Nucleation and growth mechanism of apatite on a bioactive and degradable ceramic/polymer composite with a thick polymer layer
- 138 Downloads
Nucleation and growth mechanism of apatite on a bioactive and degradable PLLA/SiO2–CaO composite with a thick PLLA surface layer were investigated compared to that on a bioactive but non-degradable polyurethane (PU)/SiO2–CaO composite with a thick PU surface layer. The bioactive SiO2–CaO particles were made by a sol–gel method from tetraethyl orthosilicate and calcium nitrate tetrahydrate under acidic condition followed by heat treatment at 600 °C for 2 h. The PLLA/SiO2–CaO and PU/SiO2–CaO composites were then prepared by a solvent casting method which resulted in thick PLLA and PU surface layers, respectively, due to precipitation of SiO2–CaO particles during the casting process. Two composites were exposed to SBF for 1 week and this exposure led to form uniform and complete apatite coating layer on the PLLA/SiO2–CaO composite but not on the PU/SiO2-CaO composite. These results were interpreted in terms of the degradability of the polymers. A practical implication of the results is that a post-surface grinding or cutting processes to expose bioactive ceramics to the surface of a composite with a thick biodegradable polymer layer is not required for providing apatite forming ability, which has been considered as one of the pragmatic obstacles for the application as a bone grafting material.
KeywordsApatite PLLA Surface Crack Bioactive Glass Composite Surface
This work was supported by the Nano Bio R&D Program (Platform technologies for organ/tissue regeneration (Regenomics), Grant No. M0528010001-06N2801-00110) of the Korea Science & Engineering Foundation.
- 1.Hench LL, Splinter RJ, Allen WC, Greenlee TK Jr (1972) J Biomed Mater Res Symp 2:117Google Scholar
- 2.Kokubo T, Shigematsu M, Nagashima Y, Tashiro T, Nakamura T, Yamamuro T, Higashi S (1982) Bull Inst Chem Res, Kyoto Univ 60:260Google Scholar
- 16.Kamitakahara M, Kawashita M, Miyata N, Kokubo T, Nakamura T (2002) J Mater Sci: Mater Med 13(11):1015Google Scholar
- 22.Väkiparta M, Forsback A-P, Lassila LV, Jokinen M, Yli-Urpo AUO, Vallittu PK (2005) J Mater Sci: Mater Med 16(9):873Google Scholar
- 25.Nam J, Ray S, Okamoto M (2003) Macromolecules 23(2):634Google Scholar
- 27.Kokubo T, Kushitani H, Ohtsuki C, Sakka S, Yamamuro T (1992) J Mater Sci: Mater Med 3:79Google Scholar
- 29.Abe Y, Kokubo T, Yamamuro T (1990) J Mater Sci: Mater Med 1:233Google Scholar
- 30.Neuman WF, Neuman MW (1958) The chemical dynamics of bone mineral. University of Chicago, ChicagoGoogle Scholar