JPH01306675A - Suture coated with sucrose ester of fatty acid - Google Patents

Abstract

PURPOSE:To obtain a suture, good in water repellency and excellent also in smooth knot slipping and knot holding characteristics, by coating the suture with sucrose ester of a fatty acid containing a monoester in a specific proportion or below. CONSTITUTION:A suture, obtained by applying sucrose ester of a fatty acid which is an ester of sucrose with a fatty acid (e.g. palmitic or stearic acid) containing <=20wt.% monoester and good in water repellency. The water repellency is improved by adjusting the monoester content to <=20wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a suture thread coated with sucrose fatty acid ester (
The present invention relates to surgical sutures (surgical sutures), and more particularly to sutures coated with sucrose fatty acid ester that exhibits good water-repellent properties.

[Conventional technology]

Suture materials are classified as either absorbable or non-absorbable, and are considered absorbable if they disappear from the sutured tissue within about a year after surgery, but the materials traditionally used Many absorbable suture materials disappear within a shorter period of time. Such absorbable suture materials are useful in applications where the sutured tissues would stick together after healing without suture reinforcement and where unabsorbed sutures could cause long-term adverse physical reactions. It is preferable to use it for purposes where it imparts properties.

Modern absorbable suture materials include homopolymers and copolymers of lactide and glycolide, but these absorbable synthetic materials are generally stiff and therefore absorbable synthetic sutures do not have the desired degree of softness and flexibility. Usually used in multifilament braided constructions to provide Non-absorbable materials such as polyester are also used in braided structures for similar reasons.

By the way, whether absorbable or non-absorbable sutures, multifilament sutures made of synthetic materials have what is called a knotting property, that is, the ease with which the 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,
Japanese Patent Application Laid-open No. 59-181160 describes suture threads coated with beeswax to improve bioabsorption rate.
No. 1-30586 discloses a suture coated with a lubricious copolymer containing polyoxyethylene blocks and polyoxypropylene blocks to improve the tying properties. Further, in Japanese Patent Application No. 81380/1983, the present inventors introduced a suture system with improved tying characteristics by coating with sucrose fatty acid ester. Although the tying characteristics were improved by coating the suture 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, a suture coated with sucrose fatty acid ester to improve the knotting property has been disclosed, but by coating the sea I sugar fatty acid ester, water repellency can also be improved. In fact, when we conducted experiments, we found that some sutures were worse than uncoated sutures, which was considered a problem. Therefore, it is an object of the present invention to provide a suture coated with sucrose fatty acid ester that has improved two properties: tying properties and water repellency.

[Means to solve the problem]

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 exceeds 20% by weight, water repellency deteriorates.

〔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 8 OH groups (hydroxyl groups) in one sucrose molecule, and therefore the number of fatty acids bonded to these OH groups is 1 to 1.
There are up to 8 cases. That is, 1ail sucrose ester is a monoester, 2-substituted sucrose ester is a diester, 3 is a triester, 4 is a tetraester, 5 is a pentaester, 6 is a hexaester, 7 is a heptaester, and 8 is an octaester. It is called. Hereinafter, everything from diester to octaester will be collectively referred to as polyester.

As the fatty acid, stearic acid, balmitic 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.

As a method for producing such sucrose fatty acid ester, ■
It is broadly classified into direct esterification method, ■transesterification method, and ■enzyme method. Among these methods, the transesterification method is currently used industrially and is classified into solvent methods, microemulsion methods, and solvent-free methods. In Japan, Daiichi Kogyo Seiyaku Co., Ltd. carries out industrial production using the microemulsion method. For detailed manufacturing method, please refer to the Japanese Patent Publication No. 51-144.
It is described in Japanese Patent Publication No. 85, Japanese Patent Publication No. 51-14486, and Japanese Patent 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 amount of monoester, a method such as using a smaller amount of sucrose in moles compared to the number of moles of fatty acid 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, e.g., by moving the suture through a container containing the solution;
The solution can be applied to the suture system by any suitable method, such as by sprinkling the solution onto the suture or by rubbing the surface of the suture with a brush moistened with the solution.

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, a suture system is passed over or between the solid bronches of the coating and transferred to the surface of the suture by frictional action. Coating may be carried out once or repeatedly two or more times, 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 homopolymers obtained from lactide, glycolide, β-hydroxybutylcarboxylic acid, β-propiolactone, T-butyrolactone, T-valero 3-methylbutyrolactone, δ-valerolactone, ε-caprolactone, etc. and copolymers,
Bioabsorbable materials such as chitin and non-bioabsorbable materials such as silk, nylon, polyester, polypropylene, etc. are contemplated.

The improvement in water repellency imparted by the present invention was carried out based on the capillarity test method shown in "Standards for Plastic Suture Systems (Ministry of Health and Welfare Notification No. 444, December 28, 1971)." That is, approximately 15 mm of suture (USP No. 3-0 was used in this experiment) was placed 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 about 5c111. After one minute, the length of water absorbed by the thread was measured and the average was taken.

The knot retention properties (the extent to which the knots are held so that they do not unravel against external mechanical forces) measured at the same time are shown in Figure 1 (Apparatus for measuring the knot retention performance of the suture thread of the present invention (a)). It can be quantitatively measured by testing with the apparatus shown in (d) (partial side sectional view, (b): front view). This test method is as shown below. First, the suture thread 3 is attached to the support rod 2 provided with a groove parallel to the axis as shown in Fig. 2 (Fig. 1 (a).
) (enlarged view of part 5) and securely fix the ends by applying a load of 1.5 kg (see Figure 1(a)).

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. With this device, two sutures are
They are intertwined as shown in the figure, one is fixed at points A and B, and one end of the remaining one is connected to the weight 7 through the pulley 6.
A tensile force F is applied to the other end. A weight was used to apply tension to the two sutures, and 100 g was used in this test. FIG. 5 shows a typical recorder trace. al-bl in the figure shows roughness, and the roughness to be determined was determined by (al-bl)+.--+(an-bn), which is the average of adjacent maximum and minimum values. In the table, it is described as nodule resistance.

Furthermore, 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. That is, first, the suture thread was immersed in fresh blood treated with sodium citrate for 3 minutes, and then air-dried at room temperature for about 30 minutes. Then, the resistance and roughness when the suture thread was passed through an open-cell polyethylene sponge as shown in Fig. 6 was measured. Roughness was determined by the method described above in connection with the tying and grating characteristics.

In the table, it is described as blood-sucking.

As shown in the table, 11 types of sucrose fatty acid esters having different ester compositions were used to coat the sutures to be tested as described above. Therefore, including the uncoated sutures, 12 different samples were tested. The ester composition is analyzed using chromatography, and methods such as thin layer chromatography, 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. In the table, G' and I' are acetylated G and I, respectively.

Note that absorbable sutures made of glycolide homopolymer were used for all of these sutures.

Although these coating materials can be applied by any of the methods described above, the method used in this experiment will be described below.

That is, ethanol or ethyl acetate (H,
(use ethyl acetate only for I and I'), use ethanol or ethyl acetate 1! Contains 10 sucrose fatty acid esters
0g, and dissolve it in a water bath at 60"C.The suture thread was immersed in it for 30 seconds while maintaining the temperature at 60°C, and then taken out and soaked in 76 cm and 11g at 60°C for 30 minutes. They dried it, 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.

(Hereinafter referred to as "margin") (hereinafter referred to as "margin") As can be seen from the table above, the tying and pulling properties of all coated sutures were improved, and the knot retention strength was also superior to that of uncoated sutures. It is also understood that the lower the monoester ratio, the better the water repellency and hemoptysis. In particular, it can be seen that the water repellency of HSI, G', and B in the table is significantly superior to that of the others. Furthermore, these types have also shown good results in blood-sucking tests. Normally, during surgery, tissue is sutured using a single suture and then cut from the distal end of the suture, but the suture needle side of the suture is repeatedly inserted into the tissue. As the suture passes through the suture, it absorbs body fluid (blood) and solidifies, causing the suture to become stiff, which is a major problem. Therefore, water repellency is a very important point for suture systems. In addition, although the monoester weight% is shown in the table, the composition of other polyesters other than monoester is determined by 100 (weight%) - monoester (weight%). For example, the weight percent polyester for B would be expressed as 100-72, which would be 28 percent by weight. The degree of esterification is C! This indicates the degree to which the OH groups in the tong have been esterified.
For example, when all eight OH groups are esterified, the degree of esterification is 8, such as G' and B. The degree of esterification and the hydroxyl value in the table are in an inversely proportional relationship. That is, the higher the hydroxyl value, the lower the degree of esterification, and the lower the hydroxyl value, the lower the degree of esterification.

In addition, the knot retention force of G' is extremely high and deserves attention.

〔Effect of the invention〕

If a suture system is coated with a sucrose fatty acid ester characterized by a monoester content of 20% by weight or less, the water repellency will be significantly increased compared to the suture before coating, resulting in an extremely superior 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 the device for measuring the knot retention performance of the suture thread of the present invention.(b)...The device for measuring the knot retention performance of the suture thread of the present invention. Front view Fig. 2: Enlarged view of the suture shown in Fig. 1 in a knotted state Fig. 3: Schematic diagram of the device for measuring the tying and untying performance Fig. 4: An enlarged view of the suture shown in Fig. 3 An enlarged view of the entangled state Figure 5: A diagram showing typical recorder tracking in the sliding performance test Figure 6: A diagram showing the state of the passing resistance test to express blood sucking ability Patent applicant 2 Co., Ltd. Japan Medical Supply Figure 1 Figure 2 Figure 6

Claims (1)

[Claims] (1) A suture coated with a sucrose fatty acid ester, regarding the ester composition of the sucrose fatty acid ester,
A suture thread characterized by having a monoester content of 20% by weight or less.