Porous core-shell PLGA (poly (lactic-co-glycolic acid)) fiber for loading antibody drugs and preparation method thereof

Abstract

The invention discloses a porous core-shell PLGA fiber for loading antibody drugs and a preparation method thereof, the preparation method comprises the following steps: S1, preparing a coaxial electrostatic spinning precursor solution, the coaxial electrostatic spinning precursor solution comprising a core layer solution and a shell layer solution; the core layer solution is a polyvinyl alcohol aqueous solution, the shell layer solution is a PLGA organic solution, and a solvent of the PLGA organic solution is a mixed solvent of dichloromethane, N, N-dimethylformamide and normal hexane; s2, carrying out coaxial electrostatic spinning by adopting the coaxial electrostatic spinning precursor solution to obtain fibers; and S3, carrying out vacuum drying on the fiber to obtain the porous core-shell PLGA fiber. The porous core-shell PLGA fiber with the controllable surface aperture can be prepared, the core-shell structure can separate a drug loading area (a hydrophilic core) and a controlled release barrier (a shell layer porous structure), efficient and stable loading of antibody drugs is achieved, meanwhile, the single drug release mode that traditional PLGA fiber depends on degradation is broken through, and precise drug release is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical polymer materials, and particularly to a porous core-shell PLGA fiber for carrying antibody drugs and a preparation method thereof. Background Art

[0002] Fiber membranes with porous structures are widely used in tissue engineering (simulating the extracellular matrix to promote cell attachment) and drug controlled release (increasing drug loading capacity and regulating the release cycle) due to their high specific surface area and porosity characteristics. PLGA is an ideal material for drug carriers due to its excellent biodegradability and biocompatibility. However, its drug release behavior and the types of drugs that can be loaded are limited by the following factors: (1) The singularity of the drug release mechanism: Most existing PLGA fibers rely on bulk degradation to control the drug release rate, and it is difficult to actively regulate the drug release curve. (2) The limitation of structural design: Although traditional porous fibers (such as homogeneous porous structures) can delay degradation, the uneven pore distribution leads to large fluctuations in drug release and cannot achieve multi-stage controlled release. (3) The hydrophobicity of the material: There is a contradiction between the inherent hydrophobicity of PLGA fibers and the hydrophilic requirements of antibody proteins, resulting in problems such as low antibody encapsulation rate and loss of activity.

[0003] In addition, most existing porous structures are generated by vapor-induced phase separation or non-solvent-induced phase separation method (NIPS). Among them, in the vapor-induced phase separation method, in a high-humidity environment, the evaporation and cooling of the solvent cause water vapor to condense into a template, forming surface pores (such as circular pores). However, this method is limited by the solvent system (needs to be highly miscible with water), and is currently only seen in a few hydrophobic polymers such as PS and PMMA. Moreover, the flexibility of pore size regulation is insufficient, and it is also restricted by environmental humidity, resulting in poor process stability. NIPS directly forms pores by regulating the solvent / nonsolvent diffusion kinetics and does not require post-treatment. However, existing NIPS technologies mostly rely on the rough adjustment of the coagulation bath composition (such as the ethanol / water ratio) to regulate the porosity, and it is difficult to accurately control the surface pore size. Summary of the Invention

[0004] In view of the above problems, the present invention aims to provide a porous core-shell PLGA fiber for carrying antibody drugs and a preparation method thereof.

[0005] The technical solution of the present invention is as follows:

[0006] On the one hand, a preparation method of a porous core-shell PLGA fiber for carrying antibody drugs is provided, including the following steps:

[0007] S1: Prepare a coaxial electrospinning precursor solution, and the coaxial electrospinning precursor solution includes a core layer solution and a shell layer solution; the core layer solution is an aqueous solution of polyvinyl alcohol, and the shell layer solution is a PLGA organic solution, and the solvent of the PLGA organic solution is a mixed solvent of dichloromethane, N,N-dimethylformamide, and n-hexane;

[0008] S2: Coaxial electrospinning is carried out using the coaxial electrospinning precursor solution to obtain fibers.

[0009] S3: The fibers are vacuum dried to obtain the porous core-shell PLGA fibers.

[0010] Preferably, in step S1, the mass concentration of the polyvinyl alcohol aqueous solution is 8-10%.

[0011] Preferably, the polyvinyl alcohol aqueous solution is prepared by the following sub-steps: Weigh polyvinyl alcohol particles and add them to deionized water, swell for 1 h at room temperature, then stir at 80-90 °C until the polyvinyl alcohol is completely dissolved, let it stand and cool to room temperature, and filter to remove air bubbles to obtain the polyvinyl alcohol aqueous solution.

[0012] Preferably, in step S1, the mass concentration of the PLGA organic solution is 10%, the volume ratio of dichloromethane to the mixed solvent of N,N-dimethylformamide and n-hexane is 4:1, and the volume ratio of N,N-dimethylformamide to n-hexane is 1:0-1:2.

[0013] Preferably, the PLGA organic solution is prepared by the following sub-steps: Dissolve PLGA particles in dichloromethane and stir until it becomes a transparent colloidal state; add the mixed solvent of N,N-dimethylformamide and n-hexane, continue to stir for 1 h, and let it stand to defoam to obtain the PLGA organic solution.

[0014] Preferably, in step S2, when carrying out coaxial electrospinning, a coaxial needle with an inner diameter of 0.6 mm and an outer diameter of 1.2 mm is used.

[0015] Preferably, in step S2, when carrying out coaxial electrospinning, the advancing speed of the core layer solution is 0.1-0.2 mL / h, the advancing speed of the shell layer solution is 0.5-1 mL / h, and the flow rate ratio of the core layer solution to the shell layer solution is 1:2-1:5.

[0016] Preferably, in step S2, when carrying out coaxial electrospinning, a positive voltage of 15-18 kV, a negative voltage of -2-0 kV, and a receiving distance of 15-18 cm are used; the environmental humidity is 30-50%, and the environmental temperature is 25±3 °C.

[0017] Preferably, in step S3, when carrying out vacuum drying, vacuum drying is carried out at room temperature and a vacuum degree of -0.08 to -0.1 MPa for 48 h.

[0018] On the other hand, there is also provided a porous core-shell PLGA fiber for loading antibody drugs, which is prepared by the preparation method of the porous core-shell PLGA fiber for loading antibody drugs described in any one of the above.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The present invention can controllably adjust the surface pore size (adjustable in the range of 10 - 500 nm) by gradiently adjusting the mixing ratio of the solvent (N,N-dimethylformamide) and the non-solvent (n-hexane) to directionally induce phase separation to form a porous structure.

[0021] 2. For the porous core-shell PLGA fiber prepared by the present invention, its core-shell structure can separate the drug loading area (hydrophilic core) from the controlled release barrier (porous shell structure). By introducing a hydrophilic PVA core layer, the inherent defects of PLGA fibers for delivering antibody drugs are specifically optimized, realizing the efficient and stable loading of antibody protein drugs. At the same time, it breaks through the single drug release mode relying on degradation of traditional PLGA fibers and realizes precise drug release.

[0022] 3. The preparation method of the present invention can avoid high-energy-consuming steps (such as supercritical drying), and can improve the process efficiency by online parameter regulation instead of static immersion in a coagulation bath. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is the TEM image of the porous core-shell PLGA fiber in Example 2;

[0025] Figure 2 It is the SEM image of the porous core-shell PLGA fiber in each example;

[0026] Figure 3 It is the surface pore size distribution diagram of the porous core-shell PLGA fiber in each example;

[0027] Figure 4 It is the drug encapsulation efficiency data diagram of each example and Comparative Example 3;

[0028] Figure 5 It is the drug release curve of each example and each comparative example. Detailed Embodiments

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. It should be pointed out that unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs. The term "comprising" or "including" and similar words used in the disclosure of the present invention mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0030] On the one hand, the present invention provides a method for preparing porous core-shell PLGA fibers for carrying antibody drugs, comprising the following steps:

[0031] S1: Prepare a coaxial electrospinning precursor solution, which includes a core layer solution and a shell layer solution; the core layer solution is an aqueous solution of polyvinyl alcohol, and the shell layer solution is a PLGA organic solution, and the solvent of the PLGA organic solution is a mixed solvent of dichloromethane, N,N-dimethylformamide and n-hexane.

[0032] In a specific embodiment, the mass concentration of the aqueous solution of polyvinyl alcohol is 8-10%. Optionally, the aqueous solution of polyvinyl alcohol is prepared by the following sub-steps: Weigh polyvinyl alcohol particles and add them to deionized water (solid-liquid ratio 1:9-11), swell at room temperature for 1 h, then stir at 80-90 °C until the polyvinyl alcohol is completely dissolved, let it stand and cool to room temperature, and filter to remove air bubbles to obtain the aqueous solution of polyvinyl alcohol.

[0033] In a specific embodiment, the mass concentration of the PLGA organic solution is 10%, the volume ratio of dichloromethane (DCM) to the mixed solvent of N,N-dimethylformamide (DMF) and n-hexane is 4:1 (i.e., DCM:(DMF + n-hexane)=4:1), and the volume ratio of N,N-dimethylformamide to n-hexane is 1:0-1:2 (i.e., DMF:n-hexane = 1:0-1:2). Optionally, the PLGA organic solution is prepared by the following sub-steps: Dissolve PLGA particles in dichloromethane and stir until it becomes a transparent colloidal state; add the mixed solvent of N,N-dimethylformamide and n-hexane, continue to stir for 1 h, and let it stand to remove bubbles to obtain the PLGA organic solution.

[0034] In a specific embodiment, the LA / GA ratio of the PLGA particles is 85:15, and the molecular weight is 50-100 kDa.

[0035] S2: Perform coaxial electrospinning using the coaxial electrospinning precursor solution to obtain fibers.

[0036] In a specific embodiment, when coaxial electrospinning is carried out, a coaxial needle with an inner diameter of 0.6 mm and an outer diameter of 1.2 mm is used.

[0037] In a specific embodiment, when coaxial electrospinning is carried out, the advancing speed of the core layer solution is 0.1 - 0.2 mL / h, the advancing speed of the shell layer solution is 0.5 - 1 mL / h, and the flow rate ratio of the core layer solution to the shell layer solution is 1:2 - 1:5; a positive voltage of 15 - 18 kV (applied to the needle) and a negative voltage of -2 - 0 kV (applied to the aluminum foil collector) are used, and the receiving distance is 15 - 18 cm; the environmental humidity is 30 - 50% (regulated in real time by an atomizing humidifier), and the environmental temperature is 25 ± 3°C.

[0038] S3: Vacuum dry the fibers to obtain the porous core-shell PLGA fibers.

[0039] In a specific embodiment, when vacuum drying is carried out, vacuum drying is carried out for 48 h at room temperature and a vacuum degree of -0.08 to -0.1 MPa.

[0040] In the present invention, during the process of electric field stretching and solvent volatilization of the shell layer solution, non-solvent (moisture in the air) induced phase separation occurs, and the phase separation rate is regulated by the difference in the DMF / n-hexane ratio to form a gradient pore size structure; the core layer PVA provides mechanical support and forms a hydrophilic inner core; during vacuum drying, the residual solvent is completely removed to stabilize the porous structure.

[0041] On the other hand, the present invention also provides a porous core-shell PLGA fiber for carrying antibody drugs, which is prepared by using the preparation method of the porous core-shell PLGA fiber for carrying antibody drugs described in any one of the above.

[0042] Example 1

[0043] A porous core-shell PLGA fiber for carrying antibody drugs is prepared by the following steps:

[0044] (1) Prepare the core layer solution: Weigh 10 g of polyvinyl alcohol particles and add them to 100 mL of deionized water. Swell at 26°C for 1 h, then stir at 80 - 90°C for 2 h until the polyvinyl alcohol is completely dissolved. Let it stand and cool to room temperature, and filter through a 200-mesh filter to remove air bubbles to obtain an aqueous polyvinyl alcohol solution.

[0045] (2) Prepare the shell layer solution: Dissolve 10 g of PLGA particles in 80 mL of dichloromethane and stir until it becomes a transparent colloidal state; add a mixed solvent of N,N-dimethylformamide and n-hexane, where N,N-dimethylformamide is 13.3 mL and n-hexane is 6.7 mL, and continue to stir for 1 h. Let it stand to defoam to obtain a PLGA organic solution; the volume ratio of DCM, DMF, and n-hexane is 80:13.3:6.7.

[0046] (3) Coaxial electrospinning is carried out using the coaxial electrospinning precursor solution composed of the core layer solution and the shell layer solution to obtain fibers.

[0047] In this example, the inner diameter of the coaxial needle used is 0.6 mm, and the outer diameter is 1.2 mm; the advancing speed of the core layer solution is 0.2 mL / h, the advancing speed of the shell layer solution is 1 mL / h, and the flow rate ratio of the core layer solution to the shell layer solution is 1:5; the positive voltage is 15 kV, the negative voltage is 0 kV, and the receiving distance is 18 cm; the environmental humidity is 50%, and the environmental temperature is 26 °C.

[0048] (4) Vacuum drying: The fibers are vacuum dried at room temperature of 26 °C and a vacuum degree of -0.08 MPa for 48 h to obtain the porous core-shell PLGA fibers.

[0049] Example 2

[0050] Different from Example 1, in step (2) of this example, the volume ratio of DCM, DMF, and n-hexane is 80:10:10.

[0051] Example 3

[0052] Different from Example 1, in step (2) of this example, the volume ratio of DCM, DMF, and n-hexane is 80:6.7:13.3.

[0053] Example 4

[0054] Different from Example 1, in step (2) of this example, the volume ratio of DCM, DMF, and n-hexane is 80:20:0.

[0055] Comparative Example 1

[0056] A shell-less fiber for loading antibody drugs is prepared by the following steps:

[0057] (1) Prepare the solution: Weigh 10 g of polyvinyl alcohol particles and add them to 100 mL of deionized water. Swell for 1 h at 26 °C, then stir at 80 - 90 °C for 2 h until the polyvinyl alcohol is completely dissolved. Let it stand and cool to room temperature, and filter through a 200-mesh filter to remove air bubbles to obtain an aqueous polyvinyl alcohol solution.

[0058] (2) Carry out single-axis electrospinning using the aqueous polyvinyl alcohol solution to obtain fibers.

[0059] In this example, a single-axis needle with an inner diameter of 1.0 mm is used, the solution advancing speed is 1.0 mL / h, and the receiving distance is 18 cm; the environmental humidity is 50%, and the environmental temperature is 26 °C.

[0060] (3) Vacuum drying: Vacuum dry the fibers at room temperature of 26°C and a vacuum degree of -0.08 MPa for 48 h to obtain the shell-free fibers, thus preparing the shell-free fibers.

[0061] Comparative Example 2

[0062] A pore-free core-shell PLGA fiber for carrying antibody drugs is prepared by the following steps:

[0063] (1) Prepare the core layer solution: Weigh 10 g of polyvinyl alcohol particles and add them to 100 mL of deionized water. Swell at 26°C for 1 h, then stir at 80 - 90°C for 2 h until the polyvinyl alcohol is completely dissolved. Let it stand and cool to room temperature, and filter through a 200-mesh sieve to remove air bubbles to obtain an aqueous polyvinyl alcohol solution;

[0064] (2) Prepare the shell layer solution: Dissolve 10 g of PLGA particles in 50 mL of dichloromethane, add 50 mL of N,N-dimethylformamide, continue stirring for 1 h, and let it stand to remove bubbles to obtain a PLGA organic solution;

[0065] (3) Perform coaxial electrospinning using the coaxial electrospinning precursor solution composed of the core layer solution and the shell layer solution to obtain fibers;

[0066] In this example, the inner diameter of the coaxial needle used is 0.6 mm, and the outer diameter is 1.2 mm; the feeding rate of the core layer solution is 0.2 mL / h, the feeding rate of the shell layer solution is 1 mL / h, and the flow rate ratio of the core layer solution to the shell layer solution is 1:5; the positive voltage is 15 kV, the negative voltage is 0 kV, and the receiving distance is 18 cm; the environmental humidity is 50%, and the environmental temperature is 26°C;

[0067] (4) Vacuum drying: Vacuum dry the fibers at room temperature of 26°C and a vacuum degree of -0.08 MPa for 48 h to obtain the pore-free core-shell PLGA fibers.

[0068] Comparative Example 3

[0069] A pure PLGA homogeneous fiber for carrying antibody drugs is prepared by the following steps:

[0070] (1) Prepare the solution: Dissolve 10 g of PLGA particles in 50 mL of dichloromethane, add 50 mL of N,N-dimethylformamide, continue stirring for 1 h, and let it stand to remove bubbles to obtain a PLGA organic solution;

[0071] (2) Perform uniaxial electrospinning using the PLGA organic solution to obtain fibers;

[0072] In this embodiment, a uniaxial needle with an inner diameter of 1.0 mm is used, the solution propulsion speed is 1.0 mL / h, and the receiving distance is 18 cm; the environmental humidity is 50%, and the environmental temperature is 26°C;

[0073] (3) Vacuum drying: Vacuum dry the fibers at room temperature of 26°C and a vacuum degree of -0.08 MPa for 48 h to obtain the pure PLGA homogeneous fibers, and prepare the pure PLGA homogeneous fibers.

[0074] Test example

[0075] The morphologies of the porous core-shell PLGA fibers of each embodiment were observed by transmission electron microscopy and scanning electron microscopy. Among them, the TEM image of the porous core-shell PLGA fibers of Example 2 is as Figure 1 shown, and the SEM images of the porous core-shell PLGA fibers of Examples 1-4 are as Figure 2 shown. From Figure 1 it can be seen that the finished product prepared by the present invention has an obvious core-shell structure. Combining Figure 2 it can be seen that the finished product prepared by the present invention has a porous structure, and the present invention can successfully prepare porous core-shell PLGA fibers. From Figure 2 it can be seen that by adjusting the ratio of dichloromethane, N-N dimethylformamide and n-hexane in the shell layer solution, porous core-shell PLGA fibers with different pore sizes and porosities can be obtained, thereby adjusting the release rate of the core layer drug.

[0076] The pore sizes of the porous core-shell PLGA fibers of each embodiment were quantified by mercury intrusion porosimetry, and the results are as Figure 3 shown. From Figure 3 it can be seen that in Example 1, the pore size on the fiber surface is about 10 nm; in Example 2, the pore size on the fiber surface is about 300 nm; in Example 3, the pore size on the fiber surface is about 100 nm. With the change of the ratio of n-hexane to each solvent, the pore size on the fiber surface can be precisely regulated from 10 nm to 300 nm.

[0077] The fiber prepared by each embodiment and Comparative Example 3 was used for the encapsulation rate test of antibody drugs (taking the loaded Anti-PD-L1 antibody as an example), and the results are as Figure 4 shown. From Figure 4 it can be seen that the present invention has carried out targeted optimization for the inherent defects of PLGA fibers in delivering antibody drugs by introducing a hydrophilic PVA core layer. The encapsulation rate of antibody drugs in each embodiment is >80%, which is more than twice that of traditional PLGA fibers (30±5%).

[0078] The fibers prepared by each embodiment and each comparative example were used for in vitro drug release experiments (PBS buffer, 37°C, taking the loaded Anti-PD-L1 antibody as an example), and the results are as Figure 5 shown. FromFigure 5 It can be seen that the significant increase in surface pore size significantly shortens the drug release period. The cumulative drug release rate of the 300-nm pore size fiber (Example 3) reaches 90% in 10 days, while the 10-nm pore size fiber (Example 1) requires 21 days to release the same amount of drug, proving that the pore size is the dominant factor in controlled release. Moreover, the drug release period of the porous core-shell PLGA fiber described in the present invention can be extended from 10 days (300-nm pore size) to 21 days (10-nm pore size), and the release curve conforms to the zero-order kinetic model (R 2 > 0.98), breaking through the random drug release mode (first-order kinetics, R 2 < 0.90) that traditional PLGA fibers rely on bulk degradation.

[0079] As mentioned above, the above are only representative embodiments of the present invention and do not impose any formal limitations on the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, makes some modifications or modifications to the above-described embodiments using the disclosed technical content, which are equivalent embodiments of the present invention. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation method of a porous core-shell PLGA fiber for carrying antibody drugs, characterized in that, It includes the following steps: S1: Prepare a coaxial electrospinning precursor solution, where the coaxial electrospinning precursor solution includes a core layer solution and a shell layer solution; The core layer solution is an aqueous solution of polyvinyl alcohol, and the shell layer solution is a PLGA organic solution. The solvent of the PLGA organic solution is a mixed solvent of dichloromethane, N,N-dimethylformamide, and n-hexane; S2: Perform coaxial electrospinning using the coaxial electrospinning precursor solution to obtain fibers; S3: Vacuum dry the fibers to obtain the porous core-shell PLGA fibers.

2. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1, characterized in that, In step S1, the mass concentration of the aqueous polyvinyl alcohol solution is 8-10%.

3. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1 or 2, characterized in that, The aqueous polyvinyl alcohol solution is prepared through the following sub-steps: Weigh polyvinyl alcohol particles and add them to deionized water. Swell for 1 h at room temperature, then stir at 80-90 °C until the polyvinyl alcohol is completely dissolved. Let it stand and cool to room temperature, and filter to remove air bubbles to obtain the aqueous polyvinyl alcohol solution.

4. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1, characterized in that, In step S1, the mass concentration of the PLGA organic solution is 10%. The volume ratio of dichloromethane to the mixed solvent of N,N-dimethylformamide and n-hexane is 4:1, and the volume ratio of N,N-dimethylformamide to n-hexane is 1:0-1:

2.

5. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1 or 4, characterized in that The PLGA organic solution is prepared through the following sub-steps: Dissolve PLGA particles in dichloromethane and stir until it becomes a transparent colloidal state; add the mixed solvent of N,N-dimethylformamide and n-hexane, continue to stir for 1 h, and let it stand to defoam to obtain the PLGA organic solution.

6. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1, characterized in that, In step S2, when performing coaxial electrospinning, use a coaxial needle with an inner diameter of 0.6 mm and an outer diameter of 1.2 mm.

7. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1, characterized in that, In step S2, when performing coaxial electrospinning, the advancing speed of the core layer solution is 0.1-0.2 mL / h, the advancing speed of the shell layer solution is 0.5-1 mL / h, and the flow rate ratio of the core layer solution to the shell layer solution is 1:2-1:

5.

8. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1, characterized in that, In step S2, when performing coaxial electrospinning, use a positive voltage of 15-18 kV, a negative voltage of -2-0 kV, and the receiving distance is 15-18 cm; the environmental humidity is 30-50%, and the environmental temperature is 25±3 °C.

9. The preparation method of the porous core-shell PLGA fiber for carrying antibody drugs according to claim 1, characterized in that, In step S3, when performing vacuum drying, vacuum dry at room temperature and a vacuum degree of -0.08 to -0.1 MPa for 48 h.

10. A porous core-shell PLGA fiber for carrying antibody drugs, characterized in that, It is prepared by using the preparation method of the porous core-shell PLGA fiber for carrying antibody drugs described in any one of claims 1-9.

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