Papers by Keyword: Scaffold

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Authors: Salina Sabudin, Sudirman Sahid, Nor Shahida Kader Bashah, Shirin Ibrahim, Zul Hazmi Hussin, Muhamad Anas Marzuke
Abstract: In this study, the effects of macroporous calcium phosphate (MCP) scaffold on bioactivity as an in-vitro model has been investigated. MCP scaffold was prepared using foam replication technique by combination of ceramic and polyurethane (PU). MCP was examined by scanning electron microscope (SEM) and X-ray diffractometer (XRD) to confirm its microstructure and phase composition respectively. Bioactivity in simulated body fluid (SBF) was characterized by apatite mineralisation on MCP scaffold surface, pH, calcium (Ca2+) and phosphate (PO43-) ion dissolution and compressive strength using universal testing machine (UTM). Experimental results showed the formation of apatite around the MCP scaffold after 30 days in SBF. pH value was gradually decreased up to 7 days and constant until 30 days. Dissolution of Ca2+ and PO43- ion in SBF due to the occurrence of MCP degradation, hence the compressive strength are gradually decreased gradually in line with immersion period. This material may be promising for biomedical application.
Authors: Naznin Sultana, Min Wang
Abstract: Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) was used to make composite scaffolds for bone tissue engineering in our previous studies. To control the degradation rate and process of composite scaffolds, PHBV was blended with poly(L-lactic acid) (PLLA), which has a much higher degradation rate than PHBV, and PHBV/PLLA blends were used as polymer matrices for composite scaffolds. Composite scaffolds based on these blends and containing nano-sized hydroxyapatite (nHA) were fabricated using an emulsion freezing / freeze-drying technique. Non-porous films of PHBV/PLLA blends were prepared using the solvent casting method. In vitro degradation tests of non-porous PHBV/PLLA blends and porous composite scaffolds were conducted by immersing samples in phosphate buffered saline (PBS) for various periods of time. It was found that the composition of polymer blends affected water uptake of films and scaffolds. For PHBV/PLLA-based scaffolds, the incorporated nHA particles also significantly increased water uptake within the initial immersion time. Both PHBV/PLLA blends and composite scaffolds underwent rapid weight losses within the first few weeks. The degradation of composite scaffolds arose from the dissolution of nHA particles and degradation of the PLLA component of polymer blends. Composite scaffolds exhibited enhanced adsorption of bovine serum albumin (BSA), a model protein, in the current study.
Authors: Y. Kinoshita, S.M. Best, Mamoru Aizawa
Abstract: The aim of the present investigation was to examine Si release from the silicon-containing apatite fiber scaffold (Si-AFS) and the biocompatibility of the Si-AFS. We have successfully synthesized silicon-containing apatite fibers (Si-AF) by a homogenous precipitation method. Three-dimensional Si-AFS were fabricated using these Si-AFs. The concentrations of Si in the starting solution were 0 (AF) and 0.8 (0.8Si-AF) mass%. The 0.8Si-AFS1000 were fabricated by firing Si-AF slurry compacts (carbon/Si-AF [w/ ratio: 10/1) at 1300 °C for 5 h. Solubility experiments were carried out in 0.05 mol/dm3 Tris-HCl buffer solutions at pH 7.30 using 0.8Si-AFS1000 (porosity: ~98%), together with Si-free AFS1000 (~98%) for 21 days. The Ca2+, PO43- and SiO44- concentrations in the solution were determined by inductively-coupled plasma atomic emission spectrometry (ICP-AES). The biocompatibility of the Si-AFS was examined in vitro using osteoblastic cell, MC3T3-E1 for 21 days. The results of the ICP-AES analysis indicated that the amount of SiO44- ions released from 0.8Si-AFS1000 rapidly increased at 1 day, and then the released SiO44- ions remained constant over a period for 21 days. The cells seeded on/in the 0.8Si-AFS1000 well-proliferated as compared to those on/in the AFS1000. Consequently, we can conclude that the 0.8Si-AFS offers as a potential novel scaffold material, creating a three-dimensional cell culture environment.
Authors: Juan Vivanco, Bryce Smith, Alex Blake, Justin Williams, Kevin Turner, Heidi Ploeg
Abstract: It is known that conventional scaffold manufacturing techniques have low reproducibility and control of the micro-architecture features. Although there have been advances in bone tissue engineering fabrication, there is no consensus on the optimized parameter designs or clear understanding of the microfluidic interactions required for tissue regeneration. In this work, we introduce a new inexpensive fabrication method of producing pore designs of 3D-elastomeric structures with high controlled geometry of orthogonal arrays. The present fabrication method utilizes a permanent and reusable micro-machined mould along with a micro-casted process to efficiently fabricate diverse 3D feature directly. This fabrication method, without multiple process steps, would be suitable to support experiments of controlled environment for flow effects in 3D bone scaffolds.
Authors: Ning Zhu, Xiong Biao Chen, Dean Chapman
Abstract: In nerve tissue engineering, scaffolds act as carriers for cells and biochemical factors and as constructs providing appropriate mechanical conditions. During nerve regeneration, new tissue grows into the scaffolds, which degrade gradually. To optimize this process, researchers must study and analyze various morphological and structural features of the scaffolds, the ingrowth of nerve tissue, and scaffold degradation. Therefore, visualization of the scaffolds as well as the generated nerve tissue is essential, yet challenging Visualization techniques currently used in nerve tissue engineering include electron microscopy, confocal laser scanning microscopy (CLSM), and micro-computed tomography (micro-CT or μCT). Synchrotron-based micro-CT (SRμCT) is an emerging and promising technique, drawing considerable recent attention. Here, we review typical applications of these visualization techniques in nerve tissue engineering. The promise, feasibility, and challenges of SRμCT as a visualization technique applied to nerve tissue engineering are also discussed.
Authors: D.H. Yoon, Eui Kyun Park, Suk Young Kim, J.M. Lee, H.W. Shin, Hong In Shin
Abstract: To develop a suitable scaffold for tissue-engineered bone regeneration, we compared the efficiency of tissue-engineered bone regeneration according to the porous structure of calcium metaphosphate (CMP) ceramic scaffolds. Each scaffold was prepared with a sponge method and a foam-gel method, respectively. Both scaffolds, having either interconnected trabecular pores formed by the sponge method or fully interconnected globular pores formed by the foam-based technology, were not cytotoxic and elicited neither an immune nor an inflammatory response regardless of geometry and fabrication method. The fully interconnected globular porous scaffold showed more favorable compression strength and facilitated osteogenic repair by favoring cellular attachment and osteogenic differentiation with good osteoconductivity compared to the interconnected trabecular pore structured scaffold. These results suggest that the fully interconnected globular porous structure would be more suitable for both a bone substitute and scaffold for bioactive material-based or cell-based tissue bone regeneration.
Authors: Giulio D. Guerra, Caterina Cristallini, Elisabetta Rosellini, Niccoletta Barbani
Abstract: Composites between hydroxyapatite (HA) and collagen (Col) may be used to make bioresorbable scaffolds for bone reconstruction. A suspension of micro-particles (average diameter ≅ 30 µm) of HA annealed at 1100°C in Col solution (80:20 HA to Col weight ratio) was manufactured in films by casting, and then some films were cross-linked by glutaraldehyde vapours. Cross-linked sponges were obtained by treating the suspension with transglutaminase, and by lyophilizing the so obtained gel. Characterization by scanning electron microscopy, water sorption test, Col release in water, thermogravimetric analysis and differential scanning calorimetry shows that the cross-linking enhances the stability of the composite. Conversely, neither the interactions between HA and Col, detected by spotlight FT-IR, nor the degradation by collagenase, which is a requirement for the bioresorbibility, are affected by the cross-linking.
Authors: Zheng Guo, Jin Jing Chen, Pei Hua Zhang
Abstract: A tubal knitted scaffold fabricated from poly(lactic acid) (PLA) yarns was given in this work. The performance of the scaffold during degradation in vitro and the morphology of the scaffold with cells (monkey dermal fibroblasts) were examined. The scaffold fabricated from poly(glycolic acid) (PGA) yarns was manufactured as the control. Results showed that the PLA scaffold could keep much more tensile strength during degradation in vitro, compared with the PGA scaffold. However, cell attachment and proliferation on the PGA scaffold were better than on the PLA scaffold.
Authors: S. Singare, Shou Yan Zhong, Zhen Zhong Sun
Abstract: In this paper, the authors describe a rapid prototyping method to produce vascularized tissue such as liver scaffold for tissue engineering applications. A scaffold with an interconnected channel was designed using a CAD environment. The data were transferred to a Polyjet 3D Printing machine (Eden 250, Object, Israel) to generate the models. Based on the 3D Printing model, a PDMS (polydimethyl-silicone) mould was created which can be used to cast the biodegradable material. The advantages and limitations of Rapid Prototyping (RP) techniques as well as the future direction of RP development in tissue engineering scaffold fabrication were reviewed.
Authors: Devis Bellucci, Valeria Cannillo, Andrea Cattini, Antonella Sola
Abstract: The design of bioceramic scaffolds, i.e. artificial structures employed as temporary templates for cell proliferation, is a crucial issue in bone tissue reconstruction and regeneration. An ideal scaffold should be highly porous and bioactive. Additionally, a resistant and permeable surface is required in order to have manageable samples. The production of scaffolds by means of the widely used replication method can lead to samples with weak and brittle surfaces and poor mechanical properties, therefore alternative preparation procedures are necessary. In this work a new protocol to realize bioceramic scaffolds is presented. The obtained samples have an original structure, characterized by an external resistant surface together with a highly porous internal network. The external surface, which behaves as a load-bearing structure for the entire scaffold, guarantees high permeability and manageability. Here the proposed protocol is briefly discussed, together with an overview on the structure of the realized samples. Finally, some preliminary data regarding the scaffolds in-vitro bioactivity are reported.
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