KR20240073700A - Porous polylactic acid microfibers and their production methods - Google Patents

Abstract

One embodiment of the present invention provides porous polylactic acid microfibers and a method for producing the same. The porous polylactic acid microfiber according to an embodiment of the present invention has excellent drug release properties when used as a drug carrier due to its interconnected internal structure, large surface area, large pore size, and large pore volume.
In addition, by using the physical properties of the porous polylactic acid microfibers according to an embodiment of the present invention, the release of the drug can be controlled from 1 to 7 days after carrying the drug, so the use can be adjusted according to the duration. It works.
In addition, the method for producing porous polylactic acid microfibers can easily produce porous polylactic acid microfibers containing pores with an interconnected internal structure by mixing solvents with different vaporization rates and using the difference in vaporization rates of the solvents during electrospinning. There is an effect.

Description

Porous polylactic acid microfibers and their production methods}

The present invention relates to porous polylactic acid microfibers and a method for manufacturing the same. More specifically, the present invention relates to a porous polylactic acid microfiber and a method of manufacturing the same. More specifically, the present invention relates to a porous polylactic acid microfiber and a method for manufacturing the same. More specifically, the present invention relates to a mixture of solvents with different vaporization rates and when electrospinning, the difference in vaporization rate of the solvents is used to utilize the difference in vaporization rate of the solvents to have an internal structure that is easily interconnected and contains pores. It relates to a technology for manufacturing porous polylactic acid microfibers.

Aminoglycoside derivatives (ADs) are broad-spectrum antibiotics that can treat fatal infections by inhibiting a variety of Gram-positive and Gram-negative bacteria, but specific drug carriers that can effectively protect and deliver these antibiotic substances are required.

Existing drug carriers are generally characterized by being used in the form of capsules, porous fibers, and core-shell forms.

Among these carriers, porous fibers are being actively studied because they do not require additional chemical reactions during electrospinning and there is no change in the chemical structure of the antibiotic. By controlling process variables such as concentration and polymer-solvent selection, fibers with a variety of morphologies and high surface-to-volume ratios can be produced.

At this time, the shape of the porous fiber may affect the release characteristics of the antibiotic, including initial stage diffusion, release period, decomposition, and burst release.

However, although many researchers have successfully developed various types of porous nanofibers using various methods, including electrospinning, research on the preparation of porous microfibers according to the polymer-solvent system and fiber structure-antibacterial properties relationship is limited.

Therefore, many challenges still remain to efficiently manufacture fibers with excellent porosity properties.

Republic of Korea Patent Publication No. 2019-0126306

The technical problem to be achieved by the present invention is to provide porous polylactic acid microfibers with excellent drug release properties when used as drug carriers due to their interconnected internal structure, large surface area, large pore size, and large pore volume, and a method for manufacturing the same.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a method for producing porous polylactic acid microfibers.

The method for producing porous polylactic acid microfibers according to an embodiment of the present invention includes the steps of preparing a spinning solution by adding polylactic acid (PLA) to a mixed solvent containing a first solvent and a second solvent with different evaporation rates; and

It may include the step of electrospinning the spinning solution to produce porous polylactic acid microfibers in which multiple pores are formed in the polylactic acid fiber.

Additionally, according to one embodiment of the present invention, in the step of preparing the spinning solution, the first solvent may include dichloromethane (DCM).

Additionally, according to an embodiment of the present invention, in the step of preparing the spinning solution, the second solvent may include acetone (AC).

Additionally, according to one embodiment of the present invention, the evaporation rate of the first solvent is faster than the evaporation rate of the second solvent.

Additionally, according to an embodiment of the present invention, in the step of preparing the spinning solution, the mixing volume ratio of the first solvent and the second solvent in the mixed solvent may be 5:5 to 7:3.

In addition, according to one embodiment of the present invention, in the step of preparing the spinning solution, the content of polylactic acid (PLA) in the polylactic acid (PLA) mixed solution is 10% (w/v) to 12% (w/v). ) can be.

Additionally, according to one embodiment of the present invention, in the step of manufacturing the porous polylactic acid microfibers, the electrospinning may be performed at a voltage of 10 kV to 18 kV.

Additionally, according to one embodiment of the present invention, in the step of manufacturing the porous polylactic acid microfibers, the electrospinning may be performed at a supply rate of 1.5 mL/h to 3 mL/h.

In addition, according to one embodiment of the present invention, in the step of manufacturing the porous polylactic acid microfibers, when the porous polylactic acid microfibers are electrospun, the polylactic acid dissolved in the second solvent is solidified to form a matrix, Polylactic acid dissolved in the first solvent may form pores.

In order to achieve the above technical problem, another embodiment of the present invention provides porous polylactic acid microfibers.

The porous polylactic acid microfiber according to an embodiment of the present invention can be produced by the above-described porous polylactic acid microfiber production method.

Additionally, according to one embodiment of the present invention, the specific surface area may be 5 m ² /g to 58.69 m ² /g.

Additionally, according to one embodiment of the present invention, the average pore diameter may be 15.97 nm to 47.04 nm.

The porous polylactic acid microfiber according to an embodiment of the present invention has excellent drug release properties when used as a drug carrier due to its interconnected internal structure, large surface area, large pore size, and large pore volume.

In addition, by using the physical properties of the porous polylactic acid microfibers according to an embodiment of the present invention, the release of the drug can be controlled from 1 to 7 days after carrying the drug, so the use can be adjusted according to the duration. It works.

In addition, the method for producing porous polylactic acid microfibers according to another embodiment of the present invention mixes solvents with different vaporization rates and uses the difference in vaporization rates of the solvents during electrospinning to form porous polylactic acid microfibers that have an easily interconnected internal structure and include pores. It is effective in producing polylactic acid microfibers.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a flow chart showing a method for producing porous polylactic acid microfibers according to an embodiment of the present invention.
Figure 2 is a schematic diagram showing porous polylactic acid microfibers.
Figure 3 is an SEM image showing the surface and cross section of porous PLA fibers and non-porous PLA fibers.
Figure 4 is a graph of the AFM image and surface roughness of porous polylactic acid microfibers.
Figure 5 shows the in vitro release results of non-porous and porous 5:5, 6:4, 7:3 PLA fibers in the presence of gentamicin, showing (a) gentamicin concentration-OD405 standard curve and (b) gentamicin release result graph. am.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts unrelated to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. In addition, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that it does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

A method for producing porous polylactic acid microfibers according to an embodiment of the present invention will be described.

Figure 1 is a flow chart showing a method for producing porous polylactic acid microfibers according to an embodiment of the present invention.

Referring to Figure 1, the method for producing porous polylactic acid microfibers according to an embodiment of the present invention,

Preparing a spinning solution by adding polylactic acid (PLA) to a mixed solvent containing a first solvent and a second solvent having different evaporation rates (S100); And electrospinning the spinning solution to form multiple pores in the polylactic acid fiber. It may include a step (S200) of manufacturing the formed porous polylactic acid microfibers.

In the first step, it may include preparing a spinning solution by adding polylactic acid (PLA) to a mixed solvent containing a first solvent and a second solvent having different evaporation rates. (S100)

The first solvent may include dichloromethane (DCM).

Additionally, the second solvent may include acetone (AC).

Therefore, the evaporation rate of the first solvent is faster than the evaporation rate of the second solvent.

In the mixed solvent, the mixing volume ratio of the first solvent and the second solvent may be 5:5 to 7:3.

Additionally, preferably, the mixing volume ratio of the first solvent and the second solvent may be 7:3.

At this time, if the mixing volume ratio of the first solvent and the second solvent is less than 5:5, there may be a problem with little or no porosity, and if it is more than 7:3, a porous fiber is produced, but pores are determined by the size fiber diameter during spinning. It has the problematic characteristic of being uneven.

The present invention is a technology for producing microfibers containing pores during electrospinning using different vaporization rates of the first solvent and the second solvent.

For example, the vaporization rate of dichloromethane (DCM) is characterized as being faster than the vaporization rate of acetone (AC), and details regarding the formation of microfibers due to this difference in vaporization rate will be described later.

In addition, the method for producing porous polylactic acid microfibers according to an embodiment of the present invention may include polylactic acid polymer.

Polylactic acid is a biodegradable synthetic polymer synthesized through polycondensation of lactic acid or ring-opening polymerization of lactide. As the method of obtaining lactic acid, a raw material, from corn starch became known, various biodegradable plastics, including general-purpose plastics, were developed. Applications are being developed.

At this time, the content of polylactic acid (PLA) in the polylactic acid (PLA) mixed solution according to an embodiment of the present invention is characterized in that it is 10% (w/v) to 12% (w/v).

At this time, if the content of the polylactic acid (PLA) is less than 10% (w/v), the concentration of the polymer is low, so it is difficult to manufacture a fiber shape during spinning, and there may be a problem of beads forming. The polylactic acid content is 15% (w/v). If it exceeds (w/v), it may be difficult for the polymer to be discharged from the nozzle during spinning and may harden quickly, so the content of the polylactic acid may be 10% (w/v) to 12% (w/v). .

In the second step, it may include the step of electrospinning the spinning solution to produce porous polylactic acid microfibers in which multiple pores are formed in the polylactic acid fiber (S200).

Electrospinning can produce fibers with a variety of morphologies and high surface-to-volume ratios by controlling process variables such as flow rate, voltage, distance between nozzle and collector, nozzle type, humidity, concentration, polymer-solvent selection, etc.

Accordingly, electrospinning for producing porous polylactic acid microfibers according to an embodiment of the present invention may be performed at a voltage of 10 kV to 18 kV.

Additionally, the electrospinning can be performed at a feed rate of 1.5 mL/h to 3 mL/h.

Additionally, the distance between the nozzle and the collector may be 10 cm to 20 cm.

In addition, the content of polylactic acid (PLA) contained in the mixed solvent is characterized as 10% (w/v) to 12% (w/v).

At this time, in order to form pores in polylactic acid (PLA) microfibers by electrospinning, it may occur due to phase separation during electrospinning that occurs when the polymer solution is discharged from the nozzle to the solvent-free external environment.

Specifically, for example, when a polymer-solvent is discharged from a nozzle, dichloromethane (DCM) on the surface of the jet evaporates rapidly, while acetone (AC) within the jet can simultaneously diffuse outward. Rapid vaporization can induce phase separation, forming a polymer (polylactic acid)-rich phase and a polymer (polylactic acid)-poor phase.

At this time, the concentrated polymer (polylactic acid)-rich phase (AC) solidifies to form a matrix, while the concentrated polymer (polylactic acid)-poor phase (DCM) may create pores.

This phenomenon is because the p _v (58.1 kPa) and viscosity (0.449 mPa·s) of DCM are higher than those of AC ₍ 30 kPa) and viscosity (0.308 mPa·s).

Therefore, the DCM can evaporate relatively quickly during the electrospinning process, leaving AC (polymer-rich phase).

In this way, the porous polylactic acid microfiber can form an interpenetrating network structure between the polymer (polylactic acid)-rich phase and the polymer (polylactic acid)-poor phase through the electrospinning process using the difference in evaporation rate of the polymer-solvent. there is.

At this time, liquid-liquid phase separation may occur due to the coarsening effect, creating nano- or micro-sized pores in the polylactic acid fiber.

Porous polylactic acid microfibers according to another embodiment of the present invention will be described.

Figure 2 is a schematic diagram showing porous polylactic acid microfibers.

As described above, the porous polylactic acid microfibers according to an embodiment of the present invention are produced between a polymer (polylactic acid)-rich phase and a polymer (polylactic acid)-poor phase through an electrospinning process using the difference in evaporation rate of the polymer-solvent. It is characterized by the formation of an interpenetrating network structure.

Additionally, the average diameter of the polylactic acid microfibers of the present invention may be 1.3 μm to 3.5 μm.

Additionally, the specific surface area of the polylactic acid microfibers of the present invention may be 5 m ² /g to 58.69 m ² /g.

Additionally, the total pore volume of the polylactic acid microfibers of the present invention may be 0.1 cm ³ /g to 13.24 cm ³ /g.

Additionally, the average pore diameter of the polylactic acid microfibers of the present invention may be 15.97 nm to 47.04 nm.

In addition, the average pore volume of the polylactic acid microfibers of the present invention may be 0.145 cm ³ g ^-1 to 12.75 cm ³ g ^-1 .

At this time, it is possible to control the drug loading rate and drug release rate depending on the average pore volume.

In this way, through the electrospinning process described above, porous polylactic acid fibers having the characteristics shown in Table 1 below can be manufactured using dichloromethane (DCM) and acetone (AC) as solvents.

Polymer-solvent system classification average fiber diameter
(μm) Average pore diameter (nm) Specific surface area (m ² g ^-One )
total pore volume
(cm ³ g ^-One ) viscosity
(mPa·s) 5:5 DCM: AC porous PLA 1.866 (±0.56) 19.23 (±3.26) 5.877 (±0.82) 0.145 (±0.01) 193 (±2.48) 6　:4 DCM: AC porous PLA 1.816 (±0.58) 30.29 (±4.12) 28.96 (±1.14) 6.659 (±0.29) 218 (±4.02) 7:3 DCM: AC porous PLA 2.434 (±0.85) 42.19 (±4.85) 55.61 (±3.08) 12.78 (±0.46) 252 (±3.86) 7:3CF:EtOH
Non-porous PLA 2.280 (±1.11) - 0.030 (±0.04) 0.0009 (±0.0001) 292 (±6.16)

Referring to Table 1 above, when the DCM content increases to 70%, the average fiber diameter can increase from 1.3 μm to 3.5 μm, the average pore diameter can increase from 15.97 nm to 47.04 nm, and the specific surface area can increase by 5. m ² /g can increase from 58.69 m ² /g, and the total pore volume can be increased from 0.1 cm ³ /g to 13.24 cm ³ /g. Detailed description of the properties of the above-described porous polylactic acid microfibers will be described later in the experimental example below.

Therefore, the porous polylactic acid microfiber according to an embodiment of the present invention has excellent drug release properties when used as a drug carrier due to its interconnected internal structure, large surface area, large pore size, and large pore volume.

Hereinafter, the present invention will be described in more detail through manufacturing examples and experimental examples. These production examples and experimental examples are only for illustrating the present invention, and the scope of the present invention is not limited by these production examples and experimental examples.

Manufacturing Example 1: Preparation of porous polylactic acid microfibers

In this Preparation Example 1, a polylactic acid (PLA) mixture containing dichloromethane (DCM), acetone (AC), and polylactic acid (PLA) was prepared, and then the polylactic acid mixture was electrospun to prepare porous polylactic acid microfibers. did.

The volume ratio of dichloromethane (DCM) and acetone (AC) used is shown in Table 2 below.

Manufacturing Example 1.1 Manufacturing Example 1.2 Manufacturing Example 1.3 Dichloromethane (DCM): Acetone (AC) (vol:vol) 5:5 6:4 7:3

1) Manufacturing Example 1.1

In this Preparation Example 1.1, a mixed solvent was prepared by mixing 5 ml of dichloromethane (DCM) and 5 ml of acetone (AC) so that the mixing volume ratio of dichloromethane (DCM) and acetone (AC) was 5:5. .

Next, about 1 g of PLA was added to the mixed solvent to make 10 wt%, thereby preparing a polylactic acid (PLA) mixed solution.

Next, the polylactic acid (PLA) mixture was electrospun at a voltage of 18 kV and a supply rate of 3 mL/h to prepare porous polylactic acid microfibers (5:5 PLA).

At this time, the PLA fiber was treated with oxygen plasma at 200 W, 160 sccm for 5 minutes to increase wettability using a plasma system.

2) Manufacturing Example 1.2

In this Preparation Example 1.2, a mixed solvent was prepared by mixing 6 ml of dichloromethane (DCM) and 4 ml of acetone (AC) so that the mixing volume ratio of dichloromethane (DCM) and acetone (AC) was 6:4. It was manufactured in the same process as Preparation Example 1.1 except for this.

3) Manufacturing Example 1.3

In this Preparation Example 1.3, a mixed solvent was prepared by mixing 7 ml of dichloromethane (DCM) and 3 ml of acetone (AC) so that the mixing volume ratio of dichloromethane (DCM) and acetone (AC) was 7:3. It was manufactured in the same process as Preparation Example 1.1 except for this.

At this time, the distance between the nozzle tip and the roller collector is 15cm.

Comparative example: Manufacturing of non-porous polylactic acid microfibers (PLA)

In this comparative example, a mixed solvent was prepared by mixing 7 ml of chloroform and 3 ml of ethanol (EtOH) so that the volume ratio of chloroform and ethanol (EtOH) was 7:3.

Next, a polylactic acid (PLA) mixed solution was prepared by adding about 1.5 g of PLA to the mixed solvent to make 15% (w/v).

Next, the polylactic acid (PLA) mixture was electrospun at a voltage of 18 kV and a supply rate of 1.5 mL/h.

At this time, the distance between the nozzle tip and the roller collector is 15cm.

Experimental Example 1: Experiment to confirm the characteristics and shape of porous and non-porous PLA fibers

Porous PLA fibers (Preparation Example 1) and non-porous PLA fibers (Comparative Example) prepared in various solvent systems by scanning electron microscopy (SEM, Hitachi, Tokyo, Japan) using Nawhoo imaging software (Iworks 2.0, Suwon, Korea). The morphology was observed (N≥100).

Figure 3 is an SEM image showing the surface and cross section of porous PLA fibers and non-porous PLA fibers.

Figure 3 SEM images of porous polylactic acid microfibers according to the ratio of dichloromethane (DCM) and acetone (AC), Figure 3 (a) 5:5 (DCM:AC) porous polylactic acid microfibers, (b) 5: 5 Cross-sectional image of porous polylactic acid microfiber, (c) 6:4 porous polylactic acid microfiber, (d) cross-sectional image of 6:4 porous polylactic acid microfiber, (e) 7:3 porous polylactic acid microfiber, ( f) Cross-sectional image of 7:3 porous polylactic acid microfiber, (g) non-porous polylactic acid microfiber, and (h) cross-sectional image of non-porous polylactic acid microfiber.

Referring to Figures 3(g) and (h), the non-porous PLA fibers showed a smooth surface with an average fiber diameter of 2.28 μm, while Figures 3(a) to 3(f) contained pores. You can check that.

As a solvent used in the present invention, DCM evaporates relatively quickly during the electrospinning process, and AC may remain.

At this time, referring to Figure 2, it can be seen that the number of pores increases as the DCM content increases to 70% by volume.

As a result, it can be confirmed that the porous polylactic acid microfiber according to an embodiment of the present invention can form various internal structures such as pore depth, size, and volume depending on the polymer or solvent system.

Additionally, various polymer-solvent systems for preparing the porous PLA fibers lead to the formation of an interpenetrating network structure between the PLA polymer-rich phase (PLA dissolved in AC) and the polymer-poor phase (PLA dissolved in DCM). , the liquid-liquid phase separation can occur due to the maximization effect, creating nano- or micro-sized pores in the PLA fiber.

Experimental Example 2: Investigating the influence of polymer-solvent system on roughness or pore depth

With reference to Figure 4, the influence of the polymer-solvent system on the roughness or pore depth of porous polylactic acid microfibers according to an embodiment of the present invention will be described.

Figure 4 is a graph of the AFM image and surface roughness of porous polylactic acid microfibers.

Referring to Figure 4, regularly interconnected nano-sized pores can be seen on the surface of the porous polylactic acid fiber.

At this time, the measurements of roughness and corresponding average values shown in FIG. 4 represent all porous polylactic acid microfibers.

Specifically, it can be seen that the average roughness value of non-porous PLA fibers is approximately less than 5 nm, while the average roughness value of 7:3 porous polylactic acid microfibers increases above 100 nm.

At this time, as observed in the SEM image of Figure 3, it can be confirmed that the pore depth and surface area of the porous polylactic acid microfibers with a volume ratio of 7:3 (DCM:AC) are the largest.

In addition, as the viscosity increases, the coarsening time increases, forming large pores and an interpenetrating network structure of PLA fibers. Porous polylactic acid microfibers with a 7:3 volume ratio (DCM:AC) are produced in the DCM:AC polymer-solvent system. It showed the highest viscosity of 252 mPa·s, which may be an interpenetrating network structure with the largest pore size and depth, as shown in Figure 4(d).

Experimental Example 3: In vitro release analysis of gentamicin-loaded PLA fibers

In vitro release analysis of porous polylactic acid microfibers (PLA) loaded with gentamicin was performed using a quantitative colorimetric assay to compare the release pattern with that from porous and non-porous polylactic acid microfibers over 7 days. did.

Specifically, after preparing porous polylactic acid microfibers (5:5, 6:4, 7:3 PLA) and non-porous polylactic acid microfibers containing gentamicin, each gentamicin-loaded PLA sample was Incubated in 3 mL of PBS at 37°C for 7 days.

Next, 1 mL of this solution was transferred to a 5 mL vial.

Next, 1 mL of pure PBS was added to the gentamicin-loaded PLA in the original PBS sample.

Next, 0.3 mL of ninhydrin solution (5 mg/mL) was added to the 5 mL vial and incubated in a water bath at 95 °C for 15 min.

Next, it was cooled and the OD405 of the vials was measured using a microplate reader (Allsheng, Hangzhou, China) and the average value was calculated.

At this time, all experiments were performed in triplicate.

Hereinafter, the release pattern of gentamicin will be described through analysis of the release profile of gentamicin to investigate the basic release pattern of antibiotics according to the type of porous PLA fiber.

Figure 5 shows the in vitro release results of non-porous and porous 5:5, 6:4, 7:3 PLA fibers in the presence of gentamicin, showing (a) gentamicin concentration-OD405 standard curve and (b) gentamicin release result graph. am.

Here, the release profile of PLA samples loaded with gentamicin was generated in vitro for 7 days.

The standard curve of gentamicin concentration-OD405 in Figure 5(a) can be confirmed to be y = 0.0221x + 0.00154 and R ₂ = 0.951 using adj.

Referring to Figure 5(a), the non-porous PLA loaded with gentamicin was released quickly and the release could be reduced within 30 minutes, similar to the OD405 value of the control group.

Meanwhile, it can be confirmed that porous PLA (5:5, 6:4, 7:3) loaded with gentamicin shows a sustained release rate.

Among these, 7:3 PLA loaded with gentamicin showed the highest drug release during the first 30 minutes (gentamicin released at a concentration of 26.61 μg/ml) and showed an explosive release pattern for the next 3-5 hours. there is.

Additionally, 7:3 PLA containing gentamicin can exhibit higher gentamicin loading than 5:5 and 6:4 PLA while maintaining a constant release concentration of 4.23 μg/mL for 168 hours.

Additionally, in the case of 5:5 PLA, gentamicin release ceases after approximately 72 hours, and this drug release mechanism is related to diffusion.

Specifically, early release may involve rapid diffusion of the antibiotic deposited on the fiber surface, whereas slow release may primarily involve diffusion of the antibiotic through the polymer matrix.

At this time, the interconnected 7:3 porous polylactic acid can provide additional sites for the adsorption of gentamicin and enable slow and sustained release of the drug due to its high specific surface area, pore volume, and porosity.

Additionally, in this study, 7:3 PLA showed the highest drug loading and release rates among all fibers.

Additionally, the cumulative amount of gentamicin delivered by porous polylactic acid microfibers over 7 days was much higher than non-porous PLA, as indicated by 7:3 PLA > 6:4 PLA > 5:5 PLA > non-porous PLA.

As a result, it was confirmed that the release of gentamicin from the 7:3 porous polylactic acid microfiber (PLA) continued for 168 hours.

Therefore, the 7:3 porous polylactic acid microfiber according to an embodiment of the present invention can be used as a promising antibiotic carrier that can promote sustained release of gentamicin over a long period of time.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as single may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

100: Porous polylactic acid microfiber

Claims (13)

Preparing a spinning solution by adding polylactic acid (PLA) to a mixed solvent containing a first solvent and a second solvent having different evaporation rates; And
A method for producing porous polylactic acid microfibers, comprising the step of electrospinning the spinning solution to produce porous polylactic acid microfibers with multiple pores formed in the polylactic acid fibers. According to paragraph 1,
In the step of preparing the spinning solution,
The first solvent is a method for producing porous polylactic acid microfibers, characterized in that it contains dichloromethane (DCM). According to paragraph 1,
In the step of preparing the spinning solution,
The second solvent is a method of producing porous polylactic acid microfibers, characterized in that it contains acetone (AC). According to paragraph 1,
In the step of preparing the spinning solution,
A method for producing porous polylactic acid microfibers, characterized in that the evaporation rate of the first solvent is faster than the evaporation rate of the second solvent. According to paragraph 1,
In the step of preparing the spinning solution,
A method for producing porous polylactic acid microfibers, characterized in that the mixing volume ratio of the first solvent and the second solvent in the mixed solvent is 5:5 to 7:3. According to paragraph 1,
In the step of preparing the spinning solution,
A method for producing porous polylactic acid microfibers, characterized in that the content of polylactic acid (PLA) in the polylactic acid (PLA) mixture is 10% (w/v) to 12% (w/v). According to paragraph 1,
In the step of manufacturing the porous polylactic acid microfibers,
A method for producing porous polylactic acid microfibers, characterized in that the electrospinning is performed at a voltage of 10kV to 18kV. According to paragraph 1,
In the step of manufacturing the porous polylactic acid microfibers,
A method for producing porous polylactic acid microfibers, wherein the electrospinning is performed at a supply rate of 1.5 mL/h to 3 mL/h. According to paragraph 1,
In the step of manufacturing the porous polylactic acid microfibers,
The porous polylactic acid microfibers are characterized in that when electrospinning, the polylactic acid dissolved in the second solvent solidifies to form a matrix, and the polylactic acid dissolved in the first solvent forms pores. Manufacturing method. Porous polylactic acid microfibers manufactured by the manufacturing method of claim 1. According to clause 10,
Porous polylactic acid microfibers having a specific surface area of 5 m ² /g to 58.69 m ² /g. According to clause 10,
Porous polylactic acid microfibers, characterized in that the average pore diameter is 15.97 nm to 47.04 nm. According to clause 10,
Porous polylactic acid microfibers, characterized in that the average pore volume is 0.145 cm ³ g ^-1 to 12.75 cm ³ g ^-1 .

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