JPS5910189B2 - Method for preparing scleroprotein grafts with high biological stability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides scleroprotein transplants with high biological stability.
te).

It is known that human or animal hard proteins, such as collagen, keratin, elastin, etc., can be transplanted homogeneously or xenogeneically to fill defects in body tissue.

In this case, the recipient tissue is able to discriminate more or less well the presence of foreign proteins depending on the type of graft. Usually the implant is degraded. In some cases, the degradation of the implant occurs so slowly that the body can simultaneously rebuild new connective tissue. Here, a Leit-sch fringe pull as described in West German Patent No. 2004553.8-09 is used.
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It is clear that the light-seen fringe pull must be abandoned when construction proceeds more slowly than decomposition. Therefore, the mode of decomposition of the body (Abbaumas
A high resistance is usually desirable. The following references demonstrate how much value must be given to scleroprotein transplantation in medicine. In particular, freeze-dried hard human brain membranes are indispensable as the main transplant tissue in neurosurgery. Other collagens collected from animals also play a role. FirmaB, Braun Melsungen AG
UnMelsungen AG)'s 1978 edition bumplet ``Lyodoura R for homoplastic replenishment of body tissues''
odul-a world ZumHOmOiplastische
nErsatzvOnK6rperstrukture
n month and the numerous references cited therein.

Freeze-drying and acetone drying are commonly used today as methods for preparing hard protein transplants.

In this case, the chronological stability is often insufficient, especially in organs where mechanical movements are required, e.g. fascia (Fascia).
cien), ligaments, keys, etc. are insufficiently substituted.

If the stability of the graft is lost within the body faster than new body tissue can be built up by wound treatment, the desired effect of the surgery will no longer be achieved and the patient will suffer corresponding damage. . It is an object of the present invention to provide a method for improving the biological stability of scleroprotein implants. The inventors have surprisingly found in experimental studies that by modifying the drying process the resistance of scleroproteins to biological degradation can be substantially increased. Figure 1 illustrates the effects obtained by the method of the present invention, and shows a 101-wide strip of human hard brain membrane after it was transplanted onto the back of a rabbit. Tear resistance (Reis)
sfestigkeit) over time.

In this case, 210 strips were implanted, and they were peeled off at various times after surgery to measure tear resistance. Curve A is acetone-dried brain membrane, . Curve B shows the results using freeze-dried brain membranes, and curve C shows the results using brain membranes prepared by the method of the present invention. Although no significant difference in tear resistance was observed between the acetone drying method and the freeze-drying method over the experimental period (31 days), the test specimens prepared by the method of the present invention had a tear resistance of 1.7 to 7. .0 times increase in tear resistance.

The desired properties are obtained by conventional processing methods, by placing the treated product in a glycerin solution after purification and antigen separation.

In this case, water is removed from the treated material. At the same time, glycerin is incorporated into the transplanted tissue through a diffusion process. During the subsequent drying process, the percentage glycerin content increases substantially. Similar effect is obtained from polyethylene glycol 400-2.
This can be obtained by using 000. The percolated glycerin or polyethylene glycol acts as a protective factor during freezing.

Although this itself is a well-known fact, it does not account for the high biological stability after transplantation. This is because freeze-drying can be replaced by air-drying at room temperature without adversely affecting the resistance to decomposition within the organism. The method of the present invention is suitable for scleroproteins such as collagen, keratin, elastin and especially raw dura mater (ROh-Du).
ren) in water in a conventional manner, treated with H2O2, degreased, washed with water, dried and then sterilized using glycerin or polyethylene glycol between the washing and drying steps. This is done by putting .

Glycerin may be used as an aqueous solution of 5-50%, preferably 20-40%, especially 30% glycerin.

The polyethylene glycol used has a molecular weight of 400 to 20.
00 and is usually used as an aqueous solution of 5 to 50%, particularly 20 to 40%, polyethylene glycol.

The process according to the invention has the following advantages over the prior art: The product is flexible and does not require rehydration before use.

The product is transparent, allowing the fluid (LiquOr) and brain surface to be seen through the implant, for example during brain surgery.
The product shows high biological stability.

The method of the invention will now be illustrated by an example relating to the preparation of flexible dry dura mater.

EXAMPLE Raw dura preserved in concentrated NaCl was soaked in water for 24 hours.

48 in 2-20%, preferably 5% H2O2.
Saved time. This dura mater was removed using Soxhlet's device (SOxh).
The degreased dura was degreased with acetone-diethyl ether (1:1) for 4 hours in a lettapparatur and rinsed with water for 12-24 hours. The dura mater thus treated was stirred in a 30% aqueous glycerin solution for 4 hours.

The resulting wet dura mater was lyophilized in a lyophilizer. Alternatively, the resulting wet dura was air dried at room temperature. After drying for 12 hours, the flexible dry dura was removed and 2.5 Mrtbd
It was sterilized with

The obtained dura mater was flexible, transparent, and showed high biological stability.

The dura mater obtained by conventional known methods was substantially harder, more opaque, and less biologically stable.

The data for the surprising results of the comparative test shown in FIG. 1 are presented in Table 1 below. The tear resistance values in Table-l are each 1
This is based on 0 measurements.

The % display in Table 1 is the value when Rio Doura's o value is taken as 100%. The flexible dura mater obtained by the method of the invention can be implanted into various areas well known to those skilled in the art. A number of transplant areas are listed on page 2 of the brochure.

[Brief explanation of the drawing]

FIG. 1 shows the change over time (horizontal axis: days) in the tear resistance (vertical axis: Kp) of the dural band after transplantation using different preparation methods. A is acetone-dried dura mater, B is freeze-dried dura mater, C
shows dura mater treated by the method of the present invention.

Claims (1)

[Claims] 1. Scleroproteins can be produced by the conventional process of soaking raw scleroproteins collected from humans or animals in water, treating them with H_2O_2, degreasing, washing with water, drying, and then sterilizing them. 1. A method for preparing a hard protein transplant tissue having high biological stability, which comprises performing a treatment using glycerin or polyethylene glycol after washing with water and before drying when preparing the transplant tissue. 2. The method according to item 1, using a 5-50% aqueous glycerin solution. 3. The method according to item 1, which uses polyethylene glycol having a molecular weight of 400 to 2,000. 4. The method according to any one of Items 1 to 3, using a 5-50% polyethylene glycol aqueous solution. 5. The method according to any one of paragraphs 1 to 4, using collagen, keratin, or elastin as the hard protein collected from humans or animals. 6. The method according to any one of paragraphs 1 to 5, in which dura mater is used as the hard protein collected from a person. 7. Process according to clause 6, using a 20-40%, especially 30%, aqueous glycerin solution.