Osteogenic device and a method for preparing the device
The present invention is related to an osteogenic device and its preparation. Said device comprises a bone morphogenetic protein (BMP), preferably a modified BMP complex obtainable by a modification of the conventional guanidum hydrochloride extraction method and collagens, preferably collagen I or collagen IV, impregnated in and/or adsorbed on a bioceramic carrier, preferably a shapable body (block) originating from a coral skeleton. The method of isolating said modified BMP complex which lacks an immunogenic component and consists essentially of a 100–700 kD and a 15–25 kD protein with osteoinductive properties and preferably of the 15–25 kD protein which has improved storage properties as well as its use in the osteogenic device with improved osteoinductive properties is also disclosed.
1. A method for preparing a bone morphogenetic protein complex comprising:
(a) extracting protein from bone material with guanidinium hydrochloride (GuHCl);
(b) concentrating the extract by filtering with a tangential flow system and/or a ultrafiltration system;
(c) performing at least one dialysis of the concentrated extract against water or a buffer solution and dissolving insoluble material in buffered urea;
(d) performing a HPLC gel filtration of the buffered urea dissolved material to fractionate the protein material into three fractions, fraction I having a molecular weight of 100–700 kD, fraction II, having a molecular weight of 25–55 kD, and a fraction III having a molecular weight of 15–25 kD; and
(e) drying and sterilizing fraction I.
2. The method of claim 1 , further comprising combining fractions I and III and drying and sterilizing said fractions.