RU2168998C1 - Method of preparing allogenic hydroxylapatite - Google Patents

Abstract

FIELD: biotechnology. SUBSTANCE: invention is intended for use in manufacture of bone transplants for replacement and restoration of osseous structures with bone tissue defects. Method is distinguished by using, as starting material, salt solution obtained after demineralization of human bone tissue, which solution is filtered, neutralized to pH value 7.2-7.4 to form precipitate that is separated by centrifugation, washed with drinking water, recentrifuged, washed with water and phosphate buffer, pH 7.4+/-0.05 for 30 min, washed with water three times, and subjected to heat treatment at 120- 140 C for 3-3.5 h. Resultant hydroxylapatite powder is then sterilized. EFFECT: simplified and less expensive process due to reuse of bone transplant waste.

Description

 The invention relates to biotechnology and medicine, in particular to methods for producing allogeneic hydroxylapatite, and can be used in the production of bone grafts intended to replace or restore bone structures as a result of defects in bone tissue.

It is known that the material of natural bones consists in its inorganic phase of hydroxylapatite Ca ₅ (PO ₄ ) ₃ OH, which is the raw material for the manufacture of osteoplastic materials.

 The task was to create a method for producing allogeneic hydroxylapatite, which, in comparison with implantable synthetic materials, would be most adapted to the human body.

 The closest in technical essence and the achieved result is a method of manufacturing a bone marrow substitute material protected by RF patent N 2062622, MKI 6 A 61 L 27/00, published in bull. N 18 for 1996.

 In the known method, hydroxylapatite of organic origin, for example, from natural bone material, is obtained by breaking down the organic components of the bone substance, followed by strengthening, bringing the structure to a ceramic structure by sintering.

 The technical result, the achievement of which the creation of this invention is directed, is to simplify and reduce the cost of the technical process for producing allogeneic hydroxylapatite by utilizing waste in the production of bone grafts used for bone grafting.

The technical result is achieved by the fact that in the method for producing allogeneic hydroxylapatite, a saline solution is used as a raw material, which is a waste product of bone grafts after demineralization of human bone tissue, which is filtered through a paper filter, then the resulting solution is neutralized, bringing the pH of the solution to 7.2- 7.4, and the precipitate formed after neutralization is separated by centrifugation, then the latter is washed with distilled water, and phosphate buffer with a pH of 7.4 ± 0.05 for 30 minutes, and then izhdy washed with water and the precipitate is subjected to a heat treatment at a temperature of 120-140 ^o C for 3-3.5 hours, the resultant powder is sterilized hydroxyapatite.

 The method is as follows.

 The starting material for obtaining allogeneic hydroxylapatite is a saline solution obtained after demineralization of a human bone, when a human bone is placed in 1.2-3.6 N. hydrochloric acid solution, with a ratio of bone mass to acid mass as 1: 3. Once every two to three days, the spent demineralizing solution is replaced, draining it as a waste product into the sewer.

 For the manufacture of allogeneic hydroxylapatite according to the claimed method, the spent salt demineralizing solution is filtered through a paper filter, removing fine impurities and droplets of fat. Then the solution obtained after filtration is neutralized, bringing the pH of the solution to 7.2-7.4, and the precipitate formed after neutralization is separated by centrifugation.

Then the latter is washed with distilled water, after which the precipitate is again centrifuged, washed with water and phosphate buffer with a pH of 7.4 ± 0.05 for 30 minutes. Then the precipitate is washed three times with water and subjected to heat treatment at a temperature of 120-140 ^o C for 3-3.5 hours; after that, the resulting hydroxylapatite powder is sterilized.

 Example. As the source of raw materials using 50 ml of saline, which is a waste after demineralization of human bone tissue. Filter the solution to remove mechanical impurities. After that, the filtered saline solution is neutralized with 5 N. sodium hydroxide to a pH of 7.4, which required 13 ml of NaOH.

 The precipitate is then separated by centrifuging the solution obtained after neutralization for 20 minutes at 4000 rpm.

Next, the obtained precipitate is washed with distilled water, after which the precipitate is again centrifuged, washed with water with the addition of 100 ml of phosphate buffer (pH 7.4). After 30 minutes, the drying process is carried out in a thermostat for about 3.5 hours at 140 ^o C.

As a result, 4.7 g of hydroxylapatite (Ca ₅ (PO ₄ ) ₃ OH) is obtained, which is sterilized.

 The proposed method involves the use of raw materials for the production of allogeneic hydroxylapatite - an unrealizable waste product for the production of bone grafts, formed after the completion of the process of demineralization of human bone tissue.

 The advantage of the method for producing allogeneic hydroxylapatite is the fact that it does not provide for the destruction of the organic matter of bone tissue for the manufacture of hydroxylapatite, which significantly reduces the cost of the process and makes the production of bone grafts waste-free.

 The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information, and the identification of sources containing information about analogues of the claimed invention, made it possible to establish that the applicants did not find an analogue characterized by features identical (identical) to all essential features of the claimed invention.

 The definition from the list of identified analogues of the prototype allowed us to identify a set of essential in relation to the perceived technical result of the distinguishing features in the claimed method for producing allogeneic hydroxylapatite set forth in the claims.

 Therefore, the claimed invention meets the criterion of "novelty."

 To verify the compliance of the claimed invention with the condition "inventive step", the applicants conducted an additional search for known solutions in order to identify signs that match the distinctive features of the claimed invention from the prototype.

 The search results showed that the claimed invention does not follow explicitly from the prior art as determined by the applicants for the specialist, the influence of the transformations provided for by the essential features of the claimed invention on the achievement of the technical result is not revealed.

 Therefore, the claimed invention meets the criterion of "inventive step".

 The criterion of the invention "industrial applicability" is confirmed by the fact that the proposed method for producing allogeneic hydroxylapatite can be used in the production of bone grafts, making it non-waste and environmentally friendly, using the waste products of bone grafts generated after the process of demineralization of human bone tissue.

Claims (1)

A method of producing allogeneic hydroxylapatite from an organomineral substance, characterized in that a saline solution is used as a raw material, which is a waste product of bone grafts formed after demineralization of human bone tissue, which is filtered through a paper filter, then the resulting solution is neutralized, bringing the pH of the solution to 7.2 - 7.4, and the precipitate formed after neutralization is separated by centrifugation, then the latter is washed with distilled water, then centrifuged again and washed in ode and phosphate buffer with a pH of 7.4 ± 0.5 for 30 minutes, and then washed three times with water and subjected to heat treatment at 120-140 ^° C for 3-3.5 hours, as a result, the resulting hydroxylapatite powder is sterilized.