L-C. Kang et al. Materials Letters 59(2005)69-73 stand the cell behavior. It can suggest that the pores for Acknowledgement biomedical use should have the size at least 10 times larger than that of cells. Johnson et al. indicated that the bone This work was supported by the 2002 NRL research exhibited pore sizes ranging from 50 to 700 um, which program of Korean Ministry of Science and Technology impasses the optimum pore size of 150 um required for optimum osseointegration [18]. Combination of the results that the MG063 cells were well grown on 200-um pores and the reports [5-7] indicate that the porous References ceramic has a size of over 100 um for a successful cell [1 w Li, L GaO, Biomaterials 24(2003)937 attachment [2]DR. Jordan, Online Clinical Commun. for Ophthalmologists (TM)- occojoumal. com, Forum. 31 2001(No page) []G. Willmann, H.J. Fruh, H.G. Pfaff, Biomaterials 17(1996)2157. 5. Conclusion 44A. Marti, Injury, Int J. Care Inj. 2000 S-D31(2000)33. 5]KA continuously porous Al2O3 sintered body was fab- [6]LL Hench, J Am Ceram Soc. 81(1998)1705 ricated by using fibrous monolithic process, and its micro- [7RT. Chiroff, E W. White, J N. Webber, D. Roy, J. Biomed. Mater. structural change was examined. Refinement of the Res.Symp.6(1975)29 microstructure in the Al2O3 frame and pore size can be [ 8]SB Cho, YJ. Kim, Ceramist 3(2000)5. [9]K Maca, P. Dobsak, A.R. Boccaccini, Ceram. Int 27(2001)577 controlled during the fibrous monolithic process. EVA and [10 B D. Flinn, R K. Bordia, A Zimmermann, J. Rodel, J. Eur. Ceram. carbon were successfully removed by the two step binder Soc.20(2000)2561 burning out processes. The second passed and sintered body [11] V Biasini, M. Parasporo, A Bellosi, Thin Solid Film 297(1997)207 consists of pores of about 200 um in diameter embedded [12]ST. Oh, K.I. Tajima, M. Ando, T. Ohji, Mater. Lett. 48(2001)215 he Al2O3 matrix, while approximately 40-um pores were [13]C Kaya, E.G. Butler, M.H. Lewis, J. Eur. Ceram. Soc. 23(2003)935 [14SY. Lienard, D. Kovar, R.J. Moon, K.J. Bowman, J.W. Halloran, J. formed in the third filament Mater.sci.35(20003365. MG-63 cells were attached to top, inside, and bottom [15] T.S. Kim, L.C. Kang, T Goto, B T Lee, Mater. Trans. 44(9) surface of Al2O3 porous body and grew well. The high roughness formed along inside the continuous pore might [16] B.D. Boyan, C.H. Lohmann, DD. Dean, V.L. Sylvia, D.L. Cochran, ontribute to promote the attachment, spreading, and growth [17 T.J. Webster, R W. Siegel, R. Bizios, Biomaterials 20(1999)121 of cells. However, the third passed body was not suitable to [18 G.S. Johnson, M.R. Mucalo, M.A. Lorier, J. Mater. Sci. 11(2000) culture the cells due to its too-small-sized poresstand the cell behavior. It can suggest that the pores for biomedical use should have the size at least 10 times larger than that of cells. Johnson et al. indicated that the bone exhibited pore sizes ranging from 50 to 700 Am, which encompasses the optimum pore size of 150 Am required for optimum osseointegration [18]. Combination of the results that the MG063 cells were well grown on 200-Am pores and the reports [5–7] indicate that the porous ceramic has a size of over 100 Am for a successful cell attachment. 5. Conclusion A continuously porous Al2O3 sintered body was fab￾ricated by using fibrous monolithic process, and its micro￾structural change was examined. Refinement of the microstructure in the Al2O3 frame and pore size can be controlled during the fibrous monolithic process. EVA and carbon were successfully removed by the two step binder burning out processes. The second passed and sintered body consists of pores of about 200 Am in diameter embedded in the Al2O3 matrix, while approximately 40-Am pores were formed in the third filament. MG-63 cells were attached to top, inside, and bottom surface of Al2O3 porous body and grew well. The high roughness formed along inside the continuous pore might contribute to promote the attachment, spreading, and growth of cells. However, the third passed body was not suitable to culture the cells due to its too-small-sized pores. Acknowledgement This work was supported by the 2002 NRL research program of Korean Ministry of Science and Technology. References [1] W. Li, L. GaO, Biomaterials 24 (2003) 937. [2] D.R. Jordan, Online Clinical Commun.for Ophthalmologists (TM)– www.occojournal.com, Forum. 31 2001 (No page). [3] G. Willmann, H.J. Fruh, H.G. Pfaff, Biomaterials 17 (1996) 2157. [4] A. Marti, Injury, Int. J. Care Inj. 2000 S-D31 (2000) 33. [5] K.A. Hing, S.M. Best, W. Bonfield, J. Mater. Sci., Mater. Med. 10 (1999) 135. [6] L.L. Hench, J. Am. Ceram. Soc. 81 (1998) 1705. [7] R.T. Chiroff, E.W. White, J.N. Webber, D. Roy, J. Biomed. Mater. Res. Symp. 6 (1975) 29. [8] S.B. Cho, Y.J. Kim, Ceramist 3 (2000) 5. [9] K. Maca, P. Dobsak, A.R. Boccaccini, Ceram. Int. 27 (2001) 577. [10] B.D. Flinn, R.K. Bordia, A. Zimmermann, J. Rodel, J. Eur. Ceram. Soc. 20 (2000) 2561. [11] V. Biasini, M. Parasporo, A. Bellosi, Thin Solid Film 297 (1997) 207. [12] S.T. Oh, K.I. Tajima, M. Ando, T. Ohji, Mater. Lett. 48 (2001) 215. [13] C. Kaya, E.G. Butler, M.H. Lewis, J. Eur. Ceram. Soc. 23 (2003) 935. [14] S.Y. Lienard, D. Kovar, R.J. Moon, K.J. Bowman, J.W. Halloran, J. Mater. Sci. 35 (2000) 3365. [15] T.S. Kim, I.C. Kang, T. Goto, B.T. Lee, Mater. Trans. 44 (9) (2003) 1851. [16] B.D. Boyan, C.H. Lohmann, D.D. Dean, V.L. Sylvia, D.L. Cochran, Z. Schwartz, Annu. Rev. Mater. Sci. 31 (2001) 357. [17] T.J. Webster, R.W. Siegel, R. Bizios, Biomaterials 20 (1999) 1221. [18] G.S. Johnson, M.R. Mucalo, M.A. Lorier, J. Mater. Sci. 11 (2000) 427. I.-C. Kang et al. / Materials Letters 59 (2005) 69–73 73