RU2073528C1 - Suture material - Google Patents

Abstract

FIELD: medicine, surgery. SUBSTANCE: thread of polyamide is covered in sequence with a membrane of polyvinyl alcohol 5-50 mcm width and that of chitosan 5-30 mcm width. Suture thread is of sufficient strength, biocompatible and atraumatic. EFFECT: higher efficiency and accuracy.

Description

 The present invention relates to medicine and relates to surgical suture materials.

 Known suture material from a thread of polyamide PA-6 (1). High mechanical properties of PA threads, a combination of high strength with elasticity and high elongation (400 600%), low hygroscopicity made this material attractive for physicians. Of the many known polymers, PA-6 is, according to some researchers, the best implantable material, since the product of its destruction, ε-amino-caproic acid, is harmless to the body. Comparative data on the behavior of various synthetic suture materials in the body show that polyamide yarns, including PA-6, cause less tissue response than catgut and natural non-absorbable yarns, but larger than polyester yarns and yarns based on fluorine-containing polymers.

 The disadvantages of PA-6 filaments include poor knotting ability and rapid degradation in the body with loss of strength and elasticity in case of swelling in the tissue fluid. In (2), a large number of cases of incompatibility of PA filaments with tissues was reported, the reasons for which have not been established from the chemical side. In operations on the stomach, the use of PA threads led to a prolonged local inflammatory process, which forced them to abandon their further use for many internal sutures.

 An increase in the resistance of PA to living media is achieved by the introduction of small amounts of polyvalent metals (3) into the polymer or by chemical crosslinking of PA under the influence of formaldehyde (4).

 Coating is sometimes quite effective.

 Polyvinyl alcohol threads (5), which are more biocompatible with the body than catgut and collagen, are known as suture material.

 Polyvinyl alcohol threads are extremely fragile.

 Chitosan is known to be used as suture thread (6). They are biocompatible with tissues, fix them before significant healing, and later resolve without a trace. In the body, threads from chitosan break down enzymatically (enzymatically) and are characterized by resistance to chemical hydrolysis, as a result of which they are suitable for long-term storage without changing properties.

 It is known (7) that the coating of kapron filaments with a film based on silicone rubber SKTN 16 extends the period of their destruction after 5 months. after implantation, the thread retains 84% of its original strength instead of 13% without coating. This technical solution was chosen by us as a prototype. The disadvantage of silicone coatings on the suture thread is their fragility due to insufficient adhesion to the fiber-forming polymer.

 The aim of the invention is to obtain a modified suture material with sufficient strength, good tying, biocompatibility, non-infectivity and non-invasiveness.

 This goal is achieved in that the polyamide yarn PA-6 is coated with a polymer shell of chitosan, while polyvinyl alcohol is applied as an intermediate shell. When a chitosan coating was applied to a polyamide yarn, a low sheath strength was found. The chitosan layer is easily separated from the thread during any manipulations with it. Therefore, such a coating does not meet the requirements.

 The adhesive bond strength of the polyvinyl alcohol coating and the polyamide yarn is so great that there is no separation of the coating during any manipulation of the yarn. Polyvinyl alcohol in terms of the solubility parameter is close to chitosan. Therefore, when applying a layer of chitosan to a polyamide yarn with a sheath of polyvinyl alcohol, it does not peel off during manipulations with the yarn. Thus, the problem of weak adhesion of chitosan to a polyamide yarn is solved. The introduction of dyes methylene blue or indigo carmine into solutions of polyvinyl alcohol or chitosan does not affect the adhesion and strength of the resulting coatings.

 In the studied literature, no description of suture material made of polyamide yarn coated with polyvinyl alcohol and chitosan was found; therefore, the proposed technical solution is new. It also has an inventive step, since the available information does not explicitly imply the presence of good adhesion and coating strength in the polyamide yarn polyvinyl alcohol chitosan (HTZ) system.

The invention is as follows. The industrial thread PA-6 is processed to remove lubricants. Lubricants are removed by extraction with pentane or sulfuric ether in a Soxhlet apparatus. The optimal extraction time is 1.5 to 2 hours. At the same time, the strength of the yarn during extraction with sulfuric ether practically does not change, and even increases with extraction with pentane. The prepared thread is wound on a bobbin. Then the thread is passed through a die with a solution of polyvinyl alcohol in water with a concentration of 8 15% and a thermal furnace for drying at T 110 140 ^o С and then through a die with a solution of chitosan in acetic acid with a concentration of 2 8% and a thermal furnace for drying at T 180 200 ^o FROM.

 Example 1

Twisted kapron thread with a diameter of 0.15 mm is processed in a Soxhlet apparatus with pentane for 1 hour. Then pass through a die with an aqueous solution of polyvinyl alcohol with a concentration of 13 wt. and a thermal furnace with a temperature of 110 ^o C and through two dies with a solution of chitosan in a 2% aqueous solution of acetic acid with a concentration of chitosan of 5.5 wt. and a thermal furnace with a temperature of 180 ^o C. Draw speed 3 m / min. A yarn with a coating of polyvinyl alcohol with a thickness of 0.020 mm and chitosan 0.01 and 0.01 mm was obtained. The total coating thickness is 0.04 mm.

Linear tensile load of the thread 9.7 • 10 ³ kg / cm ² . Coated yarn is g-sterilized. Relative elongation at break of 36.5%. The coating gives the thread biocompatibility, the thread does not cause a reaction of body tissues. It does not have a traumatic effect on the tissue due to the smoothing effect of the "saw". The thread shows good knotting ability.

 Example 2

Twisted kapron thread with a diameter of 0.21 mm is processed in a Soxhlet apparatus with pentane for 2 hours. Then it is pulled through a die with an aqueous solution of polyvinyl alcohol with a concentration of 13 wt. thermal furnace with a temperature of 125 ^o C. Draw speed 5 m / min. The thickness of the resulting coating is 0.03 mm. Then this thread is pulled through a die with a solution of chitosan in 2% acetic acid with a concentration of chitosan of 5.5 wt. and a thermal furnace at T 180 ^° C. The broaching speed is 5 m / min, the thickness of the chitosan layer is 0.01 mm. The total coating thickness is 0.04 mm. The coating does not peel off during any manipulations with the thread. The resulting suture material is biocompatible with body tissues. It is antimicrobial due to the elimination of the effect of wickness. The thread has a good ability to knot and atraumatic.

 Example 3

Twisted kapron thread with a diameter of 0.21 mm is processed in the Soxhlet apparatus with sulfuric ether for 2 hours. Then it is pulled through a die with an aqueous solution of PVA concentration of 13 wt. and a thermal furnace at T 125 ^o C. The broaching speed of 5 m / min. Then the thread is pulled through a die with a solution of chitosan in 2% acetic acid with a concentration of 5.5 wt. and a thermal furnace at 180 ^° C at a speed of 5 m / min and a third die with the same concentration of solutions and a thermal furnace at T 200 ^° C at a speed of 3 m / min. The total thickness of the polymer coating is 0.05 mm (0.03 mm PVA and 0.01 mm HTZ and 0.01 HTZ). Linear tensile load of the thread 7.8 • 10 ³ kg / cm ² . Relative elongation at break of 52.3%. The resulting yarn is biocompatible, non-capillary, allows you to get reliable nodes, atraumatic.

 Example 4

Twisted kapron thread with a diameter of 0.28 mm is treated in a Soxhlet apparatus with heptane for 1 hour. The thread is pulled through a die with an aqueous PVA solution (concentration of 11 wt. Thermal furnace with T 120 ^o C. Draw speed 3 m / min. Coating thickness of 0.03 mm. Then the thread is pulled through a die with a colored solution of HTZ concentration of 5.5 wt. 2 acetic acid and methylene blue content of 0.05 wt. to a solution oven T 200 ^o C and a spinneret with the same solution, but without a colorant and a thermo-T 200 ^o C. pulling speed of 3.5 m / min. Total thickness coating 0.05 mm. Linear discontinuous thread load exceeds 8,1 • March ¹⁰ kg / ^cm2. The coating was reduced capillarity increase of biocompatibility. The disadvantage of the thread is its rigidity.

 Example 5

Twisted kapron thread with a diameter of 0.15 mm is treated in a Soxhlet apparatus with heptane for 2 hours. The treated thread is pulled through a die with a solution of ChTZ in 2% acetic acid at concentrations of 4.5 wt. and a furnace at T 180 ^o With a speed of 3 m / min. The resulting coating peels off during manipulation with the thread.

 Thus, the present invention allows to obtain a suture material with sufficient strength, good tyazyvaemosti, biocompatibility, non-invasiveness. The materials used are produced by the Russian industry, are approved for use in medicine, and therefore this technical solution allows the organization of industrial production of competitive suture material both on the domestic market and abroad.

Literature
1. GOST 15897-79.

 2. Tolstykh N.I. and other Surgery, 1980, N 5, p. 108 113.

 3. Titova G.E. Abstracts III scientific symp "Synthetic polymer materials for medical purposes." Belgorod-Dneprovsky, 1977, p. 12.

 4. Voronkova O.S. Thes. doc. III symp. physiologically active synthetic polymers and macromolecular models of biopolymers. Riga: Zinatne, 1971, p. 34 39.

 5. N.L. Kuzmina, B.L. Bieber, G.L. Abakumova et al. Chemical and natural sutures for surgical suture materials. Overview, NIITEhim, 1988, p. 47 48.

 6. Kuzmina N. L. Bieber B. L. Abakumova G.L. and other problems of obtaining and using surgical suture materials. M. NIITEkhim, 1989, p. sixteen.

 Privalova L. G. et al. Polymers in medicine. 1984, v. 14, N 1 4, p. 37 - 54.

Claims (1)

 Suture material based on fibers with a polymer coating, characterized in that the base is a thread of PA-6 polyamide, and the coating consistently consists of a shell with a thickness of 5-50 microns from polyvinyl alcohol and a shell with a thickness of 5-30 microns from chitosan.