β-TCP Scaffolds Research Articles

Novel linear intercept method for characterizing micropores and grains in calcium phosphate bone substitutes

The micropore and grain thicknesses of calcium phosphate (CaP) bone substitutes are believed to have strong influence on in vivo biological responses. The thickness measurement is challenging due to complex morphologies of the elongated CaP micropores and grains. This study aimed to develop and verify a novel linear intercept (NLI) algorithm based on SEM images to calculate thicknesses accurately for elongated geometrical features. The standard linear intercept (SLI) algorithm overestimates the thickness of micropores and grains wherever the defined lines are not perpendicular to such geometrical features. The NLI was developed by integrating the standard algorithm with a distance transform map to exclude the overestimation errors. Besides the accurate thickness calculation, the NLI measures the orientation angle of architectural features as an indication for isotropy level. The NLI-based thicknesses of five groups of β-TCP scaffolds were compared and verified with those of a refined centerline (RC) algorithm. The RC algorithm was accurate yet human assisted and very time intensive. Compared with RC algorithm, the NLI-based results were 2±13 and 4±9% (Mean±SD) lower for average micropore and grain thicknesses, respectively. The NLI results were also compared with two standard and commonly used algorithms. The SLI and maximal-fitted-circle (MFC) algorithms resulted in 72±25 and 91±47% overestimation errors, respectively.

Development of PLGA-coated β-TCP scaffolds containing VEGF for bone tissue engineering

Bone tissue engineering is sought to apply strategies for bone defects healing without limitations and short-comings of using either bone autografts or allografts and xenografts. The aim of this study was to fabricate a thin layer poly(lactic-co-glycolic) acid (PLGA) coated beta-tricalcium phosphate (β-TCP) scaffold with sustained release of vascular endothelial growth factor (VEGF). PLGA coating increased compressive strength of the β-TCP scaffolds significantly. For in vitro evaluations, canine mesenchymal stem cells (cMSCs) and canine endothelial progenitor cells (cEPCs) were isolated and characterized. Cell proliferation and attachment were demonstrated and the rate of cells proliferation on the VEGF released scaffold was significantly more than compared to the scaffolds with no VEGF loading. A significant increase in expression of COL1 and RUNX2 was indicated in the scaffolds loaded with VEGF and MSCs compared to the other groups. Consequently, PLGA coated β-TCP scaffold with sustained and localized release of VEGF showed favourable results for bone regeneration in vitro, and this scaffold has the potential to use as a drug delivery device in the future.

Mandibular Jaw Bone Regeneration Using Human Dental Cell-Seeded Tyrosine-Derived Polycarbonate Scaffolds.

Here we present a new model for alveolar jaw bone regeneration, which uses human dental pulp cells (hDPCs) combined with tyrosine-derived polycarbonate polymer scaffolds [E1001(1k)] containing beta-tricalcium phosphate (β-TCP) [E1001(1k)/β-TCP]. E1001(1k)/β-TCP scaffolds (5 mm diameter × 1 mm thickness) were fabricated to fit a 5 mm rat mandibular ramus critical bone defect. Five experimental groups were examined in this study: (1) E1001(1k)/β-TCP scaffolds seeded with a high density of hDPCs, 5.0 × 10(5) hDPCs/scaffold (CH); (2) E1001(1k)/β-TCP scaffolds seeded with a lower density of hDPCs, 2.5 × 10(5) hDPCs/scaffold (CL); (3) acellular E1001(1k)/β-TCP scaffolds (SA); (4) acellular E1001(1k)/β-TCP scaffolds supplemented with 4 μg recombinant human bone morphogenetic protein-2 (BMP); and (5) empty defects (EDs). Replicate hDPC-seeded and acellular E1001(1k)/β-TCP scaffolds were cultured in vitro in osteogenic media for 1 week before implantation for 3 and 6 weeks. Live microcomputed tomography (μCT) imaging at 3 and 6 weeks postimplantation revealed robust bone regeneration in the BMP implant group. CH and CL groups exhibited similar uniformly distributed mineralized tissue coverage throughout the defects, but less than the BMP implants. In contrast, SA-treated defects exhibited sparse areas of mineralized tissue regeneration. The ED group exhibited slightly reduced defect size. Histological analyses revealed no indication of an immune response. In addition, robust expression of dentin and bone differentiation marker expression was observed in hDPC-seeded scaffolds, whereas, in contrast, BMP and SA implants exhibited only bone and not dentin differentiation marker expression. hDPCs were detected in 3-week but not in 6-week hDPC-seeded scaffold groups, indicating their survival for at least 3 weeks. Together, these results show that hDPC-seeded E1001(1k)/β-TCP scaffolds support the rapid regeneration of osteo-dentin-like mineralized jaw tissue, suggesting a promising new therapy for alveolar jaw bone repair and regeneration.

Use of a biological reactor and platelet-rich plasma for the construction of tissue-engineered bone to repair articular cartilage defects.

Articular cartilage defects are a major clinical burden worldwide. Current methods to repair bone defects include bone autografts, allografts and external fixation. In recent years, the repair of bone defects by tissue engineering has emerged as a promising approach. The present study aimed to assess a novel method using a biological reactor with platelet-rich plasma to construct tissue-engineered bone. Beagle bone marrow mesenchymal stem cells (BMSCs) were isolated and differentiated into osteoblasts and chondroblasts using platelet-rich plasma and tricalcium phosphate scaffolds cultured in a bioreactor for 3 weeks. The cell scaffold composites were examined by scanning electron microscopy (SEM) and implanted into beagles with articular cartilage defects. The expression of osteogenic markers, alkaline phosphatase and bone γ-carboxyglutamate protein (BGLAP) were assessed using polymerase chain reaction after 3 months. Articular cartilage specimens were observed histologically. Adhesion and distribution of BMSCs on the β-tricalcium phosphate (β-TCP) scaffold were confirmed by SEM. Histological examination revealed that in vivo bone defects were largely repaired 12 weeks following implantation. The expression levels of alkaline phosphatase (ALP) and BGLAP in the experimental groups were significantly elevated compared with the negative controls. BMSCs may be optimum seed cells for tissue engineering in bone repair. Platelet-rich plasma (PRP) provides a rich source of cytokines to promote BMSC function. The β-TCP scaffold is advantageous for tissue engineering due to its biocompatibility and 3D structure that promotes cell adhesion, growth and differentiation. The tissue-engineered bone was constructed in a bioreactor using BMSCs, β-TCP scaffolds and PRP and displayed appropriate morphology and biological function. The present study provides an efficient method for the generation of tissue-engineered bone for cartilage repair, compared with previously used methods.

Boron Nitride Nanotubes Reinforce Tricalcium Phosphate Scaffolds and Promote the Osteogenic Differentiation of Mesenchymal Stem Cells.

Incorporating boron nitride nanotubes (BNNTs) into ceramic matrices is a promising strategy for obtaining multifunctional composites. In this study, the application of BNNTs in reinforcing β-tricalcium phosphate (β-TCP) scaffolds manufactured using laser sintering is demonstrated. BNNTs contribute to the effective inhibition of both grain growth and phase transformation in β-TCP. Moreover, they can strengthen the grain boundaries and boost the fracture mode transition from intergranular to transgranular. BNNTs play an active role in reinforcing β-TCP in terms of load transfer and energy absorption by the synergistic mechanisms of pull-out, peel-off, crack bridging and deflection. With a BNNT content of 4 wt%, the elastic modulus, hardness, compressive strength and fracture toughness of β-TCP increase by 46%, 39%, 109% and 35%, respectively. Umbilical cord mesenchymal stem cells (UC-MSCs) were isolated with high purity, and surface molecule characterization revealed that they were CD90+, CD29+, CD73+, CD31-, CD34- and CD45-. UC-MSCs on BNNTs/β-TCP scaffolds were characterized by more positive Alizarin Red staining as well as up-regulated expression of osteoblast markers, as revealed by quantitative real-time reverse transcriptase polymerase chain reaction analysis and immunofluorescence staining. These results are the first to demonstrate that BNNTs promote the osteogenic differentiation of UC-MSCs, indicating good osteoinductive properties for use in bone scaffolds. This study paves the way for the potential use of a BNNT/β-TCP scaffold in bone repair.

Variation of mechanical behavior of β-TCP/collagen two phase composite scaffold with mesenchymal stem cell in vitro

The primary aim of this study is to characterize the variational behavior of the compressive mechanical property of bioceramic-based scaffolds using stem cells during the cell culture period. β-Tricalcium phosphate (TCP)/collagen two phase composites and β-TCP scaffolds were fabricated using the polyurethane template technique and a subsequent freeze-drying method. Rat bone-marrow mesenchymal stem cells (rMSCs) were then cultured in these scaffolds for up to 28 days. Compression tests of the scaffolds with rMSCs were periodically conducted. Biological properties, such as the cell number, alkaline phosphatase (ALP) activity, and gene expressions of osteogenesis, were evaluated. The microstructural change due to cell growth and the formation of extracellular matrices was examined using a field-emission scanning electron microscope. The compressive property was then correlated with the biological properties and microstructures to understand the mechanism of the variational behavior of the macroscopic mechanical property. The porous collagen structure in the β-TCP scaffold effectively improved the structural stability of the composite scaffold, whereas the β-TCP scaffold exhibited structural instability with the collapse of the porous structure when immersed in a culture medium. The β-TCP/collagen composite scaffold exhibited higher ALP activity and more active generation of osteoblastic markers than the β-TCP scaffold.

Fabrication of 3D porous SF/β-TCP hybrid scaffolds for bone tissue reconstruction.

Bio-ceramic is a biomaterial actively studied in the field of bone tissue engineering. But, only certain ceramic materials can resolve the corrosion problem and possess the biological affinity of conventional metal biomaterials. Therefore, the recent development of composites of hybrid composites and polymers has been widely studied. In this study, we aimed to select the best scaffold of silk fibroin and β-TCP hybrid for bone tissue engineering. We fabricated three groups of scaffold such as SF (silk fibroin scaffold), GS (silk fibroin/small granule size of β-TCP scaffold) and GM (silk fibroin/medium granule size of β-TCP scaffold), and we compared the characteristics of each group. During characterization of the scaffold, we used scanning electron microscopy (SEM) and a Fourier transform infrared spectroscopy (FTIR) for structural analysis. We compared the physiological properties of the scaffold regarding the swelling ratio, water uptake and porosity. To evaluate the mechanical properties, we examined the compressive strength of the scaffold. During in vitro testing, we evaluated cell attachment and cell proliferation (CCK-8). Finally, we confirmed in vivo new bone regeneration from the implanted scaffolds using histological staining and micro-CT. From these evaluations, the fabricated scaffold demonstrated high porosity with good inter-pore connectivity, showed good biocompatibility and high compressive strength and modulus. In particular, the present study indicates that the GM scaffold using β-TCP accelerates new bone regeneration of implanted scaffolds. Accordingly, our scaffold is expected to act a useful application in the field of bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1779-1787, 2016.

Rapid prototyping assisted fabrication of patient specific β-tricalciumphosphate scaffolds for bone tissue regeneration

Beta Tri calcium phosphate scaffolds were produced by inverse casting methodology using rapid prototyping technology. Β-TCP scaffold sintered at different temperatures were analyzed by using Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, uniaxial compression test and cytotoxicity test. Results incorporate scaffold pore size, bonding, phase chance, porosity, mechanical strength, and cytotoxic profile with an increase in the sintering temperatures. Together, these properties are required for scaffold fabrication in the field of bone tissue regeneration.

A Randomized Clinical Trial Evaluating rh-FGF-2/β-TCP in Periodontal Defects

Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a β-tricalcium phosphate (β-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups—β-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with β-TCP—following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/β-TCP groups with significant improvements over control and 0.1% rh-FGF-2/β-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/β-TCP (ClinicalTrials.gov NCT01728844).

Enhancement of mechanical strength and in vivo cytocompatibility of porous β-tricalcium phosphate ceramics by gelatin coating.

BackgroundIn an attempt to prepare scaffolds with porosity and compressive strength as high as possible, we prepared porous β-tricalcium phosphate (TCP) scaffolds and coated them with regenerative medicine-grade gelatin. The effects of the gelatin coating on the compressive strength and in vivo osteoblast compatibility were investigated.MethodsPorous β-TCP scaffolds were prepared and coated with up to 3 mass% gelatin, and then subjected to thermal cross-linking. The gelatin-coated and uncoated scaffolds were then subjected to compressive strength tests and implantation tests into bone defects of Wistar rats.ResultsThe compressive strength increased by one order of magnitude from 0.45 MPa for uncoated to 5.1 MPa for gelatin-coated scaffolds. The osteoblast density in the internal space of the scaffold increased by 40 % through gelatin coating.ConclusionsCoating porous bone graft materials with gelatin is a promising measure to enhance both mechanical strength and biomedical efficacy at the same time.

Analysis of Bone Repair and Inflammatory Process Caused by Simvastatin Combined With PLGA+HA+βTCP Scaffold.

This study evaluated the tissue and inflammatory responses to the use of simvastatin and poly(lactic-co-glycolic acid) + hydroxyapatite + β-tricalcium phosphate (PLGA+HA+βTCP) scaffold for bone repair. Two defects of 5 mm in diameter were made in the calvaria of rats, which were shared into the following 6 groups: naive, sham, vehicle, PLGA+HA+βTCP scaffold, simvastatin (4 mg/mL), and simvastatin with the scaffold. Tissue samples were collected at 1, 7, 15, 30, and 60 days after surgery. Inflammation was evaluated by interleukin-1 beta and tumor necrosis factor alpha quantification and by a hemogram, whereas bone repair was evaluated using densitometry and scanning electron microscopy. Data were statistically analyzed using ANOVA followed by post hoc tests (P < 0.05). There was an increased cytokine expression in the scaffold and simvastatin groups (P < 0.001 and P < 0.05, respectively) 1 day after surgery but no alterations on the hemogram were observed. It was found on bone tissue samples that 60 days after surgery all groups presented similar densitometry values and morphology characteristics, despite the occurrence of bone formation delay in the simvastatin group (P < 0.01). The use of simvastatin and PLGA+HA+βTCP scaffold, associated or not, did not lead to improvement in bone repair.

Feasibility of alumina and alumina-silica nanoparticles to fabricate strengthened betatricalcium phosphate scaffold with improved biological responses

Betatricalcium phosphate (β-TCP), nano-alumina- and nano-alumina/nano-silica – added β-TCP scaffolds were prepared by the foam replication method followed by sintering at 1200–1300°C. The rheological properties of β-TCP and the nano-additive-containing β-TCP slurries were investigated using a computerized rheometer. The phase composition, mechanical strength, microstructure and rat-calvarium-derived osteoblast responses of the scaffolds were also studied. The results showed that nano-alumina decreased viscosity of β-TCP slurry and receded its thixotropy whereas a reverse result was obtained for the nano-silica additive. The phase composition of the scaffolds was whitlockite regardless of sintering temperature. The nano-alumina-added β-TCP scaffolds were 2–4 times stronger than pure β-TCP and their compressive strength values were in the range of 0.1–0.5MPa, depending on the additive content and temperature. However, when nano-alumina and nano-silica were simultaneously used, the compressive strength was dramatically improved to 5MPa for temperature 1250°C and 15MPa for temperature 1300°C. Adding nano-alumina and nano-alumina/nano-silica to pure β-TCP resulted in a more compacted microstructure with reduced grain size. All scaffolds exhibited adequate cell attachment, but the proliferation and alkaline phosphatase activity of the cells increased when nano-alumina and nano-silica were simultaneously used. Overall, tissue engineering scaffolds with interconnected macropores and improved mechanical and biological properties can be fabricated using a small quantity of nano-alumina and nano-silica additives.

An engineered multicomponent bone marrow niche for the recapitulation of hematopoiesis at ectopic transplantation sites.

BackgroundBone marrow (BM) niches are often inaccessible for controlled experimentation due to their difficult accessibility, biological complexity, and three-dimensional (3D) geometry. MethodsHere, we report the development and characterization of a BM model comprising of cellular and structural components with increased potential for hematopoietic recapitulation at ectopic transplantation sites. Cellular components included mesenchymal stromal cells (MSCs) and hematopoietic stem and progenitor cells (HSPCs). Structural components included 3D β-tricalcium phosphate (β-TCP) scaffolds complemented with Matrigel or collagen I/III gels for the recreation of the osteogenic/extracellular character of native BM.ResultsIn vitro, β-TCP/Matrigel combinations robustly maintained proliferation, osteogenic differentiation, and matrix remodeling capacities of MSCs and maintenance of HSPCs function over time. In vivo, scaffolds promoted strong and robust recruitment of hematopoietic cells to sites of ectopic transplantation, vascularization, and soft tissue formation.ConclusionsOur tissue-engineered BM system is a powerful tool to explore the regulatory mechanisms of hematopoietic stem and progenitor cells for a better understanding of hematopoiesis in health and disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s13045-016-0234-9) contains supplementary material, which is available to authorized users.

The outstanding mechanical response and bone regeneration capacity of robocast dilute magnesium-doped wollastonite scaffolds in critical size bone defects.

The regeneration and repair of damaged load-bearing segmental bones require considerable mechanical strength for the artificial implants. The ideal biomaterials should also facilitate the production of porous implants with high bioactivity desirable for stimulating new bone growth. Here we developed a new mechanically strong, highly bioactive dilute magnesium-doped wollastonite (CaSiO3-Mg; CSi-Mg) porous scaffold by the robocasting technique. The sintered scaffolds had interconnected pores 350 µm in size and over 50% porosity with appreciable compressive strength (>110 MPa), 5-10 times higher than those of pure CSi and β-TCP porous ceramics. Extensive in vitro and in vivo investigations revealed that such Ca-silicate bioceramic scaffolds were particularly beneficial for osteogenic cell activity and osteogenic capacity in critical size femoral bone defects. The CSi-Mg porous constructs were accompanied by an accelerated new bone growth (6-18 weeks) and a mechanically outstanding elastoplastic response to finally match the strength (10-15 MPa) of the rabbit femur host bone after 18 weeks, and the material itself experienced mild resorption and apatite-like phase transformation. In contrast, the new bone regeneration in the β-TCP scaffolds was substantially retarded after 6-12 weeks of implantation, and exhibited a low level of mechanical strength (<10 MPa) similar to the pure CSi scaffolds. These results suggest a promising application of robocast CSi-Mg scaffolds in the clinic, especially for the load-bearing bone defects.

Highly oriented PLA fiber reinforced tubular scaffold with shape recovery effect for cell guide applications

Event Abstract Back to Event Highly oriented PLA fiber reinforced tubular scaffold with shape recovery effect for cell guide applications Kazi Md Zakir Hossain1, Uresha Patel1 and Ifty Ahmed1 1 University Of Nottingham, Division of Materials, Mechanics and Structures, United Kingdom Introduction: Tubular shaped scaffolds can possess advantageous features over solid foam type scaffolds such as guiding or encouraging cells along a specific route or to a target location. Orientation of aligned fibrous structures and incorporation of media-activated shape recovery within the scaffolds which retain their initial structure throughout the period of implantation could be considered a promising strategy for defect filling and/or nerve guide applications. In addition, the scaffolds could also be used to guide tissues for regrowth along specific alignments[1]. Experimental Methods: In this study PLA fibres were manufactured using a melt-drawn process and collected on a rotating drum with traverse mode in order to maintain the unidirectional alignment of the fibres. Various mixtures of polyvinyl acetate (PVAc) and tricalcium phosphate (β-TCP) with the ratios of 100/0, 85/15 and 70/30 were used to manufacture tubular structures, where PVAc acted as a binder and the β-TCP was added to improve the biocompatibility of the scaffolds. Results and Discussion: The cross-sectional morphology of the tubular scaffolds confirmed alignment of the fibres along with a significant number of voids in between the PLA fibre layers. Incorporation of β-TCP particles increased the compressive modulus properties from 66 MPa to 83 MPa. However, a decrease in the compressive strength from 67 MPa to 41 MPa with addition of 30 wt% β-TCP in the scaffolds was also observed. This was suggested to be due to the increasing number of voids created within the scaffolds. The wet scaffolds showed a mass gain of 45% after immersion in phosphate buffer saline (PBS)media for 24h and revealed shape-recovery properties for the wet scaffolds post compression testing (presented in Fig. 1). Fig. 1: Shape recovery behavior of the tubular scaffolds: a) during compression b) compressed sample after 30 s and c) after 5 min of compression testing. It was also seen that orientation of the PLA fibres and addition of β-TCP supported MG-63 human osteosarcoma cell attachment and spreading along the longitudinal direction of the fibres compared to the non- β-TCP content scaffolds (as presented in Fig. 2). Fig. 2: Influence of PVAc/β-TCP coating materials and fibrous structure on cultured MG-63 osteosarcoma cells morphology and spreading on PLA 30% β-TCP scaffold at varying time points: a) 24h and b) 48h. Conclusions: The scaffold device could be utilised for cell guide and cancellous bone repair applications where maintaining specific alignment was required. The advantage of using β-TCP was to enhance the biocompatibility of the construct and it also had the additional benefit of being resorbable. The authors would like to thank Mrs Julie Thompson (Technician, University of Nottingham) for her kind help with the micro-CT analysis.

Simultaneous tumor-photothermal therapy and bone-tissue regeneration by a bifunctional 3D-pringting bioceramic scaffold

Event Abstract Back to Event Simultaneous tumor-photothermal therapy and bone-tissue regeneration by a bifunctional 3D-pringting bioceramic scaffold Chengtie Wu1 and Jiang Chang1 1 Shanghai Institute of Ceramics, Chinese Academy of Sciences, State Key Laboratory of High Performance Ceramics and Superfine Microstructure, China Malignant bone tumor is one of the major bone diseases. The treatment of such a bone disease typically requires the removal of bone tumor and regeneration of tumor-initiated bone defects simultaneously. To address this issue, it is required that implanted biomaterials should combine the bifunctions of both therapy and regeneration. In this work, a bifunctional graphene oxide (GO)-modified β-tricalcium phosphate (GO-TCP) composite scaffold combining high photothermal effect with significantly improved bone-forming ability was prepared by 3D-printing and surface-modification strategies. The prepared GO-TCP scaffolds exhibited excellent photothermal effects under the irradiation of 808nm near infrared laser (NIR) even at an ultra-low power density of 0.36W/cm2, while no photothermal effects were observed for pure β-TCP scaffolds. The photothermal temperature of GO-TCP scaffolds could be effectively modulated in the range of 40~90°C by controlling the used GO concentrations, surface-modification times and power densities of NIR. The distinct photothermal effect of GO-TCP scaffolds induced more than 90% of cell death for osteosarcoma cells (MG-63) in vitro, and further effectively inhibited tumor growth in mouse. Meanwhile, the prepared GO-TCP scaffolds possessed the improved capability to stimulate the osteogenic differentiation of rabbit bone mesenchymal stem cells (rBMSCs) by upregulating bone-related gene expression, and significantly promoted new bone formation in the bone defects of rabbits as compared to pure β-TCP scaffolds. These results successfully demonstrated that the prepared GO-TCP scaffolds have bifunctional properties of photothermal therapy and bone regeneration, which is believed to pave the way to design and fabricate novel implanting biomaterials in combination of therapy and regeneration functions. the National High Technology Research and Development Program of China (863 Program, SS2015AA020302) Keywords: Bone Regeneration, Tissue Engineering, 3D scaffold Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: New Frontier Oral Topic: Ceramics Citation: Wu C and Chang J (2016). Simultaneous tumor-photothermal therapy and bone-tissue regeneration by a bifunctional 3D-pringting bioceramic scaffold. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.01258 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Chengtie Wu Jiang Chang Google Chengtie Wu Jiang Chang Google Scholar Chengtie Wu Jiang Chang PubMed Chengtie Wu Jiang Chang Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

2H22 操作性・骨伝導性に優れるβ-TCP/PLLA scaffoldの作製と評価

In the field of bone regenerative medicine, the need for artificial bone substitutes has been rapidly increasing, and various porous bioactive ceramics have been developed for use as bone substitutes. While materials such as β-tricalcium phosphate (β-TCP) have good oseteoconductivity, poly (L-lactide acid) (PLLA) has been shown to have good mechanical and physical properties. Therefore, the primary aim of this study was to fabricate a porous β-TCP scaffold with a PLLA network structure (β-TCP/PLLA) for use in bone tissue engineering. The fabricated β-TCP/PLLA scaffolds were characterized by their surface micro structures and compressive moduli. The results demonstrated that the structure of the PLLA membrane, such as pore size and thickness of membrane, could be changed by varying the concentration of PLLA.

Exosomes Secreted by Human-Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Repair Critical-Sized Bone Defects through Enhanced Angiogenesis and Osteogenesis in Osteoporotic Rats.

Bone defects caused by trauma, severe infection, tumor resection and skeletal abnormalities are common osteoporotic conditions and major challenges in orthopedic surgery, and there is still no effective solution to this problem. Consequently, new treatments are needed to develop regeneration procedures without side effects. Exosomes secreted by mesenchymal stem cells (MSCs) derived from human induced pluripotent stem cells (hiPSCs, hiPSC-MSC-Exos) incorporate the advantages of both MSCs and iPSCs with no immunogenicity. However, there are no reports on the application of hiPSC-MSC-Exos to enhance angiogenesis and osteogenesis under osteoporotic conditions. HiPSC-MSC-Exos were isolated and identified before use. The effect of hiPSC-MSC-Exos on the proliferation and osteogenic differentiation of bone marrow MSCs derived from ovariectomized (OVX) rats (rBMSCs-OVX) in vitro were investigated. In vivo, hiPSC-MSC-Exos were implanted into critical size bone defects in ovariectomized rats, and bone regeneration and angiogenesis were examined by microcomputed tomography (micro-CT), sequential fluorescent labeling analysis, microfil perfusion and histological and immunohistochemical analysis. The results in vitro showed that hiPSC-MSC-Exos enhanced cell proliferation and alkaline phosphatase (ALP) activity, and up-regulated mRNA and protein expression of osteoblast-related genes in rBMSCs-OVX. In vivo experiments revealed that hiPSC-MSC-Exos dramatically stimulated bone regeneration and angiogenesis in critical-sized calvarial defects in ovariectomized rats. The effect of hiPSC-MSC-Exos increased with increasing concentration. In this study, we showed that hiPSC-MSC-Exos effectively stimulate the proliferation and osteogenic differentiation of rBMSCs-OVX, with the effect increasing with increasing exosome concentration. Further analysis demonstrated that the application of hiPSC-MSC-Exos+β-TCP scaffolds promoted bone regeneration in critical-sized calvarial defects by enhancing angiogenesis and osteogenesis in an ovariectomized rat model.

Biotin-avidin mediates the binding of adipose-derived stem cells to a porous β-tricalcium phosphate scaffold: Mandibular regeneration.

The present study aimed to investigate the properties of a promising bone scaffold for bone repair, which consisted of a novel composite of adipose-derived stem cells (ADSCs) attached to a porous β-tricalcium phosphate (β-TCP) scaffold with platelet-rich plasma (PRP). The β-TCP powder was synthesized and its composition was determined using X-ray diffraction and Fourier transform infrared spectroscopy. The surface morphology and microstructure of the fabricated porous β-TCP scaffold samples were analyzed using light and scanning electron microscopy, and their porosity and compressive strength were also evaluated. In addition, the viability of rabbit ADSCs incubated with various concentrations of the β-TCP extraction fluid was analyzed. The rate of attachment and the morphology of biotinylated ADSCs (Bio-ADSCs) on avidin-coated β-TCP (Avi-β-TCP), and untreated ADSCs on β-TCP, were compared. Furthermore, in vivo bone-forming abilities were determined following the implantation of group 1 (Bio-ADSCs/Avi-β-TCP) and group 2 (Bio-ADSCs/Avi-β-TCP/PRP) constructs using computed tomography, and histological osteocalcin (OCN) and alkaline phosphatase (ALP) expression analyses in a rabbit model of mandibulofacial defects. The β-TCP scaffold exhibited a high porosity (71.26±0.28%), suitable pore size, and good mechanical strength (7.93±0.06 MPa). Following incubation with β-TCP for 72 h, 100% of viable ADSCs remained. The avidin-biotin binding system significantly increased the initial attachment rate of Bio-ADSCs to Avi-β-TCP in the first hour (P<0.01). Following the addition of PRP, group 2 exhibited a bony-union and mandibular body shape, newly formed bone and increased expression levels of OCN and ALP in the mandibulofacial defect area, as compared with group 1 (P<0.05). The results of the present study suggested that the novel Bio-ADSCs/Avi-β-TCP/PRP composite may have potential application in bone repair and bone tissue engineering.

Fabrication and characterization of porous β-tricalcium phosphate scaffolds coated with alginate

All porous materials have a common limitation which is lack of strength due to the porosity. In this study, two different methods have been used to produce porous β-tricalcium phosphate (β-TCP) scaffolds: liquid-nitrogen freeze casting and a combination of the direct-foaming and sacrificial-template methods. Among these two methods, porous β-TCP scaffolds with acceptable pore size and compressive strength and defined pore-channel interconnectivity were successfully fabricated by the combined direct-foaming and sacrificial-template method. The average pore size of the scaffolds was in the range of 100–150µm and the porosity was around 70%. Coating with 4wt% alginate on porous β-TCP scaffolds led to higher compressive strength and low porosity. In order to make a chemical link between the β-TCP scaffolds and the alginate coating, silane coupling agent was used. Treated β-TCP scaffold showed improvements in compressive strength of up to 38% compared to the pure β-TCP scaffold and 11% compared to coated β-TCP scaffold.