Compositions: ceramic – Ceramic compositions
Reexamination Certificate
2002-09-13
2004-11-23
Koslow, C. Melissa (Department: 1755)
Compositions: ceramic
Ceramic compositions
C501S080000, C106S035000, C623S023560
Reexamination Certificate
active
06821916
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a porous calcium phosphate type ceramics, and, particularly, to a ceramics for in vivo use such as artificial bones, fillers for bones and cell culture supports, which is suitable for the purpose intended to fix and support cells and to allow these cells to grow and to be cultured.
2. Description of the Related Art
A calcium phosphate type ceramics has no harmful action on a living body and a tendency to replace for natural bones. It is therefore a preferable material as artificial bones.
However, a current calcium phosphate type ceramics used for artificial bones has large strength but involves a difficulty in fixing cells in the case where it is produced as a densified body. Also, when it is produced as a porous body, it allows cells to enter it, but it has less strength and therefore tends to be handled with difficulty.
As a method of applying such a calcium phosphate type ceramics, there is the idea that the strength is improved to a limited extent, and many cells are made to be fixed as early as possible and to grow proliferously to thereby promote the formation of bones by the power of the cell itself whereby intending to make an early recovery.
SUMMARY OF THE INVENTION
The present invention is preferably used in such an application method and provides a ceramics for in vivo use which allows cells to intrude thereinto easily and to be fixed easily, with the result that an early recovery and the like are expected.
First, the raw material of the calcium phosphate type meant in the present invention is preferably, although not particularly limited to, any one of hydroxyapatite, apatite carbonate and tricalcium phosphate or mixtures of two or more of these compounds or those containing one or more of these compounds as main component. Also, the tricalcium phosphate is preferably those having a &bgr;-phase in view of strength.
According to a first aspect of the present invention, there is provided a porous ceramics for in vivo use, the ceramics comprising a calcium phosphate type raw material and having a number of pores (having many pores) having an almost globular form, wherein these pores are in contact and are communicated with each other so that the ceramics has permeability and the permeability is 150 centidarcy or more and 8000 centidarcy or less.
According to a second aspect of the present invention, there is provided a porous ceramics for in vivo use, the ceramics comprising a calcium phosphate type raw material and having a number of pores (having many pores) having an almost globular form, wherein these pores are in contact and are communicated with each other so that the ceramics has permeability and the volume of the pores communicated with a communicating portion having a hole diameter of 8 &mgr;m or more and 20 &mgr;m or less is 2% or more and 18% or less of the volume of all pores.
According to a third aspect of the present invention, there is provided a porous ceramics for in vivo use, the ceramics comprising a calcium phosphate type raw material and having a number of pores (having many pores) having an almost globular form, wherein these pores are in contact and are communicated with each other so that the ceramics has permeability, the permeability is 150 centidarcy or more and 8000 centidarcy or less and the volume of the pores communicated with a communicating portion having a hole diameter of 8 &mgr;m or more and 20 &mgr;m or less is 2% or more and 18% or less of the volume of all pores.
According to a fourth aspect of the present invention, there is provided a porous ceramics for in vivo use, the ceramics comprising a calcium phosphate type raw material and having a number of pores (having many pores) having an almost globular form, wherein these pores are in contact and are communicated with each other so that the ceramics has permeability and the volume of the globular pores which itself have a pore diameter of 8 &mgr;m or more and 15 &mgr;m or less is 0.5% or more and 15% or less of the volume of all pores.
According to a fifth aspect of the present invention, there is provided a porous ceramics for in vivo use, the ceramics comprising a calcium phosphate type raw material and having a number of pores (having many pores) having an almost globular form, wherein these pores are in contact and are communicated with each other so that the ceramics has permeability, the permeability is 150 centidarcy or more and 8000 centidarcy or less and the volume of the globular pores which itself have a diameter of 8 &mgr;m or more and 15 &mgr;m or less is 0.5% or more and 15% or less of the volume of all pores.
According to a sixth aspect of the present invention, there is provided a porous ceramics for in vivo use, the ceramics comprising a calcium phosphate type raw material and having a number of pores (having many pores) having an almost globular form, wherein these pores are in contact and are communicated with each other so that the ceramics has permeability, the permeability is 150 centidarcy or more and 8000 centidarcy or less, the volume of the pores communicated with a communicating portion having a hole diameter of 8 &mgr;m or more and 20 &mgr;m or less is 2% or more and 18% or less of the volume of all pores and the volume of the globular pores which itself have a diameter of 8 &mgr;m or more and 15 &mgr;m or less is 0.5% or more and 15% or less of the volume of all pores.
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Patent Abstracts of Japan, JP 2000-302567, Oct. 31, 2000.
Imura Kohichi
Myoi Akira
Sugiyama Tomoyuki
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