Imaging of poly(α-hydroxy-ester) scaffolds with X-ray phase-contrast microcomputed tomography.

Porous scaffolds based on poly(α-hydroxy-esters) are under investigation in many tissue engineering applications. A biological response to these materials is driven, in part, by their three-dimensional (3D) structure. The ability to evaluate quantitatively the material structure in tissue-engineering applications is important for the continued development of these polymer-based approaches. X-ray imaging techniques based on phase contrast (PC) have shown a tremendous promise for a number of biomedical applications owing to their ability to provide a contrast based on alternative X-ray properties (refraction and scatter) in addition to X-ray absorption. In this research, poly(α-hydroxy-ester) scaffolds were synthesized and imaged by X-ray PC microcomputed tomography. The 3D images depicting the X-ray attenuation and phase-shifting properties were reconstructed from the measurement data. The scaffold structure could be imaged by X-ray PC in both cell culture conditions and within the tissue. The 3D images allowed for quantification of scaffold properties and automatic segmentation of scaffolds from the surrounding hard and soft tissues. These results provide evidence of the significant potential of techniques based on X-ray PC for imaging polymer scaffolds.

[1]  Jun Li,et al.  A computed tomography implementation of multiple-image radiography. , 2006, Medical physics.

[2]  Yubo Fan,et al.  Formation of porous PLGA scaffolds by a combining method of thermally induced phase separation and porogen leaching , 2008 .

[3]  Regina Luttge,et al.  Cryo DualBeam Focused Ion Beam-Scanning Electron Microscopy to Evaluate the Interface Between Cells and Nanopatterned Scaffolds. , 2011, Tissue engineering. Part C, Methods.

[4]  Jennifer Southgate,et al.  The relationship between the mechanical properties and cell behaviour on PLGA and PCL scaffolds for bladder tissue engineering. , 2009, Biomaterials.

[5]  S. Wilkins,et al.  X-ray phase-contrast microscopy and microtomography. , 2003, Optics express.

[6]  Dean Chapman,et al.  X-ray diffraction enhanced imaging as a novel method to visualize low-density scaffolds in soft tissue engineering. , 2011, Tissue engineering. Part C, Methods.

[7]  Linbo Wu,et al.  In vitro degradation of three-dimensional porous poly(D,L-lactide-co-glycolide) scaffolds for tissue engineering. , 2004, Biomaterials.

[8]  Byung-Soo Kim,et al.  Enhancement of ectopic bone formation by bone morphogenetic protein-2 released from a heparin-conjugated poly(L-lactic-co-glycolic acid) scaffold. , 2007, Biomaterials.

[9]  Dean Chapman,et al.  The design and application of an in-laboratory diffraction-enhanced x-ray imaging instrument. , 2009, The Review of scientific instruments.

[10]  Ari Rosling,et al.  In vitro degradation of porous poly(dl-lactide-co-glycolide) (PLGA)/bioactive glass composite foams with a polar structure , 2007 .

[11]  M. Anastasio,et al.  Propagation based differential phase contrast imaging and tomography of murine tissue with a laser plasma x-ray source , 2007 .

[12]  Antonios G Mikos,et al.  Uncultured marrow mononuclear cells delivered within fibrin glue hydrogels to porous scaffolds enhance bone regeneration within critical-sized rat cranial defects. , 2010, Tissue engineering. Part A.

[13]  R Langer,et al.  In vitro and in vivo degradation of porous poly(DL-lactic-co-glycolic acid) foams. , 2000, Biomaterials.

[14]  C. Patrick,et al.  Tissue engineering applied to reconstructive surgery , 2000, IEEE Engineering in Medicine and Biology Magazine.

[15]  Geraldine Mitchell,et al.  The influence of architecture on degradation and tissue ingrowth into three-dimensional poly(lactic-co-glycolic acid) scaffolds in vitro and in vivo. , 2006, Biomaterials.

[16]  Yuko Fujihara,et al.  The optimization of porous polymeric scaffolds for chondrocyte/atelocollagen based tissue-engineered cartilage. , 2010, Biomaterials.

[17]  E. Lavik,et al.  Fabrication of degradable polymer scaffolds to direct the integration and differentiation of retinal progenitors. , 2005, Biomaterials.

[18]  Antonios G Mikos,et al.  Dose effect of dual delivery of vascular endothelial growth factor and bone morphogenetic protein-2 on bone regeneration in a rat critical-size defect model. , 2009, Tissue engineering. Part A.

[19]  J. Loo,et al.  Degradation of poly(lactide-co-glycolide) (PLGA) and poly(L-lactide) (PLLA) by electron beam radiation. , 2005, Biomaterials.

[20]  Mark A Anastasio,et al.  X-ray imaging of poly(ethylene glycol) hydrogels without contrast agents. , 2010, Tissue engineering. Part C, Methods.

[21]  Cheng-Ying Chou,et al.  An extended diffraction-enhanced imaging method for implementing multiple-image radiography , 2007, Physics in medicine and biology.

[22]  Chad Johnson,et al.  The effect of scaffold degradation rate on three-dimensional cell growth and angiogenesis. , 2004, Biomaterials.

[23]  B. Conti,et al.  Effect of porogen on the physico-chemical properties and degradation performance of PLGA scaffolds , 2010 .

[24]  Linbo Wu,et al.  A "room-temperature" injection molding/particulate leaching approach for fabrication of biodegradable three-dimensional porous scaffolds. , 2006, Biomaterials.

[25]  Grace J. Lim,et al.  In vitro evaluation of a poly(lactide-co-glycolide)-collagen composite scaffold for bone regeneration. , 2006, Biomaterials.

[26]  E. Pisano,et al.  Diffraction enhanced x-ray imaging. , 1997, Physics in medicine and biology.

[27]  Heungsoo Shin,et al.  Matrices and scaffolds for delivery of bioactive molecules in bone and cartilage tissue engineering. , 2007, Advanced drug delivery reviews.

[28]  N. Galatsanos,et al.  Multiple-image radiography. , 2003, Physics in medicine and biology.

[29]  P. Cloetens,et al.  Holotomography: Quantitative phase tomography with micrometer resolution using hard synchrotron radiation x rays , 1999 .

[30]  Z. Xiong,et al.  Poly(l,l-lactide-co-glycolide)/tricalcium phosphate composite scaffold and its various changes during degradation in vitro , 2006 .

[31]  Mark A Anastasio,et al.  Potential for imaging engineered tissues with X-ray phase contrast. , 2011, Tissue engineering. Part B, Reviews.

[32]  Wei Zhang,et al.  Synaptic transmission of neural stem cells seeded in 3-dimensional PLGA scaffolds. , 2009, Biomaterials.

[33]  R. Lewis,et al.  Medical phase contrast x-ray imaging: current status and future prospects. , 2004, Physics in medicine and biology.

[34]  C. Ooi,et al.  Influence of electron-beam radiation on the hydrolytic degradation behaviour of poly(lactide-co-glycolide) (PLGA). , 2005, Biomaterials.