|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | Discovery of two novel EWSR1/ATF1 transcripts in four chimerical transcripts-expressing clear cell sarcoma and their quantitative evaluation. Exp Mol Pathol. 2010 Dec 23; Authors: Jakubauskas A, Valceckiene V, Andrekute K, Seinin D, Kanopka A, Griskevicius L The most common recurrent translocation in clear cell sarcoma t(12;22)(q13;q12) results in an EWSR1/ATF1 chimeric gene. We present a molecular analysis of tumor overgrowing right proximal tibia with bone destruction metastatic to two groin lymph nodes. Fluorescent in situ hybridization analysis performed on paraffin-embedded tissue sections of primary tumor sample indicated one rearranged locus of EWSR1 gene and one additional red signal. Reverse transcription - polymerase chain reaction analysis revealed the presence of four different EWSR1/ATF1 chimerical transcripts in the tumor sample as well as in both metastatic lymph nodes. Two previously described transcripts EWSR1exon7/ATF1exon5 and EWSR1exon8/ATF1exon4, and two novel transcripts EWSR1exon7/ATF1exon4 and EWSR1exon9/ATF1exon4 were identified. Both novel transcripts were out-of-frame fusions and, therefore, most likely had limited biological impact in oncogenesis of clear cell sarcoma. Quantitative evaluation demonstrated unequal distribution of these transcripts, with EWSR1exon8/ATF1exon4 type being overexpressed. PMID: 21185830 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Role of material-driven fibronectin fibrillogenesis in cell differentiation. Biomaterials. 2010 Dec 23; Authors: Salmerón-Sánchez M, Rico P, Moratal D, Lee TT, Schwarzbauer JE, García AJ Fibronectin (FN) is a ubiquitous extracellular matrix protein (ECM) protein that is organized into fibrillar networks by cells through an integrin-mediated process that involves contractile forces. This assembly allows for the unfolding of the FN molecule, exposing cryptic domains that are not available in the native globular FN structure and activating intracellular signalling complexes. However, organization of FN into a physiological fibrillar network upon adsorption on a material surface has not been observed. Here we demonstrate cell-free, material-induced FN fibrillogenesis into a biological matrix with enhanced cellular activities. We found that simple FN adsorption onto poly(ethyl acrylate) surfaces, but not control polymers, triggered FN organization into a fibrillar network via interactions in the amino-terminal 70 kDa fragment, which is involved in the formation of cell-mediated FN fibrils. Moreover, the material-driven FN fibrils exhibited enhanced biological activities in terms of myogenic differentiation compared to individual FN molecules and even type I collagen. Our results demonstrate that molecular assembly of FN can take place at the material interface, giving rise to a physiological protein network similar to fibrillar matrices assembled by cells. This research identifies material surfaces that trigger the organization of extracellular matrix proteins into biological active fibrils and establishes a new paradigm to engineer ECM-mimetic biomaterials. PMID: 21185593 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Therapeutic benefits in thalassemic mice transplanted with long term cultured bone marrow cells. Exp Hematol. 2010 Dec 21; Authors: Hatada S, Walton W, Hatada T, Wofford A, Fox R, Liu N, Lill MC, Fair JH, Kirby SL, Smithies O OBJECTIVE: Autologous bone marrow (BM) cells with a faulty gene corrected by gene targeting could provide a powerful therapeutic option for patients with genetic blood diseases. Achieving this goal is hindered by the low abundance of therapeutically useful BM cells and the difficulty of maintaining them in tissue culture long enough for completing gene targeting without them differentiating. Our objective was to devise a simple long-term culture system, using unfractioned BM cells, that maintains and expands therapeutically useful cells for ≥4 weeks. MATERIALS AND METHODS: From 2 to 60 million BM cells from wild-type (WT) mice, or from mice carrying a truncated erythropoietin receptor transgene (tEpoR-tg), were plated with or without irradiated fetal-liver derived AFT024 stromal cells in 25 cm(2) culture flasks. Four-week cultured cells were analyzed and transplanted into sublethally irradiated thalassemic mice (1 million cells / mouse). RESULTS: After 4 weeks, the cultures with AFT024 cells had extensive "cobblestone" areas. Optimum expansion of Sca-1 positive cells was 5.5-fold with 20 × 10(6) WT cells/flask and 27-fold with 2 × 10(6) tEpoR-tg cells. More than 85% of thalassemic mice transplanted with either type of cells had almost complete reversal of their thalassemic phenotype for at least 6 months, including blood smear dysmorphology, reticulocytosis, high ferritin plasma levels and hepatic/renal hemosiderosis. CONCLUSION: When plated at high cell densities on irradiated fetal-liver derived stromal cells, BM cells from WT mice maintain their therapeutic potential for 4 weeks in culture, which is sufficient time for correction of a faulty gene by targeting. PMID: 21184801 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regeneration of cartilage and bone by defined subsets of mesenchymal stromal cells - potential and pitfalls. Adv Drug Deliv Rev. 2010 Dec 21; Authors: Aicher WK, Bühring HJ, Hart M, Rolauffs B, Badke A, Klein G Mesenchymal stromal cells, also referred to as mesenchymal stem cells, can be obtained from various tissues. Today the main source for isolation of mesenchymal stromal cells in mammals is the bone marrow. Mesenchymal stromal cells play an important role in tissue formation and organogenesis during embryonic development. Moreover, they provide the cellular and humoral basis for many processes of tissue regeneration and wound healing in infancy, adolescence and adulthood as well. There is increasing evidence that mesenchymal stromal cells from bone marrow and other sources including term placenta or adipose tissue are not a homogenous cell population. Only a restricted number of appropriate stem cells markers have been explored so far. But routine preparations of mesenchymal stromal cells contain phenotypically and functionally distinct subsets of stromal cells. Knowledge on the phenotypical characteristics and the functional consequences of such subsets will not only extend our understanding of stem cell biology, but might allow to develop improved regimen for regenerative medicine and wound healing and novel protocols for tissue engineering as well. In this review we will discuss novel strategies for regenerative medicine by specific selection or separation of subsets of mesenchymal stromal cells in the context of osteogenesis and bone regeneration. Mesenchymal stromal cells, which express the specific cell adhesion molecule CD146, also known as MCAM or MUC18, are prone for bone repair. Other cell surface proteins may allow the selection of chondrogenic, myogenic, adipogenic or other pre-determined subsets of mesenchymal stromal cells for improved regenerative applications as well. PMID: 21184789 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Functional characterization of hematopoietic stem cells in the spleen. Exp Hematol. 2010 Dec 23; Authors: Morita Y, Iseki A, Okamura S, Suzuki S, Nakauchi H, Ema H OBJECTIVE: Hematopoietic stem cells (HSCs) reside in both bone marrow (BM) and spleen in adult mice. However, whether BM and spleen HSCs are functionally similar is not known. Spleen HSCs were compared with BM HSCs by various assays. MATERIALS AND METHODS: Whole BM and spleen cells were quantitatively analyzed by competitive repopulation. Single-cell transplantation was performed with HSCs purified from BM and spleen. A parabiosis model was used to distinguish organ-specific HSCs from circulating HSCs. The cell cycle was analyzed with pyronin Y staining and bromodeoxyuridine uptake. RESULTS: Repopulating and self-renewal potentials were similar on a clonal basis between BM and spleen HSCs whereas the HSC frequency in the spleen was significantly lower than that in the BM. Analysis of parabiotic mice suggested that most HSCs are long-term residents in each organ. Cell cycle analysis revealed that spleen HSCs cycle twice as frequently as do BM HSCs, suggesting that G(0) phase length is longer in BM HSCs than in spleen HSCs. The cycling difference between BM and spleen HSCs was also observed in mice that had been reconstituted with BM or spleen cells, suggesting that HSC quiescence is regulated in an organ-specific manner. CONCLUSIONS: Spleen HSCs and BM HSCs are functionally similar, but their cycling behaviors differ. PMID: 21185906 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regeneration of cartilage and bone by defined subsets of mesenchymal stromal cells - potential and pitfalls. Adv Drug Deliv Rev. 2010 Dec 21; Authors: Aicher WK, Bühring HJ, Hart M, Rolauffs B, Badke A, Klein G Mesenchymal stromal cells, also referred to as mesenchymal stem cells, can be obtained from various tissues. Today the main source for isolation of mesenchymal stromal cells in mammals is the bone marrow. Mesenchymal stromal cells play an important role in tissue formation and organogenesis during embryonic development. Moreover, they provide the cellular and humoral basis for many processes of tissue regeneration and wound healing in infancy, adolescence and adulthood as well. There is increasing evidence that mesenchymal stromal cells from bone marrow and other sources including term placenta or adipose tissue are not a homogenous cell population. Only a restricted number of appropriate stem cells markers have been explored so far. But routine preparations of mesenchymal stromal cells contain phenotypically and functionally distinct subsets of stromal cells. Knowledge on the phenotypical characteristics and the functional consequences of such subsets will not only extend our understanding of stem cell biology, but might allow to develop improved regimen for regenerative medicine and wound healing and novel protocols for tissue engineering as well. In this review we will discuss novel strategies for regenerative medicine by specific selection or separation of subsets of mesenchymal stromal cells in the context of osteogenesis and bone regeneration. Mesenchymal stromal cells, which express the specific cell adhesion molecule CD146, also known as MCAM or MUC18, are prone for bone repair. Other cell surface proteins may allow the selection of chondrogenic, myogenic, adipogenic or other pre-determined subsets of mesenchymal stromal cells for improved regenerative applications as well. PMID: 21184789 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Three-dimensional microfabricated scaffolds with cardiac extracellular matrix-like architecture. Int J Artif Organs. 2010 Dec 26;33(12):885-894 Authors: Rossellini E, Vozzi G, Barbani N, Giusti P, Cristallini C In recent years, research in the field of myocardial tissue engineering has advanced thanks to the development of new biomaterials and a more clear understanding of processes that are at the basis of cardiac tissue growth. However, classical porous scaffolds developed during these years to try to reconstruct and mimic heart function have proven to be inadequate because they are not able to reproduce the typical myocardial environment. One approach to increase functionality of tissue-engineered constructs relies on attempts to mimic the microarchitecture of natural tissues, since it is well known that topology is one of the principal stimuli that cells need to activate their functions. The aim of this work was the realization of three-dimensional microfabricated scaffolds, with cardiac extracellular matrix (ECM)-like architecture. For this purpose, samples of pig myocardium were decellularized, embedded in paraffin wax and analyzed under an optical microscope, in order to evaluate the geometrical features of the cardiac ECM. On the basis of these data, a simplified model of the cardiac ECM microarchitecture was designed. Microfabricated scaffolds were realized with Soft Lithography technique, using a bioartificial blend, based on alginate, gelatin and a novel poly(N-isopropylacrylamide)-based copolymer, which we synthesized. The scaffolds were characterized in terms of topological and mechanical properties. Moreover, cell adhesion, proliferation, and differentiation tests were performed. The microfabricated scaffolds showed they matched the anisotropic mechanical properties of adult human left ventricular myocardium, while at the same time being able to promote myoblast alignment in the absence of external stimuli. PMID: 21186470 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Accelerated angiogenic induction and vascular integration in a novel synthetic scaffolding matrix for tissue replacement. Int J Artif Organs. 2010 Dec 20;33(12):877-884 Authors: Ring A, Goertz O, Al-Benna S, Ottomann C, Langer S, Steinstraesser L, Schmitz I, Tilkorn D Purpose: Reduced or delayed neovascularization is a major obstacle with regard to tissue-engineered constructs. The aim of this study was to evaluate the early microvascular response to a novel degradable e-caprolactone terpolymer matrix. Methods: e-caprolactone terpolymer matrices (Suprathel Plus®; Institute of Textile and Process Engineering, Denkendorf, Germany) were implanted into dorsal skinfold chambers of balb/c mice (n=10). Microcirculatory changes were observed by intravital fluorescence microscopy. Scaffolding matrices from PEGT/PBT copolymer were used as controls (n=10). Results: The formation of de novo vascular networks within both scaffolding matrices was noted throughout the experiment. A vascular ingrowth of perfused microvessels into the matrices up to 600 µm apart from the edge was noted within 10 days of implantation. The earliest signs of neoangiogenesis were visible in e-caprolactone terpolymer matrices on day 1. In both scaffolds the new developed vessels extended centripetally from the border of the matrices towards the center and anastomosed to form a perfused microvascular network. There was significantly earlier onset of vascularization, increased vascularized area and higher vessel density in e-caprolactone terpolymer matrices compared to PEGT/PBT copolymer matrices were observed. Conclusions: The scaffolding matrix from e-caprolactone terpolymer allowed for an earlier and more intense induction of angiogenesis and displayed the tendency to vascularize more rapidly within a shorter period of time after transplantation compared to PEGT/PBT copolymer scaffolds, thus indicating its potential application for tissue engineering purposes. PMID: 21186469 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A model for biodegradation of composite materials made of polyesters and tricalcium phosphates. Biomaterials. 2010 Dec 24; Authors: Pan J, Han X, Niu W, Cameron RE A saturation behaviour has been observed when incorporating tricalcium phosphate (TCP) in various polyesters to control the degradation rate. This paper presents an understanding of this behaviour using a mathematical model. The coupled process of hydrolysis reaction of the ester bonds, acid dissociation of the carboxylic end groups, dissolution of the calcium phosphates and buffering reactions by the dissolved phosphate ions is modelled together using a set of differential equations. Two non-dimensional groups of the material and chemical parameters are indentified which control the degradation rate of the composites. An effectiveness map is established to show the conditions under which incorporating TCP into polyesters is effective, saturated or ineffective. Comparisons are made between the model predictions and existing experimental data in the literature. The map provides a useful tool to guide the design of polyester/TCP composites for tissue engineering and orthopaedic fixation applications. PMID: 21186057 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A comparative study of mesoporous-glass/silk and non-mesoporous-glass/silk scaffolds: physiochemistry and in vivo osteogenesis. Acta Biomater. 2010 Dec 23; Authors: Wu C, Zhang Y, Zhou Y, Fan W, Xiao Y Mesoporous bioactive glass (MBG) is a new class of biomaterials with a well-ordered nano-channel structure, whose in vitro bioactivity is far superior to that of non-mesopore bioactive glass (BG); the material's in vivo osteogenic properties is, however, yet to be assessed. Porous silk scaffolds have been used for bone tissue engineering, but this material's osteoconductivity is far from optimal. The aims of this study were to incorporate MBG into silk scaffolds in order to improve their osteoconductivity, and then to compare the effect of MBG and BG on the in vivo osteogenesis of silk scaffolds. MBG/silk and BG/silk scaffolds with a highly porous structure were prepared by a freeze-drying method. The mechanical strength, in vitro apatite mineralization, silicon (Si) ion release and pH stability of the composite scaffolds were assessed. The scaffolds were implanted into calvarial defects in SCID mice and the degree of in vivo osteogenesis was evaluated by micro-computed tomography (μCT), hematoxylin and eosin (H&E) and immunohistochemistry (type I collagen) analyses. The results showed that MBG/silk scaffolds have better physiochemical properties (mechanical strength, in vitro apatite mineralization, silicon (Si) ion release and pH stability) compared to BG/silk scaffolds. MBG and BG both improved the in vivo osteogenesis of silk scaffolds. μCT and H&E analyses showed that MBG/silk scaffolds induced a slightly higher rate of new bone formation in the defects than did BG/silk scaffolds and immunohistochemical analysis showed greater synthesis of type I collagen in MBG/silk scaffolds compared to BG/silk scaffolds. PMID: 21185954 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Role of material-driven fibronectin fibrillogenesis in cell differentiation. Biomaterials. 2010 Dec 23; Authors: Salmerón-Sánchez M, Rico P, Moratal D, Lee TT, Schwarzbauer JE, García AJ Fibronectin (FN) is a ubiquitous extracellular matrix protein (ECM) protein that is organized into fibrillar networks by cells through an integrin-mediated process that involves contractile forces. This assembly allows for the unfolding of the FN molecule, exposing cryptic domains that are not available in the native globular FN structure and activating intracellular signalling complexes. However, organization of FN into a physiological fibrillar network upon adsorption on a material surface has not been observed. Here we demonstrate cell-free, material-induced FN fibrillogenesis into a biological matrix with enhanced cellular activities. We found that simple FN adsorption onto poly(ethyl acrylate) surfaces, but not control polymers, triggered FN organization into a fibrillar network via interactions in the amino-terminal 70 kDa fragment, which is involved in the formation of cell-mediated FN fibrils. Moreover, the material-driven FN fibrils exhibited enhanced biological activities in terms of myogenic differentiation compared to individual FN molecules and even type I collagen. Our results demonstrate that molecular assembly of FN can take place at the material interface, giving rise to a physiological protein network similar to fibrillar matrices assembled by cells. This research identifies material surfaces that trigger the organization of extracellular matrix proteins into biological active fibrils and establishes a new paradigm to engineer ECM-mimetic biomaterials. PMID: 21185593 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regeneration of cartilage and bone by defined subsets of mesenchymal stromal cells - potential and pitfalls. Adv Drug Deliv Rev. 2010 Dec 21; Authors: Aicher WK, Bühring HJ, Hart M, Rolauffs B, Badke A, Klein G Mesenchymal stromal cells, also referred to as mesenchymal stem cells, can be obtained from various tissues. Today the main source for isolation of mesenchymal stromal cells in mammals is the bone marrow. Mesenchymal stromal cells play an important role in tissue formation and organogenesis during embryonic development. Moreover, they provide the cellular and humoral basis for many processes of tissue regeneration and wound healing in infancy, adolescence and adulthood as well. There is increasing evidence that mesenchymal stromal cells from bone marrow and other sources including term placenta or adipose tissue are not a homogenous cell population. Only a restricted number of appropriate stem cells markers have been explored so far. But routine preparations of mesenchymal stromal cells contain phenotypically and functionally distinct subsets of stromal cells. Knowledge on the phenotypical characteristics and the functional consequences of such subsets will not only extend our understanding of stem cell biology, but might allow to develop improved regimen for regenerative medicine and wound healing and novel protocols for tissue engineering as well. In this review we will discuss novel strategies for regenerative medicine by specific selection or separation of subsets of mesenchymal stromal cells in the context of osteogenesis and bone regeneration. Mesenchymal stromal cells, which express the specific cell adhesion molecule CD146, also known as MCAM or MUC18, are prone for bone repair. Other cell surface proteins may allow the selection of chondrogenic, myogenic, adipogenic or other pre-determined subsets of mesenchymal stromal cells for improved regenerative applications as well. PMID: 21184789 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Hippocampal neurons respond uniquely to topographies of various sizes and shapes. Biofabrication. 2010 Sep;2(3):035005 Authors: Fozdar DY, Lee JY, Schmidt CE, Chen S A number of studies have investigated the behavior of neurons on microfabricated topography for the purpose of developing interfaces for use in neural engineering applications. However, there have been few studies simultaneously exploring the effects of topographies having various feature sizes and shapes on axon growth and polarization in the first 24 h. Accordingly, here we investigated the effects of arrays of lines (ridge grooves) and holes of microscale (approximately 2 microm) and nanoscale (approximately 300 nm) dimensions, patterned in quartz (SiO2), on the (1) adhesion, (2) axon establishment (polarization), (3) axon length, (4) axon alignment and (5) cell morphology of rat embryonic hippocampal neurons, to study the response of the neurons to feature dimension and geometry. Neurons were analyzed using optical and scanning electron microscopy. The topographies were found to have a negligible effect on cell attachment but to cause a marked increase in axon polarization, occurring more frequently on sub-microscale features than on microscale features. Neurons were observed to form longer axons on lines than on holes and smooth surfaces; axons were either aligned parallel or perpendicular to the line features. An analysis of cell morphology indicated that the surface features impacted the morphologies of the soma, axon and growth cone. The results suggest that incorporating microscale and sub-microscale topographies on biomaterial surfaces may enhance the biomaterials' ability to modulate nerve development and regeneration. PMID: 20823503 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Adhesion of fibroblasts on micro- and nanostructured surfaces prepared by chemical vapor deposition and pulsed laser treatment. Biofabrication. 2010 Sep;2(3):035001 Authors: Veith M, Aktas OC, Metzger W, Sossong D, Ullah Wazir H, Grobelsek I, Pütz N, Wennemuth G, Pohlemann T, Oberringer M The development of micro- and nanostructured surfaces which improve the cell-substrate interaction is of great interest in today's implant applications. In this regard, Al/Al2O3 bi-phasic nanowires were synthesized by chemical vapor deposition of the molecular precursor (tBuOAlH2)2. Heat treatment of such bi-phasic nanowires with short laser pulses leads to micro- and nanostructured Al2O3 surfaces. Such surfaces were characterized by scanning electron microscopy (SEM), electron dispersive spectroscopy and x-ray photoelectron spectroscopy. Following the detailed material characterization, the prepared surfaces were tested for their cell compatibility using normal human dermal fibroblasts. While the cells cultivated on Al/Al2O3 bi-phasic nanowires showed an unusual morphology, cells cultivated on nanowires treated with one and two laser pulses exhibited morphologies similar to those observed on the control substrate. The highest cell density was observed on surfaces treated with one laser pulse. The interaction of the cells with the nano- and microstructures was investigated by SEM analysis in detail. Laser treatment of Al/Al2O3 bi-phasic nanowires is a fast and easy method to fabricate nano- and microstructured Al2O3-surfaces for studying cell-surface interactions. It is our goal to develop a biocompatible Al2O3-surface which could be used as a coating material for medical implants exhibiting a cell selective response because of its specific physical landscape and especially because it promotes the adhesion of osteoblasts while minimizing the adhesion of fibroblasts. PMID: 20814089 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Accelerated differentiation of osteoblast cells on polycaprolactone scaffolds driven by a combined effect of protein coating and plasma modification. Biofabrication. 2010 Mar;2(1):014109 Authors: Yildirim ED, Besunder R, Pappas D, Allen F, Güçeri S, Sun W A combined effect of protein coating and plasma modification on the quality of the osteoblast-scaffold interaction was investigated. Three-dimensional polycaprolactone (PCL) scaffolds were manufactured by the precision extrusion deposition (PED) system. The structural, physical, chemical and biological cues were introduced to the surface through providing 3D structure, coating with adhesive protein fibronectin and modifying the surface with oxygen-based plasma. The changes in the surface properties of PCL after those modifications were examined by contact angle goniometry, surface energy calculation, surface chemistry analysis (XPS) and surface topography measurements (AFM). The effects of modification techniques on osteoblast short-term and long-term functions were examined by cell adhesion, proliferation assays and differentiation markers, namely alkaline phosphatase activity (ALP) and osteocalcin secretion. The results suggested that the physical and chemical cues introduced by plasma modification might be sufficient for improved cell adhesion, but for accelerated osteoblast differentiation the synergetic effects of structural, physical, chemical and biological cues should be introduced to the PCL surface. PMID: 20811124 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Machine design and processing considerations for the 3D plotting of thermoplastic scaffolds. Biofabrication. 2010 Mar;2(1):014107 Authors: Ragaert K, Cardon L, Dekeyser A, Degrieck J 3D plotting by micro-extrusion is a promising layer-wise fabrication method for the production of scaffolds in thermoplastic polymers. It is a solvent-free direct technique which permits extensive control over geometry and porosity. This paper highlights the complications that arise when using this technique for the processing of thermally sensitive polymers. It has been noted that the material is subject to extensive thermal load during processing, which may result in degradation by chain scission. This negatively affects scaffold (mechanical) properties as well as predictability and repeatability of the fabrication technique. A rationale is offered as to the main causes of this thermally induced degradation during processing and tentative ideas towards a solution are equally put forward. PMID: 20811122 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | In vivo bioprinting for computer- and robotic-assisted medical intervention: preliminary study in mice. Biofabrication. 2010 Mar;2(1):014101 Authors: Keriquel V, Guillemot F, Arnault I, Guillotin B, Miraux S, Amédée J, Fricain JC, Catros S We present the first attempt to apply bioprinting technologies in the perspective of computer-assisted medical interventions. A workstation dedicated to high-throughput biological laser printing has been designed. Nano-hydroxyapatite (n-HA) was printed in the mouse calvaria defect model in vivo. Critical size bone defects were performed in OF-1 male mice calvaria with a 4 mm diameter trephine. Prior to laser printing experiments, the absence of inflammation due to laser irradiation onto mice dura mater was shown by means of magnetic resonance imaging. Procedures for in vivo bioprinting and results obtained using decalcified sections and x-ray microtomography are discussed. Although heterogeneous, these preliminary results demonstrate that in vivo bioprinting is possible. Bioprinting may prove to be helpful in the future for medical robotics and computer-assisted medical interventions. PMID: 20811116 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
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