Manufacture and Characterisation of Bioceramic Tissue Engineering Scaffolds Produced by Selective Laser Sintering

Author(s):  
K. Xiao ◽  
J. A. Dyson ◽  
K. W. Dalgarno ◽  
P. Genever ◽  
D. J. Wood ◽  
...  

Currently there is no adequate bone replacement available that combines a long implant life with complete integration and appropriate mechanical properties. This paper reports on the use of human mesenchymal stem cells (MSCs) to populate porous bioceramic scaffolds produced by selective laser sintering (SLS) to create bespoke bioactive bone replacement structures. Apatite-wollastonite glass ceramic was chosen for use in this study because of its combination of excellent mechanical and biological properties, and has been processed using an indirect SLS approach. Process maps have been developed to identify process conditions for the SLS stage of manufacture and an optimised furnace cycle for the material has been developed to ensure that the required material phases for bioactivity are present in the manufactured scaffold. Results from tissue culture with the MSC’s on the scaffolds (using confocal and scanning electron microscopy) show that MSCs adhere, spread and retain viability on the surface, and penetrate into the pores of apatite wollastonite (A-W) glass ceramic scaffolds over a 21 day culture period. The MSC’s also show strong indications of osteogenesis, indicating that the MSC’s are differentiating to osteoblasts. These results indicate good biocompatibility and osteo supportive capacity of SLS generated A-W scaffolds and excellent potential in bone replacement applications.

2007 ◽  
Vol 361-363 ◽  
pp. 923-926 ◽  
Author(s):  
David J. Wood ◽  
J. Dyson ◽  
K. Xiao ◽  
Kenny W. Dalgarno ◽  
P. Genever

There is a clinical and socio-economic need to produce synthetic alternatives to autologous or allogenic bone grafts. Bioactive glasses and glass-ceramics offer great potential in this area. The aims of this study were to optimise production of apatite-wollastonite (A-W) glassceramic scaffolds produced by selective laser sintering, in terms of their physical and biological properties and to look at how human Mesenchymal Stem Cells (MSCs) responded to these 3-D scaffolds in vitro. An indirect selective laser sintering process successfully produced strong, porous scaffolds. Depending upon particle size(s) and infiltration of the porous structure, flexural strengths between 35 MPa and 100 MPa were obtained. Following static seeding of A-W scaffolds with MSCs, fluoresecent actin and nuclei staining, as observed by confocal microscopy, showed that these scaffolds supported the adherence of human MSC’s at time periods of up to 21 days. As such these seeded scaffolds show great potential for use in bone regenerative medicine.


Author(s):  
K Xiao ◽  
K W Dalgarno ◽  
D J Wood ◽  
R D Goodridge ◽  
C Ohtsuki

This paper develops an indirect selective laser sintering (SLS) processing route for apatite—wollastonite (A—W) glass—ceramic, and shows that the processing route, which can create porous three-dimensional products suitable for bone implants or scaffolds, does not affect the excellent mechanical and biological properties of the glass—ceramic. ‘Green parts’ with fine integrity and well-defined shape have been produced from glass particles of single-size range or mixed-size ranges with acrylic binder in various ratios by weight. A subsequent heat treatment process has been developed to optimize the crystallization process, and an infiltration process has been explored to enhance mechanical strength. Three-point bending test results show flexural strengths of up to 102 MPa, dependent on porosity, and simulated body fluid (SBF) tests show that the laser sintered porous A—W has comparable biological properties to that of conventionally produced A—W.


Author(s):  
Brock Partee ◽  
Scott J. Hollister ◽  
Suman Das

Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present practice generally requires the use of porous, bioresorbable scaffolds to serve as temporary 3D templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissue such as bone, cartilage, ligament and tendon. Recent research strongly suggests the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile biomaterials processing and fabrication methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. It is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to fulfill these needs. Our research aims to investigate the viability of using SLS to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this work, we report our recent progress on porous scaffold design and fabrication, optimal SLS processing parameter development using systematic factorial design of experiments, and structural characterization via optical microscopy.


2006 ◽  
Vol 309-311 ◽  
pp. 289-292
Author(s):  
Ruth D. Goodridge ◽  
Chikara Ohtsuki ◽  
Masanobu Kamitakahara ◽  
David J. Wood ◽  
Kenny W. Dalgarno

The feasibility of processing glass-ceramics using the layer manufacturing technique, selective laser sintering (SLS), to produce parts with suitable biological and mechanical properties for use in bone replacement applications, has been investigated. Glass-ceramics derived from glasses based on several different systems have been considered. Initial experiments using an apatite-mullite glass-ceramic (4.5SiO2⋅3Al203⋅1.6P2O5⋅3CaO⋅2CaF2) demonstrated the ability to process glass-ceramic materials using this technique, creating parts with a strength similar to that of cancellous bone, and a porous structure that was shown in vivo to be suitable for the ingrowth of bone. Concerns over the inability of the apatite-mullite material to form an apatite layer on its surface when soaked in a simulated body fluid (SBF) has led to the development of Al2O3-free glasses based on the systems (50-x)CaO⋅45SiO2⋅5P2O5⋅xCaF2 and (48-x)CaO⋅45SiO2⋅5P2O5⋅2CaF2⋅xNa2O. These materials have demonstrated good in vitro bioactivity, and therefore have good potential as candidates for processing by an indirect SLS method for the production of custom-made bone implants.


2007 ◽  
Vol 3 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Ruth D. Goodridge ◽  
David J. Wood ◽  
Chikara Ohtsuki ◽  
Kenneth W. Dalgarno

2007 ◽  
Vol 334-335 ◽  
pp. 1225-1228 ◽  
Author(s):  
Wen You Zhou ◽  
S.H. Lee ◽  
Min Wang ◽  
W.L. Cheung

This paper reports a study on the modification of a commercial selective laser sintering (SLS) machine for the fabrication of tissue engineering scaffolds from small quantities of poly(L-lactide) (PLLA) microspheres. A miniature build platform was designed, fabricated and installed in the build cylinder of a Sinterstation 2000 system. Porous scaffolds in the form of rectangular prism, 12.7×12.7×25.4 mm3, with interconnected square and round channels were designed using SolidWorks. For initial trials, DuraFormTM polyamide powder was used to build scaffolds with a designed porosity of ~70%. The actual porosity was found to be ~83%, which indicated that the sintered regions were not fully dense. PLLA microspheres in the size range of 5-30 μm were made using an oil-in-water emulsion solvent evaporation procedure and they were suitable for the SLS process. A porous scaffold was sintered from the PLLA microspheres with a laser power of 15W and a part bed temperature of 60oC. SEM examination showed that the PLLA microspheres were partially melted to form the scaffold. This study has demonstrated that it is feasible to build tissue engineering scaffolds from small amounts of biomaterials using a commercial SLS machine with suitable modifications.


RSC Advances ◽  
2016 ◽  
Vol 6 (110) ◽  
pp. 108196-108202 ◽  
Author(s):  
Wei Huang ◽  
Ping Wu ◽  
Pei Feng ◽  
Youwen Yang ◽  
Wang Guo ◽  
...  

In this study, poly(vinylidene fluoride) (PVDF) scaffolds with MgO whiskers were prepared through selective laser sintering, and their properties were studied in terms of mechanical and biological properties.


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