CN109224120B

CN109224120B - In-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism and preparation method and application thereof

Info

Publication number: CN109224120B
Application number: CN201811211062.1A
Authority: CN
Inventors: 薛伟明; 魏荣; 许宁侠; 温惠云; 黄赛朋; 杨华; 潘士印
Original assignee: Northwestern University
Current assignee: Shaanxi Liangshuangtong Medical Technology Development Co ltd
Priority date: 2018-10-17
Filing date: 2018-10-17
Publication date: 2021-08-03
Anticipated expiration: 2038-10-17
Also published as: CN109224120A

Abstract

The invention discloses an in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism and a preparation method and application thereof, belonging to the technical field of medical products. The composite hydrogel is liquid sol at room temperature, has fluidity, and can be placed in the lacrimal passage of human eyes in a punctum injection mode. By utilizing the gel phase transition characteristic of the sol which has sensitive response to the body temperature, the in-situ gelation and embolism of the sol in the lacrimal passage are realized, a small amount of tears secreted by the affected eye are retained in the orbit, and the purpose of keeping the ocular surface moist for a long time is achieved. The temperature responsiveness of the hydroxypropyl chitosan and sodium glycerophosphate compound is utilized, and alginate and calcium chloride are added into the hydroxypropyl chitosan and sodium glycerophosphate compound to adjust the mechanical property, the sol-gel phase transition time, the mechanical strength and the like of the hydroxypropyl chitosan and sodium glycerophosphate compound.

Description

In-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism and preparation method and application thereof

Technical Field

The invention belongs to the technical field of medical products, and relates to in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism as well as a preparation method and application thereof.

Background

Dry eye disease is an eye disease with symptoms such as decreased tear film stability, abnormal quality and quantity due to various causes such as congenital lacrimal gland hypoplasia, trachoma and ocular corneal sclerosis. The etiology is complex, is related to body immunity, hormones and various growth factors, and generally needs long-term treatment. The essence of this disease is a reduction in the number and density of goblet cells in the tear film, causing changes in the quality or quantity of tear secretion. The clinical symptoms mainly comprise dry eyes, itching and the like, and the long-term accumulation of the symptoms can cause deep pathological changes of the keratoconjunctiva of a patient and cause vision loss in severe cases. Epidemiological investigation results show that the prevalence rate of the dry eye disease is related to regions, occupations, ages and sexes, for example, the prevalence rate of Asian race is about 27% -33%, and the prevalence rate of the dry eye disease is higher when a video terminal is used as an occupation, such as teachers, staff and drivers.

In the clinical application, for patients with insufficient tear production, the treatment measures comprise reduction or avoidance of induction factors, artificial tears, wet house mirror, punctal plugs or punctal closure, operations (autologous submandibular gland transplantation, autologous sublingual gland transplantation, labial gland transplantation), soft corneal contact lenses and the like; in patients with excessive evaporation, eyelid cleaning, oral antibiotics, topical medications, and the like are required, and these treatments can alleviate the symptoms of dry eye to some extent. However, the current treatment of dry eye is mainly to supplement artificial tears, and more than 50 kinds of artificial tears are on the market globally, and the main components of the tears are as follows: methylcellulose, polyvinylpyrrolidone, polyvinyl alcohol, hyaluronic acid, and the like. Although the artificial tears can relieve dry eye symptoms, physiological quantity of tears required by the ocular surface cannot be stably maintained, the antimicrobial agent and preservative contained in the preparation can aggravate ocular surface damage, and frequent use can reduce treatment compliance of patients. And the artificial tears are different from physiological tears and cannot completely replace the function of physiological tears. For patients with moderate or severe dry eye, the number of times of using the artificial tears is generally more than 4 times per day, and the frequent use causes inconvenience to the patients. Clinically, drugs such as mucolytic agents can also be used to promote tear secretion, but their therapeutic effects are not very definite. In 1998 Murube et al first proposed the treatment of dry eye by transplantation of the labial minor salivary glands, and then Geer-ling et al also carried out similar studies. In follow-up visit to a plurality of patients with xerophthalmia treated by the labial gland transplantation, the surgically transplanted glands still survive, the lacrimal secretion of the patients is increased, and the disordered ocular surface structure is improved, but the success rate of the surgery is extremely low.

At present, the treatment scheme with the most obvious curative effect is lacrimal duct embolization, and after the lacrimal punctum is embolized by adopting a micro-size lacrimal duct embolus, natural tears can be increased to provide longer moistening for the ocular surface; meanwhile, the increased natural tears can stimulate tear secretion and promote goblet cells to survive, thereby increasing the stability of the tear film; the medicine loss can be reduced and the medicine taking times can be reduced by embolizing the lacrimal passage. When the lacrimation or other complications occur in the treatment of the lacrimal duct embolism, the embolus can be taken out at any time, so that the irreversibility of the traditional operation is avoided. Therefore, non-medicine and non-operation lacrimal passage suppository are selected to treat dry eye diseases in clinic.

The study of lacrimal duct plugs began in the early 20 th century, and Foulds in 1961 blocked the canaliculus with nondegradable endophytic plants, and in 1975, Freeman Plug, designed by Freeman, became the prototype for the preparation of future lacrimal duct plugs, and the current foreign brand of lacrimal duct plugs: SmartPlug^TM、Form Fit^TM、Snug Plugs^TM、Soft Plug^TM、Tears Naturale^TM

Extend^TM、

And the like. At present, lacrimal passage embolism products used for clinically treating xerophthalmia in China all depend on import, are expensive (1000-3000 yuan), have material cost accounting for more than 80-90% of operation cost, and greatly increase economic burden of patients. In addition, more importantly, the imported lacrimal passage suppository product designed based on the European and American population cannot completely adapt to the eye anatomical characteristics of Asian population, and the problem of operation failure caused by displacement or falling-off of the embolus in clinical application often exists.

Therefore, the lacrimal passage suppository product which is suitable for Asian patients and has the advantages of eye physiological characteristics, good lacrimal passage embolism effect and moderate cost is developed, and has important significance and development value.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism and the preparation method and application thereof, and the composite hydrogel has good fluidity, adjustable size and shape, better biocompatibility and low toxic and side effects; the preparation method is simple and convenient to operate, mild in reaction condition and low in cost; the composite hydrogel can be applied as a medicine for treating xerophthalmia.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

the invention discloses an in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism, which comprises the following raw materials in percentage by mass:

1 to 15 percent of hydroxypropyl chitosan, 4 to 10 percent of sodium glycerophosphate, 1 to 5 percent of alginate and 0.03 to 0.1 percent of calcium chloride.

Preferably, the molecular weight of the hydroxypropyl chitosan is 100000-200000, and the substitution degree is 70-90%.

Preferably, the sodium glycerophosphate is beta-sodium glycerophosphate, alpha-sodium glycerophosphate or alpha beta-sodium glycerophosphate.

Preferably, the alginate is sodium alginate or calcium alginate.

Preferably, the calcium chloride is anhydrous calcium chloride or calcium chloride dihydrate.

The invention also discloses a preparation method of the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism, which comprises the following steps:

1) weighing the raw materials according to a metering ratio, and dissolving hydroxypropyl chitosan in deionized water to prepare a hydroxypropyl chitosan aqueous solution;

2) dissolving sodium glycerophosphate in deionized water to prepare a sodium glycerophosphate aqueous solution;

3) mixing the hydroxypropyl chitosan aqueous solution prepared in the step 1) and the sodium glycerophosphate aqueous solution prepared in the step 2) according to the weight ratio of 1: (0.6-1.2) to obtain a mixed solution A, adding alginate into the mixed solution A, and stirring to dissolve the alginate sufficiently to obtain a mixed solution B;

4) dissolving calcium chloride in deionized water to prepare a calcium chloride aqueous solution, adding the prepared calcium chloride aqueous solution into the mixed solution B prepared in the step 3), and fully and uniformly stirring to obtain a mixed solution C;

5) and transferring the mixed solution C into a mold, and carrying out gelation treatment at 35-39 ℃ to prepare the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism.

Preferably, in the step 1), hydroxypropyl chitosan accounts for 4-15% of the hydroxypropyl chitosan aqueous solution by mass percent; in the step 2), the sodium glycerophosphate accounts for 8-20% of the sodium glycerophosphate aqueous solution by mass; in the step 4), the calcium chloride accounts for 0.5-5% of the calcium chloride aqueous solution by mass percent.

The invention also discloses application of the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism in preparation of a medicine for treating xerophthalmia.

Preferably, the medicine is a medicine for relieving dry eye by utilizing the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel to block lacrimal canaliculus.

Preferably, the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism is liquid sol at room temperature, has fluidity and gel phase change characteristic of sensitive response to body temperature, and can form in-situ gelation embolism in lacrimal passage.

Compared with the prior art, the invention has the following beneficial effects:

the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism disclosed by the invention is liquid sol at room temperature and has fluidity, the composite hydrogel material utilizes the body temperature responsiveness of a hydroxypropyl chitosan and sodium glycerophosphate composite, alginate and calcium chloride are added into the hydroxypropyl chitosan and sodium glycerophosphate composite to adjust the mechanical property, the sol-gel phase transition time, the mechanical strength and the like, the sol can be implanted into lacrimal passages in a punctum injection mode, and gelation is generated through response to the change of the environmental temperature, so that the method has the advantages of small wound, low cost, capability of filling lacrimal passages with any shape and size, low toxic and side effects and good relieving effect on patients with xerophthalmia.

The preparation method of the composite hydrogel disclosed by the invention is simple to operate, mild in reaction conditions and low in cost, and can fill lacrimal passages with any shapes and sizes as required, so that the aim of relieving the symptoms of xerophthalmia patients is fulfilled.

Furthermore, the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism is liquid sol at room temperature, has fluidity and gel phase change characteristic of sensitive response to body temperature, and can form in-situ gelation embolism in lacrimal passage.

Drawings

FIG. 1 is a flow chart of an experiment for sample preparation according to the present invention;

FIG. 2 is a diagram of the mechanism of gelation of HPCS-GP;

FIG. 3 shows Na-Alg-Ca²⁺A gelation mechanism diagram of (1);

FIG. 4 shows HPCS-GP and Na-Alg-Ca²⁺A gelation mechanism diagram of (1);

FIG. 5 is a photograph showing the morphology of a polymer before gelation;

FIG. 6 is a photograph showing the morphology of the polymer after gelation;

FIG. 7 is a graph showing the effect of hydroxypropyl chitosan (HPCS) concentration on gelation time;

FIG. 8 is a microstructure (100X) view of a gel section;

FIG. 9 is a graph showing the results of the location and morphology of the plugs in the lacrimal passage;

FIG. 10 is a graph showing the effect of hydrogel lacrimal plugs on the height of the lacrimal river under rabbit eyes;

FIG. 11 is a diagram of a right eye conjunctival blot cell examination of a rabbit before hydrogel implantation;

FIG. 12 is a photograph of a right eye conjunctival blot of rabbits after hydrogel implantation.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention is described in further detail below with reference to the accompanying drawings:

example 1

Referring to fig. 1, an experimental flow chart of the present invention is shown. The method comprises the following steps: dissolving hydroxypropyl chitosan with the mass percentage of 5% in deionized water to prepare a hydroxypropyl chitosan (HPCS) water solution, fully stirring 15% of beta-sodium Glycerophosphate (GP) in the deionized water, and dissolving the two water solutions according to the volume ratio of 1: after 0.8, stirring uniformly, then adding 2% of sodium alginate (Na-Alg) powder into the mixed solution, and stirring fully to dissolve the sodium alginate. To the mixed solution of example 1 was added 3% anhydrous with stirringCalcium chloride (CaCl)₂) And (3) water solution, transferring the obtained mixed solution into a mold, and placing the mold in a constant-temperature water bath kettle at 37 ℃ to ensure that the mixed solution is gelatinized and converted into hydrogel.

The mechanism in the gelation process is shown in fig. 2, fig. 3 and fig. 4, fig. 2 is a gelation mechanism diagram of HPCS-GP, and at room temperature, water molecules form hydrogen bonds with HPCS, and water molecules form a water film on the long chain of HPCS; after the GP solution is added into the system, GP and partial protonated amino on the HPCS molecule are subjected to electrostatic interaction, so that more GP small molecules are attached to the HPCS long chain to form an anchor point. Due to the high GP concentration, a large number of GP molecules are anchored to the HPCS backbone. In GP molecules on the anchor points, because the phosphate group is an electron-withdrawing group, adjacent C atoms all have positive charges, because the electronegativity of O atoms is greater than that of C atoms, O atoms connected with the C atoms have negative charges, and H atoms connected with the O atoms have positive charges. And a large number of GP anchor points on the HPCS chain are crosslinking sites, and hydrogen bonds formed between O atoms of one molecule with negative charges and H atoms of the other molecule with positive charges of GP are more stable. The energy required for bonding is increased, energy is required to be provided for promoting the formation of GP-GP and GP-HPCS hydrogen bonds, the temperature of the system is increased to 37 ℃, when the temperature is increased, the molecular thermal motion is enhanced, the probability of collision between anchor points is increased, and the system is further subjected to gelation phase transformation.

FIG. 3 shows Na-Alg-Ca²⁺A gelation mechanism diagram, Na-Alg is composed of guluronic acid (G unit) and mannuronic acid (M unit) arranged randomly, Ca²⁺The mechanism causing Na-Alg gelation is as follows: 1 piece of Ca²⁺Forms a complex with 2 GG segments in the Na-Alg molecular chain segment through 4 coordination bonds, namely an egg lattice structure (figure 3). FIG. 4 shows the HPCS-GP system with Na-Alg-Ca²⁺The system forms an interpenetrating network structure through random interpenetration.

Example 2

The mixed solution of example 1 was transferred into a vial, and as can be seen from fig. 5, the mixed solution had fluidity at room temperature; when the hydrogel is gelatinized at 37 ℃, the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism is obtained (figure 6), and as can be seen from figure 6, the mixed solution loses fluidity after the temperature is raised for a certain time.

Example 3

Dissolving hydroxypropyl chitosan with the mass percentages of 1%, 3%, 5%, 7% and 9% in deionized water to prepare a hydroxypropyl chitosan aqueous solution, fully stirring 15% of beta-sodium glycerophosphate in the deionized water, and dissolving the two aqueous solutions according to the volume ratio of 1: after 0.8, uniformly stirring, pouring the obtained mixed solution into a mold, gelatinizing the mixed solution at 37 ℃ to obtain the in-situ injectable temperature-sensitive response hydroxypropyl chitosan hydrogel for lacrimal passage embolism, and observing the gelatinization time of the hydroxypropyl chitosan hydrogel by the phenomenon in the embodiment 1, wherein the specific implementation method comprises the following steps: a group of parallel samples with the same formula are transferred into a penicillin bottle, placed in a constant-temperature water bath kettle at 37 ℃, counted by a stopwatch, one test tube is inclined or inverted every 10 seconds, the flowing behavior of the sol is observed, and if the sol does not flow after one test tube is inverted, the time is recorded as the phase transition time of the gel. Observing the influence of the change of the component concentration on the gelation time (fig. 7), the gelation time is firstly shortened and then increased along with the increase of the hydroxypropyl chitosan concentration in the system from fig. 7, thereby further indicating that the system has temperature sensitivity and the aim of adjusting the gelation time can be achieved by adjusting the proportion of the components.

Example 4

The gel sample prepared in example 3 was freeze-dried in a vacuum freeze-dryer, the dried gel sample was taken out, the sample was cut in liquid nitrogen, and the gel cross section was fixed with conductive gel, and subjected to gold spraying, and then the microscopic morphology of the sample cross section was observed by a scanning electron microscope (fig. 8, scanning electron microscope image (× 100)), and fig. 8 shows that the hydrogel has a dense three-dimensional network porous structure, which can entrap more water molecules and has a certain mechanical strength and elasticity.

Example 5

The mixed solution prepared in example 3 was poured into a mold having a length and width of 1cm each, and a height of 1cm, and the opening of the mold was sealed with a wrap film, and then placed in a constant temperature water bath at 37 ℃ for 24 hours. Taking out the gel to obtain a cubic hydrogel with the side length of 1 cm. The mechanical properties of the gel are characterized by the compression elastic modulus measured by compressing a sample to 70% through a universal material testing machine 3365 of INSTRON company, and the compression moduli of the gel obtained by parallel preparation of example 3 are respectively 60.8kPa, 61kPa and 61.3kPa, thereby indicating that the hydrogel has enough mechanical properties to stably exist when the lacrimal canaliculus of a human body contracts or vibrates normally.

Example 6

All the aqueous solutions prepared in example 3 were aseptically filtered and mixed to obtain a final mixed solution, and a sterile contrast agent was added thereto in a volume fraction of 1%, thoroughly mixed, and a certain amount of the mixed solution was sucked up with a sterile syringe.

Selecting 3 rabbits, adopting a self-contrast method, observing whether cornea, conjunctiva and the like of each rabbit have pathological changes or inflammations before injection, and removing the rabbits without using the rabbit; and by dripping the fluorescein solution into the conjunctival sac, if the colored solution in the conjunctival sac disappears within a certain time, the colored solution appears in the nasal cavity, which indicates that the lacrimal passage is smooth and the drainage function is good; if the colored solution remains in the conjunctival sac and does not appear in the nasal cavity after a period of time, the lacrimal passage is blocked, and the patients with the lacrimal passage obstruction are removed.

In the test, the mixed solution is injected into the lacrimal passage through a right lacrimal punctum and implanted into the lacrimal passage, a blank left eye is used as a control, and the mixed solution is subjected to in-situ gel phase transition through response to the change of the environmental temperature, so that the lacrimal passage is blocked. Dropping anesthetic into rabbit left eye conjunctival sac, sucking a certain amount of contrast medium to inject into left eye lacrimal passage as contrast, observing by electronic Computed Tomography (CT), wherein FIG. 9 is a specific position of gel blocking lacrimal passage observed under CT, a position symmetrical to a position of a yellow circle can be observed as a position of a red circle, and the position of the red circle as hydrogel can be known according to brightness difference, the position of the yellow circle is a blank lacrimal passage injected with contrast medium, and hydrogel can be observed from the position of the red circle to fill the lacrimal passage, and the shape is irregular.

Example 7

All the aqueous solutions prepared in example 3 were aseptically filtered and mixed to obtain a final mixed solution, and a certain amount of the mixed solution was sucked up with a sterile syringe.

In the test, the mixed solution is injected into the lacrimal passage through the right punctum and implanted into the lacrimal passage, the lacrimal passage of the left eye is used as a blank control group, and the mixed solution is gelatinized through responding to the change of the environmental temperature after being injected into the lacrimal passage, so that the lacrimal passage is blocked. After the hydrogel lacrimal passage embolism is implanted for a certain time, the lacrimal river height of the rabbit eye is detected by an anterior segment coherence tomography (AS-OCT), and the result is shown in fig. 10, after the prepared hydrogel blocks the lacrimal passage of the rabbit for a certain time, the change of the lower lacrimal river height obtained by detecting the lacrimal river height of the rabbit eye by the anterior segment coherence tomography (AS-OCT) is shown, AS can be seen from fig. 10, the lower lacrimal river height of the rabbit eye after the hydrogel lacrimal passage embolism is implanted is higher than that before the implantation, and the lacrimal river height of an experimental group is similar to or higher than that of a blank group at the same time, so that the lacrimal accumulation of the rabbit eye is increased after the hydroxypropyl chitosan hydrogel lacrimal passage embolism is implanted, and the effect of relieving xerophthalmia is achieved.

Example 8

In the test, the mixed solution is injected into the lacrimal passage through the right punctum and implanted into the lacrimal passage, the lacrimal passage of the left eye is used as a blank control group, and the mixed solution is gelatinized through responding to the change of the environmental temperature after being injected into the lacrimal passage, so that the lacrimal passage is blocked. After a certain period of implantation, the pathological changes in the mucus layer of the tear film of rabbit eyes were observed by conjunctival blot cytology (CIC). Firstly, dibbling 0.5 percent of cocaine for a rabbit eye twice, and opening the eyelids by an eyelid opener; removing tear in the lower dome by sucking with filter paper; printing the corneal temporal bulbar conjunctiva epithelial cells by using small temporal sub-clip cellulose acetate filter paper; then placing the mixture into 10% formalin; PAS staining, dehydration and drying, and then observing under an optical microscope. In the examination chart (fig. 11) of conjunctival blot cells in the right eye of the rabbit before hydrogel lacrimal duct embolism, a large amount of neutrophils and eosinophils, a small amount of inclusion bodies in cytoplasm, a small amount of nuclein and a small amount of conjunctival goblet cells in a sampling area can be seen. In the examination chart (fig. 12) of conjunctival blot cells of the right eye of the rabbit after the hydrogel lacrimal duct embolism, a large amount of neutrophils and a small amount of eosinophils can be seen, a small amount of dissolved cells can be seen, and a large amount of conjunctival goblet cells exist in a sampling area. The comparison shows that the hydrogel lacrimal passage suppository has a promoting effect on the proliferation of the conjunctiva goblet cells of the rabbit eyes and has no inflammatory reaction.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. The in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism is characterized by comprising the following raw materials in percentage by mass:

1-15% of hydroxypropyl chitosan, 4-10% of sodium glycerophosphate, 1-5% of alginate and 0.03-0.1% of calcium chloride;

the molecular weight of the hydroxypropyl chitosan is 100000-200000, and the substitution degree is 70-90%;

the sodium glycerophosphate is beta-sodium glycerophosphate, alpha-sodium glycerophosphate or alpha beta-sodium glycerophosphate;

the preparation method comprises the following steps:

2. The in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism according to claim 1, wherein the alginate is sodium alginate or calcium alginate.

3. The in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism according to claim 1, wherein the calcium chloride is anhydrous calcium chloride or calcium chloride dihydrate.

4. The preparation method of the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism, which is characterized by comprising the following steps:

5) transferring the mixed solution C into a mold, and carrying out gelation treatment at 35-39 ℃ to prepare the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism;

in the step 1), hydroxypropyl chitosan accounts for 4-15% of the hydroxypropyl chitosan aqueous solution by mass; in the step 2), the mass percent of the sodium glycerophosphate in the sodium glycerophosphate aqueous solution is 8-20%; in the step 4), the calcium chloride accounts for 0.5-5% of the calcium chloride aqueous solution by mass.

5. The application of the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism in the preparation of drugs for treating dry eye syndrome according to any one of claims 1 to 3, is characterized in that the in-situ injectable temperature-sensitive response hydroxypropyl chitosan composite hydrogel for lacrimal passage embolism is a liquid sol at room temperature, has fluidity and gel phase transition characteristics with sensitive response to body temperature, and can block lacrimal canaliculus to form in-situ gelling embolism in lacrimal passage.