Fastner for soft tissue suturing comprising biodegradable metal material and manufacturing method therefor

Abstract

Provided is a fastner for soft tissue suturing, which is composed of magnesium, calcium, and zinc, wherein the fastner for suturing is inserted into the soft tissue and decomposed. The fastner according to the present invention is manufactured on the basis of a magnesium alloy material, and the magnesium alloy material prepared in the present invention has a high tensile strength along with a sufficient decomposition rate in soft tissues (particularly, in transdermal tissues), such as the skin, and thus is excellent as a material for soft tissue suturing.

Description

Staple for soft tissue suturing comprising biodegradable metal material and method for manufacturing the same

[0001] The present invention relates to a staple for soft tissue suturing comprising a biodegradable metal material, and more particularly, to a staple for soft tissue suturing which is excellent for soft tissue suturing because it is inserted into the skin and has a high tensile strength along with a sufficient decomposition rate within the soft tissue.

[0002] Typically, during surgical or plastic surgery, areas of skin torn by surgery are closed with sutures and needles to close soft tissues like skin. These soft tissues include muscle, nerve, connective, and epithelial tissues, and using needles can significantly increase the surgical time. Therefore, staplers, a device specifically designed to close soft tissues like skin, were developed.

[0003] The above stapler uses staples instead of sutures to secure skin tissue. The shape of the staples is similar to those commonly used in office settings. However, conventional staples have the inconvenience of having to be removed after suturing.

[0004] To address these issues, U.S. Patent Application No. 11 / 022319 and others disclose devices for inserting and securing biodegradable polymer staples into the skin. However, because these devices utilize polymers lacking sufficient fixation strength, a separate transport device is required to initially transport the staples into the skin, potentially leaving unnecessary scars or marks on the skin. Therefore, the development of novel staples that possess both sufficient fixation strength and biodegradability is needed.

[0005] The problem to be solved by the present invention is to provide a new staple material having both mechanical properties such as sufficient tensile strength and biodegradability, and a method for manufacturing the same.

[0006] In order to solve the above problem, the present invention provides a staple for soft tissue suturing, wherein the staple for suturing is composed of magnesium, calcium, and zinc, and the staple for suturing is characterized in that it is inserted into soft tissue and decomposes.

[0007] In one embodiment of the present invention, the staple for soft tissue suturing is composed of 0.5 to 5 wt% zinc, 0.05 to 1 wt% calcium, and the remainder magnesium.

[0008] In one embodiment of the present invention, the staple for soft tissue suturing is manufactured by extruding in two stages after casting.

[0009] In one embodiment of the present invention, the extrusion temperature during the last extrusion among the two-stage extrusion is performed at 350°C to 390°C.

[0010] In one embodiment of the present invention, the staple for soft tissue suturing has a faster degradation rate in percutaneous tissue than a faster degradation rate in bone or muscle tissue.

[0011] The present invention also provides a method for manufacturing a staple for soft tissue suturing, comprising the steps of: melting and casting a mixture of magnesium, zinc, and calcium; extruding a cast product obtained from the casting step in a single stage at 370°C; and extruding an extruded product obtained from the single stage extrusion step in a second stage at a temperature of 350°C to 390°C.

[0012] In one embodiment of the present invention, the mixture is composed of 0.5 to 5 wt% zinc, 0.05 to 1 wt% calcium, and the remainder magnesium.

[0013] The staple according to the present invention is manufactured based on a magnesium alloy material, and the magnesium alloy material manufactured in the present invention has a high tensile strength along with a sufficient decomposition rate within soft tissues such as skin (particularly within percutaneous tissue), and is therefore excellent as a material for soft tissue suturing.

[0014] FIG. 1 is a photograph of a staple manufactured according to one embodiment of the present invention.

[0015] Figure 2 shows the results showing the decomposition rate according to the extrusion temperature, and Table 1 shows the quantified results.

[0016] Figure 3 shows the results showing the tensile strength according to the extrusion temperature, and Table 2 shows the quantified results.

[0017] Figure 4 shows the results of an experiment on the decomposition rate according to tissue type.

[0018] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the following detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. In describing the present invention, detailed descriptions of related known technologies will be omitted if they are deemed to obscure the gist of the present invention.

[0019] To address the aforementioned issues, the present invention provides a staple for soft tissue suturing made of a magnesium alloy material. The magnesium alloy material produced in the present invention exhibits high tensile strength along with a sufficient degradation rate within skin tissue (particularly within dermal tissue), making it an excellent material for soft tissue suturing.

[0020] The present invention is described in more detail through the following examples and experimental examples.

[0021] Example

[0022] In order to improve the biodegradable soft tissue suture staple, a Mg-Zn-Ca alloy was manufactured using pure Mg (99.99%) ingot, Ca (99.5%) metal particles, and Zn (99.99%) metal particles. The composition of the alloy is preferably 0.5 to 5 wt% zinc, 0.05 to 1 wt% calcium, and the remainder magnesium. In the following examples of the present invention, the alloy composition was set to Mg-1Zn-0.1Ca (wt.%).

[0023] Here, the coefficient in front of the metal component is the weight % of the component, and if there is no coefficient, it means the remaining content excluding the metal component with the coefficient. That is, Mg-1Zn-0.1Ca means 1 wt% zinc, 0.1 wt% calcium, and the remainder magnesium.

[0024] A manufacturing process according to one embodiment of the present invention is as follows.

[0025] First, the vacuum furnace atmosphere was filled with high-purity argon gas (99.99%) to ensure compositional stability. Next, the melting temperature was set to 750°C, and the metals weighed as Mg-Zn-Ca were mixed, melted, and cast into an STS430 steel mold. The casting mold for the casting stage was manufactured into a cylindrical shape with a diameter of 120 mm and a height of 300 mm.

[0026] Additionally, the chemical composition of the alloy was analyzed using optical emission spectroscopy (OES) method, which allowed the components of the alloy to be accurately identified.

[0027] In one embodiment of the present invention, a two-stage mechanical extrusion process is adopted for microstructural adjustment.

[0028] That is, in the above casting step, the cast ingot (cast product) was preheated to 370°C, then extruded at an extrusion ratio of 6:1 to cool a circular sample with a diameter of 50 mm in the air (single-stage extrusion).

[0029] Afterwards, the extruded product of the first extrusion stage was preheated again to 350°C (Comparative Example 1), 370°C (Example), and 390°C (Comparative Example 2), and then re-extruded (second extrusion) at an extrusion ratio of 129:1 to finally manufacture a plate-shaped sample having a width of 20 mm and a height of 0.7 mm in the form of Fig. 1.

[0030] The present invention has found that the extrusion temperature prior to the production of the final product has a particularly significant effect on the biodegradability results, which is explained in more detail in the experimental examples below.

[0031] Mg-Zn-Ca alloys manufactured through this method have excellent mechanical properties and biocompatibility and can be utilized in various biomaterial applications.

[0032] FIG. 1 is a photograph of a staple manufactured according to one embodiment of the present invention.

[0033] Referring to FIG. 1, it can be seen that a staple manufactured according to one embodiment of the present invention has different thicknesses in the direction of insertion depth, and in particular has a thin width portion (neck) above a sharp arrow-like end portion.

[0034] In one embodiment of the present invention, in consideration of the problem of the neck breaking when inserting a staple into skin tissue, calcium was added to the magnesium alloy material to ensure sufficient breaking stress at the neck portion.

[0035]

[0036] Experimental example

[0037] Experimental Example 1

[0038] Mechanical properties

[0039] Decomposition rate

[0040] The degradation test according to this experimental example is conducted to evaluate the degradation rate of staples. The temperature of a constant temperature water bath is set to 37℃ and then increased. Next, 500 mL of PBS solution is placed in a 1,000 mL beaker and placed in the constant temperature water bath to ensure that the solution temperature reaches 37℃. After checking the temperature of the solution with a thermometer and confirming that it has reached 37℃, the specimen is immersed so that it is positioned in the center of the beaker and a burette funnel is placed on top. After that, air is removed from the burette using a syringe and the scale is adjusted to 10 mL. Finally, the temperature is checked and the amount of hydrogen generated is measured at regular intervals. The measurement time is based on the point at which the corrosion rate reaches a certain value and begins to be maintained during the immersion period.

[0041] Figure 2 shows the results showing the decomposition rate according to the extrusion temperature, and Table 1 shows the quantified results.

[0042] Extrusion temperature 350℃ 370℃ 390℃ Sample 10.0165 0.0094 0.0247 Sample 20.0079 0.0090 0.0167 Sample 30.0084 0.0089 0.0096 Average 0.0110 0.009 10.0170 Standard deviation 0.0049 0.000 30.0076

[0043]

[0044] Referring to Figure 2 and Table 1, it can be seen that the extrusion temperature has a particularly low decomposition rate at 370°C. This is a very important effect given the characteristics of staples that must maintain strength for a certain period of time.

[0045] tensile strength

[0046] Tensile tests are performed to evaluate the mechanical strength of Mg alloy staples. Polymer wires are suspended between the barbs on both sides of the staple to apply tension. The staples are subjected to tensile testing at a strain rate of 6 mm / min using a universal testing machine (MTS Landmark 1, MTS, USA) until fracture.

[0047] Figure 3 shows the results showing the tensile strength according to the extrusion temperature, and Table 2 shows the quantified results.

[0048] Extrusion temperature 350 ℃ 370 ℃ 390 ℃ Sample 125.8 28.3 127.64 Sample 225.44 28.86 27.66 Sample 325.85 28.3 27.72 Average 25.6 9 28.4 9 27.67 Standard deviation 0.2 20.3 10.04

[0049] Referring to the results in Fig. 3 and Table 2, it can be seen that the staple extruded at 370°C has high tensile strength, which means that in order to obtain excellent mechanical properties of the staple, the extrusion temperature in the last extrusion process of the two-stage extrusion is 350 to 390°C, more preferably 360 to 380°C, and most preferably 370°C. In-vivo degradation rate

[0050] Figure 4 shows the results of an experiment on the decomposition rate according to tissue type.

[0051] Referring to Figure 4, the magnesium-based staple according to the present invention exhibits a uniquely faster degradation rate in dermal tissues, particularly among soft tissues, than in bone or muscle. This suggests that the magnesium-based staple according to the present invention is highly suitable as a biodegradable material for soft tissue sutures.

[0052] As described above, the staple according to the present invention is manufactured based on a magnesium alloy material, and the magnesium alloy material manufactured in the present invention has a high tensile strength along with a sufficient decomposition rate within skin tissue (particularly within percutaneous tissue), and is therefore excellent as a material for soft tissue suturing.

[0053] The present invention relates to a staple for soft tissue suturing comprising a biodegradable metal material and a method for manufacturing the same, and is recognized to have industrial applicability.

Claims

1. As a staple (fastener) for soft tissue suturing, The above suturing staples are composed of magnesium, calcium and zinc. A staple for suture of soft tissue, characterized in that the staple for suture is inserted into soft tissue and disintegrates.

2. In paragraph 1, A staple for soft tissue suturing, characterized in that the staple for soft tissue suturing comprises 0.5 to 5 wt% of zinc; 0.05 to 1 wt% of calcium; and the remainder of magnesium.

3. In paragraph 2, The above soft tissue suturing staple is characterized in that it is manufactured by extruding in two stages after casting.

4. In paragraph 3, A staple for soft tissue suturing, characterized in that the extrusion temperature during the last extrusion among the above two-stage extrusion is 350°C to 390°C.

5. In paragraph 4, The above-mentioned staple for soft tissue suturing is a staple for soft tissue suturing characterized by a faster decomposition rate in percutaneous tissue than in bone or muscle tissue.

6. A method for manufacturing staples (fasteners) for soft tissue suturing, A step of melting and casting a mixture of magnesium, zinc, and calcium; A step of extruding the casting obtained from the above casting step in one stage at 370°C; A method for manufacturing a staple for soft tissue suturing, comprising a step of extruding the extruded product obtained in the above first extrusion step in a second stage at a temperature of 350°C to 390°C.

7. In paragraph 1, A method for manufacturing a staple for soft tissue suturing, characterized in that the mixture comprises 0.5 to 5 wt% of zinc; 0.05 to 1 wt% of calcium; and the remainder of magnesium.

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