A tetragonal polyvinyl alcohol (PVA) scaffold with 3D orthogonal periodic porous architecture was fabricated via selective laser sintering (SLS) technology. The scaffold was fabricated under the laser power of 8 W, scan speed of 600 mm min(-1), laser spot diameter of 0.8 mm and layer thickness of 0.15 mm. The microstructure analysis showed that the degree of crystallization decreased while the PVA powder melts gradually and fuses together completely with laser power increasing. Thermal decomposition would occur if the laser power was further higher (16 W or higher in the case). The porous architecture was controllable and totally interconnected. The porosity of the fabricated scaffolds was measured to be 67.9 ± 2.7% which satisfies the requirement of micro-pores of the bone scaffolds. Its bioactivity and biocompatibility were also evaluated in vitro as tissue engineering (TE) scaffolds. In vitro adhesion assay showed that the amount of pores increased while the scaffold remains stable and intact after immersion in simulated body fluid for seven days. Moreover, the number of MG-63 cells and the bridge between cells increased with increasing time in cell culture. The present work demonstrates that PVA scaffolds with well-defined porous architectures via SLS technology were designed and fabricated for bone TE.

In this study, nano-hydroxypatite (n-HAP) bone scaffolds are prepared by a homemade selective laser sintering (SLS) system based on rapid prototyping (RP) technology. The SLS system consists of a precise three-axis motion platform and a laser with its optical focusing device. The implementation of arbitrary complex movements based on the non-uniform rational B-Spline (NURBS) theory is realized in this system. The effects of the sintering processing parameters on the microstructure of n-HAP are tested with x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The particles of n-HAP grow gradually and tend to become spherical-like from the initial needle-like shape, but still maintain a nanoscale structure at scanning speeds between 200 and 300 mm min(-1) when the laser power is 50 W, the light spot diameter 4 mm, and the layer thickness 0.3 mm. In addition, these changes do not result in decomposition of the n-HAP during the sintering process. The results suggest that the newly developed n-HAP scaffolds have the potential to serve as an excellent substrate in bone tissue engineering.

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β‐Tricalcium phosphates have been widely used as biomaterials for bone substitutes; however, the poor mechanical properties limit the application in bearing loading bones. In this study, nano‐hydroxyapatite has been introduced to improve the mechanical properties for porous bioceramic scaffolds. Nanocomposites containing 0–10 wt% needle‐like nano‐hydroxyapatite were prepared for investigation. It has been found that needle‐like nano‐hydroxyapatite improves the toughness, hardness, and compressive strength of the porous β‐tricalcium phosphates scaffolds, as well as the microstructure properties. The study provides a reference for the development of safe, excellent bone scaffolds for bone tissue engineering.

Nanotechnology has been widely used to overcome the brittleness of coarse ceramics. Laser sintering is an effective approach for the preparation of nanoceramics due to the laser properties such as high energy density and rapid heating. In this study, the nanohydroxypatite (HAP) was used to prepare for artificial bone scaffold using a home-made selective laser sintering (SLS) system. The microstructure and the properties of the sintered nanoHAP are tested with scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We found that the shape of nanoHAP particle changes from long needle-like to spherical or ellipsoidal after sintering, and the HAP particles grow up until they merge together with the increasing temperature. The tendency of preferred orientation reduces and the degree of crystallinity increases with the growth of nanoHAP. HAP dehydroxylation occurs during sintering. HAP decomposes to tetracalcium phosphate and -calcium phosphate when the sintering temperature is over 1354 C (the laser power is 8.75 W). Sintered nanoHAP maintains a high degree of crystalline and nanometre scale when the laser power is 7.50 W, spot radius 2 mm, sintering time 4 s and thickness of the layer is 0.2 mm. This study presented the optimised technology parameters for the preparation of nanoceramics with a novel SLS system and demonstrated that the nanoceramics with nanosize scale can be obtained by this system.