SU1003842A1 - Method of obtaining resolving surgical threads from copolymers of d-anhydroglucuronic acid - Google Patents

Description

The invention relates to medicine and veterinary medicine, in particular to absorbable sutures, used in surgical operations. It can also be used in the textile and knitwear industry to obtain openwork fabrics by dissolving the yarns that make up the pattern.

As surgical rassasyvgishkhoihs threads known filaments from

/ cellulose materials obtained

by oxidation with nitrogen oxides to convert cellulose to d-glucopyranose and d-anhydroglucuronic acid copolymer, followed by washing

 However, in the known method of oxidation, a large drop in the mechanical strength of the initial threads occurs. Thus, for example, the strength of oxidized filaments averages only 43.5% and 36.8% with an oxidation state of 15%, 3.75% of the carbide group — KG | and 61% 15.25%: CG), respectively, on the strength of the original yarns. Large

drop in strength and high swelling do not allow to obtain filaments,

fit for surgical practice.

The purpose of the invention is to increase the mechanical strength and reduce the swelling of filaments from oxidized cellulose.

The goal is achieved by treating oxidized cellulosic filaments of various origins with protogenic substances for 1-2 hours at room temperature followed by exposure for 1-2 hours at 70-90 ° C.

As profile substances contributing to an increase in the mechanical strength of oxidized filaments, 2-10% aqueous solutions of ionogenic substances selected from the group of sodium chloride, calcium chloride, calcium acetate, acetic acid, are not used.

In addition, 2-10% water

solutions of smfiprotonny MHoroaTOfiooix alcohols such as: glycerin, pentazritrite, mannitol, sorbitol glucose, sucrose, dextrose.

In addition, protophilic organic solvents such as dimethylformamide, dimethyl acetamide, dimethyl sulfoxide are also used.

The proposed method is carried out 30 as follows.

Oxidized with oxides of nitrogen and oTi "tty from traces of oxides, nitric and nitrous acids, the threads wound with fixed ends on a special device are kept in one of these substances or their mixtures for a period of time — i

time for their complete swelling in this environment. At the same time, due to the shrinkage that occurred during the process of predistribution of treatments, the threads are in a tight state since the ends IX are fastened. Wet filaments extracted from a liquid medium and wound

69/18 Thread 4.75 6.5

8B viscose

- - - ,.

60/18 Thread 4.75 6.5 high viscose

5.95 4.7

P 1

4.75 6.5 -

and

.

-. ".

.

 n

P.

.

P

P .

at .

said device is placed in a chamber heated to 70-90 and air toxm of the same temperature is blown through; and it is kept for 1-2 hours. With this treatment, the swelling of the threads in water decreases by 20-60% compared with the swelling of the same ni2, 0 4.25

1.0

70

-the pretreatment and mechanical pro- cess increases to 80–105% of the strength of the initial threads. In the table are shown examples of changes in the indicators of swelling and strength of cellulosic filaments from their processing.

iContinue table

102

15160.5 102

152,559,6 102

152,500,5

97.7

143.061.3

97

141,560,5

99

145,060,5

88.4

129,069,7 89,5

130,767.2

130.7

89.5;

68.9

An example. 60/18 viscose yarns with a mechanical tensile strength of 4.75 kg, wound with fixed ends on the device, are oxidized with oxides of nitrogen and washed with distilled water from traces of oxides of nitric and nitrous acids. A sample of the filaments is dried to an air-dry state and analyzed. The results of the analysis: the content of carboxyl groups of 6.5%; bound nitrogen 0.12%; moisture 12.8%; strength

Table continuation

at a gap of 3.25 kg; the degree of swelling in water is 5.95%; Solubility in 1% aqueous solution of sodium hydroxide is full.

Wet oxidized and open filaments wound on the device are immersed in a 10% aqueous solution of sorbitol and held for 2 h. Then the coil with wound filaments is removed from the solution and kept in a chamber blown with air heated to 80 for 1.5 h. I

The threads treated in this way have a characteristic with edukcie; carboxyl content of 6.3% bound nitrogen 0.12%; moisture 9.0%, tensile strength - 5.0 kg; The degree of swelling in water is 3.11%.

Thus, the treatment carried out allows you to increase the mechanical strength of the threads by 54%, reduce the degree of swelling by 1.9 times, achieve the strength of the threads, amounting to 105.3% of the strength of the original thread.

This does not affect the solubility of the strands, and, consequently, their full dissipation in the body.

The same oxidized yarns were treated with a 2% aqueous solution of sodium chloride, washed with distilled water for 15 minutes and subjected to heat treatment according to the method described above. The threads treated in this way have the following characteristic: the content of carboxyl groups

Claims (4)

Claim 1. A method for producing absorbable surgical sutures from copolymers of d-glucopyranose and d-anhydroglucuronic acid by oxidation of cellulose filaments with nitrogen oxides, followed by washing, with the aim of increasing the mechanical strength of the filaments and to reduce their swelling, oxidized filaments are treated with protophilic substances for 1-2 hours at room temperature and incubated for 1-2 hours at 70-90 ° C. · 2. The method of pop. 1, characterized in that as protophilic substances use 2-10% aqueous solutions of ionic compounds selected from the group :; sodium chloride, calcium chloride, calcium acetate, acetic acid. 3. The method of pop. ^ characterized in that 210% aqueous solutions of amphiprotonic polyhydric alcohols selected from the group of glycerol, pentaerythritol, mannitol, sorbitol, glucose, sucrose, dextrose are used as protophilic substances ... 4. The method of pop. 1, it is distinguished by the fact that organic solvents selected from the group are used as protophilic substances: dimethylformamide, dimethyl sulfoxide, dimethylacetamide.