2 purified water Gel particle agglomeration Comparative Example 3 PBS7.4 Gel particle agglomeration Comparative Example 4 0.9% NaCl Gel particle agglomeration Comparative Example 5 2.6% glycerol Gel particle agglomeration Example 1 20% PEG6K / purified water Gel particle dispersion Example 2 20% PEG6K / PBS7.4 Gel particle dispersion Example 3 20% PEG6K / PBS7.4 / glycerol Gel particle dispersion

[0065] In different carriers, the gel particles showed different changes after high temperature and high pressure treatment. For example, in Comparative Examples 1 to 5, the gel particles agglomerated, while the gel particles in Examples 1 to 3 remained dispersed. The above data show that the carrier solution containing linear PEG effectively inhibited the self-healing reaction of the gel particles during the sterilization process. The use of the carriers in Examples 1 to 3 can inhibit the self-healing reaction of the gel particles. When the carriers are removed, the gel particles can re-stimulate the self-healing reaction and form gel blocks.

[0066] It should be noted that, for the samples prepared in the following Comparative Examples 6 to 10 and Examples 4 to 19, in order to facilitate the observation of the swelling changes of the gel in the carrier, the step of preparing the gel blocks into gel particles was omitted in these Examples and Comparative Examples.

[0067] Comparative Example 6

[0068] The only difference between Comparative Example 6 and Comparative Example 3 is that Comparative Example 6 does not have the gel particle preparation step of step S3, and step S1 and step S4 are different. Specifically, the specific operation of step S1 of Comparative Example 6 is: preparing a 20% aldehyde-terminated eight-arm polyethylene glycol solution (8-PEG-CHO, 20KDa), the solvent is 0.02M phosphate solution, pH is 3.81, as component A; preparing a 1.3% polylysine solution, the solvent is 0.05M sodium hydroxide aqueous solution, pH is 7.36, as component B; the specific operation of step S4 is: directly mixing the gel block prepared in step S2 with PBS 7.4, wherein the mass ratio of the gel block to the carrier is 2:1, and then filling and sealing to obtain the sample of Comparative Example 6.

[0069] Comparative Example 7

[0070] The only difference between Comparative Example 7 and Comparative Example 6 is that the mass ratio of the gel block to the carrier in step S4 is 1:1.

[0071] Comparative Example 8

[0072] The only difference between Comparative Example 8 and Comparative Example 6 is that the mass ratio of the gel block to the carrier in step S4 is 1:2.

[0073] Comparative Example 9

[0074] The only difference between Comparative Example 9 and Comparative Example 6 is that the mass ratio of the gel block to the carrier in step S4 is 1:10.

[0075] Comparative Example 10

[0076] The only difference between Comparative Example 10 and Comparative Example 6 is that Comparative Example 10 further omits step S4; that is, in Comparative Example 10, the gel block prepared in step S2 is directly used as a sample.

[0077] Example 4

[0078] The only difference between Example 4 and Comparative Example 6 is that the specific operation of step S4 is: mixing the gel block with 20% PEG6K / PBS7.4, wherein the mass ratio of the gel block to the carrier is 2:1, and then filling and sealing to obtain the sample of Example 4.

[0079] Example 5

[0080] The only difference between Example 5 and Example 4 is that the mass ratio of the gel block to the carrier in step S4 is 1:1.

[0081] Example 6

[0082] The only difference between Example 6 and Example 4 is that the mass ratio of the gel block to the carrier in step S4 is 1:2.

[0083] Example 7

[0084] The only difference between Example 7 and Example 4 is that the mass ratio of the gel block to the carrier in step S4 is 1:10.

[0085] Example 8

[0086] The only difference between Example 8 and Comparative Example 6 is that the specific operation of step S4 is: mixing the gel block with a 40% PEG6K / PBS7.4 solution, wherein the mass ratio of the gel block to the carrier is 2:1, and then filling and sealing to obtain the sample of Example 8; the specific preparation steps of the 40% PEG 6K / PBS7.4 solution are: using PBS7.4 as a solvent to prepare a PEG6K / PBS7.4 solution with a mass fraction of 40%.

[0087] Example 9

[0088] The only difference between Example 9 and Example 8 is that the mass ratio of the gel block to the carrier in step S4 is 1:1.

[0089] Example 10

[0090] The only difference between Example 10 and Example 8 is that the mass ratio of the gel block to the carrier in step S4 is 1:2.

[0091] Example 11

[0092] The only difference between Example 11 and Example 8 is that the mass ratio of the gel block to the carrier in step S4 is 1:10.

[0093] Example 12

[0094] The only difference between Example 12 and Comparative Example 6 is that the specific operation of step S4 is: mixing the gel block with a 20% PEG20K / PBS7.4 solution, wherein the mass ratio of the gel block to the carrier is 2:1, and then filling and sealing to obtain the sample of Example 12; the specific preparation steps of the 20% PEG20K / PBS7.4 solution are: using PBS7.4 as a solvent to prepare a PEG20K / PBS7.4 solution with a mass fraction of 20%.

[0095] Example 13

[0096] The only difference between Example 13 and Example 12 is that the mass ratio of the gel block to the carrier in step S4 is 1:1.

[0097] Example 14

[0098] The only difference between Example 14 and Example 12 is that the mass ratio of the gel block to the carrier in step S4 is 1:2.

[0099] Example 15

[0100] The only difference between Example 15 and Example 12 is that the mass ratio of the gel block to the carrier in step S4 is 1:10.

[0101] Example 16

[0102] The only difference between Example 16 and Comparative Example 6 is that the specific operation of step S4 is: mixing the gel block with a 20% PEG6K / PBS7.4 / glycerol solution, wherein the mass ratio of the gel block to the carrier is 2:1, and then filling and sealing to obtain the sample of Example 16;

[0103] Example 17

[0104] The only difference between Example 17 and Example 16 is that the mass ratio of the gel block to the carrier in step S4 is 1:1.

[0105] Example 18

[0106] The only difference between Example 18 and Example 16 is that the mass ratio of the gel block to the carrier in step S4 is 1:2.

[0107] Example 19

[0108] The only difference between Example 19 and Example 16 is that the mass ratio of the gel block to the carrier in step S4 is 1:10.

[0109] Test Example 2: Effect of carrier solution on the physical morphology of gel under room temperature storage conditions

[0110] After the samples prepared in Examples 4 to 11 and Comparative Examples 6 to 9 were prepared, an appropriate amount of each sample was immediately placed in a 37°C water bath for 24 hours. The change in gel mass was then calculated using the following formula: (m1-m0) / m0, where m0 is the initial gel mass and m1 is the gel mass after water bath treatment. The results after treatment are shown in Tables 2 and 3. Figure 3 As shown, Figure 3 These are actual photos of gel blocks after incubation in different carrier solutions at 37°C for 24 hours.

[0111] Table 2: Effect of carrier on gel (incubated at 37°C for 24 h)

[0112]

[0113] Through Table 2 and Figure 3 The test results shown show that the gels prepared in Comparative Examples 6 to 9 will swell in the PBS carrier. During long-term storage, the gel particles gradually heal into gel blocks, making it impossible to inject. The gel will gradually swell until saturation and even gradually degrade, affecting the long-term stability of the product. The gels prepared in Examples 4 to 11 will undergo negative swelling in the PEG-containing carrier, and the gel volume and mass will decrease, but this does not affect the subsequent injection use of the gel.

[0114] Test Example 3: Effect of carrier solution on gel physical morphology under high temperature and high pressure conditions

[0115] After the samples prepared in Examples 4 to 19 and Comparative Examples 6 to 10 were prepared, an appropriate amount of each sample was immediately subjected to high temperature and high pressure treatment. The specific conditions of the high temperature and high pressure test were 121°C and 0.1 MPa for 30 minutes. The change in gel mass was then calculated using the following formula: (m1-m0) / m0, where m0 is the initial mass of the gel and m1 is the mass of the treated gel. The calculation results are shown in Table 3. Photos of some gel blocks after high temperature and high pressure treatment are shown in Table 3. Figure 4 As shown;

[0116] Table 3: Effect of carrier on gel (high temperature and high pressure treatment 121 ° C, 30 min)

[0117]

[0118]

[0119] The gel prepared in Comparative Example 10 has no carrier and will experience negative swelling of about 20% after high temperature and high pressure treatment, which may be caused by dehydration.

[0120] In Comparative Examples 6 to 9, after high temperature and high pressure sterilization using PBS7.4 as the gel carrier, the gel mass increased and swelled by about 30%. This is because the gel has a three-dimensional network structure and has a certain degree of water storage capacity, and the isotonic neutral carrier solution can gradually enter the interior of the gel.

[0121] Compared with Comparative Example 10, in Examples 4 to 7, using 20% ​​PEG6K / PBS7.4 as the carrier, the mass change ratio of the gel in different carrier ratios is relatively close, with a negative swelling of about 50%.

[0122] Compared with Examples 4 to 7, the concentration of PEG6K was increased in Examples 8 to 11, the shrinkage of the gel was increased, and the negative swelling was about 65%; while increasing the molecular weight of PEG or adding glycerol in Examples 12 to 19 had no obvious effect on the mass change.

[0123] Test Example 4 In vitro accelerated degradation test of gel in different carriers

[0124] After the samples prepared in Examples 4 to 19 and Comparative Examples 6 to 10 were prepared, an appropriate amount of each sample was immediately subjected to high temperature and high pressure treatment. The high temperature and high pressure conditions of this test were the same as those in Test Example 3. The solution was then cooled to room temperature (25°C), the carrier solution was taken out, and 10 times the mass of the initial gel with a pH of 7.4 PBS buffer was added. The solution was then placed in a 60°C oven for accelerated degradation. The gel state after accelerated degradation was observed, and the mass of the gel after accelerated degradation, m1, was weighed. The swelling degree after 7 days of gelation was calculated as follows: (m1-m0) / m0. The calculation results are shown in Table 4.

[0125] Table 4: In vitro degradation test results after high temperature and high pressure treatment

[0126]

[0127]

[0128] The gel of Comparative Example 10 that was not subjected to high temperature and high pressure treatment was subjected to an in vitro accelerated degradation experiment. The degradation results are shown in Table 5.

[0129] Table 5: In vitro degradation test results without high temperature and high pressure treatment

[0130]

[0131] The curve graph drawn based on the average value of the data in Table 4 and Table 5 is as follows Figure 5 shown.

[0132] Factors that significantly influence the degree of gel swelling in vitro include the type of carrier, the concentration of linear PEG, and the method of sterilization. Therefore, the swelling behavior of the gel can be regulated by designing the carrier components to meet different clinical application requirements.

[0133] Combined with previous studies, the gels formed by different concentrations of component A and component B have different in vitro degradation times and swelling degrees. By combining different carrier solutions and whether or not to treat with high temperature and high pressure, the regulation of the degradation time and swelling degree of the gel can be further expanded, thereby expanding its application range and application scenarios.

[0134] The preparation steps of Example 20 differ from those of Example 1 only in: the concentrations of component A and component B in step S1; cutting the gel block into small gel blocks with a diameter of 2 to 5 mm visible to the naked eye in step S3; the selection of the carrier solution in step S4; and the mass ratio of the gel to the carrier in step S4. The specific configurations of Examples 20 to 22 and Comparative Examples 11 to 13 are according to the configuration in Table 6 below, and the remaining parameters and steps are the same.

[0135] The preparation steps of Examples 21 to 22 and Comparative Examples 11 to 13 differ from those of Example 1 only in: the concentrations of component A and component B in step S1; the selection of the carrier solution in step S4; the mass ratio of the gel to the carrier in step S4. The specific configurations of Examples 20 to 22 and Comparative Examples 11 to 13 are according to the configuration in Table 6 below, and the remaining parameters and steps are the same.

[0136] Table 6: Comparative table of specific configurations of samples of Examples 20-22 and Comparative Examples 11-12

[0137]

[0138] Test Example 5: Self-healing properties of gel particles after separation from the carrier

[0139] The sample prepared in Example 20 was placed in a 60°C oven and allowed to stand for 24 hours to observe whether the small gel pieces adhered or healed themselves; then, the excess carrier solution in the sample was removed, and a PBS7.4 solution with a gel mass 10 times that of the gel was added, and the sample was placed in a 60°C oven and allowed to stand to observe whether the small gel pieces healed themselves to form gel blocks.

[0140] For the convenience of observation, the sample prepared in Example 20 was prepared by cutting the gel block into small gel blocks that were easy to observe with the naked eye, such as Figure 6Figure a shows the state of the gel pieces after being placed in a 60℃ oven for 24 hours. It can be seen that the gel particles immersed in 20% PEG20K / PBS7.4 carrier solution did not adhere to each other after 24 hours of incubation. To remove the excess carrier solution, 10 times the mass of PBS7.4 solution was added to the gel particles, and the gel particles were placed in a 60℃ oven for 2-3 minutes and then observed. The state of the gel pieces is as follows: Figure 6 As shown in Figure b, take the gel piece out of the bottle and observe it. Figure 6 As shown in Figure c, the gel fragments have clearly healed into gel blocks. Therefore, the carrier effectively prevents the gel particles from self-healing. However, even after the carrier solution is removed, the gel particles still have the ability to self-heal. In this test example, the carrier solution was removed by allowing the vial to stand for a while until the carrier and gel separated. The excess carrier solution was then removed directly with a dropper. This removal of the carrier solution accelerated the exchange of the carrier solution with the PBS solution, thus accelerating the self-healing of the gel particles.

[0141] If the gel particles + carrier suspension is injected, the excess carrier solution can also be removed by letting it stand. For example, before injection, the gel particles can be allowed to settle at the bottom, and a portion of the carrier solution can be squeezed out before injection. Alternatively, the suspension can be injected directly without removing the carrier solution. After the components of the carrier solution are absorbed by the tissue, the gel particles will self-heal and aggregate into block-shaped gel.

[0142] Test Example 6

[0143] The samples prepared in Examples 21 to 22 and Comparative Examples 11 to 13 were placed in an oven at 60° C. for 24 hours, and then the gel particles were observed to see whether they adhered or healed themselves.

[0144] The samples prepared in Example 21 and Example 22 still maintain good dispersibility, as shown in FIG. Figure 7 and Figure 8 As shown, in order to facilitate photographing and recording the dispersion of gel particles, the carrier in the sample prepared in Example 22 was also dyed, that is, a small amount of brilliant blue was added.

[0145] like Figure 9 As shown, the samples prepared in Comparative Examples 11 and 12 all self-healed into gel blocks after 24 hours.

[0146] like Figure 10 As shown in the figure, PEG-400 is in solution state at room temperature and can be directly used as a carrier solution for gel particles. The gel particles of the sample prepared in comparative example 13 did not heal themselves after 24 hours, indicating that 100% PEG400 can be used as a dispersion solution for gel particles. However, long-term storage will cause the gel particles to dehydrate and shrink significantly, which is not conducive to subsequent injection use.

Claims

1. A prefilled injection gel preparation, characterized in that: The pre-filled injectable gel preparation is a gel particle preparation comprising micron-sized gel particles formed by crushing a pre-made gel, mixing the particles with a carrier solution, degassing the mixture, and then filling the mixture into a pre-filled injectable device for storage. The pre-made gel block is prepared by mixing equal volumes of an aldehyde-terminated multi-arm polyethylene glycol solution and a polyamino compound solution. The aldehyde-terminated multi-arm polyethylene glycol solution is prepared by mixing the aldehyde-terminated multi-arm polyethylene glycol with a phosphate buffer solution, and the pH of the prepared aldehyde-terminated multi-arm polyethylene glycol solution is 3-6. The polyamino compound solution is prepared by mixing a polyamino compound with an alkaline solution, and the pH of the prepared polyamino compound solution is 7-9. The particle size of the gel particles ranges from 30 to 800 microns. The carrier solution comprises at least a mixture of linear polyethylene glycol and a neutral solvent, wherein the neutral solvent is purified water or a neutral buffer solution, the pH of the carrier solution is 6.5 to 7.5, and the molecular weight of the linear polyethylene glycol is 500 to 100,000 Da; the concentration of the linear polyethylene glycol in the prepared carrier solution is 1% to 60% w / w.

2. The prefilled injection gel preparation according to claim 1, characterized in that: The carrier solution also includes glycerol.

3. The prefilled injection gel preparation according to claim 1, wherein: The neutral buffer solution is selected from physiological saline or phosphate buffer, and has a pH of 6.5 to 7.

5.

4. The prefilled injection gel preparation according to claim 1, wherein: In the aldehyde-terminated multi-arm polyethylene glycol, the aldehyde groups and the multi-arm polyethylene glycol can be connected through an ester bond, an amide bond, an ether bond, a urethane bond, an imine bond or a urea bond. The number of arms of the aldehyde-terminated multi-arm polyethylene glycol is 4 to 8, and the molecular weight is not less than 2000 Da. The aldehyde groups are selected from one or more of aromatic aldehydes and alkyl aldehydes.

5. The prefilled injection gel preparation according to claim 1, wherein: The aldehyde-terminated multi-arm polyethylene glycol is replaced by an iodinated aldehyde-terminated multi-arm polyethylene glycol, wherein at least one arm of the multi-arm polyethylene glycol is terminated by an aldehyde group, and at least one arm is terminated by an iodine-substituted phenyl group; the aldehyde group or the iodine-substituted phenyl group is connected to the multi-arm polyethylene glycol by an ester bond, an amide bond, an ether bond, a urethane bond, an imine bond or a urea bond.

6. The prefilled injection gel preparation according to claim 1, wherein: The polyamino compound is one or more of polylysine, polyethyleneimine, chitosan and gelatin.

7. The prefilled injection gel preparation according to claim 1, wherein: The aldehyde-terminated multi-arm polyethylene glycol solution is an aldehyde-terminated eight-arm polyethylene glycol solution 8-PEG-CHO with a mass fraction of 10% to 20%, the solvent is a 0.02M phosphate solution, and the pH is 3.81; the molecular weight of the aldehyde-terminated eight-arm polyethylene glycol is 20KDa, and the structural formula is as follows: The polyamino compound solution is a polylysine ε-PL solution with a mass fraction of 0.65% to 30%, the solvent is a 0.05M sodium hydroxide aqueous solution, and the pH is 7.36; wherein the polylysine structural formula is shown below, and the molecular weight is 3600 to 4300 Da; 8. The prefilled injection gel preparation according to claim 7, characterized in that: The mass fraction of aldehyde-terminated eight-arm polyethylene glycol in the aldehyde-terminated eight-arm polyethylene glycol solution is 20%, the mass fraction of ε-PL in the polylysine solution is 30%, the carrier solution is 20% PEG20K / PBS7.4, and the mass ratio of gel particles to carrier is 1:

10.

9. The prefilled injection gel preparation according to claim 1, wherein: The prefilled injection gel preparation is also sterilized.

10. Use of the prefilled injectable gel preparation according to claim 1 in the preparation of soft tissue filling hydrogels, tissue isolation and protection hydrogels, and vascular embolization hydrogels.

Images