JPS5841054B2 - Antibacterial medical composite material - Google Patents

Description

Detailed Description of the Invention The present invention relates to an antibacterial medical composite material in which an antibacterial function is added to the surface texture of a collagen-synthetic polymer composite. The object of the present invention is to provide an antibacterial medical composite material that is free from the risk of bacterial infection when implanting an artificial trachea, an artificial chest wall, an artificial esophagus, etc., into the human body.

In recent years, collagen-synthetic polymer composites have been developed as artificial organ materials with high tissue affinity, and have been used experimentally and clinically to be used in artificial tracheas, artificial chest walls, artificial esophagus, etc.

However, bacterial infection poses a serious obstacle to the success of implanting such artificial materials.

In particular, dogs are at the greatest risk of infection, as artificial tracheas and esophagus come into direct contact with the outside world, and aseptic surgery is usually not possible.

On the other hand, various substances with antibacterial functions have been discovered, and the polypeptide antibiotic polymyxin B is one of them.

This stuff is threonine, leucine, phenylalanine,
It contains α,γ-diaminobutyric acid and has a cyclic structure.

It has a bactericidal effect on Durham-negative bacteria such as Pseudomonas aeruginosa and Escherichia coli, and its mechanism of action is thought to be that it causes a change in permeability due to damage to the cytoplasmic membrane.

However, this drug currently has strong side effects such as nephrotoxicity and neurotoxicity, and the liquid form is considered problematic for systemic use.

As a result of various studies in view of the above points, the present inventor thought of adding antibacterial functions to the artificial material itself, and applied enzyme immobilization techniques to collagen-synthesize the polypeptide antibiotic polymyxin B. They attempted to immobilize it on a polymer complex and completed the present invention.

That is, the antibacterial medical composite material according to the present invention is a collagen film prepared by coating a synthetic polymer material with a collagen membrane layer.
It is characterized by immobilizing polypeptide antibiotic polymyxin B on the surface of a synthetic polymer complex.

Examples of the synthetic polymer material used in the present invention include polyethylene and polypropylene, which are used in the form of a film or mesh.

In order to coat the collagen membrane layer on the synthetic polymer material, the surface of the synthetic polymer material is subjected to plasma treatment, then a collagen solution is applied, neutralized in ammonia gas, and then air-dried. conduct.

Next, regarding the method of immobilizing the polypeptide antibiotic polymyxin B to the collagen membrane layer of the collagen-synthetic polymer complex, the carboxyl group of collagen was fixed with N-oxysuccinic acid according to the method of Cuatricas et al. Imide (N-hydroxysu)
ccinimide) and immobilized with the amino group of the side chain of polymyxin B through a peptide bond.

Since the antibacterial medical composite material according to the present invention has the above-described structure, the following effects can be achieved.

That is, since polymyxin B is immobilized on the collagen membrane layer of the collagen-synthetic polymer composite, the antibacterial function is exhibited from its surface.

In addition, polymyxin B has strong side effects such as nephrotoxicity, neurotoxicity, and allergic reactions, and if it is humoral, it may be used systemically. However, in the present invention, polymyxin B is made into a collagen-synthetic polymer complex. Since it is fixed, it can be used locally, and the side effects that occur in the case of the liquid type can be reduced.

Therefore, the antibacterial medical composite material according to the present invention is particularly suitable for application to artificial tracheas, artificial esophagus, etc. that are in direct contact with the outside world, and can be implanted in patients without the risk of bacterial infection. Its utility value is extremely high.

Next, the present invention will be explained in detail based on examples.

After subjecting the surface of a synthetic polymer material consisting of film-like polyethylene and mesh-like polypropylene to plasma treatment, 1 m9 of a collagen solution (pH: 3) was applied/covered per 1 d of the polymer material, and then treated in ammonia gas. After neutralization, it was air-dried.

The collagen used at this time was soluble collagen obtained by treating bovine skin collagen fibers with protase to remove the antigenic telopeptide at the terminal end of the collagen molecule, and showed almost no antigenicity.

The crosslinking method for collagen membranes is geltaraldehyde (GA'
) treatment, and both polyethylene film composites (complexes in which film-like polyethylene is coated with a collagen membrane layer) and polypropylene mesh composites (complexes in which mesh-like polypropylene is coated with a collagen membrane layer) are 2.5. %GA-containing methanol for 10 minutes.

Thereafter, it was thoroughly washed with methanol and air-dried.

Next, 0% N-oxysuccinimide was added to the distilled water in which the collagen-synthetic polymer complex obtained in this way was immersed.
．． Add 1 M and then add 1-ethyl-3 while stirring well.
-(3-dimethylaminopropyl)carbodiimide hydrochloride was added at 0.1 M; The reaction was carried out at room temperature for about 12 hours while maintaining the pH at 5 to 6 by adding IN NaOH.

After the reaction, the carrier was thoroughly washed several times with distilled water, and then reacted with a phosphate buffer solution (pH 7,4) of polymyxin B at 4°C for 2 hours to immobilize polymyxin B on the collagen membrane layer.

Then, after washing this with IMKCt for 1 hour,
0.06M phosphate buffer (pH 7,
4) It was stored at 4°C.

Polymyxin B is a sugar-containing product manufactured by Pfizer (1η is 1000
0 units) and the concentration at immobilization is I Q 7n9/rnl!
And so.

The activity of the antibacterial medical composite material according to the present invention was measured using the Durham-negative bacillus Bordetella pronchicepti.
ella brnnchieeptica ) ATCC
4617 was used as the test bacterium, and according to the Japan Antibiotics Medical Standards and cylinder/plate standard curve method, a disk (F5 paper,
5x5mm).

After dissolving antibiotic medium 10 (manufactured by Difco) in purified water,
Dispense into a petri dish as a base layer and solidify, and the temperature of the medium is 5.
When the temperature dropped to 0°C, the seed layer was further solidified and stored at 4°C for 1 hour or more to prepare an agar plate.

After reacting at 28° C. for about 40 hours, the inhibition circle diameter was measured and determined.

The immobilized polymyxin B preparation was pasted as a 5×57 Wffl section and diluted with 0.06 M phosphate buffer (
Polymyxin B solutions at various concentrations (10 to 1
60 units/ml) and 15 μt of it was injected into the disk.

The immobilized polymyxin B exhibited a good inhibition circle against the test bacterium Bordetella bronchiseptica, and the amount of immobilized polymyxin H calculated from the inhibition circle diameter was 43 units/cwt1 polypropylene mesh on the polyethylene film composite. The amount of complex was 97 units/d.

Regarding the amount of immobilized polymyxin B, in the case of the immobilized polymyxin B sample, unlike the case of liquid polymyxin B, it is immobilized and cannot diffuse, resulting in a small inhibition circle. It should be noted that the values are also low.

The polypropylene mesh composite showed higher antibacterial activity than the polyethylene film composite, which is thought to be due to the difference in surface properties.

The antibacterial activity was measured after repeated use three times and after long-term storage for four months, and although the inhibition circle diameter became smaller, the activity was sufficiently maintained.

Note that no leakage of polymyxin B was observed in the storage solution.

Furthermore, when the immobilized polymyxin B preparation was immersed in human serum for 30 minutes and its antibacterial activity was examined after washing, it was found to be sufficiently retained.

Section of polypropylene mesh complex immobilized with polypeptide antibiotic polymyxin B (10xlOim)
Six of them were implanted subcutaneously in the back of an adult rabbit, but even after 4 weeks, no renal function abnormalities such as increased serum urea nitrogen or serum electrolyte abnormalities were observed, nor were there any abnormalities such as lethargy, ataxia, and respiratory depression. There were no behavioral or physical changes, and no side effects were observed.

Claims (1)

[Claims] 1. An antibacterial medical composite material, characterized in that a polypeptide antibiotic polymyxin B is immobilized on the surface of a collagen-synthetic polymer composite prepared by coating a synthetic polymer material with a collagen membrane layer.