A comparison of micro CT with other techniques used in the characterization of scaffolds.

The structure and architecture of scaffolds are crucial factors in scaffold-based tissue engineering as they affect the functionality of the tissue engineered constructs and the eventual application in health care. Therefore, effective scaffold assessment techniques are required right at the initial stages of research and development so as to select or design scaffolds with suitable properties. Various techniques have been developed in evaluating these important features and the outcome of the assessment is the eventual improvement on the subsequent design of the scaffold. An effective evaluation approach should be fast, accurate and non-destructive, while providing a comprehensive overview of the various morphological and architectural characteristics. Current assessment techniques would include theoretical calculation, scanning electron microscopy (SEM), mercury and flow porosimetry, gas pycnometry, gas adsorption and micro computed tomography (CT). Micro CT is a more recent method of examining the characteristics of scaffolds and this review aims to highlight this current approach while comparing it with other techniques.

[1]  J. A. Cooper,et al.  Tissue engineering: orthopedic applications. , 1999, Annual review of biomedical engineering.

[2]  P. Rüegsegger,et al.  A microtomographic system for the nondestructive evaluation of bone architecture , 2006, Calcified Tissue International.

[3]  Carlalberta Verna,et al.  Healing patterns in calvarial bone defects following guided bone regeneration in rats. A micro-CT scan analysis. , 2002, Journal of clinical periodontology.

[4]  P. Ma,et al.  Synthetic nano-scale fibrous extracellular matrix. , 1999, Journal of biomedical materials research.

[5]  T. Lim,et al.  Induction of Ectopic Bone Formation by Using Human Periosteal Cells in Combination with a Novel Scaffold Technology , 2002, Cell transplantation.

[6]  S. Hollister,et al.  Optimal design and fabrication of scaffolds to mimic tissue properties and satisfy biological constraints. , 2002, Biomaterials.

[7]  Robert E Guldberg,et al.  Microarchitectural and mechanical characterization of oriented porous polymer scaffolds. , 2003, Biomaterials.

[8]  Miqin Zhang,et al.  Preparation of porous hydroxyapatite scaffolds by combination of the gel-casting and polymer sponge methods. , 2003, Biomaterials.

[9]  D J Mooney,et al.  Development of biocompatible synthetic extracellular matrices for tissue engineering. , 1998, Trends in biotechnology.

[10]  Gordana Vunjak-Novakovic,et al.  Bone Tissue Engineering Using Human Mesenchymal Stem Cells: Effects of Scaffold Material and Medium Flow , 2004, Annals of Biomedical Engineering.

[11]  J. Vacanti,et al.  A biodegradable nanofiber scaffold by electrospinning and its potential for bone tissue engineering. , 2003, Biomaterials.

[12]  Joo L. Ong,et al.  Diffusion in Musculoskeletal Tissue Engineering Scaffolds: Design Issues Related to Porosity, Permeability, Architecture, and Nutrient Mixing , 2004, Annals of Biomedical Engineering.

[13]  R. Landers,et al.  Rapid prototyping of scaffolds derived from thermoreversible hydrogels and tailored for applications in tissue engineering. , 2002, Biomaterials.

[14]  J. Tanaka,et al.  Preparation of porous composite implant materials by in situ polymerization of porous apatite containing epsilon-caprolactone or methyl methacrylate. , 2001, Biomaterials.

[15]  Adrian E. Scheidegger,et al.  The physics of flow through porous media , 1957 .

[16]  M Kellomäki,et al.  Bioabsorbable scaffolds for guided bone regeneration and generation. , 2000, Biomaterials.

[17]  W. R. Taylor,et al.  Quantitative microcomputed tomography analysis of collateral vessel development after ischemic injury. , 2004, American journal of physiology. Heart and circulatory physiology.

[18]  A.C.W. Lau,et al.  Precision extruding deposition and characterization of cellular poly‐ε‐caprolactone tissue scaffolds , 2004 .

[19]  D Chappard,et al.  Synchrotron X-ray microtomography (on a micron scale) provides three-dimensional imaging representation of bone ingrowth in calcium phosphate biomaterials. , 2003, Biomaterials.

[20]  Irving Langmuir,et al.  VAPOR PRESSURES, EVAPORATION, CONDENSATION AND ADSORPTION , 1932 .

[21]  P Rüegsegger,et al.  Non-invasive bone biopsy: a new method to analyse and display the three-dimensional structure of trabecular bone. , 1994, Physics in medicine and biology.

[22]  David G Simpson,et al.  Electrospinning collagen and elastin: preliminary vascular tissue engineering. , 2004, Frontiers in bioscience : a journal and virtual library.

[23]  E L Ritman,et al.  Microcomputed tomography of kidneys following chronic bile duct ligation. , 2000, Kidney international.

[24]  Erik L Ritman,et al.  The use of microcomputed tomography to study microvasculature in small rodents. , 2002, American journal of physiology. Regulatory, integrative and comparative physiology.

[25]  Han Tong Loh,et al.  Fabrication of 3D chitosan–hydroxyapatite scaffolds using a robotic dispensing system , 2002 .

[26]  I. Langmuir THE ADSORPTION OF GASES ON PLANE SURFACES OF GLASS, MICA AND PLATINUM. , 1918 .

[27]  Ulrich Bonse,et al.  X-ray computed microtomography (μCT) using synchrotron radiation (SR) , 1996 .

[28]  P. Ma,et al.  Microtubular architecture of biodegradable polymer scaffolds. , 2001, Journal of biomedical materials research.

[29]  S M Jorgensen,et al.  Three-dimensional imaging of vasculature and parenchyma in intact rodent organs with X-ray micro-CT. , 1998, The American journal of physiology.

[30]  I. Zein,et al.  Fused deposition modeling of novel scaffold architectures for tissue engineering applications. , 2002, Biomaterials.

[31]  Robert Langer,et al.  Biodegradable Polymer Scaffolds for Tissue Engineering , 1994, Bio/Technology.

[32]  C. V. van Blitterswijk,et al.  Design of porous scaffolds for cartilage tissue engineering using a three-dimensional fiber-deposition technique. , 2004, Biomaterials.

[33]  C. M. Agrawal,et al.  Effects of fluid flow on the in vitro degradation kinetics of biodegradable scaffolds for tissue engineering. , 2000, Biomaterials.

[34]  S. Goldstein,et al.  The direct examination of three‐dimensional bone architecture in vitro by computed tomography , 1989, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[35]  P. Ma,et al.  Poly(alpha-hydroxyl acids)/hydroxyapatite porous composites for bone-tissue engineering. I. Preparation and morphology. , 1999, Journal of biomedical materials research.

[36]  Hojoong Kim,et al.  Effect of different particles on cell proliferation in polymer scaffolds using a solvent-casting and particulate leaching technique. , 2001 .

[37]  M J Yaszemski,et al.  Bone formation by three-dimensional stromal osteoblast culture in biodegradable polymer scaffolds. , 1997, Journal of biomedical materials research.

[38]  Scott J Hollister,et al.  Mechanical and in vivo performance of hydroxyapatite implants with controlled architectures. , 2002, Biomaterials.

[39]  Peter X. Ma,et al.  Scaffolds for tissue fabrication , 2004 .

[40]  I Naert,et al.  Individualised, micro CT-based finite element modelling as a tool for biomechanical analysis related to tissue engineering of bone. , 2004, Biomaterials.

[41]  C. M. Agrawal,et al.  The use of the vibrating particle technique to fabricate highly porous and permeable biodegradable scaffolds , 2000 .

[42]  T. Lim,et al.  Repair of calvarial defects with customized tissue-engineered bone grafts I. Evaluation of osteogenesis in a three-dimensional culture system. , 2003, Tissue engineering.

[43]  Paul A. Webb,et al.  Volume and Density Determinations for Particle Technologists , 2001 .

[44]  D. Mooney,et al.  Engineered bone development from a pre-osteoblast cell line on three-dimensional scaffolds. , 2000, Tissue engineering.

[45]  L. Murr,et al.  Effect of stress amplitude and stress duration on twinning and phase transformations in shock-loaded and cold-rolled 304 stainless steel , 1975 .

[46]  R Langer,et al.  Stabilized polyglycolic acid fibre-based tubes for tissue engineering. , 1996, Biomaterials.

[47]  E. Teller,et al.  ADSORPTION OF GASES IN MULTIMOLECULAR LAYERS , 1938 .

[48]  B Derby,et al.  Novel collagen scaffolds with predefined internal morphology made by solid freeform fabrication. , 2003, Biomaterials.