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| Design and development of a novel biostretch apparatus for tissue engineering.
June 9, 2010 at 10:50 AM
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| | Design and development of a novel biostretch apparatus for tissue engineering. J Biomech Eng. 2010 Jan;132(1):014503 Authors: Pang Q, Zu JW, Siu GM, Li RK A uniaxial cyclic stretch apparatus is designed and developed for tissue engineering research. The biostretch apparatus employs noncontact electromagnetic force to uniaxially stretch a rectangular Gelfoam or RTV silicon scaffold. A reliable controller is implemented to control four stretch parameters independently: extent, frequency, pattern, and duration of the stretch. The noncontact driving force together with the specially designed mount allow researchers to use standard Petri dishes and commercially available CO(2) incubators to culture an engineered tissue patch under well-defined mechanical conditions. The culture process is greatly simplified over existing processes. Further, beyond traditional uniaxial stretch apparatuses, which provide stretch by fixing one side of the scaffolds and stretching the other side, the new apparatus can also apply uniaxial stretch from both ends simultaneously. Using the biostretch apparatus, the distributions of the strain on the Gelfoam and GE RTV 6166 silicon scaffolds are quantitatively analyzed. PMID: 20524751 [PubMed - in process] | | |
| Reconstruction of oviduct and demonstration of epithelial fate determination in mice.
June 9, 2010 at 8:04 AM
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| | Reconstruction of oviduct and demonstration of epithelial fate determination in mice. Biol Reprod. 2010 Mar;82(3):528-33 Authors: Yamanouchi H, Umezu T, Tomooka Y The mouse oviductal epithelium is a simple monolayer until Postnatal Day 7 and subsequently consists of differentiated secretory cells and ciliated cells. In adult oviduct, the two types of epithelial cells are unevenly distributed; ciliated cells are dominant in the ampulla and secretory cells are dominant in the isthmus. Recombinants of enzymatically separated epithelial and mesenchymal tissues of oviducts were grafted under kidney capsule for 4 wk. The recombinants developed structures with a lumen covered with a monolayer of ciliated cells and secretory cells, demonstrating that the recombinant tissues reconstructed oviductal structure. Geographically (ampulla versus isthmus) heterotypic recombinants were prepared from neonatal oviducts at Day 3. The epithelia in reconstructed oviducts took the patterns of cell distribution depending on the origin of the mesenchymal tissues. The results indicate that the mesenchyme geographically has distinct abilities to determine undifferentiated epithelial cells to ciliated cells or secretory cells in the mouse oviduct. PMID: 19906687 [PubMed - indexed for MEDLINE] | | |
| Use of a rotary bioartificial liver in the differentiation of human liver stem cells.
June 9, 2010 at 8:04 AM
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| | Use of a rotary bioartificial liver in the differentiation of human liver stem cells. Tissue Eng Part C Methods. 2010 Feb;16(1):123-32 Authors: Fonsato V, Herrera MB, Buttiglieri S, Gatti S, Camussi G, Tetta C The use of bioartificial livers (BALs) for the expansion of human adult liver stem cells and the production of growth factors could be a potential strategy for cell-based extracorporeal liver support. The present study aimed to assessing the differentiation of human adult liver stem cells in a rotary BAL. Liver stem cells were seeded into a polysulphone membrane filter at a density of 3 x 10(8) cells, and the filter was connected to a rotary bioreactor perfusion system (37 degrees C, 50 mL/min, 48 h). Viability, cell differentiation, and metabolic performances were evaluated at 24 and 48 h. Hepatocyte growth factor production from human adult liver stem cells, mature hepatocytes, and mesenchymal stem cells in adhesion and in the rotary BAL conditions was compared. Liver stem cells cultured in the rotary BAL produced the highest amounts of albumin (p = 0.002) and ammonia-induced urea (p = 0.0001), and had an increased cytochrome P450 expression in respect to liver stem cells in adhesion. Remarkably, liver stem cells in the rotary BAL produced very high amounts of hepatocyte growth factor (p = 0.005) in respect to hepatocytes and mesenchymal stem cells. Moreover, the cells lost their stem cell markers and acquired several markers of mature hepatocytes. In conclusion, the rotary BAL favored liver stem cell differentiation into mature hepatocyte-like cells. PMID: 19397473 [PubMed - indexed for MEDLINE] | | |
| Dynamic 3D culture promotes spontaneous embryonic stem cell differentiation in vitro.
June 9, 2010 at 8:04 AM
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| | Dynamic 3D culture promotes spontaneous embryonic stem cell differentiation in vitro. Tissue Eng Part C Methods. 2010 Feb;16(1):115-21 Authors: Gerlach JC, Hout M, Edsbagge J, Björquist P, Lübberstedt M, Miki T, Stachelscheid H, Schmelzer E, Schatten G, Zeilinger K Spontaneous in vitro differentiation of mouse embryonic stem cells (mESC) is promoted by a dynamic, three-dimensional (3D), tissue-density perfusion technique with continuous medium perfusion and exchange in a novel four-compartment, interwoven capillary bioreactor. We compared ectodermal, endodermal, and mesodermal immunoreactive tissue structures formed by mESC at culture day 10 with mouse fetal tissue development at gestational day E9.5. The results show that the bioreactor cultures more closely resemble mouse fetal tissue development at gestational day E9.5 than control mESC cultured in Petri dishes. PMID: 19382830 [PubMed - indexed for MEDLINE] | | |
| Effect of chitosan as a dispersant on collagen-hydroxyapatite composite matrices.
June 9, 2010 at 8:04 AM
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| | Effect of chitosan as a dispersant on collagen-hydroxyapatite composite matrices. Tissue Eng Part C Methods. 2010 Feb;16(1):71-9 Authors: Zhang L, Tang P, Zhang W, Xu M, Wang Y PURPOSE: Hydroxyapatite (HA) powder is difficult to disperse evenly in collagen (Col) gelatum, which can affect the properties of the final Col-HA composite. Here, we used chitosan (CS) as a dispersant in a bone matrix constructed with Col and Ca(5)(PO(4))(3)OH (HA), which are the main components of natural bone. Solid-liquid phase separation was used to shape a three-dimensional porous structure to support cell growth. METHODS: The two bone matrices (Col-CS-HA and Col-HA) were investigated by transmission electron microscopy, scanning electron microscopy, and electron spectroscopy for chemical analysis for structural characteristics and physicochemical properties. Their ability to repair bone defects was evaluated in vivo. RESULTS: HA particles were dispersed in Col gelatum evenly by mixing with CS gelatum. The surface morphology and three-dimensional structure of the matrix became more regular, which improved cell growth. After CS modification, the percentage of C-N groups increased to 6.40% and C-OH groups increased from 1.05% to 6.92%. The total amount of nonpolar groups (C-C groups and C-H groups) decreased from 82.48% to 74.05%. The vitrification and denaturation temperatures increased from 40.59 degrees C and 106.36 degrees C, respectively, to 42.23 degrees C and 111.04 degrees C, respectively. CONCLUSION: CS modified the surface chemistry to create a favorable environment for osteoblast adhesion and proliferation in vivo, which would accelerate the process of bone regeneration. The Col-CS-HA matrix possessed superior biological and mechanical properties for bone defect repair. PMID: 19364274 [PubMed - indexed for MEDLINE] | | |
| Three-dimensional localization of implanted biomaterials in anatomical and histological specimens using combined X-ray computed tomography and three-dimensional surface reconstruction: a technical note.
June 9, 2010 at 8:04 AM
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| | Three-dimensional localization of implanted biomaterials in anatomical and histological specimens using combined X-ray computed tomography and three-dimensional surface reconstruction: a technical note. Tissue Eng Part C Methods. 2010 Feb;16(1):63-9 Authors: Cuijpers VM, Walboomers XF, Jansen JA For adequate histological processing of implanted biomaterials or tissue-engineered constructs, it is sometimes essential to obtain insight into the localization of structures inside the tissue samples. Observation of three-dimensional (3D) surface reconstruction, including basic photorealistic texture characteristics as surface pattern and color combined with X-ray computed tomography 3D reconstruction at different levels, is a useful approach to localize anatomical or implanted structures within experimental tissue samples. Because of the possible observation of structures of interest in a 3D environment, fusion of these techniques can greatly facilitate histological processing. PMID: 19358629 [PubMed - indexed for MEDLINE] | | |
| Use of iodixanol self-generated density gradients to enrich for viable urothelial cells from nonneurogenic and neurogenic bladder tissue.
June 9, 2010 at 8:04 AM
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| | Use of iodixanol self-generated density gradients to enrich for viable urothelial cells from nonneurogenic and neurogenic bladder tissue. Tissue Eng Part C Methods. 2010 Feb;16(1):33-40 Authors: Bruce AT, Sangha N, Richmond A, Johnson K, Jones S, Spencer T, Ludlow JW Suspensions of viable urothelial cells (UC) isolated from patient bladder biopsies often contain considerable amounts of extraneous materials comprised of cellular debris, dead and dying UC, and red blood cells. We have consistently observed an inversely proportional relationship between UC attachment efficiency and the amount of extraneous materials in the suspension; viable UC cell attachment efficiency decreases as the amount of extraneous materials in the cell suspension increases. Processing the initial cell isolate to reduce the amount of extraneous materials can enrich for viable UC capable of attaching and proliferating in ex vivo cultures. In this report, we describe the isolation of an enriched population of viable UC from nonneurogenic and neurogenic bladder tissue biopsies using iodixanol self-generated density gradients (OptiPrep), and characterization by trypan blue exclusion, fluorescence-activated cell sorting, immunofluorescence, and growth kinetics. PMID: 19351240 [PubMed - indexed for MEDLINE] | | |
| [Immortalization of endothelial cells differentiated from mouse embryonic stem cells]
June 9, 2010 at 8:04 AM
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| | [Immortalization of endothelial cells differentiated from mouse embryonic stem cells] Shi Yan Sheng Wu Xue Bao. 2002 Sep;35(3):218-28 Authors: Shen G, Cong XQ, Du ZW, Wu CF, Liu XY, Liu W, Cao YL This study is designed to immortalize endothelial cells differentiated from embryonic stem cells. The embryoid bodies (EB) formed in vitro from embryonic stem cells, were induced to differentiate into many "round cells" (the precursor of endothelial cells) by retinoic acid (RA) and transforming growth factor-beta1 (TGF-beta1). These "round cells" later formed the vascular tube-like structures. Studies by scanning electronic microscopy and light microscopy and immunocytochemistry, demonstrated that these tube-like structures were constituted by a large number of round and flat cells, which were positive for "vWF" and "CD34"staining. These results indicate they are vascular endothelial cells. To immortalize these cells, human telomerase reverse transcriptase (hTERT) cDNA was transfected into "round cells" by lipofectine. hTERT mRNA expression in transfected cells was confirmed by Dot blot, RT-PCR. Furthermore, 95% these transfected cells maintain the characteristic of endothelial cell, can proliferate in large quantity in vitro, and are able to form tubular structures. These results suggest that hTERT cDNA transfection can immortalize the induced endothelial cells and therefore may provide a new source of seed cells for vascular engineering. PMID: 15344385 [PubMed - indexed for MEDLINE] | | |
| [Bcl-2 expression in enteric neurons of Hirschsprung's disease and its significance]
June 9, 2010 at 8:04 AM
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| | [Bcl-2 expression in enteric neurons of Hirschsprung's disease and its significance] Shi Yan Sheng Wu Xue Bao. 2002 Jun;35(2):155-8 Authors: Song Y, Li JC, Li MJ The bcl-2 protein, which widely expressed in the developing central and peripheral nervous systems, has the functional role of blocking apoptosis. The purpose of this study was to map bcl-2 expression in the human enteric nervous system and investigate the value of bcl-2 immunohistochemical method in the diagnosis of Hirschsprung's disease (HD), as this has not previously been done. Rectal specimens were obtained from definitive operation of 20 patients with HD. Specimens were analyzed with immunohistochemical methods, using antibodies against bcl-2. The bcl-2 protein was expressed in myenteric and submucous neurons in normal adult and HD expand segment, but no bcl-2 immunoreactive enteric neurons was revealed in the narrow segment. And nerve fibers of the enteric plexuses that were bcl-2 immunoreactive were few in all examined specimens. From the conclusion, expression of bcl-2 is displayed in enteric neurons and immunohistochemical analysis of bcl-2 may also be valuable for identification of the enteric neurons in HD. PMID: 15344336 [PubMed - indexed for MEDLINE] | | |
| [Isolation and culture of human pluripotent embryonic germ cells]
June 9, 2010 at 8:04 AM
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| | [Isolation and culture of human pluripotent embryonic germ cells] Shi Yan Sheng Wu Xue Bao. 2002 Jun;35(2):142-6 Authors: Li XH, Cong HC, Wang Z, Wu CF, Cao YL To establish human pluripotent embryonic germ (EG) cell lines, human primordial germ cells (PGCs) of embryos aborted in 5-9 week were cultured on inactive mouse STO fibroblast feeder. The medium contained human leukemia inhibitory factor (hLIF), human basic fibroblast growth factor (hbFGF) and forskolin. The EG cells could be passaged continuously until 12 generations. Most cells were positive in alkaline phosphatase staining and expressed cell surface antigen SSEA-3 and pluripotent marker Oct-4. These EG cell populations that retained normal karyotype could form embryoid body in culture and differentiate further into neuron-like cells, mucous epithelial cells, epithelial cells and other types of the cells spontaneously. These results indicated the cell clones derived from human PGCs resemble pluripotent EG cells from mouse PGCs in appearance or nature. PMID: 15344333 [PubMed - indexed for MEDLINE] | | |
| Biodegradation of porous calcium phosphate scaffolds in an ectopic bone formation model studied by X-ray computed microtomograph.
June 9, 2010 at 8:04 AM
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| | Biodegradation of porous calcium phosphate scaffolds in an ectopic bone formation model studied by X-ray computed microtomograph. Eur Cell Mater. 2010;19:136-46 Authors: Komlev VS, Mastrogiacomo M, Pereira RC, Peyrin F, Rustichelli F, Cancedda R Three types of ceramic scaffolds with different composition and structure [namely synthetic 100% hydroxyapatite (HA; Engipore), synthetic calcium phosphate multiphase biomaterial containing 67% silicon stabilized tricalcium phosphate (Si-TCP; Skelite) and natural bone mineral derived scaffolds (Bio-oss)] were seeded with mesenchymal stem cells (MSC) and ectopically implanted for 8 and 16 weeks in immunodeficient mice. X-ray synchrotron radiation microtomography was used to derive 3D structural information on the same scaffolds both before and after implantation. Meaningful images and morphometric parameters such as scaffold and bone volume fraction, mean thickness and thickness distribution of the different phases as a function of the implantation time, were obtained. The used imaging algorithms allowed a direct comparison and registration of the 3D structure before and after implantation of the same sub-volume of a given scaffold. In this way it was possible to directly monitor the tissue engineered bone growth and the complete or partial degradation of the scaffold. Further, the detailed kinetics studies on Skelite scaffolds implanted for different length of times from 3 days to 24 weeks, revealed in the X-ray absorption histograms two separate peaks associated to HA and TCP. It was therefore possible to observe that the progressive degradation of the Skelite scaffolds was mainly due to the resorption of TCP. The different saturation times in the tissue engineered bone growth and in the TCP resorption confirmed that the bone growth was not limited the scaffold regions that were resorbed but continued in the inward direction with respect to the pore surface. PMID: 20349404 [PubMed - indexed for MEDLINE] | | |
| In vitro reprogramming of pancreatic cells to hepatocytes.
June 9, 2010 at 8:04 AM
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| | In vitro reprogramming of pancreatic cells to hepatocytes. Methods Mol Biol. 2010;636:285-92 Authors: Eberhard D, O'Neill K, Burke ZD, Tosh D Transdifferentiation is defined as the conversion of one cell type to another. One well-documented example of transdifferentiation is the conversion of pancreatic cells to hepatocytes. Here we describe a robust in vitro model to study pancreas to liver transdifferentiation. It is based on the addition of the synthetic glucocorticoid dexamethasone to the rat pancreatic exocrine cell line AR42J. Following glucocorticoid treatment, cells resembling hepatocytes are induced. Transdifferentiated hepatocytes express many of the properties of bona fide hepatocytes, e.g. production of albumin and ability to respond to xenobiotics. These hepatocytes can be used for studying liver function in vitro as well as studying the molecular basis of transdifferentiation. PMID: 20336529 [PubMed - indexed for MEDLINE] | | |
| Advancing towards a tissue-engineered tympanic membrane: silk fibroin as a substratum for growing human eardrum keratinocytes.
June 9, 2010 at 8:04 AM
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| | Advancing towards a tissue-engineered tympanic membrane: silk fibroin as a substratum for growing human eardrum keratinocytes. J Biomater Appl. 2010 Mar;24(7):591-606 Authors: Ghassemifar R, Redmond S, Zainuddin , Chirila TV Human tympanic membrane cells (hTMCs), harvested from tympanic membrane (TM) explants, were grown in culture and then seeded on membranes prepared from silkworm (Bombyx mori) silk fibroin (BMSF) and on tissue-culture plastic membranes (PET). Fibroin was isolated from silk cast into membranes with a thickness of 10-15 microm. The hTMCs were cultured on both materials for 15 days in a serum-containing culture medium. The cells grown on both substrata were subjected to nuclear staining (DAPI) and counted. Further, the cultures were immunostained for a number of protein markers related to the epithelial/keratinocyte phenotype and cell adhesion complexes. The BMSF membranes supported levels of hTMC growth higher than that observed on the PET membranes. The immunofluorochemical analysis indicated unequivocally that BMSF is a more suitable substratum than PET with respect to the growth patterns, proliferation, and cell-cell contact and adhesion. BMSF appear as a promising substratum in the tissue-engineered constructs for the replacement of TM in case of nonhealing perforations. PMID: 20308345 [PubMed - indexed for MEDLINE] | | |
| Abnormally up-regulated cystic fibrosis transmembrane conductance regulator expression and uterine fluid accumulation contribute to Chlamydia trachomatis-induced female infertility.
June 9, 2010 at 8:04 AM
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| | Abnormally up-regulated cystic fibrosis transmembrane conductance regulator expression and uterine fluid accumulation contribute to Chlamydia trachomatis-induced female infertility. Fertil Steril. 2010 May 15;93(8):2608-14 Authors: He Q, Tsang LL, Ajonuma LC, Chan HC OBJECTIVE: To investigate whether abnormal expression of cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic adenosine 3':5' monophosphate (cAMP)-activated chloride channel, and uterine fluid accumulation upon Chlamydia trachomatis infection may result in implantation failure, thus contributing to C. trachomatis-induced female infertility. DESIGN: Experimental animal study. SETTING: University laboratory animal service center. ANIMAL(S): Adult female mice with regular estrous cycles. INTERVENTION(S): Intrauterine injection of C. trachomatis lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF-alpha), and estrogen (E) at diestrus and preimplantation. MAIN OUTCOME MEASURE(S): The CFTR messenger RNA (mRNA) and protein levels were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively, in mouse uterus treated with C. trachomatis LPS, TNF-alpha or E. Endometrial electrolyte transport and uterine fluid accumulation were determined by the short circuit current and uterine wet weight, respectively. Number of implanted embryos was also counted to demonstrate the effect of treatments. RESULT(S): Uterine C. trachomatis LPS infection induced up-regulation of CFTR expression with enhanced anion secretion, abnormal fluid accumulation in mouse uterus at diestrus, and reduced implantation rate. Administration of exogenous TNF-alpha to mouse uterus mimicked the C. trachomatis LPS infection-induced CFTR up-regulation, enhanced CFTR channel activity, and fluid accumulation. Abnormal uterine fluid accumulation and implantation failure were also observed when CFTR was up-regulated by E. CONCLUSION(S): The present results suggest that C. trachomatis infection-induced release of cytokines could abnormally up-regulate CFTR expression leading to abnormal uterine fluid accumulation, which may result in infertility often associated with C. trachomatis infection. PMID: 20227074 [PubMed - indexed for MEDLINE] | | |
| Episodes of prolactin gene expression in GH3 cells are dependent on selective promoter binding of multiple circadian elements.
June 9, 2010 at 8:04 AM
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| | Episodes of prolactin gene expression in GH3 cells are dependent on selective promoter binding of multiple circadian elements. Endocrinology. 2010 May;151(5):2287-96 Authors: Bose S, Boockfor FR Prolactin (PRL) gene expression in mammotropes occurs in pulses, but the mechanism(s) underlying this dynamic process remains obscure. Recent findings from our laboratory of an E-box in the rat PRL promoter (E-box133) that can interact with the circadian factors, circadian locomoter output cycles kaput (CLOCK) and brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein (BMAL)-1, and was necessary for pulse activity raised the intriguing possibility that the circadian system may be central to this oscillatory process. In this study, we used serum-shocked GH(3) cells, established previously to synchronize PRL pulses between cells in culture, to reveal that pulses of PRL mRNA are linked temporally to the expression of bmal1, cry1, per1, and per3 mRNA in these cells. Moreover, we found that each of these circadian factors binds to the rat PRL promoter by chromatin immunoprecipitation analysis. Using EMSA analysis, we observed that two sites present in the proximal promoter region, E-box133 and E-box10, bind circadian factors differentially (E-box133 interacted with BMAL1, cryptochrome-1, period (PER)-1, and PER3 but not PER2 and E-box10 bound BMAL1, cryptochrome-1, PER2, PER3 but not PER1). More importantly, down-regulation of any factor binding E-box133 significantly reduced PRL mRNA levels during pulse periods. Our results demonstrate clearly that certain circadian elements binding to the E-box133 site are required for episodes of PRL mRNA expression in serum-shocked GH(3) cultures. Moreover, our findings of binding-related differences between functionally distinct E-boxes demonstrate not only that E-boxes can bind different components but suggest that the number and type of circadian elements that bind to an E-box is central in dictating its function. PMID: 20215567 [PubMed - indexed for MEDLINE] | | |
| Towards an intraoperative engineering of osteogenic and vasculogenic grafts from the stromal vascular fraction of human adipose tissue.
June 9, 2010 at 8:04 AM
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| | Towards an intraoperative engineering of osteogenic and vasculogenic grafts from the stromal vascular fraction of human adipose tissue. Eur Cell Mater. 2010;19:127-35 Authors: Müller AM, Mehrkens A, Schäfer DJ, Jaquiery C, Güven S, Lehmicke M, Martinetti R, Farhadi I, Jakob M, Scherberich A, Martin I Grafts generated by cultivation of progenitor cells from the stromal vascular fraction of human adipose tissue have been proven to have osteogenic and vasculogenic properties in vivo. However, in vitro manufacture of such implants is challenged by complex, impractical and expensive processes, and requires implantation in a separate surgery. This study investigates the feasibility of an intraoperative approach to engineer cell-based bone grafts with tissue harvest, cell isolation, cell seeding onto a scaffold and subsequent implantation within a few hours. Freshly isolated adipose tissue cells from a total of 11 donors, containing variable fractions of mesenchymal and endothelial progenitors, were embedded at different densities in a fibrin hydrogel, which was wrapped around bone substitute materials based on beta-tricalcium phosphate (ChronOS), hydroxyapatite (Engipore), or acellular xenograft (Bio-Oss). The resulting constructs, generated within 3 hours from biopsy harvest, were immediately implanted ectopically in nude mice and analysed after eight weeks. All explants contained blood vessels formed by human endothelial cells, functionally connected to the recipient's vasculature. Human origin cells were also found within osteoid structures, positively immunostained for bone sialoprotein and osteocalcin. However, even with the highest loaded cell densities, no frank bone tissue was detected, independently of the material used. These results provide a proof-of-principle that an intraoperative engineering of autologous cell-based vasculogenic bone substitutes is feasible, but highlight that - in the absence of in vitro commitment--additional cues (e.g., low dose of osteogenic factors or orthotopic environmental conditions) are likely needed to support complete osteoblastic cell differentiation and bone tissue generation. PMID: 20198567 [PubMed - indexed for MEDLINE] | | |
| [Repair non-healing wound with artificial dermis and autologous skin graft]
June 9, 2010 at 8:04 AM
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| | [Repair non-healing wound with artificial dermis and autologous skin graft] Zhonghua Shao Shang Za Zhi. 2009 Dec;25(6):444-7 Authors: Chen X, Wang XJ, Wang C, Chen H, Zhang GA OBJECTIVE: To observe the feasibility of repairing non-healing wound with artificial dermis and autologous skin graft, and to evaluate its efficacy. METHODS: Twenty in-patients with 25 non-healing wounds lasting more than 8 weeks were divided into chronic ulcer group (9 patients with 11 ulcerating scars after trauma and burn), and bone exposing group (11 patients with 14 wounds with exposed bone ranging from 0.8 - 77.0 cm(2) in size, the largest 22.0 cm x 3.5 cm). Wounds were debrided and repaired with artificial dermis in the first stage. Autologous split-thickness skin was grafted in the II stage when the wounds were well vascularized locally and exposed bone and tendon were covered with dermis-like tissue within 2 - 6 weeks. RESULTS: In chronic ulcer group, 9 of the 11 wounds healed well, the other 2 healed after routine dressing change. In bone exposing group, 12 of the 14 wounds healed well and the exposed bone was effectively covered; artificial dermis on the other 2 wounds failed to survive due to infection, and they were repaired with skin flap later. Patients were followed up for 5 - 24 months. Wounds healed with satisfactory appearance and no recurrence of wound or obvious hyperplasic scar was observed; no obvious scar was observed in the donor site. CONCLUSIONS: The method of repairing non-healing wound with artificial dermis combining with autologous skin graft is simple; and it results in healing of wounds with high quality and little damage to the donor site. It provides a new choice for repairing non-healing wound. PMID: 20193168 [PubMed - indexed for MEDLINE] | | |
| Quantitative ultrasound biomicroscopy for the analysis of healthy and repair cartilage tissue.
June 9, 2010 at 8:04 AM
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| | Quantitative ultrasound biomicroscopy for the analysis of healthy and repair cartilage tissue. Eur Cell Mater. 2010;19:58-71 Authors: Gelse K, Olk A, Eichhorn S, Swoboda B, Schoene M, Raum K The increasing spectrum of different cartilage repair strategies requires the introduction of adequate non-destructive methods to analyse their outcome in-vivo, i.e. arthroscopically. The validity of non-destructive quantitative ultrasound biomicroscopy (UBM) was investigated in knee joints of five miniature pigs. After 12 weeks, six 5-mm defects, treated with different cartilage repair approaches, provided tissues with different structural qualities. Healthy articular cartilage from each contralateral unoperated knee joint served as a control. The reflected and backscattered ultrasound signals were processed to estimate the integrated reflection coefficient (IRC) and apparent integrated backscatter (AIB) parameters. The cartilage repair tissues were additionally assessed biomechanically by cyclic indentation, histomorphologically and immunohistochemically. UBM allowed high-resolution visualisation of the structure of the joint surface and subchondral bone plate, as well as determination of the cartilage thickness and demonstrated distinct differences between healthy cartilage and the different repair cartilage tissues with significant higher IRC values and a steeper negative slope of the depth-dependent backscatter amplitude AIBslope for healthy cartilage. Multimodal analyses revealed associations between IRC and the indentation stiffness. Furthermore, AIBslope and AIB at the cartilage-bone boundary (AIBdC) were associated with the quality of the repair matrices and the subchondral bone plate, respectively. This ex-vivo pilot study confirms that UBM can provide detailed imaging of articular cartilage and the subchondral bone interface also in repaired cartilage defects, and furthermore, contributes in certain aspects to a basal functional characterization of various forms of cartilage repair tissues. UBM could be further established to be applied arthroscopically in-vivo. PMID: 20186666 [PubMed - indexed for MEDLINE] | | |
| VEGF incorporated into calcium phosphate ceramics promotes vascularisation and bone formation in vivo.
June 9, 2010 at 8:04 AM
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| | VEGF incorporated into calcium phosphate ceramics promotes vascularisation and bone formation in vivo. Eur Cell Mater. 2010;19:30-40 Authors: Wernike E, Montjovent MO, Liu Y, Wismeijer D, Hunziker EB, Siebenrock KA, Hofstetter W, Klenke FM Bone formation and osseointegration of biomaterials are dependent on angiogenesis and vascularization. Angiogenic growth factors such as vascular endothelial growth factor (VEGF) were shown to promote biomaterial vascularization and enhance bone formation. However, high local concentrations of VEGF induce the formation of malformed, nonfunctional vessels. We hypothesized that a continuous delivery of low concentrations of VEGF from calcium phosphate ceramics may increase the efficacy of VEGF administration.VEGF was co-precipitated onto biphasic calcium phosphate (BCP) ceramics to achieve a sustained release of the growth factor. The co-precipitation efficacy and the release kinetics of the protein were investigated in vitro. For in vivo investigations BCP ceramics were implanted into critical size cranial defects in Balb/c mice. Angiogenesis and microvascularization were investigated over 28 days by means of intravital microscopy. The formation of new bone was determined histomorphometrically. Co-precipitation reduced the burst release of VEGF. Furthermore, a sustained, cell-mediated release of low concentrations of VEGF from BCP ceramics was mediated by resorbing osteoclasts. In vivo, sustained delivery of VEGF achieved by protein co-precipitation promoted biomaterial vascularization, osseointegration, and bone formation. Short-term release of VEGF following superficial adsorption resulted in a temporally restricted promotion of angiogenesis and did not enhance bone formation. The release kinetics of VEGF appears to be an important factor in the promotion of biomaterial vascularization and bone formation. Sustained release of VEGF increased the efficacy of VEGF delivery demonstrating that a prolonged bioavailability of low concentrations of VEGF is beneficial for bone regeneration. PMID: 20178096 [PubMed - indexed for MEDLINE] | | |
| [Treatment for osteonecrosis of femoral head by hVEGF-165 gene modified marrow stromal stem cells under arthroscope]
June 9, 2010 at 8:04 AM
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| | [Treatment for osteonecrosis of femoral head by hVEGF-165 gene modified marrow stromal stem cells under arthroscope] Zhonghua Yi Xue Za Zhi. 2009 Oct 13;89(37):2629-33 Authors: Liu BY, Zhao DW OBJECTIVE: To understand the biological characteristics and osteogenic potential of hVEGF-165 gene modified marrow stromal stem cells and investigate the effect and value of treatment for osteonecrosis of femoral head by hVEGF-165 gene modified marrow stromal stem cells under arthroscope. METHODS: rAAV-2-hVEGF-165 plasmids were extracted and transfected into rabbit marrow stromal stem cells. hVEGF-165 mediated by adeno-associated virus (AAV) was used to transfect rMSCs. The transfection efficiency was detected with enhanced green fluorescent protein under fluorescence microscope. hVEGF-165 mediated by adeno-associated virus (AAV) was used to transfect rMSCs. Virus transfection stayed overnight after 90% cell converged. MOI was 105. The transcription and expression of hVEGF-165 protein expression were detected by RT-PCR and Western blot. The necrotic bone was emptied and then MSCs were implanted under arthroscope. The histology of femoral head was inspected at postoperative 2 - 8 weeks. RESULTS: The expression of hVEGF-165 gene could be found distinctly in the transfected rabbit MSCs and hVEGF-165 protein in the supernatants of transfected cell cultures. The transfection efficiency of adeno-associated virus (AAV) transfected rMSCs was 70%. And rAAV-2-hVEGF-165 transfected rMSCs achieved an effective expression by RT-PCR and Western blot. hVEGF-165 could be found after a 48-hour transfection and peaked at Day 10. Immunohistochemical detection showed that the implanted rMSCs was positive at Week 2 and strong positive at Week 8. The compressive strength of the hVEGF-165 gene group approached that of normal control. CONCLUSION: hVEGF-165 gene transfected rabbit MSCs can express hVEGF-165 with highly biological activity. It provides provided a basis for employing hVEGF-165 gene and MSCs based gene therapy for ONFH repairing and regeneration. rAAV-2-hVEGF-165/MSCs may be implanted accurately under arthroscope. Implantation of human BMP-2 gene transfected BMSCs can repair early-stage experimental femoral head necrosis. PMID: 20137681 [PubMed - indexed for MEDLINE] | | |
| Clinical impact of suicide gene therapy in allogeneic hematopoietic stem cell transplantation.
June 9, 2010 at 8:04 AM
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| | Clinical impact of suicide gene therapy in allogeneic hematopoietic stem cell transplantation. Hum Gene Ther. 2010 Mar;21(3):241-50 Authors: Lupo-Stanghellini MT, Provasi E, Bondanza A, Ciceri F, Bordignon C, Bonini C Allogeneic hematopoietic stem cell transplantation (allo-SCT) from an HLA-matched related or unrelated donor is a curative option for patients with high-risk hematological diseases. In the absence of a matched donor, patients have been offered investigational transplantation strategies such as umbilical cord blood SCT or family haploidentical SCT. Besides the activity of the conditioning regimen, most of the antileukemic potential of allo-SCT relies on alloreactivity, promoted by donor lymphocytes reacting against patient-specific antigens, such as minor and major histocompatibility antigens, ultimately translating into cancer immunotherapy. Unfortunately, alloreactivity is also responsible for the most serious and frequent complication of allo-SCT: graft-versus-host-disease (GvHD). The risk of GvHD increases with the level of HLA disparity between host and donor, and leads to impaired quality of life and reduced survival expectancy, particularly among patients receiving transplants from HLA-mismatched donors. Gene transfer technologies are promising tools to manipulate donor T cell immunity to enforce the graft-versus-tumor effect, to promote functional immune reconstitution (graft vs. infection), and to prevent or control GvHD. To this purpose, several cell and gene transfer approaches have been investigated at the preclinical level, and are being implemented in clinical trials. Suicide gene therapy is to date the most extensive clinical application of T cell-based gene therapy. In several phase I-II clinical studies conducted worldwide this approach proved highly feasible, safe, and effective in promoting a dynamic and patient-specific modulation of alloreactivity. This review focuses on this approach. PMID: 20121594 [PubMed - indexed for MEDLINE] | | |
| Mutations in a gene encoding a midbody protein in binucleated Reed-Sternberg cells of Hodgkin lymphoma.
June 9, 2010 at 8:04 AM
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| | Mutations in a gene encoding a midbody protein in binucleated Reed-Sternberg cells of Hodgkin lymphoma. Cell Cycle. 2010 Feb;9(4):670-5 Authors: Krem MM, Salipante SJ, Horwitz MS Classical Hodgkin lymphoma (cHL) is a cancer in which malignant "Reed-Sternberg" cells comprise just a fraction of the bulk of the tumor and are characteristically binucleated. We recently identified a novel gene, KLHDC8B, which appears responsible for some familial cases of cHL. KLHDC8B encodes a midbody kelch protein expressed during cytokinesis. Deficiency of KLHDC8B leads to binucleated cells, implicating its involvement in Reed-Sternberg cell formation. Interestingly, other cancer genes, such as BRCA1 and BRCA2, also encode proteins locating to the midbody during cytokinesis, even though their participation in other pathways has received greater attention. Midbody components may be an overlooked source of tumor suppressor genes. PMID: 20107318 [PubMed - indexed for MEDLINE] | | |
| Intramuscular transplantation of engineered hepatic tissue constructs corrects acute and chronic liver failure in mice.
June 9, 2010 at 8:04 AM
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| | Intramuscular transplantation of engineered hepatic tissue constructs corrects acute and chronic liver failure in mice. J Hepatol. 2010 Feb;52(2):211-9 Authors: Navarro-Alvarez N, Soto-Gutierrez A, Chen Y, Caballero-Corbalan J, Hassan W, Kobayashi S, Kondo Y, Iwamuro M, Yamamoto K, Kondo E, Tanaka N, Fox IJ, Kobayashi N BACKGROUND & AIMS: Transplantation of isolated hepatocytes holds great promise as an alternative to whole organ liver transplantation. For treatment of liver failure, access to the portal circulation has significant risks and intrahepatic hepatocyte engraftment is poor. In advanced cirrhosis, transplantation into an extrahepatic site is necessary and intrasplenic engraftment is short-lived. Strategies that allow repeated extrahepatic infusion of hepatocytes could improve the efficacy and safety of hepatocyte transplantation for the treatment of liver failure. METHODS: A non-immunogenic self-assembling peptide nanofiber (SAPNF) was developed as a three-dimensional scaffold and combined with growth factors derived from a conditionally immortalized human hepatocyte cell line to engineer a hepatic tissue graft that would allow hepatocyte engraftment outside the liver. RESULTS: The hepatic tissue constructs maintained hepatocyte-specific gene expression and functionality in vitro. When transplanted into skeletal muscle as an extrahepatic site for engraftment, the engineered hepatic grafts provided life-saving support in models of acute, fulminant, and chronic liver failure that recapitulates these clinical diseases. CONCLUSIONS: SAPNF-engineered hepatic constructs engrafted and functioned as hepatic tissues within the muscle to provide life-sustaining liver support. These engineered tissue constructs contained no animal products that would limit their development as a therapeutic approach. PMID: 20022655 [PubMed - indexed for MEDLINE] | | |
| Development and characterization of a three-dimensional organotypic human vaginal epithelial cell model.
June 9, 2010 at 8:04 AM
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| | Development and characterization of a three-dimensional organotypic human vaginal epithelial cell model. Biol Reprod. 2010 Mar;82(3):617-27 Authors: Hjelm BE, Berta AN, Nickerson CA, Arntzen CJ, Herbst-Kralovetz MM We have developed an in vitro human vaginal epithelial cell (EC) model using the innovative rotating wall vessel (RWV) bioreactor technology that recapitulates in vivo structural and functional properties, including a stratified squamous epithelium with microvilli, tight junctions, microfolds, and mucus. This three-dimensional (3-D) vaginal model provides a platform for high-throughput toxicity testing of candidate microbicides targeted to combat sexually transmitted infections, effectively complementing and extending existing testing systems such as surgical explants or animal models. Vaginal ECs were grown on porous, collagen-coated microcarrier beads in a rotating, low fluid-shear environment; use of RWV bioreactor technology generated 3-D vaginal EC aggregates. Immunofluorescence and scanning and transmission electron microscopy confirmed differentiation and polarization of the 3-D EC aggregates among multiple cell layers and identified ultrastructural features important for nutrient absorption, cell-cell interactions, and pathogen defense. After treatment with a variety of toll-like receptor (TLR) agonists, cytokine production was quantified by cytometric bead array, confirming that TLRs 2, 3, 5, and 6 were expressed and functional. The 3-D vaginal aggregates were more resistant to nonoxynol-9 (N-9), a contraceptive and previous microbicide candidate, when compared to two-dimensional monolayers of the same cell line. A dose-dependent production of tumor necrosis factor-related apoptosis-inducing ligand and interleukin-1 receptor antagonist, biomarkers of cervicovaginal inflammation, correlated to microbicide toxicity in the 3-D model following N-9 treatment. These results indicate that this 3-D vaginal model could be used as a complementary tool for screening microbicide compounds for safety and efficacy, thus improving success in clinical trials. PMID: 20007410 [PubMed - indexed for MEDLINE] | | | | 
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