Selective laser sintering of porous tissue engineering scaffolds from poly(l-lactide)/carbonated hydroxyapatite nanocomposite microspheres

Abstract

This study focuses on the use of bio-nanocomposite microspheres, consisting of carbonated hydroxyapatite (CHAp) nanospheres within a poly(L: -lactide) (PLLA) matrix, to produce tissue engineering (TE) scaffolds using a modified selective laser sintering (SLS) machine. PLLA microspheres and PLLA/CHAp nanocomposite microspheres were prepared by emulsion techniques. The resultant microspheres had a size range of 5-30 microm, suitable for the SLS process. Microstructural analyses revealed that the CHAp nanospheres were embedded throughout the PLLA microsphere, forming a nanocomposite structure. A custom-made miniature sintering platform was installed in a commercial Sinterstation((R)) 2000 SLS machine. This platform allowed the use of small quantities of biomaterials for TE scaffold production. The effects of laser power; scan spacing and part bed temperature were investigated and optimized. Finally, porous scaffolds were successfully fabricated from the PLLA microspheres and PLLA/CHAp nanocomposite microspheres. In particular, the PLLA/CHAp nanocomposite microspheres appeared to be promising for porous bone TE scaffold production using the SLS technique.

Selective Laser Sintered Poly(L-Lactide)/Carbonated Hydroxyapatite Nanocomposite Scaffolds: A Bottom-up Approach

“…Secondly, PLLA microspheres and PLLA/CHAp nanocomposite microspheres (~5-30 µm) were prepared by the oil-in-water and solid-in-oil-in-water emulsion solvent evaporation procedures respectively (Zhou, Wang et al 2007). Finally, with the modified SLS platform, prototypes of bone tissue engineering scaffolds (~10 mm) with meso-porous structure were successfully built from the PLLA microspheres and PLLA/CHAp nanocomposite microspheres (Zhou, Lee et al 2007; Zhou, Lee et al 2008). This study demonstrated a bottom-up nanotechnology approach in tissue engineering which assembling smaller scale simple biomaterials (nanoemulsion synthesized nanoscale particles, emulsion solvent evaporation prepared microscale nanocomposite spheres) into larger scale complex macro-scaffolds by laser technology.…”

“…The structure and properties, e.g. porosity, compression properties, in vitro degradation behavior and cytocompatibility (such as cell adhesion and growth), of these scaffolds were evaluated (Zhou, Lee et al 2008;Zhou, Wang et al 2010). The nanocomposite scaffolds provide a biomimetic environment for osteoblastic cell attachment, proliferation and differentiation and have great potential for bone tissue engineering applications (Duan, Wang et al 2010).…”

Interaction of cell culture with composition effects on the mechanical properties of polycaprolactone-hydroxyapatite scaffolds fabricated via selective laser sintering (SLS)

“…The SLS parameter settings for this PCL were optimized by Partee et al [13]. In a more recent study [14], 2D lattice structures were fabricated from PLLA/HA microspheres.…”

Selective laser sintering of hydroxyapatite/poly-ε-caprolactone scaffolds

“…However, much of this research has only demonstrated the feasibility of fusing powder particles together, and not the fabrication of complex predesigned 3D structures. Studies which did produce complex predesigned 3D structures via SLS were those by Williams et al, Zhou et al and Partee et al [13][14][15]. Williams et al fabricated cylindrical porous scaffolds with a 3D orthogonal periodic architecture using polycaprolactone with a designed pore size of 1.75 mm.…”