Porous Ceramic Scaffolds Research Articles

Novel Resorbable and Osteoconductive Calcium Silicophosphate Scaffold Induced Bone Formation.

This aim of this research was to develop a novel ceramic scaffold to evaluate the response of bone after ceramic implantation in New Zealand (NZ) rabbits. Ceramics were prepared by the polymer replication method and inserted into NZ rabbits. Macroporous scaffolds with interconnected round-shaped pores (0.5–1.5 mm = were prepared). The scaffold acted as a physical support where cells with osteoblastic capability were found to migrate, develop processes, and newly immature and mature bone tissue colonized on the surface (initially) and in the material’s interior. The new ceramic induced about 62.18% ± 2.28% of new bone and almost complete degradation after six healing months. An elemental analysis showed that the gradual diffusion of Ca and Si ions from scaffolds into newly formed bone formed part of the biomaterial’s resorption process. Histological and radiological studies demonstrated that this porous ceramic scaffold showed biocompatibility and excellent osteointegration and osteoinductive capacity, with no interposition of fibrous tissue between the implanted material and the hematopoietic bone marrow interphase, nor any immune response after six months of implantation. No histological changes were observed in the various organs studied (para-aortic lymph nodes, liver, kidney and lung) as a result of degradation products being released.

Approaches to the fabrication of calcium phosphate-based porous materials for bone tissue regeneration

This paper reviews advances in the fabrication of calcium phosphate materials for injured bone tissue regeneration. We examine the key features of rapid prototyping for the fabrication of porous ceramic scaffolds with tailored architectures, the technology of biopolymer-based composite materials reinforced with calcium phosphate particles, and the fabrication of porous scaffolds via cement route.

Fabrication of alumina porous scaffolds with aligned oriented pores for bone tissue engineering applications

In the present study, porous alumina scaffolds with specific orientation and anisotropic properties are fabricated for application in bone tissue repair. The scaffolds with double shape pores, tubular oriented and isotropic rounded pores, were prepared using alumina and silica as starting materials by the slip casting route. Milled polyurethane foam and silk fibers were applied as replica materials as well. The effect of fiber types and diameter and number of fibers on the microstructure and pore size was studied. Moreover, different characteristics such as porosity, density, orientation, flexural strength and compressive strength of the samples were investigated. Results showed that various fibers with different diameters and numbers led to forming the pores with different pore sizes, microstructure and consequently changes in the physical and mechanical properties. In addition, the simultaneous presence of fibers and particles led to more porous scaffolds. The oriented tiny micro-tube and rounded pores were observed in all porous ceramic scaffolds. Mechanical testing showed an anisotropy in the mechanical behaviors such that higher strengths were observed in the oriented pore direction than that of transverse. With increasing the number and diameter of silk fibers, the scaffolds with a high porosity up to 68 vol% and proper flexural strength were obtained.

Compressive strength and biomineralisation improvement by water glass coating on porous calcium phosphate scaffolds

Calcium phosphate (Ca–P) based scaffolds were found to be a favourable alternative for orthopaedic applications because of their similar chemical composition to natural bone. In this study, porous triphasic Ca–P scaffolds containing macropores (∽200 μm) interconnected with micropores (∽20 μm) were fabricated using an extrusion method. The hydroxyapatite/tricalcium phosphate ratio of the porous scaffolds was varied using different ratios of starting materials while keeping the Ca/P ratio fixed (1.5). A water glass coating on the porous Ca–P scaffolds increased the compressive strength by 45% without significantly decreasing the porosity of the H100D50 scaffold. The maximum compressive strength, ∼15 MPa, was achieved on the H100D50 scaffold. The ability for apatite formation in simulated body fluid was amplified by the water glass coating on the sintered Ca–P scaffolds. Therefore, a water glass coating can be used to enhance the mechanical properties as well as the biomineralisation of the porous ceramic scaffolds.

Direct Ink Writing of micrometric SiOC ceramic structures using a preceramic polymer

In this work we manufactured micro-sized SiOC ceramic components by 3D printing (Direct Ink Writing) of a preceramic polymer. Model porous ceramic scaffolds with the lateral dimension of a few millimeters and composed of a continuous ceramic filament ∼120μm thick were produced, and a suitable rheological behavior was obtained by mixing cross-linked preceramic particles with a siloxane resin dissolved in a solvent. The addition of a low amount (0.025–0.1wt%) of graphene oxide to the ink formulation further improves the structural stability during pyrolysis reducing the shrinkage of the preceramic polymer. Upon pyrolysis at low temperature (1000°C), graphene oxide converted into graphene. The resulting scaffolds possess a good compression strength, of ∼2.5MPa for a total porosity of ∼64 vol% (∼3.1MPa after the addition of 0.1wt% graphene oxide).

Bone neoformation of a novel porous resorbable Si-Ca-P-based ceramic with osteoconductive properties: physical and mechanical characterization, histological and histomorphometric study.

The aims of the present work were to study a new porous Nurse's A ceramic (Si-Ca-P-based material) bone substitute and examine its mechanical properties invitro and the biocompatibility, osteoconductivity and resorption process invivo. Porous ceramic scaffolds were prepared by solid-state reaction and implanted in critical-sized defect created in 15 NZ rabbits. Strength values were determined by the diametrical compression of disk test. Weibull analyses were performed following the European Standard for technical ceramics EN-843-5: 1996, considering 90% of confidence intervals. Results were correlated with scanning microscope observations of fracture surfaces. Implanted scaffolds were characterized by histological and histomorphometric point of view. The parameters of the Weibull distribution of strength, determined by diametrical compression of disks, were modulus m=13, and characteristic strength σ0 =0.60 MPa (90% confidence limit: m=7.2-17.6, σ0 =0.570-0.578). Porous calcium silicophosphate scaffolds showed significantly more bone formation in the pores and in the periphery of the implant than the control group. Histomorphometric analysis revealed that the ceramic scaffold (62.23±0.34*) produced higher values of bone-to-implant contact (BIC) percentages (higher quality, closer contact); moreover, defect closure was significative in relation with control group. The porous calcium silicophosphate ceramic is biocompatible, partially resorbable and osteoinductive material. This rabbit study provides radiological and histological evidences confirming the suitablity of this new material for bone tissue regeneration on critical defects.

Atomic layer deposited TiO2 protects highly porous ceramic bone scaffolds from grain boundary corrosion

Event Abstract Back to Event Atomic layer deposited TiO2 protects highly porous ceramic bone scaffolds from grain boundary corrosion Benjamin Müller1*, Håvard J. Haugen1*, Ola Nilsen2 and Hanna Tiainen1* 1 University of Oslo, Department of Biomaterials, Norway 2 University of Oslo, Department of Chemistry, Norway Introduction: Corrosion in ceramics occurs preferentially at high energy sites such as grain boundaries (GB) and GB corrosion is a well-known phenomenon for polycrystalline oxide ceramics.[1] When highly porous ceramic materials such as bone scaffolds with large surface-to-volume ratios are exposed to corrosive environment, GB corrosion can have a particularly detrimental impact on the mechanical properties of the scaffold. This study aims to investigate the suitability of atomic layer deposition (ALD) of TiO2 thin films to protect a macro-porous TiO2 scaffold from GB corrosion and maintain its mechanical properties in physiologically low pH conditions. Two different deposition temperatures were chosen to assess the effect of film structure on the barrier properties of the deposited layers. Materials and Methods: TiO2 thin films were deposited at 150°C and 250 °C on the surface of highly porous TiO2 scaffolds using the chloride-water ALD process. The ALD films were characterised by scanning electron and atomic force microscopy, x-ray diffraction, and ellipsometry. The compressive strength of the ALD-coated scaffolds was tested following up to 28 d exposure to corrosive medium (1mM HCl). Results and Discussion: Although the ALD coatings deposited at 150 °C were mostly characterised as having amorphous structure, some randomly formed anatase crystallites were observed to protrude through the amorphous film as shown in Figure 1A. Films deposited at 250 °C had anatase crystal structure and were composed of densely packed grains with an average diameter of 31 ± 6 nm was (Figure 1B). The thicknesses of the amorphous and anatase coatings were 26 ± 1 and 22 ± 2 nm, respectively, and these thicknesses were not altered by 28 d exposure to 1mM HCl as measured by ellipsometry. In addition, strong adhesion between the coating and substrate was observed with no cracking or delamination upon fracture of the scaffold struts. Figure 1: Atomic force micrographs merged from height and amplitude scans (10×10 µm2) and height profiles in cross-section (below) for TiO2 deposited at 150 °C (A) and 250 °C (B) with high resolution scans (300×300 nm2) as 3D illustrations. After 7 and 28 days immersion into 1 mM HCl, a significant reduction in the compressive strength of the uncoated scaffolds was observed due to dissolution of siliceous GB phase, whereas both ALD coated scaffolds maintained the initial strength (Figure 2). This indicates that GB corrosion in highly porous scaffolds is mitigated under acidic conditions up to an exposure period of 28 days. In contrast to the unchanged strength of amorphous coated scaffolds, a slight decrease for the anatase coated scaffolds to 94 % of the initial strength after 28 days immersion was observed. Figure 2: Compressive strength of non-coated and ALD coated scaffolds prior and after immersion into 1 mM HCl for 7 and 28 days (n=10). Conclusions: GB corrosion in highly porous TiO2 scaffolds was successfully diminished by atomic layer deposition of both amorphous and anatase TiO2. The compressive strength of ALD coated scaffolds was maintained in physiologically low pH conditions up to 28 days. Amorphous TiO2 films offered excellent protection against GB corrosion, whereas anatase coated scaffolds with nano-sized grains may allow for improved osteoconduction in vitro and in vivo. This study was supported by Research Council of Norway grant 228415.; Jonas Wengenroth is acknowledged for his help with the AFM imaging of the surfaces.

Surface modification of strontium-doped porous bioactive ceramic scaffolds via poly(DOPA) coating and immobilizing silk fibroin for excellent angiogenic and osteogenic properties.

For bioceramic scaffolds employed in clinical applications, excellent bioactivity and tenacity were of great importance. Modifying inorganic SCPP scaffolds with biological macromolecules could obviously improve its bioactivity and eliminate its palpable brittleness. However, it was hard to execute directly due to extremely bad interfacial compatibility between them. In this research, dopamine (DOPA) was introduced onto strontium-doped calcium polyphosphate (SCPP) scaffolds, subsequently the preliminary material was successfully further modified by silk fibroin (SF). SCPP/D/SF possessed suitable biomechanical properties, ability to stimulate angiogenic factor secretion and excellent biocompatibility. Biomechanical examination demonstrated that SCPP/D/SF scaffolds yielded better compressive strength because of improved interfacial compatibility. MTT assay and CLSM observation showed that SCPP/D/SF scaffolds had good cytocompatibility and presented better inducing-cell-migration potential than pure SCPP scaffolds. Meanwhile, its ability to stimulate angiogenic factor secretion was measured through the ELISA assay and immunohistological analysis in vitro and in vivo respectively. The results revealed, superior to SCPP, SCPP/D/SF could effectively promote VEGF and bFGF expression, possibly leading to enhancing angiogenesis and osteogenesis. In a word, SCPP/D/SF could serve as a potential bone tissue engineering scaffold for comparable biomechanical properties and excellent bioactivity. It provided a novel idea for modification of inorganic materials to prepare promising bone tissue engineering scaffolds with the ability to accelerate bone regeneration and vascularization.

Evaluation of the effects of nano-TiO2 on bioactivity and mechanical properties of nano bioglass-P3HB composite scaffold for bone tissue engineering.

To emulate bone structure, porous composite scaffold with suitable mechanical properties should be designed. In this research the effects of nano-titania (nTiO2) on the bioactivity and mechanical properties of nano-bioglass-poly-3-hydroxybutyrate (nBG/P3HB)-composite scaffold were evaluated. First, nBG powder was prepared by melting method of pure raw materials at a temperature of 1400°C and then the porous ceramic scaffold of nBG/nTiO2 with 30 wt% of nBG containing different weight ratios of nTiO2 (3, 6, and 9 wt% of nTiO2 with grain size of 35-37nm) was prepared by using polyurethane sponge replication method. Then the scaffolds were coated with P3HB in order to increase the scaffold's mechanical properties. Mechanical strength and modulus of scaffolds were improved by adding nTiO2 to nBG scaffold and adding P3HB to nBG/nTiO2 composite scaffold. The results of the compressive strength and porosity tests showed that the best scaffold is 30 wt% of nBG with 6 wt% of nTiO2 composite scaffold immersed for 30s in P3HB with 79.5-80% of porosity in 200-600μm, with a compressive strength of 0.15MPa and a compressive modulus of 30MPa, which is a good candidate for bone tissue engineering. To evaluate the bioactivity of the scaffold, the simulated body fluid (SBF) solution was used. The best scaffold with 30 wt% of nBG, 6 wt% of P3HB and 6 wt% of nTiO2 was immersed in SBF for 4weeks at an incubation temperature of 37°C. The bioactivity of the scaffolds was characterized by AAS, SEM, EDXA and XRD. The results of bioactivity showed that bone-like apatite layer formed well at scaffold surface and adding nTiO2 to nBG/P3HB composite scaffold helped increase the bioactivity rate.

Preparation and characterization of highly porous ceramic scaffolds based on thermally treated fish bone

The present study aims at the preparation of highly porous 3D scaffolds from the biological resource; fish bone skeletons. To the best of the authors׳ knowledge, few works were reported for preparation of highly porous scaffolds from biogenic hydroxyapatite. The preparation method includes two essential steps: the first is the extraction of pure hydroxyapatite powder having an average particle size of 50–80nm from fish bone skeletons. The second is the formation of highly porous hydroxyapatite scaffolds prepared from fish bone skeletons via polymeric sponge method. Such scaffolds are highly bioactive as they are able to attract calcium and phosphorous ions to the scaffold surface in a very short time; less than one hour. The produced hydroxyapatite powder was investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), while the formed porous scaffolds were evaluated for their physical and chemical properties in addition to their pore size, microstructure and bioactivity.The results revealed that the porosity of the obtained 3D scaffolds is 85±0.4 and the median pore diameter ranging between about 1 and 3μm. The compressive and bending strengths of the scaffolds are 0.13±0.007MPa and 1.72±0.02MPa respectively, which is very near to the strength of trabecular bone.

Enhancement of the Pore Interconnectivity and Porosity of Calcium Phosphate Scaffolds by Acid-Etching Method

Porous hydroxyapatite (HA)–tricalcium phosphate (TCP) ceramic scaffolds were prepared using a screw-type extrusion method with polymer beads. HA and dicalcium phosphate dehydrates (DCPD) were added at various ratios to obtain different HA/TCP ratios in sintered ceramic scaffolds. To further enhance the pore interconnectivity and porosity, the developed porous ceramic scaffolds were etched with acid solutions. The maximum porosity (~85%) was observed in the Ca-P scaffold with the lowest HA (~7%) content. On the other hand, the maximum compressive strength was noted in the scaffolds with the highest HA content (~85%). X-ray diffraction showed that the extent of the β-TCP to α-TCP phase transformation increased with decreasing HA/DCPD ratio. All HCl-etched scaffolds were observed to generate micropores, which improved the interconnectivity, while biomineralization was found to be the same for both the HCl-etched and non-etched scaffolds. In particular, hydrochloric acid etching is a promising method for improving the interconnectivity and porosity of the ceramic scaffolds.

The effect of TiO2 nanopowder coating on in vitro bioactivity of porous TiO2 scaffolds

Porous TiO2 ceramic has attracted considerable research interest as a scaffold material for bone tissue engineering. However, no special considerations are given to the in vitro bioactivity of highly porous TiO2 ceramic scaffolds and they are assumed as bioinert ceramic. The main goal of the present work was to fabricate novel highly porous and bioactive TiO2 ceramic scaffolds with interconnected pore structure for bone tissue engineering. TiO2 ceramic scaffolds with pore size in the range from 300 to 700μm and porosity >90% were produced via polymer foam replica method. Scaffolds were coated with TiO2 nanopowder and the effect of TiO2 nanopowder coating on in vitro bioactivity in simulated body fluid was studied. Uncoated TiO2 scaffolds showed no in vitro bioactivity after immersion in SBF for 21 days, but sphere-like particles were observed on the surface of coated TiO2 scaffolds that were considered being B type CO32− substituted or bonelike apatite.

Production of porous Calcium Phosphate (CaP) ceramics with aligned pores using ceramic/camphene-based co-extrusion.

BackgroundCalcium phosphate (CaP) ceramics are one of the most valuable biomaterials for uses as the bone scaffold owing to their outstanding biocompatability, bioactivity, and biodegradation nature. In particular, these materials with an open porous structure can stimulate bone ingrowth into their 3-dimensionally interconnected pores. However, the creation of pores in bulk materials would inevitably cause a severe reduction in mechanical properties. Thus, it is a challenge to explore new ways of improving the mechanical properties of porous CaP scaffolds without scarifying their high porosity.ResultsPorous CaP ceramic scaffolds with aligned pores were successfully produced using ceramic/camphene-based co-extrusion. This aligned porous structure allowed for the achievement of high compressive strength when tested parallel to the direction of aligned pores. In addition, the overall porosity and mechanical properties of the aligned porous CaP ceramic scaffolds could be tailored simply by adjusting the initial CaP content in the CaP/camphene slurry. The porous CaP scaffolds showed excellent in vitro biocompatibility, suggesting their potential as the bone scaffold.ConclusionsAligned porous CaP ceramic scaffolds with considerably enhanced mechanical properties and tailorable porosity would find very useful applications as the bone scaffold.

Porous alumina ceramic scaffolds with biomimetic macro/micro-porous structure using three-dimensional (3-D) ceramic/camphene-based extrusion

This study demonstrates the versatility of 3-dimensional ceramic/camphene-based extrusion (3D-Ex) using a frozen alumina/camphene body as a feedstock for the production of porous alumina scaffolds with a biomimetic macro/micro-porous structure. Three-dimensionally interconnected macropores were constructed through the deposition of frozen alumina/camphene filaments at a stacking sequence of 0°/90°, while aligned micropores were created in alumina frameworks as the replica of camphene dendrites that had been extensively elongated by the extrusion of a frozen alumina/camphene body. The macro/micro-porous structure and compressive strength of porous alumina scaffolds could be tailored by adjusting initial alumina content in alumina/camphene slurries.

The effect of autologous bone marrow stromal cells differentiated on scaffolds for canine tibial bone reconstruction

Bone marrow contains mesenchymal stem cells that form many tissues. Various scaffolds are available for bone reconstruction by tissue engineering. Osteoblastic differentiated bone marrow stromal cells (BMSC) promote osteogenesis on scaffolds and stimulate bone regeneration. We investigated the use of cultured autologous BMSC on different scaffolds for healing defects in tibias of adult male canines. BMSC were isolated from canine humerus bone marrow, differentiated into osteoblasts in culture and loaded onto porous ceramic scaffolds including hydroxyapatite 1, hydroxyapatite gel and calcium phosphate. Osteoblast differentiation was verified by osteonectine and osteocalcine immunocytochemistry. The scaffolds with stromal cells were implanted in the tibial defect. Scaffolds without stromal cells were used as controls. Sections from the defects were processed for histological, ultrastructural, immunohistochemical and histomorphometric analyses to analyze the healing of the defects. BMSC were spread, allowed to proliferate and differentiate to osteoblasts as shown by alizarin red histochemistry, and osteocalcine and osteonectine immunostaining. Scanning electron microscopy showed that BMSC on the scaffolds were more active and adhesive to the calcium phosphate scaffold compared to the others. Macroscopic bone formation was observed in all groups, but scaffolds with stromal cells produced significantly better results. Bone healing occurred earlier and faster with stromal cells on the calcium phosphate scaffold and produced more callus compared to other scaffolds. Tissue healing and osteoblastic marker expression also were better with stromal cells on the scaffolds. Increased trabecula formation, cell density and decreased fibrosis were observed in the calcium phosphate scaffold with stromal cells. Autologous cultured stromal cells on the scaffolds were useful for healing of canine tibial bone defects. The calcium phosphate scaffold was the best for both cell differentiation in vitro and bone regeneration in vivo. It may be possible to improve healing of bone defects in humans using stem cells from bone marrow.

Preparation and Characterization of Porous Titania Ceramic Scaffolds

Biocompatible ceramics have recently attracted increasing attention as porous scaffolds that stimulate and guide natural bone regeneration. Due to excellent biocompatibility of titania (titanium dioxide or TiO2) porous three-dimensional (3D) TiO2 structures have been proposed as promising scaffolding materials for inducing bone formation from the surrounding environment and for enhancement of vascularisation after implantation. In this paper, 3D porous TiO2 ceramic scaffolds were produced via polymer foam replica method. This work deals with several important issues that are considered to be important for 3D scaffolds applied to regenerate bone tissue: pore size, porosity and mechanical strength. TiO2 ceramic scaffolds with pore size 300 μm − 700 μm and porosity > 90 % were obtained. Scaffolds showed fully open and interconnected pore structure that remained after recoating them with low viscosity TiO2 slurry. By optimising thermal treatment conditions grain growth and collapse of struts could be controlled in a way that resulted in higher compressive strength. Recoating greatly improved compressive strength and it reached 0.74±0.08 MPa after two coatings without causing changes in the open porestructure.

Mechanical properties of porous ceramic scaffolds: Influence of internal dimensions

Highly porous ceramic scaffolds have been fabricated from a 70% SiO2–30% CaO glass powder using stereolithography and the lost-mould process combined with gel-casting. After sintering at 1200°C the glass crystallised to a structure of wollastonite and pseudowollastonite grains in a glassy matrix with a bulk porosity of 1.3%. All scaffolds had a simple cubic strut structure with an internal porosity of approximately 42% and internal pore dimensions in the range 300–600μm. The mean crushing strength of the scaffolds is in the range 10–25MPa with the largest pore sizes showing the weakest strengths. The variability of scaffold strengths has been characterised using Weibull statistics and each set of scaffolds showed a Weibull modulus of m≈3 independent of pore size. The equivalent strength of the struts within the porous ceramics was estimated to be in the range 40–80MPa using the models of the Gibson and Ashby. These strengths were found to scale with specimen size consistent with the Weibull modulus obtained from compression tests. Using a Weibull analysis, these strengths are shown to be in accordance with the strength of 3-point bend specimens of the bulk glass material fabricated using identical methods. The strength and Weibull modulus of these scaffolds are comparable to those reported for other porous ceramic scaffold materials of similar porosity made by different fabrication routes.

Evaluation of mechanical property and bioactivity of nano-bioglass 45S5 scaffold coated with poly-3-hydroxybutyrate.

One of the major challenges facing researchers of tissue engineering is scaffold design with desirable physical and mechanical properties for growth and proliferation of cells and tissue formation. In this research, firstly, nano-bioglass powder with grain sizes of 55-56 nm was prepared by melting method of industrial raw materials at 1,400 °C. Then the porous ceramic scaffold of bioglass with 30, 40 and 50 wt% was prepared by using the polyurethane sponge replication method. The scaffolds were coated with poly-3-hydroxybutyrate (P3HB) for 30 s and 1 min in order to increase the scaffold's mechanical properties. XRD, XRF, SEM, FE-SEM and FT-IR were used for phase and component studies, morphology, particle size and determination of functional groups, respectively. XRD and XRF results showed that the type of the produced bioglass was 45S5. The results of XRD and FT-IR showed that the best temperature to produce bioglass scaffold was 600 °C, in which Na2Ca2Si3O9 crystal is obtained. By coating the scaffolds with P3HB, a composite scaffold with optimal porosity of 80-87% in 200-600 μm and compression strength of 0.1-0.53 MPa was obtained. According to the results of compressive strength and porosity tests, the best kind of scaffold was produced with 30 wt% of bioglass immersed for 1 min in P3HB. To evaluate the bioactivity of the scaffold, the SBF solution was used. The selected scaffold (30 wt% bioglass/6 wt% P3HB) was maintained for up to 4 weeks in this solution at an incubation temperature of 37 °C. The XRD, SEM EDXA and AAS tests were indicative of hydroxyapatite formation on the surface of bioactive scaffold. This scaffold has some potential to use in bone tissue engineering.

Porous β-Ca2SiO4 ceramic scaffolds for bone tissue engineering: In vitro and in vivo characterization

The biodegradable ceramic scaffolds with desirable pore size, porosity and mechanical properties play a crucial role in bone tissue engineering and bone transplantation. A novel porous β-dicalcium silicate (β-Ca2SiO4) ceramic scaffold was prepared by sintering the green body consisting of CaCO3 and SiO2 at 1300°C, which generated interconnected pore network with proper pore size of about 300μm and high compressive strength (28.13±5.37–10.36±0.83MPa) following the porosity from 53.54±5.37% to 71.44±0.83%. Porous β-Ca2SiO4 ceramic scaffolds displayed a good biocompatibility, since human osteoblast-like MG-63 cells and goat bone mesenchymal stem cells (BMSCs) proliferated continuously on the scaffolds after 7d culture. The porous β-Ca2SiO4 ceramic scaffolds revealed well apatite-forming ability when incubated in the simulated body fluid (SBF). According to the histological test, the degradation of porous β-Ca2SiO4 ceramic scaffolds and the new bone tissue generation in vivo were observed following 9 weeks implantation in nude mice. These results suggested that the porous β-Ca2SiO4 ceramic scaffolds could be potentially applied in bone tissue engineering.

Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering.

Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL), we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (β-TCP) with room temperature vulcanization (RTV) silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects.