CN114949377A

CN114949377A - Submucosal injection and application thereof in preparation of auxiliary agent for endoscopic submucosal dissection

Info

Publication number: CN114949377A
Application number: CN202210709862.6A
Authority: CN
Inventors: 钱志勇; 胡兵; 史琨; 叶连松; 陈柳香
Original assignee: West China Hospital of Sichuan University
Current assignee: West China Hospital of Sichuan University
Priority date: 2022-06-22
Filing date: 2022-06-22
Publication date: 2022-08-30

Abstract

The invention provides a submucosal injection and application thereof in preparing an auxiliary agent for endoscopic submucosal dissection, belonging to the technical field of biological materials. The invention solves the problem of poor effect of the injection under the mucosa in the prior art by selecting the solvent with specific type and concentration and the PDLLA-PEG-PDLLA triblock copolymer. Experiments prove that the injection under the mucosa has good injectability; the injection resistance does not obviously influence the whole operation process of the injection under the mucosa, the mucosa of the injection part is obviously raised after the injection under the mucosa, the liquid cushion is well formed, and the liquid cushion does not obviously descend along with the time extension; the injection under mucosa is not needed to be carried out again in the ESD operation process, the total amount of the injection liquid under the mucosa is less, and the safety is good.

Description

Submucosa injection and application thereof in preparation of auxiliary agent for endoscopic submucosa dissection

Technical Field

The invention relates to the technical field of biological materials, in particular to a submucosal injection and application thereof in preparing an auxiliary agent for endoscopic submucosal dissection.

Background

Endoscopic Submucosal Dissection (ESD) has small wound and quick recovery, can furthest retain the structure and the function of a normal organ, and becomes a preferred scheme for treating early cancer and precancerous lesion of the digestive tract. Important obstacles to the popularity of ESD technology are greater operational difficulties and higher incidence of perforation. The formation of a Submucosal Fluid Cushion (SFC) by sub-mucosal injection in the alimentary canal is the best way to simplify the procedure and avoid perforation, so that a suitable injection material becomes an important link for improving the technique of the minimally invasive endoscope. SFC can hold up the pathological change mucous membrane, forms a kind of protective submucosal water pad, makes local submucosal layer thickness increase, and mucous membrane layer and muscular layer separate, the resistance increase, and when using the electrotome to excise the pathological change mucous membrane, the coagulation action of high-frequency current is only limited to submucosal layer, avoids destroying muscular layer and following tissue, prevents the emergence of complication such as perforation. Meanwhile, the raised submucosa enables the operation space to be increased, the operation is simpler, the identification and treatment of the blood vessels by operators are more accurate (the bleeding risk is lower), and the loss of the muscle layer and tissues below the muscle layer can be avoided. The longer the protective mucosal water cushion is maintained, the less the need for repeated injections to maintain the height of the liquid cushion, and thus, the easier the procedure, shorter the procedure time, and less complications.

The currently clinically used submucosal injection mainly comprises normal saline, glycerol fructose, sodium hyaluronate and the like. Normal saline is most commonly used, but the normal saline can be dispersed within a few minutes after submucosal injection, so that the long-lasting liquid cushion protection effect cannot be achieved, repeated injection is needed in the ESD process, the operation time is prolonged, and the anesthesia risk is increased. The liquid pad formed after injection under the mucosas of glycerol fructose is maintained for a relatively long time, but more smoke can be generated during ESD electrotomy, the operation visual field is interfered, the endoscope operation is influenced, and even the success rate of the operation is influenced. The liquid pad formed after sodium hyaluronate submucosa injection is maintained for a longer time, but the price is extremely expensive, the injection resistance is large, and the possibility of stimulating the local tumor cell proliferation of the wound surface exists.

The inventor discloses in patent document CN103251986B a PDLLA-PEG-PDLLA triblock copolymer for preparing medical anti-adhesion material, which is capable of being liquid at room temperature and gel at 37 ℃, so as to ensure the thickness and the maintenance time of the submucosa layer, possibly meet the requirements for submucosa injection liquid, and become an ideal submucosa injection material.

Disclosure of Invention

The invention aims to provide a submucosal injection to solve the problem of poor effect of the submucosal injection in the prior art.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a submucosal injection, which comprises a PDLLA-PEG-PDLLA triblock copolymer solution;

the solvent of the PDLLA-PEG-PDLLA triblock copolymer solution is PBS buffer solution.

Preferably, the molecular weight of the PDLLA-PEG-PDLLA triblock copolymer is 4000-5000 daltons.

Preferably, the PDLLA-PEG-PDLLA triblock copolymer is L ₁₅₀₀ -E ₁₅₀₀ -L ₁₅₀₀ Wherein L represents a PDLLA segment, E represents a PEG segment, and subscripts respectively represent molecular weights of the respective segments.

Preferably, the molar concentration of the PBS buffer solution is 0.06-0.07 mol/L.

Preferably, the pH value of the PBS buffer solution is 7.5-8.5.

Preferably, the concentration of the injection under the mucosa is 5 wt% to 20 wt%.

The invention also provides application of the submucosa injection in preparing an auxiliary agent for endoscopic submucosa dissection.

The invention also provides application of the submucosal injection in preparing an auxiliary agent for endoscopic submucosal tunneling resection, an auxiliary agent for oral endoscopic sphincterotomy and an auxiliary agent for endoscopic total layer resection.

The invention has the technical effects and advantages that:

the invention selects the solvent with specific category and concentration to ensure that the PDLLA-PEG-PDLLA triblock copolymer solution can be successfully applied to ESD, and experiments prove that the viscosity of the solution at room temperature (20-25 ℃) can meet the injection requirement, is similar to normal saline and glycerol fructose, and has good injectability; the injection resistance does not obviously affect the whole operation process of submucosal injection; in vitro animal models and in vivo animal experiments can both show that the mucosa of the injection part is obviously raised after the injection under the mucosa, the liquid cushion is well formed, and the liquid cushion is not obviously reduced along with the time extension; the injection under mucosa is not needed to be carried out again in the ESD operation process, and the total amount of the liquid injected under the mucosa is less. The living animal experiment also shows that abnormal reaction, obvious inflammatory cell infiltration, cell edema or necrosis and other conditions do not occur at the moment after submucosal injection and after 1 week of operation, which indicates that the safety is good.

Drawings

FIG. 1 shows the results of viscosity measurements in Experimental example 1;

FIG. 2 shows the results of the test of injection resistance in Experimental example 2;

FIG. 3 is a graph showing the change in height of a liquid pad in Experimental example 2;

FIG. 4 is a result of measuring a change in height of a liquid pad in Experimental example 2;

FIG. 5 shows the ESD operation of the in vitro animal model of Experimental example 3;

FIG. 6 shows the total amount of injection in ESD operation in the isolated animal model of Experimental example 3;

FIG. 7 shows the results of esophageal surgery in Experimental example 4;

FIG. 8 shows the results of the gastric surgery of Experimental example 4;

FIG. 9 shows the case of live animal experiment (I) in Experimental example 5;

FIG. 10 shows experimental example 5, a live animal experiment;

FIG. 11 shows the results of mucosal injection in living animals in Experimental example 5;

FIG. 12 shows the results of the gastric ESD operation of the living animals in Experimental example 6;

FIG. 13 shows the total amount of injection in gastric ESD operation of living animals in Experimental example 6.

Detailed Description

In the invention, the molecular weight of the PDLLA-PEG-PDLLA triblock copolymer is preferably 4000-5000 daltons, and more preferably L ₁₅₀₀ -E ₁₅₀₀ -L ₁₅₀₀ Wherein L represents a PDLLA segment, E represents a PEG segment, and subscripts respectively represent molecular weights of the respective segments; the preparation method of the PDLLA-PEG-PDLLA triblock copolymer disclosed by the invention is disclosed in Chinese patent 201310185030.

In the invention, the molar concentration of the PBS buffer solution is preferably 0.06-0.07 mol/L, and more preferably 0.062-0.068 mol/L; the pH value of the PBS buffer solution is preferably 7.5-8.5, and further preferably 7.8-8.2; the concentration of the injection under the mucosa is preferably 5 wt% to 20 wt%, more preferably 8 wt% to 17 wt%, and still more preferably 12 wt% to 14 wt%.

The invention also provides application of the submucosal injection in preparing an auxiliary agent for endoscopic submucosal dissection, an auxiliary agent for endoscopic submucosal tunneling resection, an auxiliary agent for oral endoscopic lower sphincterotomy and an auxiliary agent for endoscopic total layer resection.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

In the drawings: p < 0.05, P < 0.01, P < 0.001.

Example 1

The PDLLA-PEG-PDLLA triblock copolymer L is prepared according to the preparation method in the Chinese patent 201310185030.X ₁₅₀₀ -E ₁₅₀₀ -L ₁₅₀₀ . This was dissolved in PBS buffer (pH 8.0, 66.7mM) sufficiently to obtain a transparent and uniform submucosal injection solution with a concentration of 10 wt%.

Example 2

The PDLLA-PEG-PDLLA triblock copolymer L is prepared according to the preparation method in the Chinese patent 201310185030.X ₁₅₀₀ -E ₁₅₀₀ -L ₁₅₀₀ . This was dissolved in PBS buffer (pH 8.0, 66.7mM) sufficiently to obtain a transparent and uniform submucosal injection solution with a concentration of 15 wt%.

Example 3

The PDLLA-PEG-PDLLA triblock copolymer L is prepared according to the preparation method in Chinese patent 201310185030 ₁₅₀₀ -E ₁₅₀₀ -L ₁₅₀₀ . This was dissolved in PBS buffer (pH 8.0, 66.7mM) sufficiently to obtain a transparent and uniform submucosal injection solution with a concentration of 20 wt%.

Experimental example 1

Detection analysis was performed by means of a rotational rheometer HAAKE rheostass 6000(Thermo scientific, USA). The submucosal injection obtained in examples 1-3 was used as an experimental group, and physiological saline and glycerol fructose were used as a control group. Placing the sample on a circular detection table with the diameter of 20mm, wherein the distance between a clamp and a shaft bottom table is 1 mm; before testing, low-viscosity silicone oil is dripped at the edge of the sample for liquid sealing, so that the influence of water volatilization on detection in the measuring process is prevented; the data were collected at constant frequency (1.0Hz), 20 ℃ and constant stress (1Pa) and the viscosity change was observed, with the results shown in Table 1 below and in FIG. 1.

Table 1 results of viscosity measurements

As can be seen from the results, the viscosity of 10 wt%, 15 wt%, 20 wt% submucosa injection at room temperature (20-25 ℃) is not greatly different and is similar to that of physiological saline and glycerol fructose, indicating good injectability.

Experimental example 2

The upper section 1/3 of the fresh in vitro pig stomach body is cut into tissue blocks of 5cm multiplied by 5cm to be used as an in vitro model, and the injection resistance and the liquid cushion forming condition of the submucosal injection for injection are evaluated in a 37 ℃ constant temperature water bath kettle. And a precise digital pressure gauge is adopted for measurement, one side of the three-way pipe is connected with the submucosal injection needle, one side of the three-way pipe is connected with the precise digital pressure gauge, and one side of the three-way pipe is connected with the injector to obtain injection resistance.

Five groups of physiological saline, glycerol fructose, 10 wt% submucosal injection, 15 wt% submucosal injection and 20 wt% submucosal injection were set, 5ml of each solution was injected into the submucosal tissue of the in vitro model using a submucosal injection needle for a 23G endoscope, and the injection resistance results are shown in table 2 and fig. 2, with each solution being repeated three times.

TABLE 2 test results of injection resistance

Group of	Mean injection resistance, atm	Standard deviation of injection resistance
			Physiological saline	1.54	0.10
Glycerol fructose	1.63	0.11
			10 wt% submucosal injection	1.85	0.08
15 wt% submucosal injection	2.22	0.11
			20 wt% submucosal injection	2.98	0.13

According to the detection results, the injection resistance of the three submucosa injections with different concentrations is obviously higher than that of normal saline and glycerol fructose (P is less than 0.05) when the three submucosa injections are used for submucosa injection, but the whole operation process of the submucosa injection is not obviously influenced.

The recorded measurement of the height change of the liquid pad is shown in fig. 3-4.

As can be seen from FIGS. 3 to 4, after the five solutions are injected under the mucosa, the mucosa at the injection part is obviously raised, the liquid cushion is well formed, and the initial height of the liquid cushion has no statistical difference. Over time, the liquid pads formed by the three different concentrations of the submucosal injection all descend at a speed which is obviously slower than that of the normal saline and the glycerol fructose, and are still maintained at more than 70 percent of the initial height after 2 hours, while the liquid pads formed by the normal saline and the glycerol fructose descend to about 40 percent of the initial height.

Experimental example 3

The method comprises the steps of taking a fresh in-vitro pig stomach as an in-vitro animal model, placing the in-vitro animal model in a thermostat at 37 ℃, respectively using normal saline and the submucosal injection obtained in the embodiments 1-3 as the submucosal injection to perform the ESD operation, and repeating the steps for three times in each group. The results show that all ESD procedures were successfully completed, the experimental conditions are shown in fig. 5, and the total injection amount is shown in table 3 and fig. 6.

TABLE 3 Total amount of injection

Group of	Average amount of submucosal fluid, ml	Standard deviation of sub-mucosal injection fluid volume
			Physiological saline	24.33	2.52
10 wt% submucosal injection	14.00	5.20
			15 wt% submucosal injection	11.67	4.04
20 wt% submucosal injection	9.33	1.15

The results show that the physiological saline needs to be injected under the mucosa again when being used as the injection under the mucosa, the injection under the mucosa does not need to be injected again when the injection under the mucosa of the invention with three concentrations is used, and the total amount of the injection liquid under the mucosa of the physiological saline group is obviously higher than that of the experimental group of the invention (P < 0.01). Experiments also show that when the injection liquid under 20 wt% mucous membrane is used for ESD, the endoscope cutting is not smooth, and the endoscope operation is interfered; the smoothness of the incision was comparable to that of physiological saline when 10 wt% submucosa injection and 15 wt% submucosa injection were used.

Experimental example 4

Using 20kg of long white pigs (edudou large laboratory animals limited) as the living animal model, the submucosal injections obtained in examples 1 and 2 were injected into the esophagus and the stomach, and the local mucosa was observed at that time and 1 week after the injection under the mucosa, and the results are shown in fig. 7 to 8:

as can be seen from FIGS. 7 to 8, no abnormal reactions such as redness, swelling, ulcer and necrosis of the local mucosa occurred at that time and 1 week after the submucosal injection. The local tissues on the pathological section have no obvious inflammatory cell infiltration and have no cell edema or necrosis.

Experimental example 5

The experimental procedure is shown in fig. 9 to 10, and the results are shown in fig. 11, in which a Changbai pig (Duoduo animal Co., Ltd.) was used as a living animal model, and physiological saline and 5ml of the submucosal injection obtained in examples 1 and 2 were injected into the submucosa of the stomach.

As can be seen from fig. 11, after submucosal injection, the local mucosa was significantly elevated and the liquid pad was well formed; the liquid cushion formed by the physiological saline rapidly declined with time, but the liquid cushion formed by the submucosal injection obtained in examples 1 and 2 did not decline significantly.

Experimental example 6

The gastric ESD surgery was performed using a long white pig (dongdaho laboratory animals ltd) as an in vivo animal model, and using physiological saline and the submucosal injection obtained in examples 1 and 2 as the mucosal injection, respectively, and each group was repeated at least three times, and the experimental results are shown in fig. 12, and the total amount of the injection is shown in tables 4 and 13.

TABLE 4 Total injection dosage

Group of	Average amount of submucosal fluid, ml	Standard deviation of sub-mucosal injection fluid volume
			Physiological saline	12.33	1.15
10 wt% submucosal injection	6.33	2.31
			15 wt% submucosal injection	5.00	1.00

As can be seen from Table 4 and FIGS. 12-13, all ESD procedures were successfully completed without bleeding and perforation complications. Compared with normal saline, the submucosal injection obtained in the examples 1 and 2 does not need to be injected again, and the total amount of the submucosal injection liquid is less (P is less than 0.01).

The above examples show that the viscosity of the submucosa injection provided by the invention at room temperature (20-25 ℃) can meet the injection requirement, is similar to that of normal saline and glycerol fructose, and has good injectability; the injection resistance does not obviously affect the whole operation process of submucosal injection; in vitro animal models and in vivo animal experiments can both show that the mucosa of the injection part is obviously raised after the injection under the mucosa, the liquid cushion is well formed, and the liquid cushion is not obviously reduced along with the time extension; the injection under mucosa is not needed to be carried out again in the ESD operation process, and the total amount of the liquid injected under the mucosa is less. The living animal experiment also shows that abnormal reaction, obvious inflammatory cell infiltration, cell edema or necrosis and the like do not occur at the moment after submucosal injection and 1 week after operation, which indicates that the safety is good.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A submucosal injection comprising a solution of a PDLLA-PEG-PDLLA triblock copolymer;

2. The submucosal injection according to claim 1, wherein the PDLLA-PEG-PDLLA triblock copolymer has a molecular weight of 4000 to 5000 daltons.

3. The submucosa injection of claim 2, wherein the PDLLA-PEG-PDLLA triblock copolymer is L ₁₅₀₀ -E ₁₅₀₀ -L ₁₅₀₀ Wherein L represents a PDLLA segment, E represents a PEG segment, and subscripts respectively represent molecular weights of the respective segments.

4. The submucosal injection according to claim 3, wherein the PBS buffer has a molarity of 0.06-0.07 mol/L.

5. The submucosal injection according to claim 4, wherein the PBS buffer has a pH of 7.5 to 8.5.

6. The submucosa injection according to claim 5, wherein the concentration of the PDLLA-PEG-PDLLA triblock copolymer in the submucosa injection is from 5 to 20 wt%.

7. Use of the submucosal injection according to any one of claims 1 to 6 in the preparation of an adjuvant for endoscopic submucosal dissection.

8. Use of the submucosal injection according to any one of claims 1 to 6 in the preparation of an endoscopic submucosal tunneling aid, an oral endoscopic sphincterotomy aid, or an endoscopic dissection aid.