CN114177347A

CN114177347A - Antibacterial oxygen release functional gel dressing and preparation and application thereof

Info

Publication number: CN114177347A
Application number: CN202111293146.6A
Authority: CN
Inventors: 李航; 周青; 周栩洁; 汤顺清
Original assignee: Jinan University
Current assignee: Shaanxi Pumei Aisi Biotechnology Co ltd
Priority date: 2021-11-03
Filing date: 2021-11-03
Publication date: 2022-03-15
Anticipated expiration: 2041-11-03
Also published as: CN114177347B

Abstract

The invention discloses an antibacterial oxygen release functional gel dressing and preparation and application thereof. The chitosan-polyethylene glycol-pyrogallol gel dressing is prepared by the oxidative crosslinking of chitosan-hydrogenated caffeic acid and four-arm polyethylene glycol-pyrogallol, and the tissue adhesion, mechanical property and antibacterial ability of the dressing can be obviously improved; uniform loading of delta-MnO inside dressing₂The nano enzyme can help to remove ROS generated at the diabetic wound, eliminate cell oxidative stress and release oxygen continuously. The gel dressing prepared by the invention has injectability, good mechanical properties (strong tensile property and compressive property), strong tissue adhesion and antibacterial property, has strong tissue adhesion and good tensile property, can be better attached to wounds, particularly joint parts, and can be used as a new dressingThe biological material is applied to the biological fields of cells, tissue engineering, drug delivery and the like.

Description

Antibacterial oxygen release functional gel dressing and preparation and application thereof

Technical Field

The invention belongs to the field of medical dressings, and particularly relates to an antibacterial oxygen-releasing functional gel dressing as well as preparation and application thereof.

Background

Normal wound healing processes can occur through a variety of cellular responses, including the activation of keratinocytes, fibroblasts, endothelial cells, macrophages, and platelets. The pathological environment of the diabetic wound is obviously different from that of the normal skin wound, and the oxidative microenvironment and the hyperglycemia environment at the wound seriously obstruct the healing process of the diabetic skin wound. In diabetic wounds, immune cells including neutrophils (leukocytes) generate a large amount of Reactive Oxygen Species (ROS) in a hyperglycemic environment, and the increase of ROS levels can cause damage to cells in the wound and render the wound incurable. However, hyperglycemia easily causes bacterial infection at the wound, and at present, the main treatment means is to use antibiotics to inhibit bacteria, but after the bacteria have drug resistance, the antibiotics do not work. In addition, hyperglycemia can cause vasoconstriction and inhibit angiogenesis, thereby blocking the oxygen supply and impeding the healing process. Although there are some existing treatments for diabetic wounds, the existing treatments rarely take into account the specific pathological environment of diabetic wounds. Therefore, the design and synthesis of the functional hydrogel which can overcome the problems and effectively treat the diabetic wounds has important clinical significance.

Chitosan (CS) is a deacetylated product of chitin, is a positively charged high molecular compound rarely found in nature, and has remarkable biological properties, such as biodegradability, biocompatibility, and good cell binding ability. Chitosan hydrogels have recently been applied in various biomedical applications, including drug delivery, wound dressings, tissue engineering scaffolds, and the like. However, the chitosan material of a single component has limited antibacterial properties and wet tissue adhesion, thereby limiting the use of CS in the medical field. To improve the physicochemical properties of CS, CS is often modified to improve its performance.

Mussels can be attached to various substrate surfaces under wet conditions through byssus, the main component of which is adhesive protein rich in catechol (catechol) groups, playing an important role in the crosslinking and adhesion process of mussel protein. Previous studies have shown that chitosan materials modified by catechol can be oxidized to gel and have a certain tissue adhesion, but the mechanical properties of the materials are limited and the materials do not have good antibacterial properties.

Although some synthetic gel dressings have been reported in the field of wound repair for diabetes, a preparation technology of a composite hydrogel dressing which has injectability, strong tissue adhesion, strong antibacterial property, ROS elimination and continuous oxygen release has not been reported.

Disclosure of Invention

In view of the shortcomings and drawbacks of the prior art, a primary object of the present invention is to provide a method for preparing an antibacterial oxygen-releasing functional gel dressing. The chitosan-polyethylene glycol-pyrogallol gel dressing is prepared by the oxidative crosslinking of chitosan-hydrogenated caffeic acid and four-arm polyethylene glycol-pyrogallol, and the tissue adhesion, mechanical property and antibacterial ability of the dressing can be obviously improved; uniform loading of delta-MnO inside dressing₂The nano enzyme can help to remove ROS generated at the diabetic wound, eliminate cell oxidative stress and release oxygen continuously. The release of oxygen has two effects, namely, the first effect can improve the survival rate of skin cells in the hypoxic state of diabetic wounds; and secondly, oxygen can stimulate skin cells to generate growth factors for wound repair, and finally helps to remold tissues and accelerate wound healing.

The invention also aims to provide the antibacterial oxygen release functional gel dressing prepared by the method.

The invention further aims to provide application of the antibacterial oxygen release functional gel dressing.

The purpose of the invention is realized by the following technical scheme:

a preparation method of an antibacterial oxygen release functional gel dressing comprises the following steps:

(1) preparation of chitosan-hydrogenated caffeic acid: adding hydrogenated caffeic acid (HA) into the Chitosan (CS) solution, stirring for a period of time, adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDC) solution, continuing stirring for reaction, dialyzing the reaction product, and performing vacuum freeze-drying to obtain chitosan-hydrogenated caffeic acid (CS-HA);

(2) four-arm polyethylene glycol-preparation of pyrogallol: mixing four-Arm polyethylene glycol-amino (4Arm PEG-NH)₂) Mixing the PBS solution with the PBS solution of 2,3, 4-Trihydroxybenzaldehyde (THB) and stirring for a period of time to prepare a four-Arm polyethylene glycol-pyrogallol (4Arm PEG-THB) solution;

(3)δ-MnO₂preparing nano enzyme: will dissolve in H₂O₂Tetramethylammonium hydroxide pentahydrate (TMAEOH 5H) in solution₂O) to MnCl₂·4H₂Stirring in O water solution, centrifuging to obtain delta-MnO₂Washing, centrifuging, drying, and adding delta-MnO₂Adding the mixture into deionized water, and centrifuging after ultrasonic treatment to obtain delta-MnO₂Nano-enzyme;

(4) preparing the chitosan-polyethylene glycol-pyrogallol gel dressing: dissolving the chitosan-hydrogenated caffeic acid prepared in the step (1) in a PBS solution, adding the four-arm polyethylene glycol-pyrogallol solution prepared in the step (2), uniformly mixing to obtain a mixed solution, and adding periodate and delta-MnO prepared in the step (3)₂Mixing the nano-enzyme uniformly and standing to obtain the chitosan-polyethylene glycol-pyrogallol (CS-PEG-THB) antibacterial oxygen-releasing functional gel dressing.

The 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride added in the step (1) can activate carboxyl in the hydrogenated caffeic acid, so that the carboxyl can react with amino in chitosan.

Preferably, the chitosan of step (1) has a molecular weight of 3 to 10 ten thousand, more preferably 5 ten thousand, and a degree of deacetylation of 50 to 85%.

Preferably, the chitosan solution in step (1) has a concentration of 1 wt%, and is adjusted to a solution pH of 5.0-5.4 by a 1mol/L NaOH solution.

Preferably, the mass ratio of the chitosan to the hydrogenated caffeic acid in the step (1) is 1 (0.5-3), and the mixture is stirred for 1-3h at room temperature after the hydrogenated caffeic acid is added.

More preferably, the mass ratio of chitosan to hydrogenated caffeic acid in step (1) is 1: 0.8.

Preferably, the concentration of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution in the step (1) is 24-50mg/mL, the solvent of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution is deionized water and ethanol in a volume ratio of 1:1, and the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution is added and then stirred for reaction for 1-3 h.

Preferably, the molecular weight of said four-arm peg-amino group of step (2) is 2000 or 10000, more preferably 10000.

Preferably, the mass ratio of the four-arm polyethylene glycol-amino group to the 2,3, 4-trihydroxybenzaldehyde in the step (2) is 1 (0.3-0.5), and the stirring is performed at room temperature for 6-12h, more preferably 6 h.

More preferably, the mass ratio of the four-arm polyethylene glycol-amino group to the 2,3, 4-trihydroxybenzaldehyde in the step (2) is 1: 0.3.

Preferably, in step (3), tetramethylammonium hydroxide pentahydrate and MnCl are used₂·4H₂The molar ratio of O is 4: 1.

Preferably, the stirring time in the step (3) is 24-36h, the drying time is 12-24h, and the ultrasonic time is 10-15 h.

Preferably, in step (4), the chitosan-hydrogenated caffeic acid, the four-arm polyethylene glycol-pyrogallol, the periodate and the delta-MnO are used₂The mass ratio of the nano enzyme is (120-200): (67-120): 0.5-1): 2.5-12.5, and more preferably 120:67:1: 12.5.

Preferably, the periodate in the step (4) is sodium periodate or potassium periodate, the periodate is put into the reaction kettle in the form of solution, the concentration of the periodate solution is 2-5mg/mL, and the solvent is PBS solution.

Preferably, the delta-MnO in step (4)₂The nano enzyme is put into the solution in the form of delta-MnO₂The concentration of the nano enzyme solution is 5 wt%.

Preferably, the standing in the step (4) is standing for 5-10min at room temperature.

The antibacterial oxygen release functional gel dressing prepared by the invention can be prepared into clinical instruments such as freeze-dried sponges, hydrogel and the like for healing diabetic wounds.

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

(1) the preparation method of the antibacterial oxygen release functional gel dressing provided by the invention is simple, convenient and feasible, green, pollution-free and convenient for commercialization.

(2) Aiming at the characteristics that the wounds of the diabetes are easily infected by bacteria and are rich in active oxygen, the invention designs the antibacterial oxygen-releasing functional gel dressing which has strong antibacterial performance, can clear the active oxygen and can continuously release the oxygen.

(3) The gel dressing prepared by the invention has injectability, good mechanical properties (strong tensile property and compressive property), strong tissue adhesion and antibacterial property, has strong tissue adhesion and good stretchability, can be better attached to wounds, particularly to joint parts, and can be used as a novel biological material to be applied to the biological fields of cells, tissue engineering, drug delivery and the like.

Drawings

FIG. 1 is a delta-MnO prepared in example 1₂TEM image of nanoenzyme.

FIG. 2 is a delta-MnO prepared in example 1₂The particle size distribution diagram of the nanoenzyme.

FIG. 3 is a schematic diagram of the procedure of testing the tensile and compressive properties of the gel.

FIG. 4 is a graph showing the results of the tensile and compressive property test of the gel.

FIG. 5 is a graph showing the results of the tissue adhesion performance test of the gel.

FIG. 6 is a graph showing the results of the antibacterial property test of the gel.

FIG. 7 is a schematic diagram of the procedure of oxygen release performance test of the gel.

FIG. 8 is a graph showing the results of an oxygen release property test of a gel in which 0 wt% MnO is₂Representing no delta-MnO₂CS-PEG-THB gel dressing of nanoenzyme, 1 wt% MnO₂Representing a 1 wt% delta-MnO content₂CS-PEG-THB gel dressing of nanoenzyme, 0.25 wt% MnO₂Representing 0.25 wt% delta-MnO prepared in example 1₂CS-PEG-THB gel dressing of nano-enzyme.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto. The chitosan (molecular weight 5 ten thousand, degree of deacetylation 75%) used in the examples was purchased from sigma, hydrogenated caffeic acid, 2,3, 4-trihydroxybenzaldehyde from michelin, and a four-armed polyethylene glycol-amino group (molecular weight 10000) from shanghai-source leaf biotechnology limited. For process parameters not specifically noted, reference may be made to conventional techniques.

Example 1

Preparation of chitosan-hydrogenated caffeic acid (CS-HA)

(1) 0.5g of Chitosan (CS) was weighed into 49.5mL of deionized water (adjusted with 1mol/LHCl solution) with pH 1.6 to make a 1 wt% chitosan solution, and the solution was adjusted to pH 5.4 with 1mol/L NaOH;

(2) weighing 0.4g of hydrogenated caffeic acid (HA) and adding the weighed hydrogenated caffeic acid (HA) into the chitosan solution prepared in the step (1), stirring for 1h, and adjusting the pH of the mixed solution to 3.7-4.0 (adjusting by 1mol/L HCl solution);

(3) weighing 1.2448g of EDC, preparing 50mL of EDC solution by using deionized water and ethanol with the volume ratio of 1:1 as a solvent, adding the EDC solution into the CS-HA mixed solution prepared in the step (2), and stirring for 1 h;

(4) the reaction product of step (3) was dialyzed against deionized water (adjusted with 1mol/L HCl solution) at pH 3.5 for 48h and lyophilized in vacuo to give CS-HA.

Preparation of two-Arm and four-Arm polyethylene glycol-pyrogallol (4Arm PEG-THB)

(1) 100mg of four-Arm polyethylene glycol-amino (4Arm PEG-NH) was weighed₂) Adding into 1mL PBS solution to obtain 0.1g/mL 4Arm PEG-NH₂A solution;

(2) weighing 300mg of 2,3, 4-Trihydroxybenzaldehyde (THB) and adding into 3mL of PBS solution to prepare 0.1g/mL of THB solution;

(3) adding 0.3mL of THB solution prepared in the step (2) into 4Arm PEG-NH prepared in the step (1)₂Stirring the solution at room temperature for 6 hours to obtain a 4Arm PEG-THB solution.

Tri, delta-MnO₂Preparation of nanoenzyme

(1) 2.2g of tetramethylammonium hydroxide pentahydrate (TMAEOH.5H)₂O) was dissolved in 20mL of 3 wt% H with stirring₂O₂Preparing a solution;

(2) 0.594g of MnCl₂·4H₂Dissolving O in 10mL deionized water by ultrasonic treatment to obtain concentrated solutionMnCl with the degree of 0.3mol/L₂A solution;

(3) rapidly adding the solution prepared in the step (1) into the MnCl prepared in the step (2) within 10s₂Stirring the solution at 600rpm for 24h, and centrifuging at 2000 Xg for 5min to obtain bulk delta-MnO₂Washing with water for 3 times, shaking and centrifuging with ethanol for 2 times, and drying for 12 hr to obtain delta-MnO₂；

(4) delta-MnO prepared in the step (3)₂Adding into deionized water, ultrasonic treating for 10 hr, centrifuging the solution at 8800 Xg for 10min, and making into 5 wt% delta-MnO with deionized water₂Aqueous solution of nanoenzyme, p.delta. -MnO₂The nanoenzyme was observed by Transmission Electron Microscopy (TEM). TEM image is shown in FIG. 1, delta-MnO₂The nano-sheet is flat and smooth, has clear edges and corners, is clearly visible, and has the size of 325.6 nm.

Preparation of chitosan-polyethylene glycol-pyrogallol (CS-PEG-THB) gel dressing

(1) Weighing 150mg of CS-HA prepared in the first step, and dissolving the CS-HA in 5mL of PBS solution to prepare 0.03g/mL of CS-HA solution;

(2) weighing 5mg of potassium periodate, and dissolving the potassium periodate in 1mL of deionized water to prepare 5mg/mL of potassium periodate solution;

(3) placing 0.4mL of the CS-HA solution prepared in the step (1) into a glass bottle, and adding 0.025mL of delta-MnO prepared in the step three₂And (3) uniformly stirring the nano enzyme aqueous solution, adding 0.02mL of the potassium periodate solution prepared in the step (2), adding 0.05mL of the PBS solution, uniformly mixing to obtain a CS-HA gel front solution, sucking the CS-HA gel front solution by a medical injector, injecting the CS-HA gel front solution into a mold, and performing self-crosslinking at room temperature for 2-5 minutes to form CS-HA gel.

(4) Placing 0.4mL of the CS-HA solution prepared in step (1) into a glass bottle, adding 0.05mL of the 4Arm PEG-THB solution prepared in step two (containing 0.0067g of 4Arm PEG-THB) and 0.025mL of the delta-MnO solution prepared in step three₂Nano enzyme aqueous solution (containing 0.00125g delta-MnO)₂Nanoenzyme), adding 0.02mL of the potassium periodate solution prepared in the step (2), uniformly mixing to obtain a solution before CS-PEG-THB gel, sucking the solution by a medical injector, injecting the solution into a mold, and automatically stirring the solution 5 to 10 minutes at room temperaturePrimary crosslinking to form CS-PEG-THB gel dressing (delta-MnO)₂Nanoenzyme content 0.25 wt%).

Gel dressing performance testing

First, testing the tensile and compression properties of the gel

(1) After fixing both ends of the gel, the gel was stretched evenly to both sides and the change in stretchable length was recorded.

(2) The gel was placed on a glass slide and another slide was placed over the compressed gel until the total volume was reduced by about 90%, and the morphological change before and after compression of the gel was recorded.

The test results are shown in FIG. 4, the tensile property of the CS-PEG-THB gel prepared in example 1 is improved by nearly 2 times compared with the CS-HA gel, and the compression property of the CS-PEG-THB gel is obviously improved compared with the CS-HA gel.

Second, testing the tissue adhesion performance of the gel

Tissue adhesion performance of the gel pig skin was used as a substrate using lap shear test: fresh pig skin was cut into a rectangular shape (50 mm. times.10 mm), and the CS-HA gel precursor solution and the CS-PEG-THB gel precursor solution prepared in example 1 were transferred to two pieces of pig skin and applied uniformly with an adhesive area of 4cm²(ii) a The adhesive strength was measured by pressing with a 500g weight for about 24 hours and then using a universal tester at a tensile rate of 5 mm/min.

As shown in FIG. 5, the adhesive strength of the CS-PEG-THB gel reached 69.3 kPa.

Third, antibacterial property test of gel

200. mu.L of each of the pre-CS-HA gel solution and the pre-CS-PEG-THB gel solution prepared in example 1 was co-cultured with 10mL of the bacterial suspension (the bacterial suspension without gel was used as a blank control), the bacterial suspension was diluted one hundred-fold after 12 hours, 1mL of the suspension was plated on an LB agar plate and cultured for 18 hours, and the bacterial survival rate was finally calculated.

The test results are shown in FIG. 6, and the antibacterial performance of the CS-PEG-THB gel is nearly 4 times that of the CS-HA gel.

Fourthly, testing the oxygen release performance of the gel

Various contents of delta-MnO prepared by the method of example 1₂Nanolase (0, 1 wt%) CS-PEG-THB gelDressing to be prepared without delta-MnO₂CS-PEG-THB gel dressing of nano enzyme containing 1 wt% delta-MnO₂CS-PEG-THB gel dressing of nanoenzymes and the gel dressing prepared in example 1 containing 0.25 wt% delta-MnO₂The CS-PEG-THB gel dressing of the nano enzyme is used for testing the oxygen release performance of the gel, and the steps are as follows: gel dressings were loaded into 48-well plates and immersed in a solution containing 100. mu. M H₂O₂The cell culture solution was subjected to continuous measurement for 2 hours while monitoring changes in oxygen concentration in the measurement solution in real time with an oxygen probe (PreSens, OXY-1ST Trace, germany).

The test results are shown in FIG. 8, loading delta-MnO₂The CS-PEG-THB gel dressing of the nano-enzyme can continuously release oxygen for more than 2 hours in a high active oxygen environment.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. The preparation method of the antibacterial oxygen release functional gel dressing is characterized by comprising the following steps:

(1) adding hydrogenated caffeic acid into the chitosan solution, stirring, adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution, continuously stirring for reaction, dialyzing the reaction product, and performing vacuum freeze-drying to obtain chitosan-hydrogenated caffeic acid;

(2) mixing and stirring the four-arm polyethylene glycol-amino PBS solution and the PBS solution of 2,3, 4-trihydroxybenzaldehyde uniformly to prepare a four-arm polyethylene glycol-pyrogallol solution;

(3) will dissolve in H₂O₂Tetramethylammonium hydroxide pentahydrate in solution was added to MnCl₂·4H₂Stirring in O water solution, centrifuging to obtain delta-MnO₂Washing, centrifuging, drying, and adding delta-MnO₂Adding into water, ultrasonic treating and centrifuging to obtain delta-MnO₂Nano-enzyme;

(4) prepared by the step (1)Dissolving chitosan-hydrogenated caffeic acid in PBS solution, adding the four-arm polyethylene glycol-pyrogallol solution prepared in the step (2), uniformly mixing to obtain a mixed solution, and adding periodate and delta-MnO prepared in the step (3)₂And mixing the nano-enzyme uniformly and standing to obtain the chitosan-hydrogenated caffeic acid-pyrogallol antibacterial oxygen-releasing functional gel dressing.

2. The preparation method according to claim 1, wherein the chitosan of step (1) has a molecular weight of 3 to 10 ten thousand and a degree of deacetylation of 50 to 85%; the concentration of the chitosan solution is 1 wt%, and the solution pH is adjusted to 5.0-5.4 by 1mol/L NaOH solution.

3. The preparation method according to claim 1, wherein the mass ratio of chitosan to hydrogenated caffeic acid in step (1) is 1 (0.5-3), and the mixture is stirred at room temperature for 1-3h after the addition of hydrogenated caffeic acid.

4. The preparation method according to claim 1, wherein the concentration of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution in the step (1) is 24-50mg/mL, the solvent of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution is deionized water and ethanol in a volume ratio of 1:1, and the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride solution is added and then the stirring reaction is continued for 1-3 h.

5. The method according to claim 1, wherein the molecular weight of the four-arm polyethylene glycol-amino group of step (2) is 2000 or 10000; the mass ratio of the four-arm polyethylene glycol-amino to the 2,3, 4-trihydroxybenzaldehyde is 1 (0.3-0.5), and the stirring is performed at room temperature for 6-12 h.

6. The method according to claim 1, wherein the tetramethylammonium hydroxide pentahydrate is mixed with MnCl in the step (3)₂·4H₂The molar ratio of O is 4: 1; the stirring time is 24-36h, the drying time is 12-24h, and the ultrasonic time is 10-15 h.

7. The method according to claim 1, wherein the chitosan-hydrogenated caffeic acid, the four-arm polyethylene glycol-pyrogallol, the periodate, and the delta-MnO in the step (4)₂The mass ratio of the nano enzyme is (120-200): (67-120): (0.5-1): (2.5-12.5).

8. The method according to claim 1, wherein the periodate in the step (4) is sodium periodate or potassium periodate, the periodate is added in the form of a solution having a concentration of 2 to 5mg/mL, and the solvent is PBS solution; the delta-MnO₂The nano enzyme is put into the solution in the form of delta-MnO₂The concentration of the nano enzyme solution is 5 wt%.

9. An antibacterial oxygen-releasing functional gel dressing prepared by the method of any one of claims 1-8.

10. Use of the antimicrobial oxygen-releasing functional gel dressing of claim 9 in the manufacture of a device for healing diabetic wounds.