KR102102342B1 - Method for manufacturing suture using biodegradable resin and suture manufactured by the method - Google Patents

Abstract

Provided are a method for manufacturing suture using a biodegradable resin and a suture manufactured thereby. The method for manufacturing suture using a biodegradable resin includes the steps of: preparing a raw material containing a polycaprolactone-paradioxanone block copolymer; applying the prepared raw material to a hopper connected to the top of a die head; maintaining the die head at a temperature range of 175 °C to 200 °C and a pressure of 85 bar to 115 bar and rotating a discharge screw inside the die head in a range of 11 rpm to 13.5 rpm to melt the applied raw material and extrude the same through a nozzle part connected to the bottom of the die head; immersing a spinning mass extruded through the nozzle part in cooling water of 16 °C to 18 °C to cool the spinning mass; winding the cooled spinning mass on 7 to 11 rollers to perform aging for 15 to 25 minutes; stretching the aged spinning mass; stabilizing by contracting the stretched spinning mass; and winding the stabilized spinning mass. The present invention enables continuous production and mass production of suture using a biodegradable resin.

Description

Method for manufacturing sutures using biodegradable resin and sutures produced thereby {METHOD FOR MANUFACTURING SUTURE USING BIODEGRADABLE RESIN AND SUTURE MANUFACTURED BY THE METHOD}

The present invention relates to a method for manufacturing a suture using a biodegradable resin and a suture produced thereby.

Recently, plastic resins are commonly used in everyday life, but the decomposition rate is too long to take years, decades, or even hundreds of years, and environmental pollution caused by plastic waste is a social problem. In addition, recently, it has been known that micro plastics accumulate in a living body and are very harmful to health, which has become a social problem. Accordingly, research has been conducted on biodegradable resins that degrade in vivo while satisfying a certain strength and replace existing plastic resins to prevent environmental pollution and not impair health.

On the other hand, when a surgical operation is performed in the hospital, a suture is used to reseal the incised skin. Conventional sutures have been inconvenient through the process of removing the suture when the skin is joined after a certain time after the operation. To eliminate this inconvenience, the suture itself increases the demand for sutures that have the property of being decomposed in the patient's skin after a certain period of time, and to sutures using biodegradable resin that has a certain strength and decomposes after a certain time. Korean studies are in progress.

However, the biodegradable resin used in these sutures was not easy to polymerize and pelletized in a continuous production method. In particular, using a biodegradable resin to produce a suture having the desired conditions (spec) by a continuous, mass production method Things were also very tricky.

Therefore, there is a need for a method for manufacturing sutures using biodegradable resins capable of continuously mass-producing and producing uniform quality sutures.

Korean Patent Publication No. 10-2017-0095172 (published on 2017.07.27.)

Accordingly, the technical problem to be solved by the present invention is to provide a suture manufacturing method and a suture produced by the suture manufacturing method capable of continuously producing while using a biodegradable resin as a raw material, and manufacturing the suture by a mass production method. Is to do.

In addition, it is intended to provide a suture manufacturing method and a suture manufactured by the suture manufacturing method capable of manufacturing a suture of good quality by minimizing the defect rate.

The problems of the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The method for manufacturing a suture using a biodegradable resin according to an embodiment of the present invention for achieving the above subject is preparing a raw material comprising a polycaprolactone-paradioxanone block copolymer, in a hopper connected to the top of the die head Injecting the prepared raw material, the die head is maintained at a temperature in the range of 175 ° C to 200 ° C and a pressure of 85 bar to 115 bar, and the discharge screw inside the die head is rotated in a range of 11 rpm to 13.5 rpm to be injected. Melting the raw material and extruding through a nozzle part connected to the bottom of the die head, cooling the spinning material extruded through the nozzle part by immersing it in cooling water at 16 ° C to 18 ° C, and cooling the cooled spinning material for 15 minutes to Aging by winding on 7 to 11 rollers for a time of 25 minutes, stretching the aged spinning material, and stretching the spinning material And a step of winding the radiation the method comprising: stabilizing the shrinkage, and stabilization.

In addition, in the step of preparing the raw material, the polycaprolactone-paradioxanone block copolymer has a ratio of ε-caprolactone: para-dioxanone in a molar ratio of 1 It can be characterized by being in the range of: 8 to 1:10.

In addition, before the step of injecting the raw material, preheating the nozzle portion for a time of 100 minutes to 150 minutes so that the nozzle portion is in a temperature range of 175 ° C to 200 ° C, and the inside of the die head is 175 ° C to 200 ° C. It may be characterized in that it further comprises the step of assembling the nozzle portion which has undergone the step of changing to a temperature range of ℃ and a pressure of 85 bar to 115 bar and preheating the lower end of the die head.

In addition, in the process of heating the inside of the die head to a temperature range of 175 ° C to 200 ° C, the temperature range corresponding to 40% of the temperature range is such that the inside of the die head becomes a temperature range of 175 ° C to 200 ° C. The first preheating step to be possible; A second preheating step to make a temperature range corresponding to 30% of the temperature range; A third preheating step to make a temperature range corresponding to 20% of the temperature range; A fourth preheating step to make a temperature range corresponding to 10% of the temperature range; And a fifth preheating step to be within the temperature range, and after the fifth preheating step, rotating the discharge screw inside the die head in a range of 4 rpm to 6 rpm to discharge the residue inside the die head. It may be characterized in that it further comprises.

In addition, the discharged material is discharged through the nozzle of the nozzle unit, the pressure measured at the nozzle immediately after discharge of the discharged product passing through the nozzle may be characterized in that the range of 70bar to 80bar.

In addition, the step of stretching the radioactive material may include a first stretching step in a stretching ratio of 1: 5 to 1: 7; And a second stretching step of stretching at a stretching ratio of 1: 1.05 to 1: 1.15.

In addition, the first stretching step may be performed in a temperature range of 110 ° C to 120 ° C, and the second stretching step may be performed in a temperature range of 115 ° C to 125 ° C.

In addition, the first stretching step is performed between the first roller at the front end and the second roller at the rear end, and the second stretching step is performed between the second roller at the front end and the third roller at the rear end. The first roller rotates in the range of 3.3 rpm to 5.3 rpm, the second roller rotates in the range of 24 rpm to 26 rpm, and the third roller rotates in the range of 24.7 rpm to 26.7 rpm. .

In addition, the step of stabilizing the spinning proceeds between the third roller at the front end and the fourth roller at the rear end, and may be characterized by shrinking in the range of 1.05: 1 to 1.15: 1.

In addition, the step of stabilizing the spinning is performed in a temperature range of 115 ° C to 125 ° C, the third roller rotates in the range of 24.7rpm to 26.7rpm, and the fourth roller ranges from 22.3rpm to 24.3rpm. It can be characterized by rotating.

The suture according to an embodiment of the present invention for achieving the above object is manufactured by the suture manufacturing method using the biodegradable resin described above, and the ratio of caprolactone to paradioxanone ranges from 1: 8 to 1:10 in molar ratio. Phosphorus polycaprolactone-paradioxanone block copolymer.

Specific details of other embodiments are included in the detailed description and drawings.

According to embodiments of the present invention has at least the following effects.

According to the method for manufacturing a suture using a biodegradable resin of the present invention, it is possible to continuously produce while using a biodegradable resin as a raw material, and a suture can be manufactured by a mass production method.

In addition, it is possible to manufacture a good quality suture by minimizing the defect rate.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic flowchart of a method for manufacturing a suture using a biodegradable resin according to an embodiment of the present invention.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. 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 allow the disclosure of the present invention to be complete, and the ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical spirit of the present invention.

In addition, the steps constituting the manufacturing method described in this specification are sequential or continuous, or unless otherwise specified, one step constituting one manufacturing method and another step are in the order described on the specification. It is not limited and interpreted. Therefore, it is possible to change the order of the constituent steps of the manufacturing method within a range that can be easily understood by those skilled in the art, and in this case, changes apparent to those skilled in the art are included in the scope of the present invention.

1 is a schematic flowchart of a method for manufacturing a suture using a biodegradable resin according to an embodiment of the present invention.

Referring to Figure 1, the method of manufacturing a suture using a biodegradable resin according to an embodiment of the present invention, preparing a raw material comprising a polycaprolactone-paradioxanone block copolymer, a hopper connected to the top of the die head Injecting the raw material prepared in, maintaining the die head at a temperature range of 175 ℃ to 200 ℃ and a pressure of 85 bar to 115 bar, while rotating the discharge screw inside the die head in the range of 11rpm to 13.5rpm Melting the injected raw material and extruding through a nozzle part connected to the bottom of the die head, immersing and cooling the spinning material extruded through the nozzle part in cooling water at 16 ° C to 18 ° C, and cooling the cooled spinning material for 15 minutes Aging by winding on 7 to 11 rollers for a time of 25 minutes, stretching the aged spinning material, stabilizing the drawn spinning material Includes the step of winding the phase, and said radiation stabilized.

In the step of preparing the raw material, the polycaprolactone-paradioxanone block copolymer has a ratio of ε-caprolactone: para-dioxanone in a molar ratio of 1: 8 to 1 It can be characterized by being in the range of: 10. By including the para-dioxanone in the blow copolymer, it is possible to shorten the splitting of the suture made of a biodegradable resin. That is, it is possible to ensure that the suture is decomposed in a short time while securing the appropriate strength as the suture in the range of the molar ratio. In other words, it is possible to shorten the period of decomposition while securing flexibility as a suture in the above range so as to have excellent knotting properties.

Meanwhile, the prepared raw material may be introduced into a hopper connected to the upper end of the nozzle unit. The injected raw material is melted in the die head or extruded through the nozzle of the nozzle part to be discharged. In the die head, the temperature range of 175 ° C to 200 ° C and the pressure of 85 Bar to 115 Bar are maintained, and the discharge screw inside the die head is 11 rpm to While rotating in the range of 13.5rpm, the injected raw material is melted and extruded through a nozzle.

The raw material injected in the temperature range of the die head is melted, and the discharged material discharged to the outside of the nozzle through the nozzle in the pressure range and the rotational rpm range of the discharge screw can be discharged to a suitable size as a suture, and the change in the diameter of the spinning material Can be minimized. Thereby, the strength and diameter of the suture finally manufactured can be optimized. The inventors of the present invention have confirmed that, after various trial and error, if the temperature range and pressure range of the die head and the range of the rpm of the discharge screw are satisfied, it is the optimal condition to minimize the defect rate, thereby securing the desired strength of the suture. However, it can be manufactured to have a uniform diameter. Therefore, in the case of the present invention, it is possible to manufacture a suture in a continuous production method and a mass production method while using a biodegradable resin as a raw material.

On the other hand, before the step of injecting the raw material for mass production, it may further include the step of preheating the nozzle portion, preheating the die head, and assembling and combining the nozzle portion and the die head. In addition, before assembling the nozzle portion to the die head, a small amount of raw material may be injected into the die head (ie, a hopper on the top) to discharge the existing resin. That is, the process of preheating and assembling the nozzle part and the die head may be applied to a process that is started after the initial process or the process is stopped in a continuous production method, and discharges the resin existing in the die head. The process may be, for example, a process of manufacturing a suture having different colors, or discharging a material used for the suture of the previous step, or a process of cleaning by discharging a resin remaining in the conventional process when the process is newly started after the process is stopped. have.

Specifically, before the step of injecting the raw material, preheating the nozzle portion for a time of 100 minutes to 150 minutes so that the nozzle portion is in a temperature range of 175 ° C to 200 ° C, and the inside of the die head is 175 ° C to It may be characterized in that it further comprises the step of assembling the nozzle unit which has undergone the step of changing to a temperature range of 200 ° C and a pressure of 85 bar to 115 bar and preheating the lower end of the die head. By preheating the nozzle portion to a temperature equivalent to that of the die head in advance and assembling it in the die head, the temperature of the nozzle portion and the die head can be changed to substantially the same level, whereby the resin melted in the die head is a nozzle. When discharged through the part, it is possible to minimize the temperature difference to discharge the desired diameter and physical properties.

For example, in the case of a die head, heat may be supplied from a heat source to melt the input material, and a nozzle having a diameter connected to the die head may discharge a desired diameter. At this time, when the temperature near the heat source of the die head and the temperature of the nozzle portion are different, curing may occur at the nozzle portion or a radiant having a desired diameter may not be discharged. In advance, the nozzle portion is substantially maintained at the same temperature as the die head By combining them in a state, defects due to temperature differences can be minimized.

When spinning is performed only by controlling the temperature of a simple die head as in the prior art, temperature may be rapidly decreased in the nozzle part due to a temperature difference in the nozzle part, whereby a spinning material having a desired physical property and diameter may not be discharged. The present invention minimizes unwanted physical property changes and diameter changes due to the temperature difference as in the prior art because the nozzle is pre-heated at a temperature substantially the same as the die head to which heat is provided, and then discharged by assembling with the die head. You can.

On the other hand, the process of heating the inside of the die head to a temperature range of 175 ° C to 200 ° C for stability and optimization of the process, the temperature range (ie, the inside of the diehead is a temperature range of 175 ° C to 200 ° C) , 175 ℃ to 200 ℃ range) a first preheating step to be a temperature range corresponding to 40%; A second preheating step to be a temperature range corresponding to 30% of the temperature range (ie, 175 ° C to 200 ° C); A third preheating step to be a temperature range corresponding to 20% of the temperature range (ie, 175 ° C to 200 ° C); A fourth preheating step to be a temperature range corresponding to 10% of the temperature range (ie, 175 ° C to 200 ° C); And a fifth preheating step to be in the temperature range (ie, 175 ° C to 200 ° C). As described above, by gradually activating the same conditions under which the raw materials are continuously injected before the raw materials are added, the process can be stably performed.

In addition, after the fifth preheating step, the discharge screw inside the die head may be further rotated in a range of 4 rpm to 6 rpm to further discharge the residue inside the die head. The step of discharging the residue may be performed by injecting a small amount of raw material into the hopper at the top of the die head and melting it to push it away, thereby removing unnecessary residue inside the die head to remove unnecessary foreign matter in the suture manufacturing process ( It is possible to remove the raw materials that were previously manufactured and remain) to the maximum, and to be made of the same raw material as the suture to manufacture the material remaining in the die head. The step of discharging the residue for removing the foreign matter may be performed for 5 minutes to 15 minutes without limitation.

The spinning material is extruded and discharged through the nozzle of the nozzle unit, and the pressure measured at the nozzle immediately after the emission of the spinning material passing through the nozzle may be in the range of 70 bar to 80 bar. That is, it is possible to measure the pressure of the discharge from the nozzle part of the nozzle at the nozzle end, which can be measured directly, and through this, it is possible to accurately grasp the flow state of the molten raw material flowing through the nozzle, and the process is properly performed in the above range. Can confirm.

In other words, it is possible to maintain the pressure inside the die head at a constant level, and to allow the discharge of the desired physical properties due to other factors such as temperature, by measuring the pressure of the discharge discharged through the nozzle unit, You can check whether the process is working properly. That is, the pressure inside the die head is operated by the user to maintain the pressure for an artificially suitable process, and it will be understood that the pressure measured at the nozzle of the nozzle part is to confirm that the process is properly performed.

Next, the spinning material extruded through the nozzle is immersed in cooling water at 16 ° C to 18 ° C to be cooled. The cooling water may be stored in the form of a water tank, and a heat exchanger may be provided to maintain the temperature range at all times. By passing through the cooling step, it is possible to prevent shrinkage from occurring due to excessive cooling of the discharged discharged material, and to prevent the elongation from naturally occurring due to high temperature and changing to an undesired diameter. In addition, it can be prevented from being cut during the stretching process. The cooling may be performed at a speed of 5m / min to 6m / min. At the above speed, sufficient cooling can be achieved in the process of manufacturing sutures of continuous and mass production, and productivity can be improved.

Next, the aging of the cooled spinning material is wound on 7 to 11 rollers for a period of 15 minutes to 25 minutes. Since the aging step is a state in which the spinning material that has undergone the cooling step has not been completely crystallized, the aging step is to completely crystallize the spinning material, so that in the subsequent stretching step, proper stretching is performed so that a product having a desired specification is manufactured. You can. That is, the aging step may crystallize the radiant that has undergone the cooling step, and the radiant that has undergone the cooling step may be in a state in which the polymer is not completely crystallized and thus is not suitable for performing stretching immediately. By going through the step of aging it, it can be made to be in a state suitable for stretching by substantially completely crystallizing. Therefore, it is possible to enable accurate stretching through a desired stretching ratio.

The aging step may be crystallized by delaying the time while the spinning material is wound between 7 and 11 rollers for a period of 15 minutes to 25 minutes, and a predetermined time before stretching is wound between the rollers.

Next, a step of stretching the radioactive material is performed. By the stretching step, the orientation of the spinning material can be excellent and uniform. The step of stretching the radioactive material includes a first stretching step at a stretching ratio of 1: 5 to 1: 7, and a second stretching step at a stretching ratio of 1: 1.05 to 1: 1.15. It can be characterized as. By the stretching ratio, it is possible to prevent the spinning material from being cut off during the stretching process, and to produce a suture having a desired diameter.

By the first stretching step, the stretching is primarily performed at a large stretching ratio, and the second stretching step can be used to produce a suture manufactured with a desired stretching ratio. Meanwhile, the first stretching step may be performed in a temperature range of 110 ° C to 120 ° C, and the second stretching step may be performed in a temperature range of 115 ° C to 125 ° C. In the above-described range, the spinning material is not cut during the stretching process, and there is no change in physical properties, so that a suture of a desired diameter can be manufactured.

On the other hand, the next step of stabilizing the elongated stretched material. The step of stabilizing the spinning material is performed while passing the spinning material between the roller and the roller, and the rotation rate of the roller at the rear end may be smaller than that of the roller at the front end. Thereby, the step of stabilizing without stretching the radiating material may be performed. The stabilizing step may be characterized by shrinking in the range of 1.05: 1 to 1.15: 1. In addition, the step of stabilizing the radiation may be characterized in that it is carried out in a temperature range of 115 ℃ to 125 ℃. The suture produced through the stabilizing step may shrink itself by elasticity generated during the stretching process, and through this process, shrinkage may be prevented from occurring in the final finished suture. That is, by preparing the suture after stabilization by making the natural shrinkage to a certain degree by the stabilizing step, the final finished suture is prevented from shrinking again by elasticity, and the product diameter, physical properties, etc. are deformed. Can be minimized.

Meanwhile, the first stretching step is performed between the first roller at the front end and the second roller at the rear end, and the second stretching step is performed between the second roller at the front end and the third roller at the rear end. The step may be performed between the third roller at the front end and the fourth roller at the rear end. The first stretching step, the second stretching step and the stabilizing step are continuously performed between the first roller and the fourth roller, so that the suture can be stably manufactured in a continuous and mass-production manner.

The first roller may rotate in the range of 3.3 rpm to 5.3 rpm, the second roller may rotate in the range of 24 rpm to 26 rpm, and the third roller may rotate in the range of 24.7 rpm to 26.7 rpm. In addition, the fourth roller can rotate in the range of 22.3rpm to 24.3rpm. In the above-described range, the stretching may be performed at a desired stretching ratio in the first stretching step and the second stretching step, and appropriate shrinkage may occur in the stabilizing step.

Next, through the step of winding the stabilized spinning, it may be subjected to a process of winding a certain amount and replacing. In addition, non-limiting, it may further include the step of confirming that the suture is manufactured with appropriate strength, diameter, and physical properties. Meanwhile, the winding step and the checking step are well known in the art, so a detailed description thereof will be omitted.

On the other hand, the present invention provides a suture, and the suture of the present invention is prepared by a method for manufacturing a suture using the biodegradable resin, wherein the ratio of caprolactone to paradioxanone is 1: 8 to 1:10 in a molar ratio. Caprolactone-paradioxanone block copolymers. The polycaprolactone-paradioxanone block copolymer may have a molecular weight of 70,000 g / mol to 90,000 g / mol, without limitation, and a glass transition temperature of 100 ° C to 110 ° C.

All of the embodiments described above are exemplary, and of course, the different embodiments can be applied in combination with each other.

Claims (11)

The ratio of ε-caprolactone: para-dioxanone ranges from 1: 8 to 1:10 in molar ratio, and molecular weight ranges from 70,000 g / mol to 90,000 g / mol. , Preparing a raw material comprising a polycaprolactone-paradioxanone block copolymer having a glass transition temperature in the range of 100 ° C to 110 ° C;
Introducing the prepared raw material into a hopper connected to the top of the die head;
The die head is melted by maintaining the temperature of the die head at a temperature in the range of 175 ° C to 200 ° C and a pressure of 85 bar to 115 bar, and rotating the discharge screw inside the die head in a range of 11 rpm to 13.5 rpm to melt the injected raw materials. Extruding through a nozzle portion connected to the bottom;
Cooling the spinning material extruded through the nozzle unit by immersing in cooling water at 16 ° C to 18 ° C;
Aging the cooled spinning material on 7 to 11 rollers for a period of 15 to 25 minutes;
Stretching the aged spinning material;
Contracting and stabilizing the elongated stretched material;
Winding the stabilized spinning material;
Before the step of injecting the raw material, preheating the nozzle portion for a time of 100 minutes to 150 minutes, such that the nozzle portion is in a temperature range of 175 ° C to 200 ° C; And
Biodegradable resin comprising; assembling the nozzle portion through the step of changing the interior of the die head to a temperature range of 175 ° C to 200 ° C and a pressure of 85 bar to 115 bar and preheating the lower end of the die head Method for manufacturing suture using. delete delete According to claim 1,
The process of heating the inside of the die head to a temperature range of 175 ° C to 200 ° C,
A first preheating step to make a temperature range corresponding to 40% of the temperature range so that the inside of the die head becomes a temperature range of 175 ° C to 200 ° C; A second preheating step to make a temperature range corresponding to 30% of the temperature range; A third preheating step to make a temperature range corresponding to 20% of the temperature range; A fourth preheating step to make a temperature range corresponding to 10% of the temperature range; And a fifth preheating step to be within the temperature range.
After the fifth preheating step further comprising rotating the discharge screw inside the die head in a range of 4 rpm to 6 rpm to discharge the residue inside the die head, the method of manufacturing a suture using a biodegradable resin. . According to claim 1,
The radiation is discharged through the nozzle of the nozzle unit,
The method of manufacturing a suture using a biodegradable resin, characterized in that the pressure measured at the nozzle immediately after the discharge of the emitted radiation passing through the nozzle is in the range of 70 bar to 80 bar. According to claim 1,
The step of stretching the radioactive material is
A first stretching step at a stretching ratio of 1: 5 to 1: 7; And
A method of manufacturing a suture using a biodegradable resin comprising; a second stretching step of stretching at a stretching ratio of 1: 1.05 to 1: 1.15. The method of claim 6,
The first stretching step is performed in a temperature range of 110 ℃ to 120 ℃,
The second stretching step is a suture production method using a biodegradable resin, characterized in that is performed in a temperature range of 115 ℃ to 125 ℃. The method of claim 7,
The first stretching step is performed between the first roller at the front end and the second roller at the rear end, and the second stretching step is performed between the second roller at the front end and the third roller at the rear end,
Biodegradation characterized in that the first roller rotates in the range of 3.3 rpm to 5.3 rpm, the second roller rotates in the range of 24 rpm to 26 rpm, and the third roller rotates in the range of 24.7 rpm to 26.7 rpm. Method for manufacturing suture using sex resin. According to claim 1,
The step of stabilizing the spinning proceeds between the third roller at the front end and the fourth roller at the rear end,
Method of manufacturing a suture using a biodegradable resin, characterized in that the shrinkage in the range of 1.05: 1 to 1.15: 1. The method of claim 9,
The step of stabilizing the spinning material is performed in a temperature range of 115 ° C to 125 ° C, the third roller rotates in the range of 24.7rpm to 26.7rpm, and the fourth roller rotates in the range of 22.3rpm to 24.3rpm A method of manufacturing a suture using a biodegradable resin, characterized in that. A polycapro prepared by a method for manufacturing a suture using the biodegradable resin of any one of claims 1 and 4 to 10, wherein the ratio of caprolactone to paradioxanone is in the range of 1: 8 to 1:10 in molar ratio. A suture comprising a lactone-paradioxanone block copolymer.

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