KR102506968B1 - A biodegradable polymer resin composition for manufacturing high-performance sutures and high functional suture prepared thereof - Google Patents

Abstract

The present invention relates to a biodegradable polymer resin composition for manufacturing high-functional sutures and a high-functional suture manufactured therefrom. The suture according to the present invention is harmless to the human body, safe, biodegradable after use, and environmentally friendly, has excellent processing properties during injection molding, and has a high elongation rate, so that the ductility (stretchability and stability) of the suture after injection can be greatly improved. In the present invention, a basic sample composition of a high-functional suture is prepared through the steps of preparing a sample by dehumidifying, drying, mixing, and compressing a lactide polymer (PLA) and a caprolactone polymer (PCL).

Description

Biodegradable polymer resin composition for manufacturing high-function suture and high-function suture prepared therefrom

The present invention relates to a biodegradable polymer resin composition for manufacturing a high-function suture and a high-function suture prepared therefrom, which is harmless to the human body, safe, biodegradable after use, environmentally friendly, excellent in processing properties during injection molding, and high in elongation, so that the suture after injection It is about greatly improving furnace ductility (stretchability and stretchability stability).

In order to prevent skin aging, the use of cosmetics, massage, etc. is steadily increasing, and recently, skin wrinkle improvement procedures have been widely performed.

Skin wrinkle improvement procedures include a direct method such as a face lift and an indirect method such as a lifting procedure.

A face lift refers to a procedure in which the skin is pulled upward to remove excess skin and then stitched to tighten the skin.

Although this procedure is effective, the risk of surgery is high, scars may remain in front of the ears and the forehead line, and the recovery period is over a month, so it is not easy to choose.

In addition, aging skin not only continues to develop wrinkles, but also has a problem of accelerated aging due to thin skin.

The lifting procedure stimulates the skin tissue by inserting a suture harmless to the human body into the skin, thereby promoting skin contraction and regeneration, and furthermore, by using the tension of the suture to pull the part adhered to the skin tissue upward to fix it, the sagging skin tissue is lifted. Lift up.

Compared to conventional surgical procedures, this procedure is simple and rarely interferes with daily life, and has recently been widely used.

Such a normal medical thread, that is, a suture, is a single-line thread with good tensile strength, such as nylon or synthetic resin, and hook-shaped spinous projections (hereinafter referred to as 'cogs') are formed in a certain direction on the surface of the thread (the spinous projections are facing each other or protruding obliquely in a zigzag direction) to improve the supporting force when suturing the incised skin or pulling the skin.

On the other hand, conventional suture yarns are mainly imported from Japan, and the imported sutures have a disadvantage in that their economic feasibility is low due to the high purchase cost. It is common to evaluate that the quality of the product itself is bad and the satisfaction with the post-medical procedure is not high.

For reference, although there are currently domestic products among suture products, the performance of manufactured raw materials is not good, so the demand for the products is very low, so they cannot be replaced by imported products.

Therefore, in recent years, the industry has promoted the localization of a suture with improved performance along with cost reduction, and in accordance with such interest and demand, research on domestic manufacturing of a suture (research on raw materials for a composition) is being actively conducted.

KR 10-1057376

The object of the present invention is harmless to the human body, safe, biodegradable after use, eco-friendly, excellent processing properties during injection molding, and high elongation, so that the ductility (stretchability and stability of stretching) of the suture after injection is greatly improved. It is to provide a biodegradable polymer resin composition for manufacturing a high-function suture and a high-function suture prepared therefrom.

In order to solve the above problems, the inventors of the present invention localize and highly functionalize the polymer resin (raw material), which is a raw material for sutures, to ensure excellent manufacturability or processability (ejectability and ductility), but to ensure stability and eco-friendliness by biodegradability, In this study, we tried to manufacture a high-performance suture using a mixed polymer that improves tissue fixation and traction strength so that the tissue to be medically or surgically treated can be smoothly restored.

Therefore, in the present invention, a basic sample composition of a high-function suture is prepared through the steps of preparing a sample by dehumidifying, drying, mixing, and compressing the lactide polymer (PLA) and the caprolactone polymer (PCL).

Accordingly, the mass ratio of the caprolactone polymer (PCL):lactide polymer (PLA) is preferably 10 to 30%:70 to 90%.

In the present invention, the lactide polymer (PLA) and the caprolactone polymer (PCL) mixed according to the manufacturing method of the present invention may be used in combination as PLA/PCL, PLCL, or PLACL.

In one embodiment, the suture according to the present invention is the initial PLA / PCL according to the comparative analysis according to the PLA / PCL raw material manufacturer, the chemical characterization of the PLA / PCL blend chip according to the blending ratio and the extrusion process, and the production process Blend suture physical properties were evaluated.

As a result, it was confirmed that injection molding, elongation, and ductility of the suture according to the present invention were improved.

In the production method of the present invention, a twin-screw compressor capable of temperature control and automatic input was used for the production of PLA and PCL mixtures.

That is, the compressing step in the present invention may be performed using a twin-screw compressor under conditions of a feeding temperature of 95 to 105 °C, a mixing temperature of 130 to 170 °C, and a die temperature of 165 to 175 °C.

In the present invention, the step of preparing the sample may be performed under conditions of a screw speed of 250 to 270 rpm and a feeding speed of 15 to 18 rpm after the compression.

In another aspect of the present invention, a high-function suture can be prepared from a biodegradable polymer resin composition for preparing a high-function suture, which includes preparing a pellet by melting a sample; preparing an injection-molded suture thread by injecting the pellet into an extruding mold; And it is prepared by a step of stretching the injection-molded suture in the air or in water to lengthen it.

At this time, the suture of the present invention is a cog-type suture having protrusions formed on the outer circumferential surface.

In the present invention, the term "comprises" or "has" is intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

The advantages and features of the present invention, and how to achieve them, will become clear with reference to the detailed description of the following embodiments. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the present embodiments will complete the disclosure of the present invention and allow common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The suture according to the present invention is harmless and safe to the human body, is biodegradable after use, is environmentally friendly, has excellent processing properties during injection molding, and has a high elongation rate, so the ductility (stretchability and stability of stretching) of the suture after injection is greatly improved. .

1 shows a PLACL extrusion process prepared according to the present invention as part of the pellet manufacturing process according to the present invention.
Figure 2 shows the result of extrusion of PLACL prepared according to the present invention as part of the pellet manufacturing process according to the present invention.
Figure 3 shows a PLACL prototype (pellet) manufacturing process according to the present invention as part of the pellet manufacturing process according to the present invention.
4 shows a design diagram of a single-line suture having a structure in which a cog is integrated according to the present invention. (Basic shape design of injection molding)
5 shows a design diagram of a single-line suture structure in which a cog is integrated according to the present invention. (trial injection mold design)
6 shows a design diagram of a single-line suture having a structure in which a cog is integrated according to the present invention. (Section size)
7 shows the results produced according to the temporary injection conditions of the present invention.
8 shows the result of analyzing the temporary injection molding material for establishing injection conditions according to the present invention.
9 shows the thermal processability test results of the PLACL 10% chip and the PLACL 15% chip manufactured according to the present invention.
10 shows integrated cog suture designs (2D and 3D) according to the present invention.
11 shows the results of GPC analysis of the PLA raw material according to the present invention.
Figure 12 shows the results of differential scanning calorimetry (DSC) analysis of PLACL 15% at two different heating/cooling rates according to the present invention.
13 shows DSC thermograms of the second heating cycle for PLA/PCL5, 10, and 15% chips according to the present invention.
14 shows the results of ATR-FTIR (IR Spectral Interpretation) measurement for chemical structure analysis of the PLA/PCL blend chip according to the present invention.
15 shows the ATR-FTIR spectrum results of PLA/PCL mixtures with different PCL contents according to the present invention.
16 shows XRD patterns of selected materials showing the relative positions of diffraction peaks of PLA/PCL blend samples according to the present invention. (a) PCL (b) PLA (c) PLACL 5 (d) PLACL 10 (e) PLACL 15

Hereinafter, one or more specific examples will be described in more detail through examples. However, these examples are intended to illustrate one or more specific examples, and the scope of the present invention is not limited to these examples.

[Example]

Preparation Example 1: PLA/PCL raw material mixing and PLA/PCL blending chip manufacturing

1) Raw materials

2) Preparation of PLACL blends

- Water removal pretreatment: dehumidifying dryer (ASF-50) 80℃, 10 hours

- Polymer chip manufacturing equipment: twin screw extruder, (Jinsan PRM Co., Ltd., custom-made)

[Table 1] PLA/PCL blending conditions

A twin-screw compressor capable of temperature control and automatic injection was used to manufacture the blend of PLA and PCL. Each resin mass ratio of the PLACL blend preparation was mixed at 95:5, 90:10, and 85:15.

After mixing, the blend was prepared using a twin-screw extruder to set a feeding temperature of 100 ° C, a mixing temperature of 130 to 170 ° C, and a die temperature of 170 ° C, respectively, at a screw speed of 250 to 270 rpm and a feeding speed of 15 to 18 made at rpm.

At this time, the sample prepared in the die was cooled in water to suppress the phase separation phenomenon, and after drying, it was made into a pellet.

As a result of the extrusion, it was impossible to produce pellets at the 5% blending ratio of PLACL, and homogeneity was confirmed in PLACL 10 and PLACL 15, and the extruded product was supplied to a cutter to produce pellets, which were prototypes of PLACL.

Preparation Example 2: Initial mold design fabrication and temporary injection for developing a PLACL suture

1) Injection product for manufacturing a single-line suture with an integrated cog structure

The section size conditions of the initial mold design for the development of a single-line suture with a cog-integrated structure are as follows (FIG. 6).

[Table 2]

1) Temporary injection to establish injection conditions

[Table 3] Temporary Injection Conditions

In the case of injection analysis, flowability is also influenced by the material properties, but it can affect short shots, burr generation, and density due to the influence of temperature, pressure, and time of the injection machine.

As a result of the analysis of the temporary injection molding material for establishing the injection conditions, difficulties were confirmed as the 1:1 condition was set (FIG. 7).

Example 1: Study of temporary stretching process through thermal processability test

The heat processability test of the previously manufactured PLACL 10 chip and PLACL 15 was conducted.

As a result, as shown in FIG. 9, the PLACL 10% chip had a lot of short molding due to the difference in flowability, a difference in elongation, and was stiff. In contrast, the final prototype was fabricated after confirming that the PLACL 15% chip improved injection molding, elongation, and ductility compared to the PLACL10% chip.

Example 2: Comparative analysis of PLA/PCL raw materials

1) Results of PLA raw material GPC (gel permeation chromatography) analysis

[Table 4]

As shown in Table 4 and FIG. 11, in the case of Nature Works, it was confirmed that the weight average molecular weight (Mw) was 252,239 and the total cobion was 216,203.

2) PLA/PCL raw material melt flow index measurement

- Melt Flow Indexer (WL-1400 With Lab Co., Ltd.) : 190℃, 2.16kg

[Table 5] Melt flow index of blending according to PLA/PCL mixing ratio

[Table 6] Melt flow index of PLACL 15% according to the raw material of PLA

Example 3: Evaluation of Chemical Characteristics of PLA/PCL Blend Chips According to Mixing Ratio and Extrusion Process

1) Evaluation of thermal characteristics

It was measured using a differential calorimetry (DSC: DSC-60A, Shimadzu).

In order to equalize the thermal histories, the sample was first heated to 200 °C at a heating rate of 10 °C/min, and then cooled to -100 °C at -10 °C/min.

Thereafter, the temperature was raised to 200 °C at 10 °C/min and the thermal properties were investigated.

PLA exhibited melting behavior between about 174°C and PCL exhibited melting behavior at 56.3°C. As the PCL content increased by 5%, the Tm temperature shown in PLA decreased by about -1 ℃, and it was confirmed that the Tm temperature shown in PCL decreased by about -4 ℃ due to the decrease in PCL content by 15%. In addition, PLACL appeared independently at the same temperature as shown in FIG. 12, and through this, it was confirmed that there was no compatibility.

[Table 7] Thermal analysis data of PLA/PCL blending chip 2nd heating cycle

2) ATR-FTIR measurement for structural analysis

In order to investigate the chemical structure of the PLA/PCL blend chip, ATR-FTIR was analyzed in the wavelength range of 4000 to 400 cm-1 using an infrared spectroscopic absorber (Fourier Transform Infrared Specroscopy, ThermoFisher Scientific, USA). The chemical functional group was confirmed by analyzing the positions of the frequencies and the size of the pick for the sample of the selected spectrum.

As a result, as shown in FIG. 14, the PCL chip showed alcohol, olefin, aliphatic aldehydes, and aliphatic functional groups, and the PLA chip showed aliphatic ester functional groups. group), and in the case of the PLACL blend sample, it was expressed as aliphatic acetate esters.

Also, both PLA and PCL are known aliphatic polyesters with similar structures. As shown in FIG. 15, C-H, C=O, and C-O peaks were clearly identified at 2943 cm-1, 1723 cm-1, or 1750 and 1171 cm-1, respectively, in the ATR-FTIR spectrum. It was confirmed that the C=O stretching peak of the blended PLACL chips moved from the PLA chip (1723 cm-1) with increased PCL content to the PCL chip (1750 cm-1). In the case of blended PLACL according to the raw material, there is no new peak as a mixed result, and the FT-IR spectrum showing both components of PLA and PCL was confirmed.

3) XRD (X-ray diffractogram) 　Confirm crystal structure change

Crystallization characteristics were obtained from XRD data using an EMpyrean diffractometer (Germany). XRD measurements of the prepared PLACL samples were made at 60 kV and 55 mA. The sample was scanned at a scan rate of 0.06°/s in the 2θ range from 0° to 60° using a Cu-Kα radiation source. d-spacing was obtained from Bragg's law (nλ = 2 d sin θ), where θ is the diffraction angle and λ is the wavelength (λ = 1.54056 A (Angstrom), Cu target). Crystallinity ranges from 0° to 60°. The crystallinity was determined by performing the area integration method from the XRD intensity data.

As shown in FIG. 16, the PCL sample shows different diffraction peak values at 2θ = 21.3, 22.0, 23.6, 26.2, 28.9, 35.5, 39.0, 47.1, 48.1, and 57.0 °, and the PLA at 2θ = 16.5, 18.9, 29.4 ° The main diffraction peak values are shown, and the resulting values are shown in Table 8 below.

[Table 8]

The PLACL sample has two diffraction peaks at 2θ = 16.4 and 18.7 in the case of the sample of PLACL 5, but four main diffraction peaks corresponding to 2θ = 16.4, 18.7, 21.2, and 23.8 ° as the content of PCL increases. It can be seen that the diffraction pattern of the PLACL material has the characteristics of both PLA and PCL, that is, broad amorphous scattering and distinct peaks, and the absorption intensities of the three main peaks lead to a high level of crystallinity.

4) Heavy metal analysis according to cross-contamination of extrusion equipment

Heavy metal analysis of PLA, PCL raw materials and PLACL blending samples was performed by using the wet digestion method. After putting about 0.17 g of the sample into a Teflon container together with 61% HNO3　9mL, it was digested in a microwave at 190℃ for 20 minutes, and then placed in a 100mL volume flask. After transfer, it was filled up to the mark with tertiary distilled water. A calibration curve was prepared using ICP-OES (720-ES, Varian) for two types of standard materials, and the content of each sample was analyzed.

[Table 9] Microwave pretreatment equipment conditions

[Table 10] Heavy metal (cadmium, lead) measurement results

As a result, raw materials and manufactured PLACL 5% (PLA: PCL = 95%: 5% v/v) PLACL 10% (PLA: PCL = 90%: 10% v/v), PLACL 15% (PLA: PCL = 90% : 15% v/v) It was confirmed that cadmium (Cd) and lead (Pb) were not detected in the chip and suture.

Example 4: Evaluation of physical properties of the initial PLACL blind suture according to the production process

[Table 11]

Claims (5)

delete delete delete In preparing a sample by dehumidifying, drying, mixing and compressing lactide polymer (PLA) and caprolactone polymer (PCL),
The mass ratio of the caprolactone polymer (PCL):lactide polymer (PLA) is 10 to 30%: 70 to 90%,
Compression for preparing the sample is performed using a twin-screw compressor under the conditions of a feeding temperature of 95 to 105 ° C, a mixing temperature of 130 to 170 ° C, and a die temperature of 165 to 175 ° C,
In the high-function suture made of the biodegradable polymer resin composition for preparing a high-function suture, wherein the step of preparing the sample is performed under conditions of a screw speed of 250 to 270 rpm and a feeding speed of 15 to 18 rpm after compression,
The suture is a high-function suture of a cog type in which protrusions are formed on the outer circumferential surface. delete

Images