|  |  |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Biodegradable cellulose acetate nanofiber fabrication via electrospinning. J Nanosci Nanotechnol. 2010 Sep;10(9):6226-33 Authors: Christoforou T, Doumanidis C Nanofiber manufacturing is one of the key advancements in nanotechnology today. Over the past few years, there has been a tremendous growth of research activities to explore electrospinning for nanofiber formation from a rich variety of materials. This quite simple and cost effective process operates on the principle that the solution is extracted under the action of a high electric field. Once the voltage is sufficiently high, a charged jet is ejected following a complicated looping trajectory. During its travel, the solvent evaporates leaving behind randomly oriented nanofibers accumulated on the collector. The combination of their nanoscale dimensionality, high surface area, porosity, flexibility and superior strength makes the electrospun fibers suitable for several value-added applications, such as filters, protecting clothes, high performance structures and biomedical devices. In this study biodegradable cellulose acetate (CA) nanofibrous membranes were produced using electrospinning. The device utilized consisted of a syringe equipped with a metal needle, a microdialysis pump, a high voltage supply and a collector. The morphology of the yielded fibers was determined using SEM. The effect of various parameters, including electric field strength, tip-to-collector distance, solution feed rate and composition on the morphological features of the electrospun fibers was examined. The optimum operating conditions for the production of uniform, non-beaded fibers with submicron diameter were also explored. The biodegradable CA nanofiber membranes are suitable as tissue engineering scaffolds and as reinforcements of biopolymer matrix composites in foils by ultrasonic welding methods. PMID: 21133179 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Palmitoylated SDF1 α Shows Increased Resistance against Proteolytic Degradation in Liver Homogenates. ChemMedChem. 2010 Dec 7; Authors: Bellmann-Sickert K, Beck-Sickinger AG The chemokine stromal cell-derived factor-1 α (SDF1 α) is strongly involved in organogenesis, as well as inflammation and tissue repair, and acts by attracting different kinds of stem and progenitor cells. Therefore, it constitutes an interesting compound for drug development in regenerative medicine. However, it is prone to inactivation by proteolytic cleavage in human serum. Accordingly, it has to be stabilized against enzymatic degradation for any therapeutic application. We synthesized a palmitoylated SDF1 α analogue by native chemical ligation. Both the N-terminal thioester and the C-terminal palmitoylated fragment were prepared by solid-phase peptide synthesis. The activity of the refolded and pure compound was determined by an inositol phosphate turnover assay and revealed no loss in receptor activation. Additionally, resistance to proteolytic degradation was investigated in porcine liver homogenates and showed a near sevenfold increased half time. This study is a proof of principle approach for the lipidation of SDF1 α and provides a basis for further engineering of the chemokine in order to increase its therapeutic value. PMID: 21140394 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Differential effects of platelet rich plasma and washed platelets on the proliferation of mouse MSC cells. Mol Biol Rep. 2010 Dec 8; Authors: Duan J, Kuang W, Tan J, Li H, Zhang Y, Hirotaka K, Tadashi K Multipotent mesenchymal stem cell (MSC) therapies are being tested clinically for a variety of disorders. However, despite the remarkable clinical advancements in this field, most applications still use traditional culture media containing fetal bovine serum. Platelet-rich plasma (PRP) appears as a novel application for tissue engineering and its effect on bone healing is thought to be mainly dependent on the proliferation promoting function, with the molecular mechanisms largely unknown. In this study, mouse osteogenic progenitor mesenchymal stem cells (MSCs) were cultured in PRP or washed platelet (WPLT)-treated wells or in untreated wells, and analyzed on cycloxygenase 2 (COX2) expression (qRT-PCR), cell growth (MTT assay) and cell differentiation (alkaline phosphatase activity). The results showed that PRP and WPLT stimulated cell growth similarly in the first 6 days, together with the steady induction of COX2 and PGE2. 10 μmol/l celecoxib (an inhibitor of COX2) significantly inhibited the pro-proliferation effects. Interestingly, WPLT had stronger effects than PRP in proliferation at the later time points (6-9 days). ALP activity assay and collagen 1a expression revealed PRP had a mild but statistically significant pro-differentiation effect, while no obvious effects observed in WLPT group. In summary, PRP stimulates initial growth of MSCs in a COX2 partially dependent manner and the less obvious osteogenic differentiation promoting effects of WPLT strongly indicates WPLT rather than the PRP should be the optional choice for expanding MSCs in vitro for clinical use. PMID: 21140227 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Constraint-induced movement therapy as a paradigm of translational research in neurorehabilitation: Reviews and prospects. Am J Transl Res. 2010;3(1):48-60 Authors: Huang WC, Chen YJ, Chien CL, Kashima H, Lin KC There is an increasing awareness about the importance of translation from basic scientific findings into practical application for efficiently improving human health, especially in the pharmaceutical industry. In the field of neurorehabilitation, however, the bench-to-bedside process continues to be developing, and thus most of the therapeutic interventions have encountered barriers during exploration of evidence-based effectiveness. Despite this immaturity, constraint-induced movement therapy (CIT), a well-evidenced treatment evolved from research in nonhuman primates, is suggested to be an ideal paradigm of translational research in the field of neurorehabilitation. This article reviews the evolvement of CIT with regards to its behavioral efficacy and neuroimaging evidence through the translation roadmap developed by the National Institutes of Health. We also discuss prospects for the application of combined interventions, such as stem cell therapy or pharmaceutical prescription, with appropriate screening of patients beforehand, as well as an efficient delivery mode after the treatment. To achieve such goals and consolidate evidenced-based neurorehabilitation, we provide a framework for applications into the translational research of other therapeutic interventions aside from CIT. PMID: 21139805 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Reconstruction of a human cornea by the self-assembly approach of tissue engineering using the three native cell types. Mol Vis. 2010;16:2192-201 Authors: Proulx S, Uwamaliya J, Carrier P, Deschambeault A, Audet C, Giasson CJ, Guérin SL, Auger FA, Germain L PURPOSE: The purpose of this study was to produce and characterize human tissue-engineered corneas reconstructed using all three corneal cell types (epithelial, stromal, and endothelial cells) by the self-assembly approach. METHODS: Fibroblasts cultured in medium containing serum and ascorbic acid secreted their own extracellular matrix and formed sheets that were superposed to reconstruct a stromal tissue. Endothelial and epithelial cells were seeded on each side of the reconstructed stroma. After culturing at the air-liquid interface, the engineered corneas were fixed for histology and transmission electron microscopy (TEM). Immunofluorescence labeling of epithelial keratins, basement membrane components, Na(+)/K(+)-ATPase α1, and collagen type I was also performed. RESULTS: Epithelial and endothelial cells adhered to the reconstructed stroma. After 10 days at the air-liquid interface, the corneal epithelial cells stratified (4 to 5 cell layers) and differentiated into well defined basal and wing cells that also expressed Na(+)/K(+)-ATPase α1 protein, keratin 3/12, and basic keratins. Basal epithelial cells from the reconstructed epithelium formed many hemidesmosomes and secreted a well defined basement membrane rich in laminin V and collagen VII. Endothelial cells formed a monolayer of tightly-packed cells and also expressed the function related protein Na(+)/K(+)-ATPase α1. CONCLUSIONS: This study demonstrates the feasibility of producing a complete tissue-engineered human cornea, similar to native corneas, using untransformed fibroblasts, epithelial and endothelial cells, without the need for exogenous biomaterial. PMID: 21139684 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Endogenous and exogenous stem cells: a role in lung repair and use in airway tissue engineering and transplantation. J Biomed Sci. 2010 Dec 7;17(1):92 Authors: Chistiakov DA ABSTRACT: Rapid repair of the denuded alveolar surface after injury is a key to survival. The respiratory tract contains several sources of endogenous adult stem cells residing within the basal layer of the upper airways, within or near pulmonary neuroendocrine cell rests, at the bronchoalveolar junction, and within the alveolar epithelial surface, which contribute to the repair of the airway wall. Bone marrow-derived adult mesenchymal stem cells circulating in blood are also involved in tracheal regeneration. However, an organism is frequently incapable of repairing serious damage and defects of the respiratory tract resulting from acute trauma, lung cancers, and chronic pulmonary and airway diseases. Therefore, replacement of the tracheal tissue should be urgently considered. The shortage of donor trachea remains a major obstacle in tracheal transplantation. However, implementation of tissue engineering and stem cell therapy-based approaches helps to successfully solve this problem. To date, huge progress has been achieved in tracheal bioengineering. Several sources of stem cells have been used for transplantation and airway reconstitution in animal models with experimentally induced tracheal defects. Most tracheal tissue engineering approaches use biodegradable three-dimensional scaffolds, which are important for neotracheal formation by promoting cell attachment, cell redifferentiation, and production of the extracellular matrix. The advances in tracheal bioengineering recently resulted in successful transplantation of the world's first bioengineered trachea. Current trends in tracheal transplantation include the use of autologous cells, development of bioactive cell-free scaffolds capable of supporting activation and differentiation of host stem cells on the site of injury, with a future perspective of using human native sites as micro-niche for potentiation of the human body's site-specific response by sequential adding, boosting, permissive, and recruitment impulses. PMID: 21138559 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Electrospun PCL/PLA/HA based nanofibers as scaffold for osteoblast-like cells. J Nanosci Nanotechnol. 2010 Nov;10(11):7747-51 Authors: Fang R, Zhang E, Xu L, Wei S Polycaprolactone (PCL), poly (lactic acid) (PLA) and hydroxyapatite (HA) are frequently used as materials for tissue engineering. In this study, PCL/PLA/HA nanofiber mats with different weight ratio were prepared using electrospinning. Their structure and morphology were studied by FTIR and FESEM. FTIR results demonstrated that the HA particles were successfully incorporated into the PCL/PLA nanofibers. The FESEM images showed that the surface of fibers became coarser with the introduction of HA nanoparticles into PCL/PLA system. Furthermore, the addition of HA led to the decreasing of fiber diameter. The average diameters of PCL/PLA/HA nanofiber were in the range of 300-600 nm, while that of PCL/PLA was 776 +/- 15.4 nm. The effect of nanofiber composition on the osteoblast-like MC3T3-E1 cell adhesion and proliferation were investigated as the preliminary biological evaluation of the scaffold. The MC3T3-E1 cell could be attached actively on all the scaffolds. The MTT assay revealed that PCL/PLA/HA scaffold shows significantly higher cell proliferation than PCL/PLA scaffolds. After 15 days of culture, mineral particles on the surface of the cells was appeared on PCL/PLA/HA nanofibers while normal cell spreading morphology on PCL/PLA nanofibers. These results manifested that electrospun PCL/PLA/HA scaffolds could enhance bone regeneration, showing their marvelous prospect as scaffolds for bone tissue engineering. PMID: 21138024 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | A biocompatible chitosan composite containing phosphotungstic acid modified single-walled carbon nanotubes. J Nanosci Nanotechnol. 2010 Nov;10(11):7126-9 Authors: Zhao Q, Yin J, Feng X, Shi Z, Ge Z, Jin Z Surface modification of carbon nanotubes is crucial for the dispersion and interfacial adhesion of carbon nanotubes in polymer composites. Here we present a novel method to construct single-walled carbon nanotube/chitosan composites using phosphotungstic acid as an anchor reagent to modify single-walled carbon nanotubes. The most direct benefit from this method is that this modification is mild but effective: the induced defects on single-walled carbon nanotubes are negligible based on Raman and transmission electron microscopy observations; and homogeneous dispersion of single-walled carbon nanotubes in chitosan matrices and strong binding between single-walled carbon nanotubes and chitosan are achieved. Moreover, according to the results of tetrazolium-based colorimetric assays in vitro, we demonstrate that the produced phosphotungstic-acid-modified single-walled carbon nanotube/chitosan composites have good biocompatibility. Thus, our study provides a feasible route to fabricate biocompatible composites containing single-walled carbon nanotubes for potential application in bone tissue engineering. PMID: 21137879 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Tissue-engineering of oral mucosal equivalents in dentistry. Dent Update. 2010 Oct;37(8):567; author reply 568 Authors: Chai WL PMID: 21137850 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Submicron-patterned fibronectin controls the biological behavior of human dermal fibroblasts. J Nanosci Nanotechnol. 2010 Oct;10(10):6864-8 Authors: Kim CH, Kim GW, Chun HJ Cell adhesion is an important step in cell survival, and in the proliferation of anchorage-dependent cells, whose dimensions can be controlled by micro-patterning of the cell-adhesive extracellular matrix. To fabricate a micro-patterned fibronectin substrate with spacings ranging from 0.9 microm to 20 microm, we made a replica mold using e-beam lithography. The physiological behavior of human dermal fibroblasts (HDFs) on a substrate with a gradient of pattern spacings from 0.9 microm to 20 microm was evaluated after 4.5 hours and 2 days of culture. The number of proliferating cells on the fibronectin-patterned surface increased as the spacing between strip lines increased to 11 micron. However, the number of cells gradually decreased when the pattern spacing exceeded 11 microm. These findings demonstrate that the submicron-patterned topography of a substrate plays important roles in HDF survival and proliferation. PMID: 21137813 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Preparation and characterization of biodegradable electrospun polyanhydride nano/microfibers. J Nanosci Nanotechnol. 2010 Oct;10(10):6369-75 Authors: Su Q, Zhao A, Peng H, Zhou S The biodegradable polyanhydride copolymers P(CPP-SA) composed of p-carboxyhenoxy propane (CPP) and sebacic acid (SA) at weight ratios of 20:80, 35:65 and 50:50 were polymerized by a melt polycondensation process without catalyst. The copolymers were characterized by fourier transform infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance (1H-NMR), Ubbelohde viscometer, differential scanning calorimetry (DSC) and wide angle X-ray powder-diffraction (XRD). P(CPP-SA) nano/microfibers were the first time to be fabricated by electrospinning. The copolymers hold an excellent fibre-forming performance and the diameter range of 80-3,200 nm can be obtained. The in vitro degradation of the polyanhydride copolymers was evaluated in form of the nano/microfibers by investigating the change of fibrous morphology, weight loss and pH change of degradation medium. The experimental results showed that degradation rate was fast in the fist day and slow in the following period, furthermore the degradation rate decreased with the increase of the content of CPP in copolymers. Therefore, the electrospun polyanhydride nano/microfibers exhibited strong potential as drug delivery vehicle and tissue engineering scaffold. PMID: 21137732 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | [Preliminary investigation on the formation mechanism of CCL4-water-cetyl trimethyl ammonium bromide (CTAB) gel]. Guang Pu Xue Yu Guang Pu Fen Xi. 2010 Oct;30(10):2706-9 Authors: Sun Y, Chen J, He AQ, Huang K, Yu L, Liu CG, Wei YJ, Zhai YJ, Xu YZ, Wu JG Gels are gaining extensive interest owing to their versatile applications in fields such as drug delivery, tissue engineering, cosmetics, templated materials and food industry. Surfactants have an ability to self-assemble into a variety of supramolecular aggregate structures and morphologies. Of particular interest in resent years are surfactant-based gels, one special class of materials due to surfactant assemblies resulting in viscoelastic solid-like rheological behaviors. Up to now, there is only limited understanding on the mechanism of gel formation, especially on the interaction among water, organic solvents and surfactant during thegel formation. In this study we prepare a Low-molecule-gel that is composed of cetyl trimethyl ammonium bromide (CTAB), water and carbon tetrachloride. Based on the experimental result of XRD and titration, the authors find that CTAB in gel are more than in saturated CTAB solution but CTAB is not solide in gel. CTAB is not solvented in CCl4. The solubility of CTAB in saturated CTAB solution is limited. So the authors suppose that CTAB is a synergistically solubilized by water and CCl4 in the gel. In addition, both NMR and FTIR spectroscopic results demonstrate that CTAB cations form a quasi-ordered structure in the gel. PMID: 21137404 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Continuous cyclic mechanical tension inhibited Runx2 expression in mesenchymal stem cells through RhoA-ERK1/2 pathway. J Cell Physiol. 2010 Dec 6; Authors: Shi Y, Li H, Zhang X, Fu Y, Huang Y, Lui PP, Tang T, Dai K Tensile load is known to regulate the osteogenesis of mesenchymal stem cells (MSCs) and osteogenic progenitors; therefore it is widely used in clinical treatment and tissue engineering. Meanwhile, in vitro, both published studies and our lab data demonstrate that the application of intermittent tensile loading which stimulates cells several minutes or hours each day for several days has promoted the osteogenic differentiation of MSCs. Whereas, for clinic trails, it is important to know accurately how and how long mechanical tension should be applied. Hence, it is necessary to investigate different kinds of mechanical tension on osteogenesis of MSCs. Until now, during the osteogenesis, there has been no research on the effect of continuous cyclic mechanical tension (CCMT) which provides continuous stimulation throughout the study period. We firstly figure out CCMT inhibiting the expression of osteogenic genes such as key transcription factor Runx2. It is known that RhoA regulates cell differentiation in response to mechanical stimuli. MAPK signaling acts as a downstream effector of RhoA. So, we ask in MSCs, if CCMT regulates the osteogenic master gene Runx2 through RhoA-ERK1/2 pathway. And then, we find out there is a decrease in RhoA activity after CCMT stimulation. Pre-treatment of CCMT-loaded MSCs with LPA, a RhoA activator, restores ALP activity and significantly rescues Runx2 expression, while pre-treatment with C3 toxin, a RhoA inhibitor, further decreases the activity of ALP and down-regulates the expression of Runx2. Following results indicate that the inhibition of Runx2 expression after CCMT stimulation is mediated by RhoA-ERK1/2 pathway. J. Cell. Physiol. © 2010 Wiley-Liss, Inc. PMID: 21136494 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Effect of endothelial cells on bone regeneration using poly(L-lactide-co-1,5-dioxepan-2-one) scaffolds. J Biomed Mater Res A. 2010 Dec 6; Authors: Xing Z, Xue Y, Dånmark S, Schander K, Ostvold S, Arvidson K, Hellem S, Finne-Wistrand A, Albertsson AC, Mustafa K Our recent in vitro study demonstrated that endothelial cells (ECs) might influence the differentiation of bone marrow stromal cells (BMSCs). Therefore, the aim of this study was to describe this effect in vivo, using a rat calvarial bone defect model. BMSCs were isolated from femurs of two-donor Lewis rats and expanded in α-minimum essential medium containing 10% fetal bovine serum. One fifth of BMSCs were induced and differentiated into ECs in an Endothelial Cell Growth Medium-2 and then characterized by a flow cytometry. The remaining BMSCs were cultured in freshly prepared osteogenic stimulatory medium, containing dexamethasone, ascorbic acid and β-glycerophosphate. Either BMSCs alone (BMSC-group) or co-cultured ECs/BMSCs (CO-group) were seeded into poly(L-lactide-co-1,5-dioxepan-2-one) [poly(LLA-co-DXO)] scaffolds, cultured in spinner flasks, and then implanted into symmetrical calvarial defects prepared in recipient rats. The animals were sacrificed after 2 months. The formation of new bone was evaluated by radiography and histology and by the expression of osteogenic markers using reverse transcriptase-polymerized chain reaction (RT-PCR). To investigate vessel formation, histological staining was performed with EC's markers. The radiographical and histological results showed more rapid bone formation in the CO- than in the BMSC-group. However, the expression of EC's marker was similar on both groups by histological analysis after 2 months postoperatively. Furthermore, the CO-group exhibited greater expression of osteogenic markers as demonstrated by RT-PCR. The results are consistent with the previous in vitro findings that poly(LLA-co-DXO) scaffold might be suitable candidate for bone tissue engineering. In vivo, bone regeneration was enhanced by a construct of the polymer scaffold loaded with co-cultured cells. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2010. PMID: 21136474 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Synergistic effect of adipose-derived stem cell therapy and bone marrow progenitor recruitment in ischemic heart. Lab Invest. 2010 Dec 6; Authors: Ii M, Horii M, Yokoyama A, Shoji T, Mifune Y, Kawamoto A, Asahi M, Asahara T Human multipotent adipose-derived stem cells (hMADSCs) have recently been isolated featuring extensive expansion capacity ex vivo. We tested the hypothesis that hMADSC transplantation might contribute to cardiac functional recovery by its direct or indirect effect on myocardial infarction (MI). Nude rats were either transplanted with hMADSCs or PBS (control) in ischemic myocardium immediately following MI. Echocardiographical assessment of cardiac function after MI with hMADSCs showed significant improvement of each parameter compared to that with PBS. Histological analysis also showed significantly reduced infarct size and increased capillary density in peri-infarct myocardium by hMADSC treatment. However, remarkable transdifferentiation of hMADSCs into cardiac or vascular lineage cells was not observed. Despite the less transdifferentiation capacity, hMADSCs produced robust multiple pro-angiogenic growth factors and chemokines, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor-1α (SDF-1α). Specifically, hMADSC-derived SDF-1α had a crucial role for cooperative angiogenesis, with the paracrine effect of hMADSCs and Tie2-positive bone marrow (BM) progenitor recruitment in ischemic myocardium. hMADSCs exhibit a therapeutic effect on cardiac preservation following MI, with the production of VEGF, bFGF, and SDF-1α showing paracrine effects and endogenous BM stem/progenitor recruitment to ischemic myocardium rather than its direct contribution to tissue regeneration.Laboratory Investigation advance online publication, 6 December 2010; doi:10.1038/labinvest.2010.191. PMID: 21135814 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Fu-Zhai Cui's vision and leadership. Biomed Mater. 2010 Dec 6;5(6):060201 Authors: Lee IS, Spector M Our colleague and friend, Fu-Zhai Cui, has decided to step down from his position as Co-Editor-in-Chief of Biomedical materials (BMM) at the end of the year due to other commitments. BMM would not be the journal that it is, and we two would not have served as participants in its development, were it not for Fu-Zhai. It was his vision and hard work that gave birth to BMM. Fu-Zhai's e-mail to Dr Mingfang Lu at IOP Publishing in June of 2005 initiated the process that led to the new journal being established. Underscoring the importance of such an endeavor, Fu-Zhai noted that biomedical materials and tissue engineering and their applications had been rapidly developing in recent years and the trend was likely to continue for many years, that there were relatively few journals capable of handling these subjects, and even fewer journals that faced East as well as West. There are several features of Fu-Zhai's professional life which have added to the character of BMM and which reflect, and perhaps even help to explain, his country's remarkable development: resourcefulness, innovation, and drive. When we first met Fu-Zhai at Tsinghua University more than 15 years ago, the facilities available to him were notably limited, especially in comparison to those that we had access to at our respective institutions. There was almost a complete absence of biomaterials-related journals at Tsinghua, prompting us to consider ways in which we could send our surplus issues to him. But Fu-Zhai made the most of what resources he did have and directed his students in important and productive research that was published in leading English-language journals. Fu-Zhai never let his thinking and efforts be constrained by limited resources. The projects undertaken by Fu-Zhai and his students at Tsinghua have always displayed engineering innovation born of scientific understanding. He is either investigating biomaterials for new applications or taking novel approaches for the production of new types of biomaterials. In both cases, his work is founded on knowledge drawn from an array of scientific studies and his success is due in large part to the multidisciplinary teams that he assembles. For example, Fu-Zhai's group was one of the first in the world to employ biomaterial implants (hyaluronic acid hydrogels) for the treatment of brain defects, thus pioneering the area of brain tissue engineering. For other biomaterials applications, such as bone tissue engineering, Fu-Zhai took the biomimetic approach of producing mineralized collagen scaffolds. But he did so in the novel way of co-precipitating collagen and hydroxyapatite to favor self-assembly and a hierarchical microstructure. Fu-Zhai's insights into the mineralization process were derived in part from his own studies with Heng-De Li, one of the pioneers of biomineralization. Biomaterials researchers frequently think about the potential clinical applications of their developments, but rarely find or make the opportunity to commercialize their products. Fu-Zhai acted on translational research before that term entered the researcher's lexicon. He orchestrated the compilation of pre-clinical data and engaged his clinical colleagues in the necessary human trials to demonstrate the safety and efficacy of his mineralized collagen scaffolds for spine fusion and other applications. After having been approved by the China medical device regulatory process, the product is now being used in clinics. A journal like BMM would like to be known for publishing papers which exemplify some of the same traits that Fu-Zhai has demonstrated in his own career: resourcefulness, innovation, and clinical utility. Moreover, Fu-Zhai has shown by his own example why he was so right to have seen the importance of establishing a truly international biomaterials journal. We both look forward to continuing in the capacity of Co-Editors-in-Chief, with the confidence that comes with knowing that our friend, Fu-Zhai Cui, will be available to advise us. PMID: 21135469 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A support for prospective nanomaterials. Nanotechnology. 2011 Jan 7;22(1):010201-10201 Authors: Demming A In the early 1990s, scanning probe microscopy was empowering researchers to view nanoscale features, previously the domain of imaginative theorists. Such images undoubtedly sparked the imagination and goaded researchers into ever more creative endeavours to understand nanoscale systems. At the same time, reports on molecular self-assembly were revolutionizing the philosophy behind how such systems could be produced, and promoting genuine bottom-up fabrication technology. The nanoworld was not only available to be gazed at and probed, but could be recreated by imposing the right conditions for the self assembly of complex and controlled structures. Many creative variants of self-assembly processes have been investigated. Researchers in Germany demonstrated that block copolymer micelle nanolithography could be used to generate nanostructured interfaces, where the pattern dimension and geometry is controlled by a combination of the self-assembly of block copolymer micelles with pre-structures formed by photo or electron-beam lithography [1]. The building blocks of life, DNA molecules, have also bred novel synthesis techniques as described in work by researchers in Finland, in a study of two different techniques of 'DNA origami' for the fabrication of complex protein structures [2]. Some fascinating properties have been revealed in self-assembled structures. Researchers in the US demonstrated extraordinary transmission in the infrared using self-assembled monolayers, phospholipid bilayers, and membrane-bound proteins on a subwavelength metallic array [3]. The surface plasmon properties of the arrays are accentuated by stacking them one upon the other, thus enabling extraordinary transmission and providing the basis of a nanospaced capacitive sensor. So-called nanoscaffolds have been used to promote assembly of biological matter in organized forms. A particularly inspiring application of nanoscaffolds has been found in nerve regeneration. Researchers in Singapore demonstrated the potential of biodegradable poly(L-lactide-co-glycolide) nanofibres to guide axon regeneration in vivo [4] and showed that aligned nanofibrous poly(l-lactic acid) scaffolds could be used as a potential cell carrier in neural tissue engineering [5]. In this issue, researchers in Italy demonstrate the use of magnetic bio-hybrid porous scaffolds for nucleating nano-apatite in situ on self-assembling collagen in the presence of magnetite nano-particles [6]. The magnetic nanoparticles provide a sort of crosslinking agent for the collagen, inducing a chemico-physical-mechanical stabilization of the material and allowing control of the porosity of the scaffold network. The work contributes towards developing assistance to bone regeneration guided by an external magnetic field. Another application of nanoscaffolds is in the development of hydrogen storage technology. Scaffolds can be used to help avoid aggregation of hydrogen storage nanoparticles and aid efficient cycling of storage and release [7, 8]. For more on hydrogen storage and other work on developing energy sources using nanotechnology, keep an eye out for our new Energy section to be launched this spring, 2011. The section will consider both the technological aspects and fundamental physics associated with innovations in the energy industry that exploit the properties of nanoscale structures. As we usher in the new year we can be sure that nanotechnology will remain a topic at the forefront of research agendas. There has been much hype over developments in nanotechnology over the years, and without a doubt the smart self-assembling of complex systems and materials has provoked awe of both a positive and negative nature in its time. Great progress has been made in advancing our control over promoting and guiding the self assembly of biological and industrial materials. The benefits available in applications of such research in medicine, renewable energy and many other industries are evident. Richard Feynman, often touted as a pioneer of a 'bottom-up' approach to nanotechnology, once said 'I was born not knowing and have had only a little time to change that here and there'. In a similar sense, what we do not yet know and understand about the ability to create and manipulate nanosystems is apparently infinite, but as can also be acceded in the case of Richard Feynman, the 'little' we have had time learn so far holds more than a little promise. References [1] Glass R, Möller M and Spatz J P 2003 Nanotechnology 14 314 [2] Kuzyk A, Laitinen K T and Törmä P 2009 Nanotechnology 20 235305 [3] Williams S M, Rodriguez K R, Teeters-Kennedy S, Shah S, Rogers T M, Stafford A D and Coe J V 2004 Nanotechnology 15 S495 [4] Bini T B, Gao S, Tan T C, Wang S, Lim, A, Hai L B and Ramakrishna S 2004 Nanotechnology 15 1459 [5] Yang F, Murugan R, Wang S and Ramakrishna S 2005 Biomaterials 26 2603-10 [6] Tampieri A, Landi E, Valentini F, Sandri M, D'Alessandro T, Dediu V and Marcacci M 2011 Nanotechnology 22 015104 [7] Gross A F, Ahn C C, Van Atta S L, Liu P and Vajo J J 2009 Nanotechnology 20 204005 [8] Zhang S, Gross A F, Van Atta S L, Lopez M, Liu P, Ahn C C, Vajo J J and Jensen C M 2009 Nanotechnology 20 204027. PMID: 21135456 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | A role for Notch signaling in corneal wound healing. Wound Repair Regen. 2010 Dec 6; Authors: Ma A, Zhao B, Boulton M, Albon J To identify the role of the Notch signaling pathway in corneal wound healing, rat corneas receiving either epithelial or stromal wounds were placed in organ culture for up to 3 and 14 days, respectively. Localization of Notch receptors-Notch1, Notch2, and their ligands-Delta1, Jagged1 was determined by immunofluorescence. Wounds were treated with a γ-secretase inhibitor to suppress Notch signaling or recombinant Jagged1 to enhance Notch signaling and morphological changes in the epithelium and stroma were recorded. The expressions of markers of cell proliferation (Ki67) and epithelial differentiation (cytokeratin 3) were assessed by immunohistology. Notch1 and Notch2 were localized to suprabasal epithelial cells in normal corneas. During corneal wound healing, both Notch receptors were detected in suprabasal and superficial epithelial layers. Delta1 and Jagged1 were observed throughout all corneal epithelial cell layers and occasional keratocytes of the stroma in normal and wounded corneas. γ-secretase inhibition of Notch resulted in increased epithelial cell layers, with recombinant Jagged1 activation of Notch leading to a reduction in epithelial cell layers during corneal wound healing. Correspondingly, the activation of Notch resulted in a decreased cytokeratin 3 expression in the corneal epithelium, with no effect on cellular expression of Ki67. Notch signaling pathway suppressed corneal epithelial differentiation during corneal wound healing, but had no effect on epithelial cell proliferation. PMID: 21134038 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |  | |  | |  |
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