Papers by Keyword: Porous Scaffold

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Authors: Yi Wang, Hong Song Fan, Yu Mei Xiao, Zhong Wei Gu, Xing Dong Zhang
Abstract: A new way to prepare polymer/hydroxyapatite(HA) composite scaffolds with 3-D interconnected macro and micro pores at room temperature was established, basically based on solvent-casting and particle-leaching together with foaming technique. With this method, Polylactide (PLA) / HA composites of porous architecture with macro pores (50~300)m, average 200)m) and micro pores (~10)m) on the skeleton were obtained. The bending strength and the compressive strength of the composite scaffold were reached to 11.5 MPa and 7MPa respectively with the porosity of approximate to 90%. The study supplied a new short time, low energyexpending method to prepare polymer/ceramic composite with high porosity and interconnected porous structure at room temperature.
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Authors: Ichiro Torigoe, Shinichi Sotome, A. Tsuchiya, Kenichi Shinomiya
Abstract: In the field of bone tissue engineering using cells combined with scaffolds, it is important to efficiently load cells into porous scaffolds. We devised a novel cell-loading method into porous beta-tricalcium phosphate (β-TCP) blocks. In this study, we compared this method with two conventional cell-loading methods in terms of cell-loading efficiency and in vivo bone formation capability. Bone marrow stromal cells (BMSCs) were obtained from the femurs of Fisher rats. After about 10 days of culture, BMSCs were harvested and suspended in the plasma of the Fisher rats at a concentration of 2×106 cells/ml. This cell suspension was loaded into porous β-TCP cubes (5×5×5mm) by using three loading methods: a soaking method, a post low-pressure method and a pre low-pressure method (the novel method). These β-TCP cubes were cross-sectioned and stained with toluidine blue and cell-counted. Cell-loading efficiency was significantly higher when using the novel methods. For the study of in vivo bone formation capability, nearly confluent BMSCs were exposed in an osteogenic medium supplemented with 10-7 M dexamethasone, 50µg/ml L-ascorbic acid phosphate and 10mM β-glycerophosphate for 4 days. These osteogenic cells were harvested and suspended in the plasma of the Fisher rats at a concentration of 2×106 cells/ml. This cell suspension was loaded into porous β-TCP cubes (5×5×5mm) by using the three cell-loading methods. Immediately, these β-TCP cubes were implanted at subcutaneous sites in the backs of 7-week-old male Fisher rats and harvested at postoperative 3 and 6 weeks. After cross-sectioning, these sections were stained with hematoxylin and eosin, and the new bone formation area was quantified. Consistent with cell-loading efficiency, in vivo bone formation capability was significantly higher in the novel method at postoperative 6 weeks. We showed the usefulness of the novel cell-loading method in bone tissue engineering.
993
Authors: Tudor Petreus, Carmen Elena Cotrutz, Paul Dan Sirbu, Lucian Barbu Tudoran, Doinita Olinici, Laurentiu Badescu, Oana Petreus, Bogdan Alexandru Stoica
Abstract: Introduction: Many polymer supports for cell seeding formulations based on chitosan are usually prepared by chemical cross-linking with glutaraldehyde, urea formaldehyde, epichlorohydrine, even if the chemical cross-linking agents possibly induce toxicity and other undesirable effects. Experimental: Derivatized poly (vinyl alcohol) was blended and foamed with chitosan to produce porous scaffolds with improved elastic and mechanical properties and also acceptable water solubility. Derivatized PVA (in example phosphorylated PVA) (P-PVA) also exhibited improved hydrophilicity, anionic properties and molecular electrostatic repulsion, and retained the bulk morphological features, compatible property, and solution stability. Results: Porous scaffolds formed by derivatized PVA crosslinked with chitosan proved a good cytocompatibility for human fibroblasts. Viability and apoptosis assays were performed indicating that this porous scaffold allow cell multiplication and scarce apoptotic induction. Conclusion: Tested porous scaffolds may represent an interesting support for three dimensional cell cultures destined to simulate tumor or normal tissue microenvironment.
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Authors: A.L. Oliveira, Manuela E. Gomes, P.B. Malafaya, Rui L. Reis
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Authors: Luis M. Rodríguez-Lorenzo, Kārlis A. Gross
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Authors: Elena Landi, Selanna Martorana, Anna Tampieri, Stefano Guicciardi, Cesare Melandri
Abstract: A novel foaming method of design and synthesis of porous Carbonate-apatite/gelatine composite scaffolds is proposed for biomedical applications. Two different suspensions, one constituted by a biomimetic inorganic phase (B-CHA) and the second by a protein (gelatine), are mixed, foamed, lyophilized and, in some cases, cross-linked to stabilize the organic phase. Chemical, morphological and mechanical features of the scaffolds are evaluated. The samples have chemical composition, compressive and flexural strengths and Young modulus values in the range of trabecular bone ones. A high interconnected porosity (about 90%) showing a micro- to macrosize distribution, that is needed for osteoconduction and vascolarization processes in vivo, is also detected.
547
Authors: Kui Hua Zhan, Lun Bai, Guo Ping Guan, Hong Qin Dai
Abstract: Based on our experimental data of neovascularization of porous silk fibroin films (PSFF),in this study we characterized the formation of new blood vessel system at different periods. Firstly, we regarded a wound as two sections, namely, an interface layer and a material layer. Angiogenesis of the interface layer underwent three periods that were rehabilitation period of primary vascular plexus (postoperative 1st day-3rd day), rapid growth period (postoperative 3rd day - 7th day) and remodeling period (after the 7th day). In addition, angiogenesis of the material layer underwent initiation period (postoperative 5th day - 7th day), rapid growth period (postoperative 7th day - 13th day) and remodeling period (after the 13th day). According to the analysis results for angiogenesis, we realized that the efficacy of PSFF on repairing wound was reflected in coordination between infiltration of cells in the pores and angiogenesis, and in timeliness of the newly formed blood vessels’ extention from the interface layer to the material layer.
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Authors: Conor T. Buckley, K.U. O’Kelly
Abstract: Tissue-engineering scaffold-based strategies have suffered from limited cell depth viability when cultured in vitro, with viable cells existing within the outer 250-500μm from the fluid-scaffold interface. This is primarily believed to be due to the lack of nutrient delivery into and waste removal from the inner regions of the scaffold construct. Other issues associated with porous scaffolds involve poor seeding efficiencies and limited cell penetration resulting in heterogeneous cellular distributions. This work focuses on the development a novel hydroxyapatite multi-domain porous scaffold architecture (i.e. a scaffold providing a discrete domain for cell occupancy and a separate domain for nutrient delivery) with the specific objectives of embodying in one scaffold the structures required to optimise cell seeding, cell proliferation and migration and potentially to facilitate vascularisation once implanted in vivo. This paper presents the development of the multidomain architecture and preliminary results on cell viability which show a significant improvement in cell viability in the scaffold interiors.
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