bluuebunny/crossref_metadata_2025_split huggingface dataset:
The osteogenic differentiation improvement of human mesenchymal stem cells on titanium grafted with polyNaSS bioactive polymer
Authors: Oughlis S. , Lessim S. , Changotade S. , Poirier F. , Bollotte F. , Peltzer J. , Felgueiras H. , Migonney V. , Lataillade J. J. , Lutomski D. 
Published: September 2012

AbstractOsseointegration of metallic implants used in orthopedic surgery requires that osteoprogenitor cells attach and adhere to the surface, then proliferate, differentiate into osteoblasts, and finally produce mineralized matrix. Because the ability of progenitor cells to attach to a scaffold surface during early stages is important in the development of new tissue structures, we developed in our laboratory, a strategy involving grafting of implants with a polymer of sodium styrene sulfonate (polyNaSS) used as a scaffold which enables human mesenchymal stem cells (hMSCs) interactions. In the present study, we investigated the cellular response of hMSCs to polyNaSS surfaces of titanium (Ti). In particular, cell proliferation, cell viability, cell differentiation, and cell spreading were evaluated. Results showed that cell proliferation and cell viability did not differ with any statistical significance between modified and unmodified Ti surfaces. Interestingly, culture of MSCs on polyNaSS surfaces resulted in a significant increase of cell spreading and cell differentiation compared with the other tested surfaces. These results suggest that titanium surface grafted with polyNaSS is a suitable scaffold for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
The mineralization inducing peptide derived from dentin sialophosphoprotein for bone regeneration
Authors: Choi Young Suk , Lee Jue Yeon , Suh Jin Sook , Lee Gene , Chung Chong Pyoung , Park Yoon Jeong 
Published: September 2012

AbstractDentin sialophosphoprotein (DSPP) has been shown to play a primary role in the formation and growth of hydroxyapatite crystals in an extracellular matrix of hard tissue such as bone and teeth. We hypothesized that the mineralization ability of DSPP might depend on a specific domain within it. Three peptides, which have hydroxyapatite (HA) binding affinity, denoted as mineralization inducing peptide (MIP1, MIP2, and MIP3) were identified from DSPP. The both of MIP2 and MIP3 had HA nucleation activity demonstrated by XRD. Among three MIPs, MIP3 significantly supported the human bone marrow stromal cell differentiation into osteoblastic cells. An immunoblot with antibodies specific for the phosphorylated forms of ERK was conducted with cells treated by MIP3. MIP3 transduced intracellular signals via the ERK pathways and was able to induce osteoblastic differentiation, as seen by high expression of ALP, type 1 collagen, OC, OPN, and Runx2 in accordance with applied MIP3 concentration. The Asp, Glu, and Ser residues in MIP3 play important roles for the affinity of calcium in HA bone mineral. Further animal experiment with MIP3 in combination with hydroxyapatite mineral induced marked new bone formation for 4 weeks at rabbit calvarial defect model. The new bone area was much higher in test group, implying that the peptide modified group had excellent biocompatibility when compared with the unmodified group. Taken together, the MIP from DSPP has potential to enhance mineralization followed by to enhance osteoblastic differentiation and bone regeneration. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Synthesis and fabrication of a degradable poly(N‐isopropyl acrylamide) scaffold for tissue engineering applications
Authors: Galperin Anna , Long Thomas J. , Garty Shai , Ratner Buddy D. 
Published: September 2012

AbstractBiodegradable poly(N‐isopropyl acrylamide) (polyNIPAM) hydrogels with controlled molecular weight of the parent polymer and its degradation products were synthesized by atom transfer radical polymerization in the presence of a polycaprolactone‐based di‐chlorinated macroinitiator and polycaprolactone dimethacrylate. The phase transition temperature, swelling, hydrolytic degradability, and mechanical properties at 25 and 37°C were explored. A cytocompatibility study showed good NIH3T3 cell response over 5 days culture on the surface of the hydrogels, demonstrated by a consistent increase in cell proliferation detected by an Alamar Blue assay. MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] results suggested that the hydrogels and their degradation products in the concentration range of 1–25 mg/mL were not cytotoxic to NIH3T3 cells. A sphere‐templating technique was utilized to fabricate biodegradable polyNIPAM scaffolds with monodisperse, pore size. Scaffolds with pore diameter of 48 ± 6 μm were loaded with A‐10 smooth muscle cells and then warmed to 37°C entrapping cells in pores approximately 40 μm in diameter, a size we have found to be optimal for angiogenesis and biointegration. Due to their degradable nature, tunable molecular weight, highly interconnected morphology, thermally controlled monodisperse pore size, and temperature‐induced volume expansion–contraction, the polyNIPAM‐based scaffolds developed in this work will be valuable in tissue engineering. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 775–786, 2013.
Comparative analysis of photocaged RGDS peptides for cell patterning
Authors: Goubko Catherine A. , Basak Ajoy , Majumdar Swapan , Jarrell Harold , Huan Khieu Nam , Cao Xudong 
Published: September 2012

AbstractPhotocaged RGDS is a cell nonadhesive tetrapeptide that can be activated with light to become cell‐adhesive. Such molecules can find useful applications in controlling cell adhesion for biological study, drug development, and in forming dynamic, adhesion‐controlled biomaterials. Herein, we prepared RGDS peptide photocaged either on the Arg‐Gly backbone amide nitrogen atom (R[−]GDS) or Asp side chain carboxyl (RG[D]S). A critical comparison of the peptides' chemical and physiological properties relevant for biological applications was carried out. It was observed that RG[D]S was synthesized more readily via automated solid‐phase synthesis, underwent uncaging with a rate constant 3‐fold higher than R[−]GDS, and was more stable in aqueous solution. Automated docking studies were performed to examine the interactions of various caged RGDS peptides with cell surface integrin receptor to identify suitable locations for the photosensitive 2‐nitrobenzyl (NB) group for biological applications. A competitive binding ELISA method compared the ability of various peptides to bind to αVβ3 cell integrin receptors and the data were found to be consistent with the modeling predictions. Finally, the application of our caged RGDS peptides in controlling cell adhesion to form cell patterns on a hydrogel material was presented. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 787–796, 2013.
In vitro and in vivo studies of rhBMP2‐coated PS/PCL fibrous scaffolds for bone regeneration
Authors: Nguyen Thi‐Hiep , Lee Byong‐Taek 
Published: September 2012

AbstractThe control of porous microstructure and the use of rhBMP2 as surface coating on bone substitutes have been recognized as key factors to accelerate osteoconductivity. In this study, instead of using a meso‐porous fibrous scaffold of poly‐ε‐caprolactone (PCL), a micro‐ and macro‐porous fibrous scaffold, made up of blended polystyrene (PS) and PCL, was created to investigate these key factors. In vitro studies, MTT assay and scanning electron microscope (SEM) morphology confirmed that PS/PCL fibrous membrane has non‐toxicity and shows excellent cells adhesion and proliferation behavior. Significant improvements regarding cell attachment, cell growth, and cell proliferation were observed using recombinant human bone morphogenetic protein‐2 (rhBMP2)‐coated PS/PCL fibrous scaffold confirmed by SEM and confocal observation. Results of micro‐CT scanning and the Hematoxylin & Eosin/Masson's Trichrom staining of tissue sections from the post‐implantation revealed that rhBMP2‐coated PS/PCL fibrous scaffold recovered over 75 vol % of the bone defect after 8 weeks of implantation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 797–808, 2013.
A novel suture‐based method for efficient transplantation of stem cells
Authors: Guyette Jacques P. , Fakharzadeh Michael , Burford Evans J. , Tao Ze‐Wei , Pins George D. , Rolle Marsha W. , Gaudette Glenn R. 
Published: September 2012

AbstractAdvances in regenerative medicine have improved the potential of using cellular therapy for treating several diseases. However, the effectiveness of new cellular therapies is largely limited by low cell engraftment and inadequate localization. To improve on these limitations, we developed a novel delivery mechanism using cell‐seeded biological sutures. We demonstrate the ability of cell‐seeded biological sutures to efficiently implant human mesenchymal stem cells (hMSCs) to specific regions within the beating heart; a tissue known to have low cell retention and engraftment shortly after delivery. Cell‐seeded biological sutures were developed by bundling discrete microthreads extruded from extracellular matrix proteins, attaching a surgical needle to the bundle and seeding the bundle with hMSCs. During cell preparation, hMSCs were loaded with quantum dot nanoparticles for cell tracking within the myocardium. Each biological suture contained an average of 5903 ± 1966 hMSCs/cm suture length. Delivery efficiency was evaluated by comparing cell‐seeded biological suture implantation with intramyocardial (IM) cell injections (10,000 hMSCs in 35 μL) into the left ventricle of normal, noninfarcted rat hearts after 1 h. Delivery efficiency of hMSCs by biological sutures (63.6 ± 10.6%) was significantly higher than IM injection (11.8 ± 6.2%; p < 0.05). Cell‐tracking analysis indicated suture‐delivered hMSCs were found throughout the thickness of the ventricular myocardium: along the entire length of the biological suture track, localizing closely with native myocardium. These results suggest cell‐seeded biological sutures can deliver cells to the heart more efficiently than conventional methods, demonstrating an effective delivery method for implanting cells in soft tissue. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 809–818, 2013.
Characterization of polyurethane scaffold surface functionalization with diamines and heparin
Authors: de Mulder Eric L. W. , Hannink Gerjon , Koens Martin J. W. , Löwik Dennis W. P. M. , Verdonschot Nico , Buma Pieter 
Published: September 2012

AbstractPolyurethane scaffolds (PUs) have a good biocompatibility but lack cell recognition sites. In this study, we functionalized the surface of a PU, P(D/L)LA and PCL (50:50) containing urethane segments, with heparin. The first step in this functionalization, aminolysis, lead to free amine groups on the surface of the PU. Free amine content was determined to be 6.4 nmol/mL/mg scaffold, a significant increase of 230%. Subsequently, heparin was crosslinked. Immunohistochemistry demonstrated the presence of heparin homogeneous throughout the 3D porous scaffold. Young's modulus decreased significantly till 50% of the native stiffness after aminolysis and did not change after heparin crosslinking. Contact angle on PU films significantly decreased from 82.7° to 64.3° after heparin crosslinking, indicating a more hydrophilic surface. This functionalization beholds great potential for tissue engineering purposes. When used in a load‐bearing environment, caution is necessary due to reduction in mechanical stiffness. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Calcium phosphate glass improves angiogenesis capacity of poly(lactic acid) scaffolds and stimulates differentiation of adipose tissue‐derived mesenchymal stromal cells to the endothelial lineage
Authors: Vila Olaia F. , Bagó Juli R. , Navarro Melba , Alieva Maria , Aguilar Elisabeth , Engel Elisabeth , Planell Josep , Rubio Nuria , Blanco Jerónimo 
Published: September 2012

AbstractThe angiogenic capacity of a new biomaterial composite of poly(lactic acid) and calcium phosphate glass (PLA/CaP) was analyzed by noninvasive bioluminescence imaging (BLI) and histological procedures. Human adipose tissue‐derived mesenchymal stromal cells expressing cytomegalovirus (CMV) promoter regulated Photinus
pyralis luciferase (hAMSC‐PLuc) grew up to 30 times the initial cell load, in vitro, when seeded in PLA/CaP scaffolds, but suffered an initial growth crisis followed by recovery when the scaffolds were subcutaneously implanted in SCID mice. To analyze changes in gene expression, hAMSC‐PLuc cells were double labeled with a CMV promoter regulated Renilla reniformis luciferase and a Photinus
pyralis luciferase reporter regulated by either the PECAM promoter or a hypoxia response element (HRE) artificial promoter and seeded in PLA/CaP and PLA scaffolds implanted in SCID mice. Analysis by BLI showed that hAMSCs in scaffolds were induced to differentiate to the endothelial lineage and did this faster in PLA/CaP than in PLA scaffolds. Endothelial differentiation correlated with a decrease in the activity of HRE regulated luciferase expression, indicative of a reduction of hypoxia. Histological analysis showed that PLA/CaP scaffolds were colonized by a functional host vascular system. Moreover, colonization by isolectin B4 positive host cells was more effective in PLA/CaP than in PLA scaffolds, corroborating BLI results. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Generation of osteogenic construct using periosteal‐derived osteoblasts and polydioxanone/pluronic F127 scaffold with periosteal‐derived CD146 positive endothelial‐like cells
Authors: Lee Jin Ho , Kim Shin‐Won , Kim Uk‐Kyu , Oh Se Heang , June‐Kim Sang , Park Bong‐Wook , Kim Jin‐Hyun , Hah Young‐Sool , Kim Deok Ryong , Rho Gyu‐Jin , Maeng Geun‐Ho , Jeon Ryoung‐Hoon , Lee Hee‐Chun , Kim Jong‐Ryoul , Kim Gyoo‐Cheon , Byun June‐Ho 
Published: September 2012

AbstractThe purpose of this study was to generate tissue‐engineered bone using human periosteal‐derived osteoblasts (PO) and polydioxanone/pluronic F127 (PDO/pluronic F127) scaffold with preseeded human periosteal‐derived CD146 positive endothelial‐like cells (PE). PE were purified from the periosteal cell population by cell sorting. One of the important factors to consider in generating tissue‐engineered bone using osteoprecursor and endothelial cells and a specific scaffold is whether the function of osteoprecursor and endothelial cells can be maintained in originally different culture medium conditions. After human PE were preseeded into PDO/pluronic F127 scaffold and cultured in endothelial cell basal medium‐2 for 7 days, human PO were seeded into the PDO/pluronic F127 scaffold with PE, and then, this cell‐scaffold construct was cultured in endothelial cell basal medium‐2 with osteogenic induction factors, including ascorbic acid, dexamethasone, and β‐glycerophosphate, for a further 7 days. Then, this 2‐week cultured construct was grafted into the mandibular defect of miniature pig. Twelve weeks after implantation, the animal was sacrificed. Clinical examination revealed that newly formed bone was seen more clearly in the defect with human PO and PDO/pluronic F127 scaffold with preseeded human PE. The experimental results suggest that tissue‐engineered bone formation using human PO and PDO/pluronic F127 scaffold with preseeded human PE can be used to restore skeletal integrity to various bony defects when used in clinics. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Viscoelastic behavior of poly(ether imide) incorporated with multiwalled carbon nanotubes
Authors: Shepard Kimberly B. , Gevgilili Halil , Ocampo Miguel , Li Jia , Fisher Frank T. , Kalyon Dilhan M. 
Published: September 2012

AbstractThere is significant potential in improving the mechanical, electrical, and thermal properties of engineering plastics, including poly(ether imide) (PEI), with various nanoinclusions such as multiwalled carbon nanotubes (MWCNTs). However, this potential can only be fully realized through a thorough understanding of the rheological behavior and the thermomechanical histories that the nanocomposites are exposed to during their preparation and the resulting effective properties. In this study, nanocomposites of PEI and MWCNTs were prepared using a solution processing method under different dispersion conditions, and the viscoelastic material functions of the nanocomposites were characterized as functions of concentration of CNTs in the 1–5% by weight range (volume fraction, ϕ = 0.006–0.03) and temperature. The storage modulus and magnitude of complex viscosity values of the PEI nanosuspensions increased by as much as 3500% and 800%, respectively, at ϕ = 0.03, along with similar orders of magnitude increases observed or predicted in other viscoelastic material functions. Such increases reflect how nanotube incorporation and network formation can drastically alter the flow and deformation behavior of the PEI/CNT nanosuspensions at processing‐relevant temperatures and deformation rates. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
5‐HT1B autoreceptor regulation of serotonin transporter activity in synaptosomes
Authors: Hagan Catherine E. , Mcdevitt Ross A. , Liu Yusha , Furay Amy R. , Neumaier John F. 
Published: September 2012

AbstractSerotonin‐1B (5‐HT1B) autoreceptors are located in serotonin (5‐HT) terminals, along with serotonin transporters (SERT), and play a critical role in autoregulation of serotonergic neurotransmission and are implicated in disorders of serotonergic function, particularly emotional regulation. SERT modulates serotonergic neurotransmission by high‐affinity reuptake of 5‐HT. Alterations in SERT activity are associated with increased risk for depression and anxiety. Several neurotransmitter receptors are known to regulate SERT Km and Vmax, and previous work suggests that 5‐HT1B autoreceptors may regulate 5‐HT reuptake, in addition to modulating 5‐HT release and synthesis. We used rotating disk electrode voltammetry to investigate 5‐HT1B autoreceptor regulation of SERT‐mediated 5‐HT uptake into synaptosomes. The selective 5‐HT1B antagonist SB224289 decreased SERT activity in synaptosomes prepared from wild‐type but not 5‐HT1B knockout mice, whereas SERT uptake was enhanced after pretreatment with the selective 5‐HT1B agonist CP94253. Furthermore, SERT activity varies as a function of 5‐HT1B receptor expression—specifically, genetic deletion of 5‐HT1B decreased SERT function, while viral‐mediated overexpression of 5‐HT1B autoreceptors in rat raphe neurons increased SERT activity in rat hippocampal synaptosomes. Considered collectively, these results provide evidence that 5‐HT1B autoreceptors regulate SERT activity. Because SERT clearance rate varies as a function of 5‐HT1B autoreceptor expression levels and is modulated by both activation and inhibition of 5‐HT1B autoreceptors, this dynamic interaction may be an important mechanism of serotonin autoregulation with therapeutic implications. Synapse, 2012. © 2012 Wiley Periodicals, Inc.
Calibration of a burrow count index for the Indian desert jird, Meriones hurrianae
Authors: Ramesh Divya , Home Chandrima , Jhala Yadvendradev V. , Qureshi Qamar 
Published: September 2012

AbstractPopulation estimates, often difficult to acquire, warrantee the use of an index as an economical substitute for rapid assessments of populations. We estimated population size of the little known social, semi‐fossorial Indian desert jird (Meriones hurrianae) in Kachchh, Gujarat, India under closed population capture‐mark‐recapture (CMR) framework to calibrate a burrow count index for the species. A total of 147 individuals were trapped in 16 colonies using baited Sherman traps and the number of burrow entrances at each colony was recorded. Data from colonies with low number of captures were pooled to estimate capture probability using Huggins heterogeneity models with gender, site, body weight and age category as covariates in Program MARK. Colony sizes ranged from 2 to 46 individuals. The number of burrow entrances was calibrated against CMR‐based population estimates using least squares regression (n = 16, adjusted R2 = 0.96, t = 18.18, P < 0.001). The index was further validated using Jackknife (JK) analysis where JK‐predicted population estimates strongly correlated with CMR estimates (r = 0.96, P < 0.001). In habitats and climatic conditions similar to Kachchh and within the range of colony sizes sampled, our calibrated index can be a valuable and effective tool for large scale surveys of the desert jird, which occupies a keystone trophic level in the semi‐arid ecosystem.
Cognitive Apartheid: On the Manner in Which High School Students Understand Evolution without Believing in Evolution
Authors: Hermann Ronald S. 
Published: September 2012

Abstract
High school science students are often unwilling to learn about evolution due to a perceived conflict with their religious beliefs. Other students are able to understand evolution despite the fact that they do not believe in evolution. According to Cobern (Sci Educ 80:579–610, 1996), students can wall off that which is believed from that which is not believed in a process he called cognitive apartheid. A mixed-methods study was conducted to determine the extent to which understanding of evolution differed among high school Advanced Placement science students who did and did not believe in evolution. Two students who demonstrate a sophisticated understanding of evolution despite their admonition that they do not believe in evolution were then interviewed. Eight themes emerged from the interview that provide insight into the views of students learning of evolution despite the fact that they do not believe in evolution. Based on these themes, several implications for the teaching of evolution are presented.
Lamine C2 et spermatogenèse
Authors: Courtot A. -M. 
Published: September 2012

Résumé
Les lamines A/C sont des filaments intermédiaires présents dans les noyaux des cellules. Leurs rôles sont multiples et des mutations du gène LMNA sont à l’origine de nombreuses maladies appelées laminopathies. Dans les cellules germinales masculines, cette famille de protéines n’est représentée que par la lamine C2. Les données obtenues chez la souris démontrent l’importance de ces filaments dans le déroulement de la méiose masculine et présagent de l’existence d’un nouveau domaine d’infertilité d’origine masculine lié à des mutations de ce filament intermédiaire ou de ses protéines associées.