Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Implantable prosthesis – Bone
Reexamination Certificate
2000-07-21
2001-10-09
Nguyen, Dinh X. (Department: 3738)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Implantable prosthesis
Bone
C623S023720, C623S016110, C435S372000, C435S377000
Reexamination Certificate
active
06299650
ABSTRACT:
The invention relates to a method of producing bone tissue in vitro on a substrate, which can be used as a bone implant.
BACKGROUND
U.S. Pat. No. 5,306,305 (=WO 95/19152) discloses an in vitro method for producing an implant device by coating a gel containing osteoblast cells onto a porous metal surface and then incubating the gel in a growth medium. A repeatedly renewed minimal essential medium (MEM) is used for about 3 weeks for cell multiplication, followed by a medium containing &bgr;-glycerophosphate and ascorbic acid for another 1-2 weeks. The cells may originate from the patient's own bone fragments. The gel (e.g. 0.5% gelatin) is used to hold the cells to the substrate surface.
DE-A-3810803 discloses a method of producing living bone substitute materials by in vitro culturing autologous bone cells from human bone fragments in a repeatedly renewed culture medium, followed by deposition of the cultured cells in a porous calcium phosphate matrix and additional culturing. The composite material can be reimplanted.
WO 94/04657 discloses a bioactive porous glass which is pretreated in such a way that it cannot raise the pH of a tissue medium contacted with the glass. It also reports the seeding of the pretreated porous glass with osteoblasts.
These prior art methods of in vitro production of bone tissue for implanting purposes have not yet been put into practice, probably because fixation of the resulting implant in the body and thus functioning of the implant are insufficient due to limitations in the applying techniques. No biological effect of using a particular culture method was described in the prior art. Furthermore, these prior methods necessitate the introduction of a bone defect (a lesion) in the patient in order to obtain the required bone cells.
SUMMARY OF THE INVENTION
It has been found now that these drawbacks can be overcome by a method wherein, instead of differentiated bone cells such as osteoblasts, undifferentiated cells are used for covering the implant substrate, and said cells are incubated with a liquid culture medium.
Consequently, the present invention concerns, in a first aspect, a method for in vitro production of bone tissue, comprising the steps of:
(a) applying undifferentiated mammalian cells on a substrate;
(b) directly contacting said cells with a culture medium for a sufficient time to produce a mineralised or non-mineralised matrix;
(c) removing the substrate with the matrix from the culture medium.
REFERENCES:
patent: 4963489 (1990-10-01), Naughton et al.
patent: 5522895 (1996-06-01), Mikos
patent: 5908784 (1999-06-01), Johnstone et al.
patent: 5972703 (1999-10-01), Long et al.
patent: 7-194373 (1995-08-01), None
patent: WO 92/10563 (1992-06-01), None
patent: WO 95/03011 (1995-02-01), None
Puleo et al., “Osteoblast responses to orthopedic implant material in vitro,”J. Biomed. Mat. Res., 25:711-723 (1991).
Radder et al., “Bone-bonding behaviour of poly(ethylene oxide)-polybutylene terephthalate copolymer coatings and bulk implants: a comparative study,”Biomaterials, 16(7):507-513 (1995).
Bovell Yvonne Pearl
De Bruijn Joost Dick
Van Blitterswijk Clemens Antoni
Banner & Witcoff , Ltd.
Barrett Thomas
IsoTis N.V.
Nguyen Dinh X.
LandOfFree
Method for in vitro production of bone does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for in vitro production of bone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for in vitro production of bone will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2615879