CN107007620B

CN107007620B - Copolymer of p-oxycyclohexanone and L-phenylalanine and application thereof

Info

Publication number: CN107007620B
Application number: CN201710259136.8A
Authority: CN
Inventors: 王冰; 陈钏; 罗乐; 沈成义; 朱江; 牛丽静; 吴昌强; 董军; 冯成敏; 肖鑫; 张小明
Original assignee: North Sichuan Medical College
Current assignee: North Sichuan Medical College
Priority date: 2017-04-19
Filing date: 2017-04-19
Publication date: 2021-03-02
Anticipated expiration: 2037-04-19
Also published as: CN107007620A

Abstract

The invention relates to an application of a p-oxycyclohexanone/L-phenylalanine copolymer represented by a structural formula (I) in preparation of a medicine for treating diseases caused by cell fibrosis, a medicine composition taking the copolymer as an active ingredient, an application of a compound and a medicine composition in preparation of a medicine for treating diseases caused by cell fibrosis, an application in preparation of a medicine for treating skin scar tissue hyperplasia and abdominal wall fibrosis caused by repeated stimulation, and an application in preparation of a material for treating postoperative abdominal tissue adhesion.

Description

Copolymer of p-oxycyclohexanone and L-phenylalanine and application thereof

Technical Field

The invention relates to an L-phenylalanine system copolymer, in particular to a copolymer of p-oxycyclohexanone and L-phenylalanine and application thereof.

Background

Fibroblasts are the main repairing cells of body injury, and the inhibition of mass proliferation and apoptosis is one of the biological bases of scar tissue formation. Based on the current knowledge of scar tissue formation, fibroblasts are activated in a certain differentiation state due to self-change and are not regulated by growth factors, so that the fibroblast becomes a cancer cell growth mode which is the main reason of scar formation. In addition, fibroblasts proliferate and secrete a large amount of growth factors, collagen, fibrin and the like, and finally cause collagen deposition, thereby inducing abdominal fibrosis of patients with long-term peritoneal dialysis, postoperative abdominal adhesion and the like. When the peritoneum does not heal well, fibroblasts signal the deposition of extracellular matrix by cell growth factors and cytokines. The adherent fibroblasts develop a myofibroblast phenotype; fibroblasts and myofibroblasts secrete large amounts of extracellular matrix molecules, which then create a weak fibrous bridge between tissues. Finally, blood vessels and collagen are deposited on the bridge and tissue adhesion occurs. Therefore, inhibition of fibroblast proliferation is an important means to control scar tissue formation and other tissue fibrosis caused by fibroblast hyperproliferation, such as abdominal wall fibrosis caused by repeated stimulation and postoperative abdominal adhesion.

At present, the prevention and treatment means of scar hyperplasia mainly include pressure prevention and treatment, application of drugs such as hormone and the like, prevention and treatment by silica gel film application, operation, radiation, laser, freezing treatment and the like. Although the therapies can inhibit scar tissue hyperplasia, the therapies also have the defects of limited movement of patients, skin ulcer, tissue necrosis and vasodilatation caused by repeated injection, limited curative effect, secondary injury, canceration risk, easy relapse, difficult control and the like. In addition, for the postoperative abdominal adhesion, a mechanical isolation method is also a common prevention means, but the methods cannot completely solve the problems of abdominal wall fibrosis and postoperative adhesion. Therefore, at present, there is still a clinical need for drugs capable of effectively inhibiting fibroblast proliferation to prevent and treat scar hyperplasia, abdominal wall fibrosis and postoperative adhesion involving fibroblasts.

Postoperative tissue adhesions are a common complication in patients undergoing abdominal surgery. Many of these adhesions require a second surgery to break through, but this can increase patient pain and economic burden. Although there are many treatments for post-operative adhesions, solid barriers represent the most clinically successful adhesion barrier and the major prophylactic product. Solid barriers can generally be classified as degradable and non-degradable. However, non-biodegradable barriers need to be removed in subsequent procedures, which puts the patient at increased risk of adhesions and surgical complications. Thus, biodegradable disorders make it more feasible to treat post-operative adhesions.

The anti-adhesion material is used as an implant product, and the degradation performance of the anti-adhesion material is very important. Postoperative tissue adhesion usually occurs 3-7 days after surgery, so the adhesion prevention material should have a matched degradation. However, the aliphatic polyester has been found to have a degradation cycle as an anti-blocking material of much more than 7 days. Degradation of these polyesters, such as polylactic acid (PLA) and poly (lactic-glycolic acid) (PLGA), is accomplished by hydrolysis. Furthermore, this single degradation usually means that the period of degradation is difficult to control accurately.

Poly (p-dioxanone) (PPDO), a biodegradable aliphatic polyester, is widely used in the biomedical field, such as drug delivery, vascular graft materials, orthopedic fixation materials, medical absorbable surgical suture matrix materials, cartilage tissue engineering, and the like, due to its unique biodegradability, biocompatibility and bioabsorbability. However, their further use in biomedical fields such as resistance to post-operative adhesions is limited by their inherent hydrophobicity and lack of specific biological properties and high crystallinity.

Conventional methods for enhancing PPDO properties such as hydrophilicity, solubility and in vitro hydrolysis ability can introduce external components by copolymerization. This approach is based primarily on two principles, one being the introduction of hydrophilic block components, such as polyethylene glycol or poly (vinyl alcohol), to improve their hydrophilicity. The other is to interfere with the crystallinity of PPDO by random copolymerization, thereby improving solubility. Although the crystallinity and hydrophilicity of PPDO can be improved by copolymerization with other aliphatic monomers or hydrophilic macromolecules, these polymers remain simple physical barriers if they act as adhesion barriers. However, as introduced in a recent review of anti-postoperative adhesions (Chegini N. TGF-beta system: The primary fibrous media of surgical adhesion formation Semin Reprod Med 2008; 26: 298-312), a single biodegradable physical barrier is unlikely to have a significant effect on The treatment of anti-postoperative adhesions.

The known alpha-amino acids and their polymers have better hydrophilicity and biological properties, in particular cell adhesion and enzymatic degradation. In addition, the amino acid sequence may provide reactive functional groups that are copolymerized with other copolymers, and may be modified by reaction with the arginine glycine aspartate (RGD) sequence or other recognition groups of genes and proteins, thereby facilitating cellular and biological reactions of the polymer. Among those amino acid series, L-phenylalanine is the most important one. It is a naturally occurring essential alpha-amino acid that can be absorbed by the organism after decomposition of the polymer; at the same time, due to the presence of benzyl groups, digestion by proteases is also effective. In addition, few researchers have specifically reported the inhibition of proliferation of rat cardiac fibroblasts and smooth muscle cells by L-phenylalanine. This is an important and specific biological property of L-phenylalanine.

The present inventors have designed to synthesize a novel copolymer copolymerized with PDO and amino acids, which has both biological properties and improved physical properties. Specifically, L-phenylalanine is used as a template amino acid to synthesize a target copolymer PDPA (p-dioxanone-co-L-phenylalanine), because the rigid benzyl group can reduce the flexibility of a polymer chain, and the crystallinity can be reduced along with the specific inhibition of cell proliferation. The copolymer PDPA of the present invention has expected improvements over PPDO in, for example, biological properties, crystallinity, hydrophilicity, and in vitro hydrolyzability.

The inventor unexpectedly finds that the copolymer of the compound p-dioxanone-co-L-phenylalanine (PDPA) has cell-material interaction and can effectively inhibit the proliferation of fibrocyte when being used as a microbial culture surface. The present inventors also carried out a hypothetical study of a possible inhibition mechanism from a cell point of view, and studied and explored the possibility that the copolymer can be used as an adhesion barrier material from a cell point of view, through an experiment of inhibiting proliferation of fibroblasts using mouse L929 fibroblasts as a culture surface of a microorganism.

In view of the analysis of the causes of the critical role of fibroblast adhesion, the inventors believe that if the adhesion barrier material has specific cell-material interactions to inhibit excessive proliferation of fibroblasts, the material will no longer be a physical barrier alone and the anti-adhesion effect efficiency can be significantly improved. Moreover, the single PDPA, due to its limited molecular weight, produces a film with poor mechanical strength; therefore, the single membrane is still difficult to operate in practical application, and therefore, how to realize a p-oxycyclohexanone and L-phenylalanine copolymer system which can be specifically applied remains a problem for those skilled in the art, especially for the application in medicines for diseases caused by cell fibrosis, such as anti-adhesion materials and the like.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the technical problem to be solved by the present invention is to provide a use of a copolymer system of cyclohexanone-p-oxide and L-phenylalanine in a medicament for treating a condition caused by cellular fibrosis due to fibroblasts and fibrous deposition thereof.

In order to achieve the above objects, in one aspect, the present invention provides a PDPA (poly (p-dioxanone-co-L-phenylalanine)) copolymer of p-oxycyclohexanone and L-phenylalanine, which has a structure represented by formula (I).

The PDPA copolymer of cyclohexanone-p-oxide and L-phenylalanine of the present invention can be prepared by the following synthetic route. The poly (p-oxycyclohexanone-co-L-phenylalanine) is prepared by synthesizing and preparing L-phenylalanine (L-Phe) as a raw material, and the structure and the analysis literature of the poly (p-oxycyclohexanone-co-L-phenylalanine) are reported (J.APPL.POLYM.SCI.2013, DOI: 10.1002/APP.39455).

The molecular weight of the copolymer PDPA is 4-30kDa, wherein the molar content of L-phenylalanine is 2-30 percent. Preferably, the molecular weight of the copolymer PDPA is 4-5kDa and the molar content of L-phenylalanine is 5%. More preferably, the molecular weight of the copolymer PDPA is 7-10kDa and the molar content of L-phenylalanine is 4.76-25.03%.

In a specific embodiment of the present invention, a (poly (cyclohexanone-co-L-phenylalanine), PDPA)/(poly (lactic-co-glycolic acid), PLGA) electrospun membrane is also provided.

In a preferred embodiment of the present invention, the copolymer PDPA of formula (I) and PLGA are prepared into a composite electrospun membrane by an electrospinning method; wherein the molecular weight of the PLGA is 200-300kDa, and the molecular weight fraction of the PLGA in the composite membrane is 20-30%. The single PDPA, due to its limited molecular weight, produces a membrane with poor mechanical strength, and is therefore difficult to handle in practical applications such as surgical procedures, especially laparoscopic surgery; thus, how to realize applicable anti-blocking materials remains a challenge. In the composite electrostatic spinning membrane, the PLGA with high molecular weight can provide certain mechanical support for the PDPA component, so that the membrane is convenient to form; and meanwhile, the long-chain PLGA and the PDPA are blended and spun, and the PLGA molecular chain can be used as a physical cross-linking agent of the PDPA molecular chain with a shorter molecular chain, so that the molecular chains are fully entangled, and the resistance of the PLGA molecular chain to the electrostatic force of a high-voltage electric field in the processing process is improved. Compared with a pure PDPA electrostatic spinning membrane, the composite membrane has smaller fiber diameter, and the pore diameter of the membrane is smaller after the fibers are piled up to form the membrane, so that the permeation of biomacromolecules and cells to the membrane can be effectively prevented, and the anti-adhesion effect is enhanced. Therefore, the composite electrostatic spinning membrane prepared by the electrostatic spinning method can be used for surgical membranes, in particular surgical membranes of anti-adhesion materials.

The invention finds that the copolymer PDPA of the formula (I) has a therapeutic effect on other diseases caused by cell fibrosis caused by fibroblasts and fiber deposition thereof, for example, the copolymer PDPA can effectively inhibit the generation of abdominal wall fibrosis caused by repeated stimulation, such as anti-skin scar tissue hyperplasia, abdominal wall adhesion after operation. SD rats and New Zealand rabbits prove that the copolymer PDPA has potential application value in the field of inhibiting cell proliferation, such as treatment of skin scar tissue hyperplasia, abdominal wall fibrosis caused by repeated stimulation, and prevention of adhesion such as postoperative abdominal cavity tissue adhesion.

In another aspect, the present invention also provides a use of PDPA comprising a copolymer of formula (I) in the manufacture of a medicament for treating a condition caused by cellular fibrosis.

Specifically, the pharmaceutical composition for resisting the diseases caused by cell fibrosis comprises the compound of the formula (I) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable auxiliary material or a pharmaceutically acceptable carrier.

The invention also provides application of the copolymer PDPA comprising the formula (I) in preparing a medicament for treating skin scar tissue hyperplasia caused by cell fibrosis. When the compound is used for treating skin scar tissue hyperplasia, the compound can effectively inhibit the secretion of TGF-beta 1 and the proliferation of fibroblasts, which participate in scar tissue formation, of a rat wound part, and can effectively inhibit the thickening of rabbit ear cartilage to epidermal layers, so that the proliferation of scar tissues is inhibited, and experiments prove that the effect of inhibiting the proliferation of the scar tissues is better than that of independently applying L-Phe or D-Phe.

The invention also provides application of the copolymer PDPA comprising the formula (I) in preparing a medicament for treating abdominal wall fibrosis caused by repeated stimulation caused by cell fibrosis.

The invention also provides application of the copolymer PDPA comprising the formula (I) in preparing an anti-adhesion material for treating cell fibrosis, in particular to application in preparing a medicament or a material for treating postoperative abdominal cavity tissue adhesion caused by cell fibrosis.

The present inventors have also found that the toxicity of the compounds of formula (I) is very low.

The invention also provides a pharmaceutical composition and application of the pharmaceutical composition in preparing a medicament for treating diseases caused by cell fibrosis; wherein the pharmaceutical composition comprises a therapeutically effective amount of a compound of formula (I) as an active ingredient, and one or more pharmaceutically acceptable carriers.

The compound of the formula (I) and the pharmaceutical composition can be used for treating diseases caused by cell fibrosis, such as drugs for treating skin scar tissue hyperplasia, abdominal wall fibrosis caused by repeated stimulation and abdominal cavity tissue adhesion after operation.

The pharmaceutically acceptable carrier refers to a conventional pharmaceutical carrier in the pharmaceutical field, such as: diluents, excipients such as water, etc., fillers such as starch, sucrose, etc.; binders such as cellulose derivatives, alginates, gelatin, and polyvinylpyrrolidone; humectants such as glycerol; absorption enhancers such as quaternary ammonium compounds; surfactants such as cetyl alcohol; adsorption carriers such as kaolin; lubricants such as talc, calcium and magnesium stearate, and ethylene glycol. Other adjuvants such as sweetening agents, etc. can also be added to the composition.

When the compound is used for inhibiting scar hyperplasia or inhibiting abdominal wall fibrosis caused by repeated stimulation, the compound can be applied to a patient needing treatment in the form of a composition by a local injection or local implantation administration mode. For topical injection, the preparation can be made into liquid preparation such as aqueous suspension or other liquid preparation. When used for local implantation, the composition can be made into conventional preparations such as tablet, powder, granule, etc. For use in preventing post-operative tissue adhesions, the implant is in the form of a biofilm at the surgical site.

Various dosage forms of the pharmaceutical composition of the present invention can be prepared according to conventional production methods in the pharmaceutical field. For example, the active ingredient may be combined with one or more carriers and then formulated into the desired dosage form. The pharmaceutical composition of the present invention preferably contains 0.1% to 99.5% by weight of the active ingredient, and most preferably 0.5% to 95% by weight of the active ingredient.

The amount of the compound of the present invention to be administered may vary depending on the route of administration, age, body weight, type and degree of the disease of the patient, etc., and the daily dose may be 0.01 to 100mg/kg body weight, preferably 0.1 to 50mg/kg body weight, and may be administered once or more. The dosage to be administered can be readily determined by those skilled in the art, for example, 10mg/kg body weight, according to the actual circumstances.

Technical effects

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a preferred embodiment of the present invention, showing a) an apparent healing profile around a rabbit ear circular incision; b) tissue HE staining; c) scar tissue thickening multiple (1. L-Phe/Bangbao (100mg/5g), 2. L-Phe/Bangbao (10mg/5g), 3. D-Phe/Bangbao (100mg/5g), 4.PDPA-5 powder/Bangbao (100mg/5g), 5. Bangbao control group, 6. blank control group, P < 0.05);

FIG. 2 shows the results of HE staining of wound tissue of different groups a) after circular incision 2 of rabbit ear in a preferred embodiment of the invention; b) scar tissue thickening multiple of different groups of wound parts and normal tissue contrast at different time (1. a contrast group of one week after operation, 2. a PDPA-5 powder group is implanted in one week after operation, 3. a contrast group of four weeks after operation, 4. a PDPA-5 powder group is implanted in four weeks after operation, and P is less than 0.05);

FIG. 3 is a model of a rat skin incision according to a preferred embodiment of the present invention a) results of TGF- β 1 immunohistochemical staining (1. three days after surgery control group, 2. five days after surgery control group, 3. seven days after surgery control group, 4. three days after surgery experimental group, 5. five days after surgery experimental group, 6. seven days after surgery experimental group); p is less than 0.05); b) performing statistics on the average optical density of TGF-beta 1 immunohistochemical staining of the skin of the experimental part of rats of different groups at different time after operation (the data between the data of 3 rd and 5 th days are significantly different, and P is less than 0.05);

FIG. 4 is a model of thickening of rat peritoneum according to a preferred embodiment of the present invention a) TGF- β 1 immunohistochemical staining results (1-4 postoperative one-week blank control group, lipopolysaccharide control group, PDPA-5 experimental group, 5-8 postoperative two-week blank control group, lipopolysaccharide control group, PDPA-5 experimental group, 9-12 postoperative three-week blank control group, lipopolysaccharide control group, PDPA-5 experimental group);

FIG. 5 is a model of rat peritoneal thickening a) mean thickness of rat peritoneum (HE stain measurements, P < 0.05) for each group; b) TGF-beta 1 immunohistochemical staining average optical density statistics (P is less than 0.05) (1-4 postoperative week blank control group, lipopolysaccharide control group, PDPA-5 experimental group, 5-8 postoperative week blank control group, lipopolysaccharide control group, PDPA-5 experimental group, 9-12 postoperative week blank control group, lipopolysaccharide control group, PDPA-5 experimental group);

Detailed Description

The present invention is further illustrated by the following examples, and the scope of the invention is not limited thereby but by the description of the invention and the claims.

Main reagents and instruments in the examples

P-oxycyclohexanone (toddy's reagent, analytical grade), L-phenylalanine (toddy's reagent, analytical grade), triphosgene (toddy's reagent, analytical grade), stannous octoate (toddy's reagent, analytical grade), poly (L-lactide-co-glycolide) (PLGA, toddy's reagent, analytical grade) nuclear magnetic resonance apparatus (Bruker, 400M, germany).

Example 1

Preparation and characterization of PDPA Polymer

TABLE 1 PDPA series of polymers

^aGPC method for determining the weight average molecular weight

Characterization of PDPA Polymer

The polymerized L-phenylalanine content of PDPA is determined by nuclear magnetic resonance¹HNMR assay, in particular¹HNMR is disclosed in literature (J.APPL.POLYM.SCI.2013, DOI: 10.1002/APP.39455).

The molecular weight of the polymer was determined by GPC (DMF mobile phase) and the results are shown in Table 1.

Example 2

Method for producing implant materials

1) Preparation method of medicine for preventing and treating scar hyperplasia and abdominal wall fibrosis

After synthesizing a PDPA-5 polymer, the polymer was dissolved in chloroform, and insoluble matter was removed by filtration with stirring to obtain a filtrate, and diethyl ether was slowly dropped while stirring to precipitate a polymer powder, which was then vacuum-dried for 24 hours to remove the residual organic solvent. The obtained dry polymer powder is the used implanted medicine.

2) Preparation method of composite membrane for preventing and treating postoperative abdominal adhesion

PDPA and PLGA are dissolved in hexafluoroisopropanol according to corresponding mass ratio to prepare a concentrated solution with the concentration of 10% w/v, and the concentrated solution is processed by electrostatic spinning to prepare the porous fibrous membrane, wherein the preparation parameters are as follows: the injection rate is 1mL/h, the voltage is 8kv, the ambient temperature is 30 ℃, the ambient relative humidity is 40%, and the receiving distance is 10 cm.

TABLE 2 Polymer ratio Table of PDPA/PLGA series porous fiber membranes

Example 3

Experiment for preventing and treating epidermal wound scar hyperplasia

The precondition of the test is that related experimental tests are carried out by using natural uninfected New Zealand rabbits or SD rats, animals are randomly grouped into 5 animals each group, and the experimental groups are continuously tested respectively.

1) Circular incision of inner skin of rabbit ear 1

A circular incision is made on the inner skin of an auricle of a new zealand rabbit by using a circular drill to form a cartilage layer, the cut circular skin is taken down, and the polymer PDPA-5 powder/Bauduobang ointment prepared by the method in example 2 is applied to the wound surface once a day within one week after operation (the PDPA powder is uniformly stirred into the Bauduobang ointment, the preparation method is the same for the following groups), wherein the control groups are as follows: bai Du bang ointment, L-phenylalanine/Bai Du bang ointment, D-phenylalanine/Bai Du bang ointment, without treatment blank control group. And taking normal tissues of rabbit ear wounds and the side of the wounds around the operation, fixing the tissues by formalin, embedding paraffin, carrying out HE staining on sections, and taking pictures under a microscope to measure the thicknesses of the wounds and the normal tissues. The fold increase of cartilage to epidermal layer thickening at the wound site compared to normal skin surrounding the wound was measured.

The results are shown in fig. 1, from the photographs of rabbit ears and the results of tissue HE staining, the skin coated with the polymer PDPA-5 powder/polibang ointment does not affect wound healing; wounds of the experimental group and the control group are covered by squamous epithelium after four weeks of operation, and cartilage to epidermal tissues of each group are thickened to different degrees. As can be seen from FIG. 1a, the application of PDPA-5 powder did not affect wound healing compared to the blank control and the Bteponpah control; as shown in FIG. 1c, the application of PDPA-5 powder can effectively inhibit thickening of cartilage from outer to epidermal layer of rabbit ears and scar tissue hyperplasia, and the effect is better than that of L-Phe and D-Phe which are independently applied. Therefore, the application of the PDPA polymer powder can effectively inhibit the scar tissue hyperplasia.

2) Circular incision of inner skin of rabbit ear 2

A circular incision is made on the skin on the inner side of an auricle of a New Zealand rabbit by using a circular drill to reach a cartilage layer, 15mg of PDPA-5 powder is implanted into a wound surface at one time after a surgery, a control group is not treated after the surgery, normal tissues of the ear and the side of the wound of the rabbit are respectively taken at one time and the periphery after the surgery, after formalin fixation, paraffin embedding, section HE staining and then photographing is carried out under a microscope to measure the thickness of the wound and the normal tissues. The fold increase of cartilage to epidermal layer thickening at the wound site compared to normal skin surrounding the wound was measured.

In fig. 2, a1. was implanted with PDPA-5 powder one week post-surgery, a2 was implanted with PDPA-5 powder one week post-surgery, a3. was implanted with PDPA-5 powder four weeks post-surgery, and a4. was implanted with PDPA-5 powder four weeks post-surgery. As shown in FIG. 2a), the wound sites of the experimental group and the control group were covered with squamous epithelial tissue one week after the operation, and the implantation of PDPA-5 powder did not affect the wound healing. The wound site of the experimental group showed different thickening from cartilage to epidermal tissue compared to the control group, but the thickening degree of the experimental group was significantly less than that of the control group. In the fourth week, after the acute edema period, the tissue thickening degree was reduced, but the experimental group was still thickened less than the control group. Therefore, the implantation of the PDPA-5 powder can effectively inhibit the thickening of cartilage to epidermal layer and scar hyperplasia at the injured part of rabbit ears. As can be seen from fig. 2b, the application of PDPA polymer powder was effective in inhibiting scar tissue hyperplasia.

3) Rat dorsal skin incision

The back of an SD rat is cut with the length of 1cm and the depth of the SD rat reaches a fascia layer, PDPA-5 powder is applied to a wound surface of an experimental group, a control group is not treated after operation, the rat is killed at 3, 5 and 7 days after operation, a wound part is fixed and then is embedded by paraffin, the rat is sliced, a fibroblast marker C antibody is selected to carry out immunohistochemical staining on a sample slice, a high-power photo is taken, and Image J Pro Plus is applied to carry out optical density measurement and statistics on all groups of pictures.

The results are shown in FIG. 3: on the 3 rd and 5 th days after the operation that the fibroblasts are massively proliferated, compared with the control group, the TGF-beta 1 antibody immunohistochemical staining of the experimental group is obviously lightened, and after the average optical density statistics is carried out on the immunohistochemical image, the conclusion consistent with the result is also drawn, namely the average optical density of the immunohistochemical image of the experimental group is obviously lower than that of the control group on the 3 rd and 5 th days after the operation. The application of the PDPA-5 powder can effectively inhibit the secretion of TGF-beta 1 participating in scar tissue formation at a wound part and the proliferation of fibroblasts, thereby inhibiting the proliferation of scar tissue. As shown in fig. 3b, the application of the PDPA polymer powder can effectively reduce the proliferation of fibroblasts at the wound site, thereby inhibiting the proliferation of scar tissue.

Example 4

Preventing peritoneal thickening (fibrosis) due to peritoneal irritation

Cutting about 4cm along the abdominal midline of 180-g SD rats to expose abdominal cavity, placing 15mg PDPA-5 powder in the abdominal cavity of PDPA-5 powder experimental group and PDPA-5 powder control group in operation, injecting 2mL physiological saline into blank control group and PDPA-5 powder control group, suturing abdominal wall and skin, injecting bacterial endotoxin (lipopolysaccharide) into the abdominal cavity of rats on

days

1, 3, 5 and 7 after operation, injecting physiological saline into blank control group and PDPA-5 powder control group, fixing abdominal wall and intestinal wall tissues of rats after 1, 2 and 3 weeks after operation, embedding paraffin, slicing, performing HE staining, performing TGF-beta 1 antibody immunohistochemistry staining on abdominal wall tissues of one week after operation (shown in figure 4), and counting the thickness of peritoneal tissues and immunohistochemical unit area optical density of each group of rats, the results are shown in FIG. 5.

As can be seen from FIG. 4, the peritoneal tissue of the LPS control group rats was significantly thickened compared to the blank control group at week 1 after the operation, and the peritoneal tissue of the PDPA-5 control group and the PDPA-5 experimental group rats was also thickened to different degrees. At 2 and 3 weeks after operation, as PDPA-5 is degraded, L-phenylalanine is released, compared with lipopolysaccharide control group rats, the abdominal wall tissue thickness of the PDPA-5 control group rats and the experimental group rats is obviously reduced, which indicates that PDPA-5 starts to play an anti-fibrosis role at 2 weeks after operation.

From fig. 5, it is understood that the application of PDPA-5 powder effectively suppressed peritoneal fibrosis and thickening caused by repeated peritoneal irritation from the 2 nd week after the operation, after performing thickness statistics on HE images of the peritoneal tissues of the rats in each group. The mean optical density of the images was determined and counted after TGF-. beta.1 immunohistochemical staining of peritoneal tissues from each group of rats. The TGF-beta 1 coloring average optical density of rat peritoneal tissues in the PDPA-5 experimental group is obviously lower than that of each control group, and the lipopolysaccharide control group has the largest coloring average optical density, which indicates that peritoneal fibrosis is caused by repeated lipopolysaccharide stimulation. The fact that the thickness of the peritoneal tissue of the rat in the PDPA-5 experimental group is smaller than that of the rat in the PDPA-5 control group means that the degradation of the PDPA-5 is accelerated by the inflammatory reaction brought by injecting lipopolysaccharide to the rat in the experimental group, so that the concentration of local effective components in the tissue of the PDPA-5 experimental group is larger than that of the control group. In conclusion, the application of PDPA-5 powder effectively limits the proliferation of fibroblasts and the secretion of TGF-beta 1, namely, the application of PDPA-5 powder effectively inhibits the fibrosis and thickening of peritoneum caused by repeated stimulation of peritoneum.

Example 5

PDPA composite electrostatic spinning fibrous membrane for preventing postoperative abdominal adhesion

After anesthesia, the SD rat opens the abdomen, scrapes off the serosal layer (1cm multiplied by 1cm) of the cecum with a scalpel, fixes the paracecum at the corresponding position of the abdominal wall with an absorbable thread, scrapes off the serosal layer (1cm multiplied by 1cm) of the abdominal wall with a scalpel at the position of the abdominal wall corresponding to the cecum injury, places one PDPA composite electrostatic spinning fibrous membrane (diameter 1.5cm) on each of the wound surface of the cecum and the wound surface of the abdominal wall, and closes the abdomen. After one week, the abdominal cavity condition is checked by opening the abdomen, and it can be obviously observed that the cecal tissue and the corresponding abdominal wall tissue of the control group of rats which do not use the PDPA composite electrostatic spinning fiber membrane are seriously adhered, while the cecal tissue and the corresponding abdominal wall tissue of each group of rats which use the PDPA composite electrostatic spinning fiber membrane are still in a mutual free state and are not adhered under the obstruction and biological action of the fiber membrane. Therefore, the PDPA/PLGA electrostatic spinning membrane can effectively prevent abdominal cavity adhesion.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. Use of a p-oxycyclohexanone/L-phenylalanine copolymer of the following structural formula (I) in the manufacture of a medicament for treating cell fibrosis-induced adhesions:

wherein the molecular weight of the copolymer is 4-30kDa, and the molar content of L-phenylalanine is 2% -30%;

preparing the copolymer shown in the formula (I) and PLGA into a composite electrostatic spinning film by an electrostatic spinning method; the molecular weight of the PLGA is 200-300kDa, and the molecular weight fraction of the PLGA in the composite electrostatic spinning membrane is 20-30%.

2. Use according to claim 1, characterized in that: is the application of the copolymer shown in the formula (I) in preparing a medicament for treating postoperative abdominal tissue adhesion caused by cell fibrosis.

3. Use of a pharmaceutical composition for the manufacture of a medicament for the treatment of cell fibrosis induced adhesions, wherein: the pharmaceutical composition contains a therapeutically effective amount of the copolymer of formula (I) or a pharmaceutically acceptable salt thereof as an active ingredient, and one or more pharmaceutically acceptable carriers; the copolymer of formula (I) is:

wherein the molecular weight of the copolymer is 4-30kDa, and the molar content of the L-phenylalanine is 2% -30%.