| 论文简介 |
Abstract: In this study, biphasic calcium phosphate (BCP) porous scaffolds with controllable phase compositions, controllable macropore percentages and thus adjustable properties were in-situ prepared by sintering a series of composites consisted of calcium phosphate cement (CPC, acted as filling or casting pastes) and porous phenol formaldehyde resin (acted as a negative mould) made from rapid prototyping (RP) technique. The CPC pastes were formed from mixing powder mixture of tetracalcium phosphate (TTCP) and anhydrous dicalcium phosphate (DCPA) with liquid phase of deionized water or diluted phosphate acid solution. Results show that the macropore structure of the scaffold can be regulated by using different RP negative moulds with different designed macropore percentage and the phase composition was easily adjusted by controlling weight ratios of powder to liquid (P/L) and concentrations of the liquid phase. Through in vitro compressive strength and immersion tests, it was demonstrated that either macropore percentage or phase composition played an important role on both the compressive strength values and the in vitro dissolving rates of the scaffolds. As the macropore percentage of the scaffold increasing, their compressive strength value decreased but the dissolving rate increased; while, as the weight ratio of hydroxyapatite to tricalcium (HA/TCP) in the scaffold increasing, the compressive strength value firstly increased and then decreased but the dissolving rate uniformly decreased. The compressive strength values of the BCP scaffolds with a HA/TCP weight ratio of 59:41 were 5.84±1.16 MPa for a total-porosity of ~67.67% containing a macropore percentage of 30% and 3.34±0.79MPa for a total-porosity of ~70.90% containing a macropore percentage of 50%, respectively, comparable to the corresponding levels of human cancellous bone (2~12MPa). It suggests a potential application for such BCP scaffolds in the bone tissue engineering .
Key words: Bone tissue engineering; Scaffold; Biphasic calcium phosphate (BCP); Calcium phosphate cement; Ceramics |
(创新港)
