JPH0548703B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to sutures (surgical sutures) coated with sucrose fatty acid esters, and more particularly, to sutures coated with sucrose fatty acid esters that exhibit good water repellency. Regarding thread. [Prior Art] Suture materials are classified as either absorbable or non-absorbable, and are considered absorbable if they disappear from the sutured tissue within about one year after surgery; Many more used absorbable suture materials disappear within a shorter period of time. Such absorbable suture materials are useful in applications where the sutured tissues would cling together after healing without suture reinforcement and where unabsorbed sutures may cause long-term adverse physical reactions. It is preferable to use it for applications that give the possibility of causing. Modern absorbable suture materials include lactide and glycolide homopolymers and copolymers, but these absorbable synthetic materials are generally hard;
Therefore, absorbable synthetic sutures are typically used in multifilament braided constructions to provide the desired degree of softness and flexibility. Non-absorbable materials such as polyester are also used in braided structures for similar reasons. By the way, multifilament sutures made of synthetic materials, whether absorbable or non-absorbable, have what is called a knotting property, that is, the ease with which a suture knot can be slipped. , which was undesirable in terms of smoothness. In order to improve these properties, surface coatings as described below are performed. For example, Tokukai Akira
Publication No. 59-181160 describes suture threads coated with beeswax to improve bioabsorption rate.
No. 30,586 discloses a suture coated with a lubricious copolymer containing polyoxyethylene blocks and polyoxypropylene blocks to improve tying properties. Further, in Japanese Patent Application No. 81380/1983, the present inventors introduced a suture thread with improved tying properties by coating it with sucrose fatty acid ester. Although the tying characteristics were improved by coating with sucrose fatty acid ester, experiments revealed that the coated suture had poor water repellency. This water repellency is a very important property. This is because the suture thread absorbs blood during surgery and becomes stiff, making it extremely difficult to use. [Problem to be solved by the invention] As described above, the suture thread coated with sucrose fatty acid ester to improve the tying and untying properties
However, coating with sucrose fatty acid ester does not improve water repellency, and experiments have shown that some sutures are worse than uncoated sutures. , was considered a problem. It is therefore an object of the present invention to provide a suture coated with sucrose fatty acid esters that has improved two properties: tying properties and water repellency. [Means for Solving the Problems] In order to achieve this object, the present invention has the following configuration. That is, the present invention is a suture coated with a sucrose fatty acid ester, which is characterized in that the ester composition of the sucrose fatty acid ester contains 20% by weight or less of monoester. This is because if the amount is more than 20% by weight, water repellency will deteriorate. [Example] The sucrose fatty acid ester used in the present invention is an ester of sucrose and fatty acid, and any of monoester, diester and polyester can be used, and a mixture of these may be used. There are eight OH groups (hydroxyl groups) in one sucrose molecule, and therefore the number of fatty acids bonded to these OH groups can range from 1 to 8. That is, monoester of monosubstituted sucrose ester,
Di-substituted sucrose ester as diester, below 3
is called triester, 4 is called tetraester, 5 is called pentaester, 6 is called hexaester, 7 is called heptaester, and 8 is called octaester. Hereinafter, everything from diester to octaester will be collectively referred to as polyester. As the fatty acid, stearic acid, palmitic acid, lauric acid, myristic acid, etc. are used, and these may be used alone or in combination of two or more. Furthermore, a mixture of these higher fatty acids and lower fatty acids such as acetic acid and butyric acid can also be used. Sucrose fatty acid esters are already widely used in fields such as food emulsifiers, foaming agents, and dispersants, and have been confirmed to be extremely safe. Methods for producing such sucrose fatty acid esters are broadly classified into direct esterification methods, transesterification methods, and enzymatic methods. Among these, the transesterification method is the method currently being carried out industrially, and is classified into a solvent method, a microemulsion method, and a solvent-free method. In Japan, Daiichi Kogyo Seiyaku Co., Ltd. carries out industrial production using the microemulsion method. For detailed manufacturing methods, please refer to
Publication No. 14485, Publication No. 51-14486, and Publication No. 14485
It is described in Publication No. 53-6130. Briefly, the method is as follows. That is, first, sucrose, fatty acid methyl, fatty acid soap, and water are mixed and heated to form a microemulsion. Next, it is dehydrated while maintaining the microemulsion state. A small amount of catalyst is added to allow the transesterification reaction to proceed. The resulting crude sucrose fatty acid ester is purified by removing the soap, unreacted excess sucrose, and catalyst. Regarding the ester composition, which is the main point of the present invention, in order to reduce the yield of monoester, a method such as using a small amount of sucrose in moles compared to the fatty acid mole number may be adopted. In addition, after this, the proportion of monoester may be lowered by acetylation with acetic anhydride. Next, a specific example of the coating method will be shown below. The most common coating method is to apply a coating material to the surface of the suture thread in a liquid state and then to solidify it. A method for making it into a liquid state is to dissolve it in a solvent, and solidification is carried out by volatilizing the solvent. The coating solution can be applied in any manner, such as by moving the suture through a container containing the solution, by sprinkling the solution onto the suture, or by rubbing the surface of the suture with a brush moistened with the solution. The suture can be applied by any suitable method. The coating agent can also be applied as a melt instead of a solution, in which case solidification takes place by cooling. Furthermore, the coating can also be applied directly in the solid state instead of in the liquid state. In this case, the suture is passed over or between solid blocks of coating material and transferred to the surface of the suture by frictional action. Covering may be done once or twice.
The process may be repeated several times or more, and the thickness of the coating layer can be adjusted by selecting an appropriate number of times depending on the desired performance. Types of sutures include lactide, glycolide, β-hydroxybutylcarboxylic acid, β-propiolactone, and γ-
Homopolymers and copolymers obtained from butyrolactone, γ-valero-3-methylbutyrolactone, δ-valerolactone, ε-caprolactone, etc., bioabsorbable materials such as chitin, and bioabsorbable materials such as silk, nylon, polyester, polypropylene, etc. is possible. The improvement in water repellency imparted by the present invention is
The test was conducted based on the capillarity test method specified in the "Plastic Suture Standards (Ministry of Health and Welfare Notification No. 444, December 28, 1971)." That is, approximately 15 cm of suture thread (USP No. 3-0 was used in this experiment)
Put it in a beaker, add water and boil for 1 hour.
Next, remove it from the beaker, dry it with hot air, and place it in a methylene blue solution so that it is immersed in the liquid to a depth of about 5 cm. After one minute, the length of water absorbed by the thread was measured and the average was taken. At the same time, we also measured the knot retention properties (the extent to which the knot is held so that it does not unravel against mechanical external force).
can be quantitatively measured by testing with the apparatus shown in FIG. 1 (device for measuring the knot retention performance of the suture of the present invention a: partial side sectional view, b: front view). This test method is as shown below. First, tie the suture thread 3 to the support rod 2, which has a groove parallel to the axis, as shown in Figure 2 (enlarged view of part 5 in Figure 1 a) and firmly fix it by applying a load of 1.5 kg to the end. (See Figure 1a). Thereafter, a weight 4 is connected to the lower part of the suture thread 3, the presser bar 1 is moved parallel to the axial direction of the support bar 2, and the number of times the knot is untied is measured. This measurement was carried out five times and the average is shown in the table. In the table, it is described as nodule retention force. Furthermore, the tying and grating characteristics were simultaneously tested using the apparatus shown in FIG. 3, and the results are also shown. In this device, two suture threads are intertwined as shown in Fig. 4, one is fixed at points A and B, one end of the other thread is connected to a weight 7 through a pulley 6, and the other end is attached to a pulley. Add tensile force F. The weight was used to apply tension to the two sutures, and in this test 100 g was used. FIG. 5 shows a typical recorder trace. A1-b1 in the figure indicates roughness, and the roughness to be determined is the average of the neighboring maximum and minimum values (a1-b1+…+(an-bn)/n). In addition, as shown in Fig. 6, a suture passage resistance test after blood adhesion was conducted using an open-cell polyethylene sponge, and the results are described below.This test was conducted in the following manner. First, the suture thread was immersed in bovine blood treated with sodium citrate for 3 minutes, and then air-dried at room temperature for about 30 minutes.Then, the suture thread was passed through an open-cell polyethylene sponge as shown in Figure 6. The resistance and roughness of the suture were measured.The roughness was determined by the method described above in the section on the tying and pulling characteristics.In the table, it is described as blood-sucking property. As shown in the table, 11 types of sucrose fatty acid esters with different ester compositions were used as the types of sucrose fatty acid esters to be coated.
This means that 12 types of samples were tested. Analysis of ester composition is performed using chromatography, including thin layer chromatography,
Methods such as high performance liquid chromatography, paper chromatography, column chromatography and gas chromatography are used. According to these methods, the monoester content in all esters can be determined. G′ in the table represents G,
I' is an acetylated version of I. Note that absorbable sutures made of glycolide homopolymer were used for all of these sutures. These coating materials can be coated by any of the methods described above, and the method used in this experiment will be described below. That is, using ethanol or ethyl acetate (ethyl acetate is used for H, I, and I') as a solvent, put 100 g of sucrose fatty acid ester in ethanol or ethyl acetate, and dissolve it in a water bath at 60°C. let The suture thread was immersed in it for 30 seconds while maintaining the temperature at 60°C, and then taken out.
They dried it for 30 minutes at 76cmHg and 60℃, then lowered the temperature and solidified it. The test results for water repellency, blood absorption, knot resistance, and knot retention properties for the above samples are shown in the table.

【table】

【table】

〔Effect of the invention〕

If a suture is coated with sucrose fatty acid ester, which is characterized by a monoester content of 20% by weight or less, its water repellency will be significantly increased compared to the suture before coating, making it an excellent suture. Can be provided.
In addition, the coated suture naturally has excellent knot-tying and knot-holding properties, which are the other purposes of coating.

[Brief explanation of the drawing]

FIG. 1 a... Partial cross-sectional side view of an apparatus for measuring the knot retention performance of the suture thread of the present invention, b...
FIG. 2 is a front view of the apparatus for measuring the knot retention performance of the suture thread of the present invention. An enlarged view of the knotted state of the suture shown in FIG. 1. FIG. Schematic diagram of the device for
An enlarged view of the tangled state of the suture shown in the figure, Figure 5... A diagram showing typical recorder tracking in the sliding performance test, Figure 6... Condition of the passing resistance test to express blood sucking property. Diagram showing.

Claims (1)

[Claims] 1. A suture coated with a sucrose fatty acid ester, characterized in that the ester composition of the sucrose fatty acid ester contains 20% by weight or less of monoester.