|  |  |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | Fabrication of chitosan/poly(caprolactone) nanofibrous scaffold for bone and skin tissue engineering. Int J Biol Macromol. 2011 Jan 31; Authors: Shalumon KT, Anulekha KH, Chennazhi KP, Tamura H, Nair SV, Jayakumar R Chitosan/poly(caprolactone) (CS/PCL) nanofibrous scaffold was prepared by a single step electrospinning technique. The presence of CS in CS/PCL scaffold aided a significant improvement in the hydrophilicity of the scaffold as confirmed by a decrease in contact angle, which thereby enhanced bioactivity and protein adsorption on the scaffold. The cyto-compatibility of the CS/PCL scaffold was examined using human osteoscarcoma cells (MG63) and found to be non toxic. Moreover, CS/PCL scaffold was found to support the attachment and proliferation of various cell lines such as mouse embryo fibroblasts (NIH3T3), murine aneuploid fibro sarcoma (L929), and MG63 cells. Cell attachment and proliferation was further confirmed by nuclear staining using 4', 6-diamidino-2-phenylindole (DAPI). All these results indicate that CS/PCL nanofibrous scaffold would be an excellent system for bone and skin tissue engineering. PMID: 21291908 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Organic-Inorganic Hybrid Anion Exchange Hollow Fiber Membranes: a Novel Device for Drug Delivery. Int J Pharm. 2011 Jan 31; Authors: Wang N, Wu C, Cheng Y, Xu T The clinical use of nonsteroidal anti-inflammatory drugs (NSAIDs) (such as sodium salicylate (NaSA)) for the treatment of chronic arthritis is limited due to the adverse effects and patient non-compliance. In order to solve these problems, anion exchange hollow fiber membranes (AEHFMs) are proposed for the first time here as potential drug carriers. Brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) is used as the starting membrane material. In-situ sol-gel process of γ-methacryloxypropyl trimethoxysilane (γ-MPS) in BPPO matrix is operated so as to enhance the membranes' thermal and dimensional stability. The performances of the membranes in controlled release of the drug (NaSA as the model drug) are improved accordingly. Loading and release experiments illustrate that the hybrid AEHFM can bind salicylate (SA(-)) at a high loading efficiency (28.4%), and the retention of the drug on the membrane matrix is significantly prolonged (drug released in 7 days under physiological condition: 51.9%, neglecting the drug bound by protein). Meanwhile, the membrane is biocompatible and can support the adherence, growth, and survival of human cells. Overall, the prepared AEHFM is a promising scaffolding material for drug delivery and tissue engineering. PMID: 21291976 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Nanostructured glass-ceramic coatings for orthopaedic applications. J R Soc Interface. 2011 Feb 3; Authors: Wang G, Lu Z, Liu X, Zhou X, Ding C, Zreiqat H Glass-ceramics have attracted much attention in the biomedical field, as they provide great possibilities to manipulate their properties by post-treatments, including strength, degradation rate and coefficient of thermal expansion. In this work, hardystonite (HT; Ca(2)ZnSi(2)O(7)) and sphene (SP; CaTiSiO(5)) glass-ceramic coatings with nanostructures were prepared by a plasma spray technique using conventional powders. The bonding strength and Vickers hardness for HT and SP coatings are higher than the reported values for plasma-sprayed hydroxyapatite coatings. Both types of coatings release bioactive calcium (Ca) and silicon (Si) ions into the surrounding environment. Mineralization test in cell-free culture medium showed that many mushroom-like Ca and phosphorus compounds formed on the HT coatings after 5 h, suggesting its high acellular mineralization ability. Primary human osteoblasts attach, spread and proliferate well on both types of coatings. Higher proliferation rate was observed on the HT coatings compared with the SP coatings and uncoated Ti-6Al-4V alloy, probably due to the zinc ions released from the HT coatings. Higher expression levels of Runx2, osteopontin and type I collagen were observed on both types of coatings compared with Ti-6Al-4V alloy, possibly due to the Ca and Si released from the coatings. Results of this study point to the potential use of HT and SP coatings for orthopaedic applications. PMID: 21292725 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue engineering: nanofiber membranes with controllable microwells and structural cues and their use in forming cell microarrays and neuronal networks (small 3/2011). Small. 2011 Feb 7;7(3):285 Authors: Xie J, Liu W, Macewan MR, Yeh YC, Thomopoulos S, Xia Y PMID: 21294252 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Ag-doped 45S5 Bioglass(®)-based bone scaffolds by molten salt ion exchange: processing and characterisation. J Mater Sci Mater Med. 2011 Feb 4; Authors: Newby PJ, El-Gendy R, Kirkham J, Yang XB, Thompson ID, Boccaccini AR There is increasing interest in developing scaffolds with therapeutic and antibacterial potential for bone tissue engineering. Silver is a proven antibacterial agent which bacteria such as MRSA have little or no defense against. Using an ion exchange method, silver ions have been introduced into 45S5 Bioglass(®) based scaffolds that were fabricated using the foam replication technique. This technique allows the introduction of Ag(+) ions onto the surface of the scaffold without compromising the scaffold bioactivity and other physical properties such as porosity. Controlling the amount of Ag(+) ions introduced onto the surface of the scaffold was achieved by tailoring the ion exchange parameters to fabricate samples with repeatable and predictable Ag(+) ion release behavior. In vitro studies in simulated body fluid were carried out to ensure that the scaffolds maintained their bioactivity after the introduction of Ag(+) ions. It was also shown that the addition of low concentrations (2000:1 w/w) of silver ions supported the attachment and viability of human periodontal ligament stromal cells on the 3D scaffolds. This work has thus confirmed ion exchange as an effective technique to introduce Ag(+) ions into 45S5 Bioglass(®) scaffolds without compromising the basic properties of 45S5 Bioglass(®) which are required for applications in bone tissue engineering. PMID: 21293911 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Loss-of-function mutations in the glutamate transporter SLC1A1 cause human dicarboxylic aminoaciduria. J Clin Invest. 2011 Jan 4;121(1):446-53 Authors: Bailey CG, Ryan RM, Thoeng AD, Ng C, King K, Vanslambrouck JM, Auray-Blais C, Vandenberg RJ, Bröer S, Rasko JE Solute carrier family 1, member 1 (SLC1A1; also known as EAAT3 and EAAC1) is the major epithelial transporter of glutamate and aspartate in the kidneys and intestines of rodents. Within the brain, SLC1A1 serves as the predominant neuronal glutamate transporter and buffers the synaptic release of the excitatory neurotransmitter glutamate within the interneuronal synaptic cleft. Recent studies have also revealed that polymorphisms in SLC1A1 are associated with obsessive-compulsive disorder (OCD) in early-onset patient cohorts. Here we report that SLC1A1 mutations leading to substitution of arginine to tryptophan at position 445 (R445W) and deletion of isoleucine at position 395 (I395del) cause human dicarboxylic aminoaciduria, an autosomal recessive disorder of urinary glutamate and aspartate transport that can be associated with mental retardation. These mutations of conserved residues impeded or abrogated glutamate and cysteine transport by SLC1A1 and led to near-absent surface expression in a canine kidney cell line. These findings provide evidence that SLC1A1 is the major renal transporter of glutamate and aspartate in humans and implicate SLC1A1 in the pathogenesis of some neurological disorders. PMID: 21123949 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | p53 prevents progression of nevi to melanoma predominantly through cell cycle regulation. Pigment Cell Melanoma Res. 2010 Dec;23(6):781-94 Authors: Terzian T, Torchia EC, Dai D, Robinson SE, Murao K, Stiegmann RA, Gonzalez V, Boyle GM, Powell MB, Pollock PM, Lozano G, Robinson WA, Roop DR, Box NF p53 is the central member of a critical tumor suppressor pathway in virtually all tumor types, where it is silenced mainly by missense mutations. In melanoma, p53 predominantly remains wild type, thus its role has been neglected. To study the effect of p53 on melanocyte function and melanomagenesis, we crossed the 'high-p53'Mdm4+/− mouse to the well-established TP-ras0/+ murine melanoma progression model. After treatment with the carcinogen dimethylbenzanthracene (DMBA), TP-ras0/+ mice on the Mdm4+/− background developed fewer tumors with a delay in the age of onset of melanomas compared to TP-ras0/+ mice. Furthermore, we observed a dramatic decrease in tumor growth, lack of metastasis with increased survival of TP-ras0/+: Mdm4+/− mice. Thus, p53 effectively prevented the conversion of small benign tumors to malignant and metastatic melanoma. p53 activation in cultured primary melanocyte and melanoma cell lines using Nutlin-3, a specific Mdm2 antagonist, supported these findings. Moreover, global gene expression and network analysis of Nutlin-3-treated primary human melanocytes indicated that cell cycle regulation through the p21WAF1/CIP1 signaling network may be the key anti-melanomagenic activity of p53. PMID: 20849464 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Cord blood CD133 cells define an OV6-positive population that can be differentiated in vitro into engraftable bipotent hepatic progenitors. Stem Cells Dev. 2011 Feb 3; Authors: Crema A, Ledda M, De Carlo F, Fioretti D, Rinaldi M, Marchese R, Sanchez M, Giuliani M, Arena V, Durrbach A, Brunetti E, Haas C, Ponzetto A, Lisi A, Carloni G Cell therapy represents the most promising alternative strategy for end-stage liver diseases and hepatic progenitors are the best candidates. We have identified a reservoir of immature hepatic precursors within human cord blood, which can derive engraftable bipotent progenitors. We isolated a stem cell subset CD133+/CD34+OV6low expressing a surface-marker profile consistent with that of fetal liver cells. Upon induction of hepatic commitment by a medium containing cytokines and factors involved in in vivo oval-cell activation, a heterogeneous cell population displaying characteristics of functional oval-cell-like bipotent hepatic progenitors (iBHPs) was obtained. The cells expressed markers of hepatocytes and cholangiocytes and were highly enriched in OV6, c-Met, c-Kit and Thy-1. They also displayed liver functional activity as glycogen storage, urea production, albumin secretion and inducible CyP2B6 activity. When injected into liver-damaged SCID mice, iBHPs appropriately engrafted livers of recipient animals, where they formed clusters of human-derived cells expressing HLA-class I, Hep-Par1 and OV6 antigens. Human-specific albumin, alpha-fetoprotein and cytokeratin 19 were also expressed. In transplanted animals, AST serum levels showed a significative reduction respect to controls. This human model for in vitro progenitor-cell activation may provide a powerful tool for elucidating the pathways and synergies that regulate this complex process and can represent a valuable source, exploitable for liver cell-based therapies and regenerative medicine. PMID: 21291316 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A review of the biological response to ionic dissolution products from bioactive glasses and glass-ceramics. Biomaterials. 2011 Feb 1; Authors: Hoppe A, Güldal NS, Boccaccini AR Several inorganic materials such as special compositions of silicate glasses, glass-ceramics and calcium phosphates have been shown to be bioactive and resorbable and to exhibit appropriate mechanical properties which make them suitable for bone tissue engineering applications. However, the exact mechanism of interaction between the ionic dissolution products of such inorganic materials and human cells are not fully understood, which has prompted considerable research work in the biomaterials community during the last decade. This review comprehensively covers literature reports which have investigated specifically the effect of dissolution products of silicate bioactive glasses and glass-ceramics in relation to osteogenesis and angiogenesis. Particularly, recent advances made in fabricating dense biomaterials and scaffolds doped with trace elements (e.g. Zn, Sr, Mg, and Cu) and investigations on the effect of these elements on the scaffold biological performance are summarized and discussed in detail. Clearly, the biological response to artificial materials depends on many parameters such as chemical composition, topography, porosity and grain size. This review, however, focuses only on the ion release kinetics of the materials and the specific effect of the released ionic dissolution products on human cell behaviour, providing also a scope for future investigations and identifying specific research needs to advance the field. The biological performance of pure and doped silicate glasses, phosphate based glasses with novel specific compositions as well as several other silicate based compounds are discussed in detail. Cells investigated in the reviewed articles include human osteoblastic and osteoclastic cells as well as endothelial cells and stem cells. PMID: 21292319 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Dimethylnitrosamine-Induced Liver Fibrosis and Recovery in NOD/SCID mice. J Vet Med Sci. 2011 Jan 28; Authors: Hyon MK, Kwon E, Choi HJ, Kang BC There is a need for a new liver fibrosis model of immune-deficiency mice to study the effects of cell therapy on liver disease, because there are not many animal models available to study the effects of cell therapy. In this study, we induced liver fibrosis using dimethylnitrosamine (DMN) in NOD/SCID mice to create an animal model for liver disease. DMN (5 mg/kg, i.p.) was injected intraperitoneally for three consecutive days per week for 6 or 8 weeks and the mice were sacrificed at weeks 0, 4 and 8 after the last DMN injection. The 6-week DMN treated group gradually recovered from serum biochemical changes, histopathological toxic effects and lesions in the liver at weeks 4 and 8 after the last DMN injection. However, the progression of liver fibrosis and toxic levels were maintained in the 8-week DMN treated group at week 4 after the last DMN injection. The increases in iron and extracellular matrix (collagen) in the DMN treated group were confirmed by Prussian blue (PB) and Masson trichrome (MT) staining, respectively. Additionally, activation of hepatic stellate cells was observed by alpha smooth muscle actin (α-SMA) immunostaining and western blot. In conclusion, the treatment of NOD/SCID mice with 5 mg/kg of DMN for 8 weeks can be used to induce the appropriate animal model of disease for liver fibrosis. This model may be useful for the evaluation of the efficacy and safety of cell therapies such as human mesenchymal stem cell therapy. PMID: 21289474 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Osteogenic differentiation of two distinct subpopulations of human adipose-derived stem cells: an in vitro and in vivo study. J Tissue Eng Regen Med. 2011 Feb 4; Authors: Rada T, Santos TC, Marques AP, Correlo VM, Frias AM, Castro AG, Neves NM, Gomes ME, Reis RL The first stem cells considered for the reconstruction of bone were bone marrow mesenchymal stem cells (BMSCs). Subsequently, cells with similar marker expression panel and differentiation potential were found in new sources of cells, such as adipose tissue. This source of stem cells has a promising future in tissue-engineering applications, considering the abundance of this tissue in the human body, the easy harvesting and the high number of stem cells that are available from such a small amount of tissue. The isolation of the adipose stem cells is generally performed by means of enzymatic digestion of the tissues, followed by a natural selection of the stem cells based on their capacity to adhere to the culture flasks, leading to a quite heterogeneous population. This constitutes a major drawback for the use of these cells, since the heterogeneity of the cell culture obtained can compromise their proliferation and differentiation potential. In the present study we have analysed the in vitro and in vivo behaviour of two selected subpopulations with high osteogenic potential. For this purpose, ASCs$^{{\rm{CD29}}+}$ and ASCs$^{{\rm{STRO-1}}+}$ subpopulations were isolated and in vitro cultured onto a biodegradable polymeric scaffold, using osteogenic medium, before implantation in a nude mice model. The biodegradable polymeric scaffold used is a fibre-mesh structure based on a blend of starch and polycaprolatone (SPCL) that has been successfully used in several bone tissue-engineering studies. The implanted ASCs-scaffold constructs promoted the formation of new bone tissue in nude mice. However, the results obtained show differences in the behaviour of the two ASCs subpopulations under study, particularly regarding their potential to differentiate into the osteogenic lineage, and allowed the indentification of ASCs$^{{\rm{STRO-1}}+}$ as the best subpopulation for bone tissue-engineering applications. Copyright © 2011 John Wiley & Sons, Ltd. PMID: 21294275 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Generation of subtype-specific neurons from postnatal astroglia of the mouse cerebral cortex. Nat Protoc. 2011 Feb;6(2):214-28 Authors: Heinrich C, Gascón S, Masserdotti G, Lepier A, Sanchez R, Simon-Ebert T, Schroeder T, Götz M, Berninger B Instructing glial cells to generate neurons may prove to be a strategy to replace neurons that have degenerated. Here, we describe a robust protocol for the efficient in vitro conversion of postnatal astroglia from the mouse cerebral cortex into functional, synapse-forming neurons. This protocol involves two steps: (i) expansion of astroglial cells (7 d) and (ii) astroglia-to-neuron conversion induced by persistent and strong retroviral expression of Neurog2 (encoding neurogenin-2) or Mash1 (also referred to as achaete-scute complex homolog 1 or Ascl1) and/or distal-less homeobox 2 (Dlx2) for generation of glutamatergic or GABAergic neurons, respectively (7-21 d for different degrees of maturity). Our protocol of astroglia-to-neuron conversion by a single neurogenic transcription factor provides a stringent experimental system to study the specification of a selective neuronal subtype, thus offering an alternative to the use of embryonic or neural stem cells. Moreover, it can be a useful model for studies of lineage conversion from non-neuronal cells, with potential for brain regenerative medicine. PMID: 21293461 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Eugene goldwasser (1922-2010). Nature. 2011 Feb 3;470(7332):40 Authors: Wojchowski D PMID: 21293362 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | PI3K mediated electrotaxis of embryonic and adult neural progenitor cells in the presence of growth factors. Exp Neurol. 2011 Jan;227(1):210-7 Authors: Meng X, Arocena M, Penninger J, Gage FH, Zhao M, Song B Correct guidance of the migration of neural progenitor cells (NPCs) is essential for the development and repair of the central nervous system (CNS). Electric field (EF)-guided migration, electrotaxis, has been observed in many cell types. We report here that, in applied EFs of physiological magnitude, embryonic and adult NPCs show marked electrotaxis, which is dependent on the PI3K/Akt pathway. The electrotaxis was also evidenced by ex vivo investigation that transplanted NPCs migrated directionally towards cathode in organotypic spinal cord slice model when treated with EFs. Genetic disruption or pharmacological inhibition of phosphoinositide 3-kinase (PI3K) impaired electrotaxis, whereas EF exposure increased Akt phosphorylation in a growth factor-dependent manner and increased phosphatidylinositol-3,4,5-trisphosphate (PIP3) levels. EF treatments also induced asymmetric redistribution of PIP3, growth factor receptors, and actin cytoskeleton. Electrotaxis in both embryonic and adult NPCs requires epidermal growth factor (EGF) and fibroblast growth factor (FGF). Our results demonstrate the importance of the PI3K/Akt pathway in directed migration of NPCs driven by EFs and growth factors and highlight the potential of EFs to enhance the guidance of various NPC populations in CNS repair therapies. PMID: 21092738 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Osteoblast function on electrically conductive electrospun PLA/MWCNTs nanofibers. Biomaterials. 2011 Feb 1; Authors: Shao S, Zhou S, Li L, Li J, Luo C, Wang J, Li X, Weng J The electrospinning process was utilized successfully to fabricate the random oriented and aligned electrically conductive nanofibers of biodegradable poly-DL-lactide (PLA) in which multiwalled carbon nanotubes (MWCNTs) were embedded. The topographical features of the composite nanofibers were characterized by SEM. The dispersion and alignment of MWCNTs in nanofiber matrix were observed by TEM. The in vitro degradation was characterized in terms of the morphological change, the mass loss and the reduction of polymer molecular weight as well as the decrease of pH value of degradation media. In particular, these conductive nanofiber meshes offered a unique system to study the synergistic effect of topographic cues and electrical stimulation on osteoblasts outgrowth as a way of exploring their potential application in bone tissue engineering. The results of obsteoblasts assay unstimulated showed that the aligned nanofibers as topographic cues could enhance the extension and direct the outgrowth of obsteoblasts better than random fibers. In the presence of direct current (DC) of 100 μA, the obsteoblasts on all samples grew along the electrical current direction. The cellular elongation and proliferation were mainly dependent on the electrical stimulation whereas the topographical features played a minor role in them. Therefore, electrical stimulation with an appropriate DC value imparted on conductive substrate had great potential in application of bone tissue engineering. PMID: 21292320 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bilateral orbitozygomatic reconstruction with tissue-engineered bone. J Craniofac Surg. 2010 Sep;21(5):1612-4 Authors: Taylor JA Critical defects of the craniomaxillofacial region and long bones are often treated with bone grafts and vascularized osteocutaneous free flaps. These lengthy operations may be associated with considerable donor site morbidity and often have suboptimal functional and aesthetic results. The allure of providing an exact replica of a missing bone that incorporates to become indistinguishable from self, has the capacity to heal and grow, is resistant to infection, and with minimal morbidity is a "holy grail" to all surgeons who work with bone. This is a report of a 14-year-old adolescent boy with Treacher Collins syndrome whose bilateral orbitozygomatic defects were treated with engineered bone made from a combination of human bone allograft, adipose-derived mesenchymal stem cells, bone morphogenic protein-2, and periosteal grafts. This single-stage reconstruction was followed by an exuberant amount of postoperative swelling that persisted for 3 weeks. He had slight lid malposition postoperatively as well but has had no long-term negative effects from the surgery. His reconstruction has remained stable during a 6-month follow-up, and a recent biopsy of the engineered bone demonstrated healthy, lamellar bone. These data are the first to demonstrate revitalization of large volume allograft bone in humans and have positive implications for craniofacial bone tissue engineering. The combination of adipose-derived stem cells, bone morphogenic protein-2, bone allograft, and periosteum may provide an alternative method to both osteocutaneous free flaps and large structural allografts with less morbidity and improved long-term results. PMID: 20856057 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Chondrogenesis in Injectable Enzymatically Crosslinked Heparin/Dextran Hydrogels. J Control Release. 2011 Jan 31; Authors: Jin R, Teixeira LS, Dijkstra PJ, van Blitterswijk CA, Karperien M, Feijen J In this study, injectable hydrogels were prepared by the horseradish peroxidase-mediated co-crosslinking of dextran-tyramine (Dex-TA) and heparin-tyramine (Hep-TA) conjugates and used as scaffolds for cartilage tissue engineering. The swelling and mechanical properties of these hydrogels can be easily controlled by the Dex-TA/Hep-TA weight ratio. When chondrocytes were incorporated in these gels, cell viability and proliferation were highest for gels with a 50/50 weight ratio of Dex-TA/Hep-TA. Moreover, these hydrogels induced an enhanced production of chondroitin sulfate and a more abundant presence of collagen as compared to Dex-TA hydrogels. The results indicate that injectable Dex-TA/Hep-TA hydrogels are promising scaffolds for cartilage regeneration. PMID: 21291927 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Magnetic CoPt nanoparticles as MRI contrast agent for transplanted neural stem cells detection. Nanoscale. 2011 Feb 4; Authors: Meng X, Seton HC, Lu LT, Prior IA, Thanh NT, Song B Neural stem cells (NSCs) exhibit features that make them suitable candidates for stem cell replacement therapy and spinal cord reconstruction. Magnetic resonance imaging (MRI) offers the potential to track cells in vivo using innovative approaches to cell labeling and image acquisition. In this study, experiments were carried out to optimize the loading condition of magnetic CoPt hollow nanoparticles (CoPt NPs) into neural stem cells and to define appropriate MRI parameters. Both cell viability and multipotency analysis showed that CoPt NPs at a concentration of 16 µg ml(-1) reduced T(2) relaxation times in labeled rat NSCs, producing greater contrast on spin echo acquisitions at 4.7 T, yet did not affect cell viability and in vitro differentiation potential compared to controls. After optimizing nanoparticle loading concentrations and labeled cell numbers for MRI detection, CoPt-loaded NSCs were transplanted into organotypic spinal cord slices. The results showed that MRI could efficiently detect low numbers of CoPt-labeled NSCs with the enhanced image contrast. Our study demonstrated that MRI of grafted NSCs labeled with CoPt NPs is a useful tool to evaluate organotypic spinal cord slice models and has potential applications in other biological systems. PMID: 21293831 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Multifunctional Porous Silicon for Therapeutic Drug Delivery and Imaging. Curr Drug Discov Technol. 2011 Feb 4; Authors: Santos HA, Bimbo LM, Lehto VP, Airaksinen AJ, Salonen J, Hirvonen J Major challenges in drug formulation are the poor solid state stability of drug molecules, poor dissolution/solubility and/or poor pharmacokinetic properties (bioavailability), which may lead to unreliable in vitro-in vivo (IVIV) correlation. To improve current therapeutical strategies, novel means to deliver poorly water soluble active pharmaceutical ingredients, as well as to target them to specific sites or cells in the body are needed. Biomedical applications of porous silicon (PSi) have been actively investigated during the last 10 years, especially in the areas of drug delivery and imaging, due to the biocompatibility and biodegradability of PSi materials, which makes them a potential candidate for controlled drug release. In addition, the unique pore sizes and easily functionalized surface properties of PSi materials allow high drug payloads and controlled kinetics from the drug release formulations. Modification of the PSi surface properties also facilitates biofunctionalization of the surface and the possibility to attach targeting moieties (e.g., antibodies and peptides), thus enabling effective targeting of the payload. In this review, we briefly address the production methodologies of PSi, and we will mainly present and discuss several examples about the biocompatibility of PSi, the most recent in vitro and in vivo applications of PSi as a carrier in drug/protein/peptide delivery and tissue engineering, as well as PSi as a platform for drug targeting and imaging. PMID: 21291407 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Growth factors and periodontal engineering: where next? J Dent Res. 2011 Jan;90(1):7-8 Authors: Somerman M PMID: 21041551 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Epigenetic mechanisms in inflammation. J Dent Res. 2011 Jan;90(1):9-17 Authors: Bayarsaihan D Epigenetic modifications occur in response to environmental changes and play a fundamental role in gene expression following environmental stimuli. Major epigenetic events include methylation and acetylation of histones and regulatory factors, DNA methylation, and small non-coding RNAs. Diet, pollution, infections, and other environmental factors have profound effects on epigenetic modifications and trigger susceptibility to diseases. Despite a growing body of literature addressing the role of the environment on gene expression, very little is known about the epigenetic pathways involved in the modulation of inflammatory and anti-inflammatory genes. This review summarizes the current knowledge about epigenetic control mechanisms during the inflammatory response. PMID: 21178119 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Engineered Human Cardiac Tissue. Pediatr Cardiol. 2011 Feb 4; Authors: Kreutziger KL, Murry CE The human heart is the first organ to develop during embryogenesis and is arguably the most essential organ for life. However, after birth, the heart has very little capacity to repair malformations such as congenital heart defects or to regenerate after an injury such as myocardial infarction. Cardiac tissue engineering addresses the need for a therapeutic biologic implant to restore cardiac structure and muscle mass. This review highlights current research in cardiac tissue engineering that uses human cardiomyocytes derived from embryonic stem cells. Other human cell sources are discussed because future human therapies will benefit from novel techniques using human-induced pluripotent stem cells and cardiomyocytes derived from direct reprogramming of somatic cells. Furthermore, this review examines the main approaches to creating engineered cardiac tissue with synthetic scaffolds, natural scaffolds, or no exogenous scaffold (i.e., "scaffold free"). The choice of scaffold and cells ultimately depends on the goals of the therapy, so the review considers how congenital heart defects define the design parameters for cardiac tissue engineering needed for surgical repair in pediatric cardiac patients. PMID: 21293854 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | THE β-CATENIN/TCF4/SURVIVIN SIGNALING MAINTAINS A LESS DIFFERENTIATED PHENOTYPE AND HIGH PROLIFERATIVE CAPACITY OF HUMAN CORNEAL EPITHELIAL PROGENITOR CELLS. Int J Biochem Cell Biol. 2011 Jan 31; Authors: Lu R, Bian F, Zhang X, Qi H, Chuang EY, Pflugfelder SC, Li DQ It is clear that the microenvironment or niche plays an important role in determining the fate of stem cells: being stem cells or differentiated. However, the intrinsic pathways controlling the fate of adult stem cells in different niches are largely unknown. This study was to explore the role of β-catenin/Tcf4/survivin signaling in determining the fate of human corneal epithelial stem cells in different media. We observed that the low calcium serum-free media, especially CnT-20, promoted proliferative capacity, colony forming efficiency and stem cell-like phenotype of human corneal epithelial cells (HCECs) when compared with the cells cultured in a high calcium serum-containing medium SHEM. Three key factors in Wnt signaling, β-catenin, Tcf4 and survivin, were found to be expressed higher by HCECs grown in CnT-20 than those cultured in SHEM, as evaluated by real-time PCR, Western blotting and immunostaining. Transfection of siRNA-Tcf4 at 10-50nM knocked down Tcf4, and also significantly suppressed its down stream molecule survivin at both mRNA and protein levels in HCECs. Furthermore, Tcf4 silencing significantly suppressed the proliferative capacity of HCECs, measured by WST-1 assay, compared with the control groups, untreated or transfected with non-coding sequence siRNA-fluorescein. These findings demonstrate that low calcium serum free media promote ex vivo expansion of corneal epithelial progenitor cells that retain a less differentiated phenotype and high proliferative capacity via β-catenin/Tcf4/survivin signaling, a novel intrinsic pathway. This study may have high impact and clinic implication on the expansion of corneal epithelial stem cells in regenerative medicine, especially for ocular surface reconstruction. PMID: 21292023 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Comparison of Fibrin Glue versus Suture for Conjunctival Autografting in Pterygium Surgery: A Meta-Analysis. Ophthalmology. 2011 Feb 1; Authors: Pan HW, Zhong JX, Jing CX PURPOSE:: To evaluate the safety and clinical efficacy of fibrin glue in pterygium surgery with conjunctival autografting. DESIGN:: The use of fibrin glue has been introduced in the treatment of pterygium. However, its role versus traditional suturing is still a matter of debate. We performed a meta-analysis to compare the safety and clinical efficacy of fibrin glue with suture for conjunctival autograft attachment in pterygium surgery. PARTICIPANTS:: A total of 342 participants with 366 eyes in 7 studies were analyzed. METHODS:: We searched Medline, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar for relevant randomized controlled trials (RCTs). MAIN OUTCOME MEASURES:: The methodological quality of all the included trials was assessed with the Jadad score. The meta-analysis was performed with the fixed-effects model for complication rate and recurrence rate, and random-effects model for operating time. RESULTS:: Fibrin glue was associated with a significantly decreased operating time (weighted mean difference -17.61 minutes, 95% confidence interval [CI], -26.03 to -9.18, P<0.0001) and was more effective in reducing the recurrence rate (Peto odds ratio [OR] 0.33, 95% CI, 0.15-0.71, P = 0.004) compared with suture. There were no significant differences in the complication rate (Peto OR 1.82, 95% CI, 0.63-5.27, P = 0.27) between the 2 groups. CONCLUSIONS:: Our meta-analysis supports the superiority of fibrin glue to suture in pterygium surgery with conjunctival autografting in that the use of fibrin glue can significantly reduce the recurrence rate without increasing the risk of complications. Ophthalmologists should consider the use of fibrin glue in pterygium surgery. FINANCIAL DISCLOSURE(S):: The author(s) have no proprietary or commercial interest in any materials discussed in this article. PMID: 21292327 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Pharmaceutical therapy for radiculopathy. Phys Med Rehabil Clin N Am. 2011 Feb;22(1):127-37 Authors: Visco CJ, Cheng DS, Kennedy DJ Pharmaceutical treatments for radiculopathy include opioid, antiinflammatory (steroidal and nonsteroidal), neuromodulating, topical, and adjuvant treatments. These medications act locally, peripherally, or centrally on the neural axis. This article reviews the history of medication use for radiculopathy and the available literature along with the breadth of current treatment and indications. PMID: 21292149 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | In vitro and in vivo evaluation of SLA titanium surfaces with further alkali or hydrogen peroxide and heat treatment. Biomed Mater. 2011 Feb 4;6(2):025001 Authors: Zhang EW, Wang YB, Shuai KG, Gao F, Bai YJ, Cheng Y, Xiong XL, Zheng YF, Wei SC The present study aimed to evaluate the bioactivity of titanium surfaces sandblasted with large-grit corundum and acid etched (SLA) plus further alkali or hydrogen peroxide and heat treatment for dental implant application. Pure titanium disks were mechanically polished as control surface (Ti-control) and then sandblasted with large-grit corundum and acid etched (SLA). Further chemical modifications were conducted using alkali and heat treatment (ASLA) and hydrogen peroxide and heat treatment (HSLA) alternatively. The surface properties were characterized by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and contact angle and roughness measurements. Further evaluation of surface bioactivity was conducted by MC3T3-E1 cell attachment, proliferation, morphology, alkaline phosphatase (ALP) activity and calcium deposition on the sample surfaces. After insertion in the beagle's mandibula for a specific period, cylindrical implant samples underwent micro-CT examination and then histological examination. It was found that ASLA and HSLA surfaces significantly increased the surface wettability and MC3T3-E1 cell attachment percentage, ALP activity and the quality of calcium deposition in comparison with simple SLA and Ti-control surfaces. Animal studies showed good osseointegration of ASLA and HSLA surfaces with host bone. In conclusion, ASLA and HSLA surfaces enhanced the bioactivity of the traditional SLA surface by integrating the advantages of surface topography, composition and wettability. PMID: 21293055 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Developmental and regenerative biology of multipotent cardiovascular progenitor cells. Circ Res. 2011 Feb 4;108(3):353-64 Authors: Sturzu AC, Wu SM Our limited ability to improve the survival of patients with heart failure is attributable, in part, to the inability of the mammalian heart to meaningfully regenerate itself. The recent identification of distinct families of multipotent cardiovascular progenitor cells from endogenous, as well as exogenous, sources, such as embryonic and induced pluripotent stem cells, has raised much hope that therapeutic manipulation of these cells may lead to regression of many forms of cardiovascular disease. Although the exact source and cell type remains to be clarified, our greater understanding of the scientific underpinning behind developmental cardiovascular progenitor cell biology has helped to clarify the origin and properties of diverse cells with putative cardiogenic potential. In this review, we highlight recent advances in the understanding of cardiovascular progenitor cell biology from embryogenesis to adulthood and their implications for therapeutic cardiac regeneration. We believe that a detailed understanding of cardiogenesis will inform future applications of cardiovascular progenitor cells in heart failure therapy and regenerative medicine. PMID: 21293007 [PubMed - in process] | | | | | | | | | |  | |  | |  |
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