| Bone tissue engineering has been heralded as the alternative strategy to regenerate bone. The scaffolds are the core content and key of the bone tissue engineering. This paper aims to prepare a kind of bone tissue scaffolds that have surface bioactive, good mechanical properties and are in favor of cell to attach, distribute and exert function.Apatite-wollastonite bioactive glass-ceramic (AW GC) has high biocompatibility and bioactivity and better mechanical properties. AW GC has bone conductibility that can advance new bone tissue growth and aggradation, furthermore, it also has some bone inductivity and degradation. Some reports indicate the dissolution of bioglass could promote the expression of some genes, which control and induce the beginning and course of cell cycle. Consequently the bone regeneration and osteoproduction are enhanced. Therefore, choosing the bioactive glass-ceramic as the bone tissue engineering scaffolds could advance tissue growing and self-repairing, and bring hope to patients suffering from large area disfigure.Moreover, AW glass-ceramic can control the interfacial reactive kinetics and degradation rate, and improve bioactivity and biocompatibility by adjusting the structure, porosity and the surface microenvironment of the matrix, and surface modification. Owing to such excellent properties, AW GC is a prospective scaffold for bone tissue engineering.AW GC scaffold was fabricated from nano-precursor powders derived from sol-gel process, and shaped by dipping with the polymer foam. Through controlling the solid volume fraction and additives contents, the slurry was prepared by using the nano-precursor powders, then, were dipped with polymer foams for coating process, after drying and sintering, the porous AW bioactive glass-ceramic was obtained. Basis on this, in order to further increase the mechanical property, tenacity and biocompatibility and control the degradation rate, biodegradable chitosan (CS) was add into AW GC scaffolds surface to prepare AW/CS composite scaffold. The shape, pore diameter and porosity of scaffolds can be controlled by different polymer sponges.Through the thermodynamic analyzing, the mechanism of synthesizing calcium phosphate in sol-gel system of preparing AW nano-precursor powders was explained in theory, which can provide foundation for analyzing phase transition and reaction at different temperature. Meanwhile, the mechanism of HA forming on the materials (calcium phosphate system ceramics) soaked in the SBF can also be explained.The phase compositions, surface morphology, microstructure, mechanical strength, porosity of both scaffolds were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transformed infrared spectroscopy (FTIR), transmission electron microscopy (TEM), optical microscopy and so on. The bioactivity and degradation were investigated by simulated body fluid (SBF) soaking experiment in vitro and the biocompatibility was evaluated by co-culturing osteogenic marrow stromal cells (MSCs) of rabbits with the scaffolds.The results show:(1) The particle size of the AW precursor powders prepared by sol-gel process is 60-100nm, which also has better dispersal.(2) The result of experiment is according to that of thermodynamic analyzing. Base the results of XRD and thermodynamic analyzing, when the pH value of water-based sol-gel system is about 0.98-1.50, calcium biphosphate which belongs to calcium phosphate system is confirmed to be in the dry gel power.(3) The main phases of AW are apatite and wollastonite. The main phases of AW/CS are apatite, wollastonite and chitosan. The AW and AW/CS scaffolds both have three-dimensional pored structure with 100～500um macropores and 1～3um micropores, the porosity is about 80%-90%. The shape, pore diameter and porosity of scaffolds can be controlled by different polymer sponges. The average compressive strength of AW and AW/CS scaffolds respectively are 0.344MPa, 3.11MPa. The average compressive strength increases 831% after the AW scaffold being modified by CS, of which the tenacity is also improved mostly.(4) A layer of carbonate hydroxyapatite (HCA) can aggrade on the surface of both scaffolds when soaked in SBF, which indicates they both have good bioactivity. The speed of crystallite HCA forming on AW is quicker than that of AW/CS. But the crystallite HCA formed on AW/CS are interlaced with each other, so the surface microstructure and morphology of AW/CS are a little different from that of AW scaffold and the microenvironments which both of the scaffolds can providing for the cell attaching, proliferating and differentiating are correspondingly different. Further, the SBF soaking experiment also showes both scaffolds have some degradation.(5) Osteoblastic MSCs are biocompatible with both scaffolds, and can attach, proliferate and differentiate on both scaffolds.(6) The porous AW and AW/CS scaffolds prepared by new technologic methods have good bioactivity and tissue compatibility, therefore they have great potential application as bone tissue engineering scaffold.
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