CN112064193A

CN112064193A - Preparation method of cellulose diacetate based three-dimensional scaffold with antibacterial and biocompatibility functions

Info

Publication number: CN112064193A
Application number: CN202010883378.6A
Authority: CN
Inventors: 郎美东; 梁文城
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2020-12-11

Abstract

The invention discloses a preparation method of a cellulose diacetate base three-dimensional scaffold with antibacterial and biocompatibility, which comprises the following steps: dissolving cellulose diacetate and polyethyleneimine in an organic solvent to prepare a precursor spinning solution; preparing a CDA/PEI composite material nanofiber membrane from the precursor spinning solution by electrostatic spinning, crushing the CDA/PEI composite material nanofiber membrane into short fibers, adding EDC and NHS into a hyaluronic acid aqueous solution for activation, adding the dried CDA/PEI composite material nanofiber membrane, stirring and dispersing, pouring the mixture into a membrane for crosslinking and freeze-drying, performing secondary crosslinking, and washing with deionized water to obtain the cellulose diacetate base three-dimensional scaffold with antibacterial and biocompatibility. The 3D structure scaffold prepared by the invention has the characteristics of excellent mechanical property, high porosity, excellent antibacterial property and excellent cell biocompatibility.

Description

Preparation method of cellulose diacetate based three-dimensional scaffold with antibacterial and biocompatibility functions

Technical Field

The invention belongs to the preparation of three-dimensional wound dressing stents, and particularly relates to a preparation method of a cellulose diacetate base composite three-dimensional stent which simultaneously endows the stent with high antibacterial property and high biocompatibility.

Background

Wound infection with bacteria can lead to high morbidity and mortality of wounds, and therefore many wound dressings with excellent antibacterial properties are widely used to promote wound healing and resist bacterial infection. The currently used antibacterial agents include metal antibacterial agents, antibiotics, cationic polymers, and the like. However, antibacterial drugs of nano-metals and/or nano-metal oxides have many side effects on the body; the inappropriate use of antibiotics is causing the rate of drug-resistant bacteria to increase at a surprising rate. Vancomycin is generally considered to be the last antibacterial agent in humans, but studies have now found that bacteria with resistance to vancomycin appear and continue to grow in number. Therefore, cationic polymers are receiving much attention because of their good safety. Among them, Polyethyleneimine (PEI) has good antibacterial property, and is widely used in water purification and other fields at present, but PEI has significant toxic and side effects on cells, so the application in the field of wound dressings is still tedious and old, and therefore, in order to apply PEI to dressings, it is necessary to develop a material with low toxicity and good antibacterial and biocompatibility.

Disclosure of Invention

The invention aims to provide a preparation method of a cellulose diacetate base three-dimensional scaffold with antibacterial and biocompatibility.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the invention provides a preparation method of a cellulose diacetate base three-dimensional scaffold with antibacterial and biocompatibility, which comprises the following steps:

dissolving Cellulose Diacetate (CDA) and Polyethyleneimine (PEI) in an organic solvent according to a mass ratio of 99.9: 0.1-90: 10 to prepare a precursor spinning solution with a concentration of 8-20% (preferably 8%);

preparing a CDA/PEI composite material nanofiber membrane by using the precursor spinning solution through electrostatic spinning;

crushing the CDA/PEI composite material nanofiber membrane into short fibers, and drying at normal temperature in vacuum;

adding EDC (1-ethyl-3- (3-dimethylaminopropyl) carbodiimide) and NHS (N-hydroxysuccinimide) into a Hyaluronic Acid (HA) water solution with the mass concentration of 0-5% (preferably 0.01-5%) for activation for 0.5-3 h (preferably 1h) at normal temperature, wherein N (EDC) is N (NHS) 1 (1-2) (preferably 1:1), and N (-COOH) N (EDC) is 1 (1-3) (preferably 1: 2);

adding the dried CDA/PEI composite material nano short fiber, wherein the mass ratio of the CDA/PEI composite material nano short fiber to the HA aqueous solution is 1: 99-5: 95, stirring and dispersing for 1-60 min (preferably 10min), crosslinking for 1-48 h (preferably 24h) at normal temperature and normal pressure, freeze-drying for 1-48 h (preferably 48h), performing secondary crosslinking for 1-24 h (preferably 1h) at normal temperature and normal pressure by using glutaraldehyde in a closed environment, and washing for 2-4 d (preferably 2d) by using deionized water to obtain the cellulose diacetate base three-dimensional scaffold with both antibacterial property and biocompatibility.

The organic solvent is HFIP, acetone or dichloromethane.

The spinning voltage of the CDA/PEI composite material nanofiber membrane prepared by electrostatic spinning is 10-15 kv, the flow rate of the injection needle is 1-4 mL/h, and the receiving distance between the injection needle and the receiving electrode is 20 cm.

Preferably, the spinning voltage of the CDA/PEI composite nanofiber membrane prepared by electrostatic spinning is 14kv, the flow rate of the injection needle is 2mL/h, and the receiving distance between the injection needle and the receiving electrode is 20 cm.

The CDA/PEI composite material nanofiber membrane is crushed into short fibers and dried in vacuum at the normal temperature of 0.1MPa for 1-48 hours.

The mass ratio of the Cellulose Diacetate (CDA) to the Polyethyleneimine (PEI) was 19: 1.

Due to the adoption of the technical scheme, the invention has the following advantages and beneficial effects:

the method is simple and easy to operate, low in cost, easy to amplify, and safe and pollution-free in preparation process. The 3D structure scaffold prepared by the invention has the characteristics of excellent mechanical property, high porosity, interconnected pore channels, high water absorption rate, high water retention rate, excellent mechanical property, excellent antibacterial property and excellent cell biocompatibility. Compared with 3D supports prepared by other methods, the support has the advantages of low cost, easiness in operation, large-scale production potential and the like, and can be used as wound dressing, so that the support has a good application value in the field of wound dressing.

Drawings

FIG. 1 is an appearance diagram of a CDA-based composite scaffold prepared in example 1.

FIG. 2 is a scanning electron micrograph of a CDA-based composite scaffold prepared in example 1.

Fig. 3 is a graphical representation of elongation at break for CDA-based composite scaffolds.

Fig. 4 is a graph illustrating tensile strength of a CDA-based composite scaffold.

Fig. 5 is a schematic view showing the antibacterial effect of the CDA-based composite stent.

FIG. 6 is a graph showing the cell proliferation rate of CDA-based composite scaffolds.

Fig. 7 is a schematic porosity diagram of a CDA-based composite scaffold.

Fig. 8 is a schematic water absorption of a CDA-based composite scaffold.

Fig. 9 is a schematic of water retention for CDA-based composite scaffolds.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below in connection with preferred embodiments. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

Example 1

A preparation method of cellulose diacetate base three-dimensional scaffold with antibacterial and biocompatibility comprises the following steps:

0.76g CDA and 0.04g PEI (w/w, 95/5) were dissolved in 9.2g HFIP (HFIP:1,1,1,3,3, 3-hexafluoro-2-propanol also known as 1,1,1,3,3, 3-hexafluoro-2-propanol) and stirred overnight at room temperature to give a precursor spin dope with a concentration of 8%. Adding 5mL of the precursor solution into a 10mL stainless steel needle point injector, and preparing the CDA/PEI composite material nanofiber membrane by electrostatic spinning, wherein the spinning voltage is 14kv, the flow rate of an injection needle is 2mL/h, and the receiving distance between the injection needle and a receiving electrode is 20 cm; and (3) crushing the CDA/PEI composite material nanofiber membrane into short fibers by using a homogenizer at 20000 revolutions per minute, and drying for 48 hours in vacuum at the normal temperature of 0.1 MPa. Dissolving 0.025g HA in 20g deionized water, adding 0.0123g EDC (1-ethyl-3- (3-dimethylaminopropyl) carbodiimide) and 0.0074g NHS (N-hydroxysuccinimide) which are activated for 1h at normal temperature, wherein N (EDC) N (NHS) ═ 1:1, N (-COOH) N (EDC) ═ 1: 2; adding 0.4g of the dried CDA/PEI (w/w, 95/5) composite material nano short fiber, mechanically stirring and dispersing for 10min, pouring into a culture dish, crosslinking for 24h at normal temperature and pressure, freeze-drying for 48h by using a freeze dryer, performing secondary crosslinking for 1h at normal temperature and pressure by using glutaraldehyde in a closed dryer, and washing for 2d by using deionized water to obtain the cellulose diacetate base three-dimensional scaffold with both antibacterial property and biocompatibility. The proportion m (CDA/PEI) of the cellulose diacetate based three-dimensional scaffold with antibacterial and biocompatibility, which is described in the example 1, is named as CPH-2 (m) (HA).

The ratios of the substances used in examples 2 to 5 are shown in table 1, and the preparation method is the same as that of example 1:

TABLE 1

Fig. 1 to 9 are schematic diagrams of some performance tests of the cellulose diacetate-based three-dimensional scaffolds with antibacterial and biocompatibility prepared in examples 1 to 5, and fig. 1 is an appearance diagram of the CDA-based composite scaffold prepared in example 1, which shows that the scaffold can be produced in a large scale. FIG. 2 is a scanning electron microscope image of the CDA-based composite scaffold prepared in example 1, which shows that the inside of the scaffold is a fiber structure, and the pores of the scaffold are interconnected.

FIG. 3 is a graphical representation of elongation at break for a CDA-based composite stent, indicating that the stent has better toughness. Fig. 4 is a graph showing the tensile strength of a CDA-based composite stent, indicating that the stent has greater tensile strength and is less susceptible to breakage. Fig. 5 is a schematic view of the antibacterial effect of the CDA-based composite stent, showing that the antibacterial rate of the stent is above 90%, which shows that the antibacterial effect of the stent is good and is helpful for preventing bacterial infection at wounds. FIG. 6 is a graph showing the cell proliferation rate of CDA-based composite scaffolds. Indicating that the scaffold is not toxic to cells and can promote cell proliferation, which helps to accelerate cell migration at the wound and accelerate wound healing, and also indicating that PEI does not show toxicity in the scaffold. FIG. 7 is a schematic porosity diagram of a CDA-based composite scaffold, showing that the scaffold contains a large number of pores inside and has high porosity, which facilitates three-dimensional migratory growth of cells. Fig. 8 is a schematic water absorption of a CDA-based composite stent, showing that the stent has good water absorption and helps absorb exudate from a wound. Fig. 9 is a water retention diagram of a CDA-based composite scaffold, indicating that the water retention of the scaffold is good, helping to keep the wound moist and providing a moist environment for cell migration.

Comparative example 1

A 3D scaffold was prepared by a post-treatment of electrospun membranes reported by professor mouvui of the university of east hua. The method comprises the following specific steps: collagen and polylactic acid (mass ratio 5: 1) are dissolved in HFIP to prepare 11 wt% of precursor solution, and then the precursor solution is electrospun (15kV, 10cm receiving distance, 5mL/h) to form a nanofiber membrane. Homogenizing at 10000 rpm for 30min to obtain short fiber, lyophilizing for 24 hr to obtain 3D scaffold, and thermally crosslinking at 190 deg.C for 2 hr. And then dissolving 0.5% HA 50ml, 30mM EDC and 8mM NHS in 50ml of buffer solution, then soaking the scaffold in the solution, carrying out secondary crosslinking for 2 hours, washing with water and freeze-drying to obtain the composite scaffold. The composite scaffold is found to have good mechanical property, good water absorption and excellent biocompatibility through mechanical experiments, water absorption and cell experiment structures. However, the disadvantage is that the high temperature thermal crosslinking solution causes the material to pyrolyze and the surface of the material becomes hydrophobic easily, and in addition, the material has no antibacterial property.

According to the preparation method of the cellulose diacetate based three-dimensional scaffold with both antibacterial property and biocompatibility, the PEI is fixed in the scaffold, so that the scaffold has no cytotoxicity while keeping good antibacterial property; the bioactive substance hyaluronic acid is introduced, so that migration and proliferation of cells can be accelerated, and the wound healing can be accelerated; the invention combines electrostatic spinning and post-treatment, so that the bracket keeps the structure of the nano-fiber, and the post-treatment process is simple and easy to operate, has low requirement on equipment and is beneficial to realizing industrialization.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A preparation method of cellulose diacetate based three-dimensional scaffold with antibacterial and biocompatibility is characterized by comprising the following steps:

dissolving cellulose diacetate CDA and polyethyleneimine PEI in an organic solvent according to a mass ratio of 99.9: 0.1-90: 10 to prepare a precursor spinning solution with a concentration of 8-20%;

adding EDC and NHS into 0-5% hyaluronic acid HA water solution to activate for 0.5-3 h at normal temperature, wherein n (EDC) N (NHS) 1 (1-2), n (-COOH) n (EDC) 1 (1-3);

adding the dried CDA/PEI composite material nano short fiber, wherein the mass ratio of the CDA/PEI composite material nano short fiber to the HA aqueous solution is 1: 99-5: 95, stirring and dispersing for 1-60 min, crosslinking for 1-48 h at normal temperature and pressure, freeze-drying for 1-48 h, performing secondary crosslinking for 1-24 h at normal temperature and pressure in a closed environment by using glutaraldehyde, and washing for 2-4 d by using deionized water to obtain the cellulose diacetate base three-dimensional scaffold with antibacterial and biocompatibility.

2. The method for preparing the cellulose diacetate-based three-dimensional scaffold with antibacterial and biocompatibility according to claim 1, wherein the organic solvent is HFIP, acetone or dichloromethane.

3. The method for preparing the cellulose diacetate based three-dimensional scaffold with antibacterial and biocompatibility according to claim 1, wherein the spinning voltage of the CDA/PEI composite nanofiber membrane prepared by electrostatic spinning is 10-15 kv, the flow rate of the injection needle is 1-4 mL/h, and the receiving distance between the injection needle and the receiving electrode is 20 cm.

4. The method for preparing the cellulose diacetate based three-dimensional scaffold with both antibacterial and biocompatibility according to claim 1, wherein the step of crushing the CDA/PEI composite nanofiber membrane into short fibers is vacuum drying at 0.1MPa at normal temperature for 1-48 h.