Devices and Methods for Tissue Engineering
A resorbable tissue scaffold in a glass ceramic composition forms a rigid three-dimensional porous matrix having a bioactive composition. Porosity in the form of interconnected pore space is provided by the space between the glass-ceramic fiber forming the porous matrix. Strength of the porous matrix is provided by the interconnected and bonded fiber that fuses into the rigid three-dimensional matrix. The resorbable tissue scaffold supports tissue ingrowth when implanted as a device for the repair of damaged and/or diseased bone tissue.
1 . A porous tissue scaffold comprising:
a porous rigid matrix having a glass-ceramic composition of a bioactive glass phase and a calcium silicate ceramic phase;
the glass-ceramic composition having interconnected pore space within the porous rigid matrix to provide porosity of about 20% to about 85%; and
the interconnected pore space having a pore size sufficient to promote tissue ingrowth when implanted in living tissue.
2 . The porous tissue scaffold according to claim 1 wherein the calcium silicate ceramic phase is wollastonite.
3 . The porous tissue scaffold according to claim 1 wherein the calcium silicate ceramic phase is greater than 50% of the glass-ceramic composition.
4 . The porous tissue scaffold according to claim 1 wherein the calcium silicate ceramic phase is greater than 40% of the glass-ceramic composition.
5 . The porous tissue scaffold according to claim 1 wherein the calcium silicate ceramic phase is greater than 20% of the glass-ceramic composition.
6 . The porous tissue scaffold according to claim 1 wherein the bioactive glass phase is a glass composition consisting essentially of silica, magnesium, phosphorus, sodium, and potassium.
7 . The porous tissue scaffold according to claim 1 wherein the bioactive glass phase contains essentially no calcium oxide.
8 . The porous tissue scaffold according to claim 1 further comprising a compressive strength of greater than 50 MPa.
9 . The porous tissue scaffold according to claim 8 wherein the pore size has an average value between about 40 μm and about 600 μm.
10 . The porous tissue scaffold according to claim 8 wherein the glass-ceramic composition is heat treated.
11 . A method of filling a defect in a bone comprising:
filling a space in the bone with a porous tissue scaffold comprising a porous rigid matrix having a glass-ceramic composition of a bioactive glass phase and a wollastonite ceramic phase; and
inserting the porous tissue scaffold into the defect in the bone.
12 . The method according to claim 11 wherein the bone is a vertebrae.
13 . The method according to claim 11 wherein the porous tissue scaffold is substantially wedge-shaped and the defect is an osteotomy.