5^th World Congress on Materials Science & Engineering June 13-15, 2016 Alicante, Spain

Ros Tárraga P is a Biotechnology graduated at Universidad Miguel Hernández of Elche (UMH). Actually, he is a pre-doctoral student at Universidad Católica San Antonio de Murcia (UCAM), and he is working in the design and development of new bioactive materials and their use in the field of bone tissue regeneration. He is studying the physical characterization of Si-Ca-P-based scaffolds and their effect on the adult human Mesenchymal Stem Cells (ahMSC) behavior.

Biomaterials are used in tissue engineering with the aim to repair tissues and organs. Since stem cells can be readily isolated, expanded and transplanted, their application in cell-based therapies is a major focus of research. We test the behaviour of ahMSCs on silk fibroin based biomaterial in order to use it for tissue repair. Silk fibroin mesh was obtained by electrospinning of fibroin obtained from cocoons of silkworms. ahMSCs were obtained by aspiration of ileac crest from healthy volunteer and isolated by gradient ficoll (SEPAX™) and cultivated in α-MEM supplemented with FCS and penicillin G /streptomycin sulphate (100 U ml-1 and 100 g ml-1). 1.0 x 105 ahMSCs were seeded onto the material in 24-well plates and analyzed at 72 h and 1, 2, 3, and 4 weeks. The growth rate, morphology, adherence was analized at different times using ImageJ ™ software, PhCM and SEM. At 72h, the ahMSCs cultured had a flattened polygonal appearance with spread cytoplasmatic extensions. Later, at 1 week, the adhesion was enhanced by means of multiple philopodia. Abundant extracellular matrix was observed occupying intercellular gaps. At 3-4 weeks, the cells became confluent forming an homogeneous monolayer almost coating the whole of the mesh. The cells showed a strong adhesion to the microfiber and proliferated in a short period of time (1 week). At the confluence, collagen-like lattices occupied the intercellular gaps. No cytotoxicity phenomena was detected. So, we can suggest that the material is a suitable substrate for ahMSCs growth and stem cell-based tissue engineering.

Rubén Rabadán Ros is a biologist in the University of Murcia (UMU) and he have a MSc degree in Molecular Biology and Biotechnology by the same university. Currently he is a PhD student in Biomedical Sciences at Saint Anthony Catholic University of Murcia (UCAM), developing scaffolds based on the C2S-TCP phase diagram and their in vitro and in vivo study.

To take advantage of the beneficial effect of Si, novel materials with compositions derived from the Dicalcium Silicate-Tricalcium phosphate (C2S-TCP) phase diagram were developed (EC1 31wt%TCP-69wt%C2S; EC2 59.5wt%TCP-40.5wt%C2S; EC3 83wt% TCP-17wt% C2S). Phase composition effect on their ability to support adult human mesenchymal stem cells (ahMSCs) growth and osteogenic differentiation induction in presence of DMEM or an osteogenic medium (OM) was therefore investigated. The ahMSCs were examined at 1, 2, 3, 4 weeks in culture, for the osteoblast phenotypic markers alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN) and cell surface marker CD105. At week 2, the population of ALP + cells was similar for all samples. At week 4, the proportion of cells ALP + increased significantly in EC2 samples. At week 1, ahMSCs expressed the CD105 marker in all samples, but in OM CD105 expression decrease significantly for EC1 and EC2 samples. Treatment with OM increased the gene expression of the bone extracellular matrix proteins OPN and OCN as determined by RT-PCR analysis. Addition of OM changed significantly the results: best result for ALP was obtained at 28 days for EC2 biomaterial; best OCN, OPN and RUNX2 expression was obtained at 21 days for EC2 material; best CD105 surface expression decrease on 21 days in OM for all samples. This results overlap because the gene expression have to increase before protein production, and confirms our hypothesis as we don’t expected to see changes before week 3, and we hypothesize that OM effect summarizes to the biomaterial differentiation induction potential.

Ros Tárraga P is a Biotechnology graduated at Universidad Miguel Hernández of Elche (UMH). Actually, he is a pre-doctoral student at Universidad Católica San Antonio de Murcia (UCAM), and he is working in the design and development of new bioactive materials and their use in the field of bone tissue regeneration. He is studying the physical characterization of Si-Ca-P-based scaffolds and their effect on the adult human Mesenchymal Stem Cells (ahMSC) behavior.

Silicon (Si) is a trace element that enhances bone formation and maturation in the body; thus apatite ceramics containing Si are expected to increase the speed of bony regeneration. The mesenchymal stem cells from human bone marrow (ahMSCs) are a great promise for cell-based therapies by their ability to differentiate into osteoblast in certain microenvironments. For this purpose we have developed three biomaterials EC1 31% TCP-69%C2S, EC2 59.5% TCP-40.5% C2S, EC3 83% TCP-17% C2S. The presence of bone-like apatite layer on the material surface after soaking in SBF was demonstrated by X-ray diffraction scanning electron microscopy (XRD-SEM). The effect of ionic dissolution from the three materials, on ahMSCs proliferation was investigated (SEM and MTT proliferation assay) and in vitro mineralization (Alizarin Red staining) at week 1, 2, 3, 4 in DMEM and osteogenic medium (OM). When biomaterials are placed in culture medium release ions at different concentrations and an apatitic layer forms on their surfaces. ahMSCs are therefore able to adhere, but only EC2 strongly increments ahMSC proliferation. At 28 days EC1 and EC2 plus OM, significantly enhanced the formation of mineralized nodules, based on Alizarin Red hystochemical staining; giving EC2 the best result. We conclude that all the materials are non-toxics, as the cells adhere and proliferate on their surface, although on EC2 material proliferation rate is higher (SEM images and MTT quantification). The association of EC2 with OM stimulates cells better than the other combinations.

Shams completed her MSc at the age of 25 years from University of Technology, Iraq and currently she is PhD student at Newcastle University, UK. She is a member in Royal Society of Chemistry and the Iraqi Students Society IQSS. She has published 5 papers in reputed journals.

This research concerns the physical and structural properties of carbon nanotube /conductive polymer composites and their use in gas sensors. A good sensor should be sensitive, reliable, low cost, with fast response and a short recovery time. Carbon nanotubes (CNTs) are well-suited because of their unique properties; their small size, hollow centre, large surface area and good electric conductivity. However, it has been shown that pristine carbon nanotubes have a low response for volatile organic compounds – our target analyse - therefore we attempted to improve this property of CNTs by templating pyrrole on CNTs. Polypyrrole is simple to prepare by oxidation of the monomer and its resistance is very sensitive to organic vapours, although much larger than that of CNTs. TEM and AFM of polypyrrole/CNT composites prepared from single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) show polypyrrole coated the CNTs successfully. There are significant changes in the range of diameters of nano tubes for SWCNTs from (7-10) nm to (8-35) nm and from (2-10) to (21-50) nm for MWCNTs. The composites were tested for the variation in their resistance upon exposure to a range of organic vapours (acetone, chloroform) and to water. The sensing devices comprised simple two-terminal devices over which a layer of the composite was applied by drop-coating. We investigated the effect of the CNT: polypyrrole ratio on the sensor response, S= (R-R0)/R0) where R0 is the resistance in an air atmosphere and R is the resistance at steady-state after exposure to an air/analyte mixture. In general, pure CNTs show a rapid response time, but very low response (typically S < 0. 1) at room temperature. As the amount of polypyrrole in the composite is increased, S increases, the response time deteriorates. Interestingly, the response of the composites may even change sign as a function of target analyse concentration; this suggests that a simple mechanism based on swelling and its effect on the percolation behaviour of CNTs in the polypyrrole matrix is insufficient to explain the data

Mansur Yahaya received his BSc Applied Chemistry from Usmanu Danfodiyo University, Sokoto, Nigeria, and an MSc in Chemistry from Obafemi Awolowo University, Nigeria. He joined College of Basic and Advanced Studies, Kebbi, Nigeria as an assistant lecturer in 2001 and rose to the position of Senior lecturer and head of Chemistry department, before moving to Sokoto State University, Nigeria as a lecturer in Chemistry department. He has published ~ 12 research papers in chemistry. Mansur is a Chartered Chemist of Nigeria and has membership in different international chemistry associations. He is currently a 3rd year postgraduate student at Newcastle University UK, pursuing his PhD at the Chemical Nanosciences Department, School of Chemistry.

Gas sensor networks have a wide variety of applications in environmental and safety monitoring that can be very useful to businesses and the general public. Environmentalists can use sensors to measure atmospheric pollution and monitor industrial emissions, and safety monitors can use sensors to detect harmful chemical vapors and explosives in public spaces, government and military facilities, and chemical processing plants. However, gas sensor technologies are still developing and have yet to reach their full potential in capabilities and usage. Conducting polymers (CPs) are unique materials because they exhibit electronic, magnetic and optical properties of metals and semiconductors while retaining the attractive mechanical properties and processing advantages of polymers This research work reports the synthesis, chemical (FTIR, UV-vis and XPS), structural (AFM and TEM) characterisations, electrical measurements (I_V and C-V) and design of gas sensors for a range of analytes of industrial interest. The sensing elements were based on CPs nanowire created using a simple and low cost fabrication method by employing DNA as a template on which to carry out the polymerization. The gas characteristics of the different CP-DNA nanowire were investigated by recording their electrical responses when exposed to different analyte vapour, passed at different flow rate.

Oras A Al-Ani is currently studying towards the PhD degree within the Emerging Technologies and Material (ETM) group, School of Electrical and Electronics Engineering, Newcastle University, UK Her research focuses on computational and theoretical analysis of the point and extended defects in multicrystalline silicon and their impact on photovoltaic devices. She serves as research students representative in EEE School, the IEEE student branch committee member as well as member of IET, IEEE and Al-Kindi Society for Engineers; and awarded several awards for the best paper and presentation. She is currently acting as the Student Ambassador for Materials Congress 2016.

Iron is arguably the most important detrimental contamination in lower grade silicon, which is a problem in photovoltaic as interstitial iron (Fei) is understood to be an active recombination centre, lowering device efficiency. In this work, First-principles quantum-chemical simulations are combined with TCAD device modelling to examine the silicon properties with iron impurity, as an attempt to balance interoperation of the disadvantageous properties of these impurities on the performance of solar cells as function of iron concentration. The results show that Fe-impurity has reduced the hole density slightly with increasing iron concentration from 108 to 1016 cm-3, whereas, the electron density is affected significantly with increasing the impurity concentration. In contrast, carrier mobilites are almost constant at low iron concentration, however, it is found that they are decreasing when iron concentration exceeds 1014 cm-3. Moreover, it is found that the recombination rate is increasing due to the increase in the impurtiy concentration. Finally, it is noticed from these figures that short-circuit current density (Jsc) has been reduced by around 47% with increasing the Fe concentration from 108 to 1016 cm−3. On the other hand, the open-circuit voltage (Voc) is reduced by around 27% within the same range of impurity concentration. These changes in the Jsc and Voc have led to degradation in the total conversion efficiency from 16% to 6%. Furthermore, the role of iron impurities play in iron-precipitation and segregation to, for example, extended defects, is of key interest for the solar cell performance.

Аleksey Pashchenko is a Doctor of Science at the Phase Transitions Department of the Donetsk Institute for Physics and Engineering named after O.O. Galkin NAS of Ukraine. He has published more than 186 publications, which consist of reputed journals (Acta Mater., J. Magn. Magn. Mater., J. Alloys Comp., etc.), books, patents and abstracts. His main research interests are investigation and determination of structure defects of multiferroics, manganites, nanostructures and novel multifunctional materials.

Composition, structure, microstructure and dielectric properties of the Bi1-xLaxFeO3-𝛿 multiferroics were studied by the methods of X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and dielectric spectroscopy. Ceramic samples of the Bi1-xLaxFeO3-𝛿 (х = 0, 0.1, 0.3 and 0.5) were prepared by the rapid liquid-phase sintering method. According to the X-ray data the single-phase Bi1-xLaxFeO3-𝛿 ceramics have rhombohedral type of crystal structure distortion with changing of lattice parameters and space group from R3m (x = 0) to R3c (х = 0.1), (х = 0.3) and Pnma (x = 0.5). Molar formulas of a real structure Bi1-xLaxFeO3-δ have been determined. The real crystal structure is defective and contains anionic V(a) and cationic V(c) vacancies. SEM investigations data have confirmed chemical composition of Bi1-xLaxFeO3-𝛿. The microstructure of Bi1-xLaxFeO3-𝛿 consists of crystallites which size decreases from 10 to 1 μm with the growth of the concentration x from 0 to 0.5. An analysis of the relative permittivity ε(f) and dielectric loss tangent tanδ(f) frequency dependencies in the low frequency f = 1-106 Hz and microwave f = 8.24-12.05 GHz bands indicates a monotone for ε(f) and non-monotonic for tanδ(f) dispersion. The composition Bi0.9La0.1FeO3 has the greatest value of ε(1 Hz) = 5•105, which decreases to ε(1 MHz) = 209 and ε(12 GHz) = 10.5. The appearance of two peaks on non-monotonic dependencies of the tanδ(f) is caused by the presence of relaxation polarization processes in the defect structure of Bi1-xLaxFeO3-δ.

Jovana Trifunović has completed her PhD in Pharmacy from University of Novi Sad and currently is Post-doctoral student at Department of Pharmacology, Toxicology and Clinical Pharmacology at Medical Faculty, University of Novi Sad, Serbia. She was visiting student at Department of Chemistry, University of Graz and at Department of Organic Chemistry at Graz University of Technology, Austria during 2012/2013 and 2014.

Introduction: In this work were compared several calculation methods to evaluate the lipophilicity of thirteen different bile acids in two solvent sistems conditions. Lipophilicity is very important physicochemical parameter for describing ADME properties and future perspectives of molecule application . In the recent literature information about ADME properties of examined bile acids do not exist, although the interest for bile acids and their implementation as drug delivery systems is increasing.\r\n\r\nMaterials & Methods: Retention parameters are acquired by normal-phase TLC. The correlations between calculated logP values were obtained using five different softwares and experimentally determined hydrophobicity parameters (Rm0(tol/eth) , Rm0(tol/but), b(tol/eth) and b(tol/but)) were established with good correlation.\r\n\r\nResults: Excellent predictive ability of the established mathematical model of studied compounds represents significant tool in development of relations between chromatographic behavior and ADME properties. Examined correlation analysis confirmed significant dependence between Rm0 and penetration in jejunum, MDCK epithelial cells, skin permeability, ion channel modulations (ICM) and binding affinity to nuclear receptor (NRL) and G protein-coupled receptors (GPCR).\r\n\r\nConclusion: Investigated bile acids showed good pharmacokinetic properties and affinity for GPCR, NRL and ICM. Authors would suggest compounds 5 and 6 for further research. Beside that, derivatives 3 and 4 have a slightly higher hemolitic potential but better ligand properties.\r\n

Ahmed M A Sabaawi received the BSc and MSc degrees in Electronics and Communication Engineering from Mosul University, Iraq in 2002 and 2008, respectively, and PhD in Nano-electronics from Newcastle University, Newcastle Upon Tyne, UK. His research focus was on designing nanoantennas for sensing and energy harvesting applications. He is currently a Research Associate at Engineering Department, Lancaster University, UK. His current research interests include the design and optimisation of vacuum electronics for 5G mobile networks and numerical and theoretical analysis of Optical antennas.

Multicrystalline Silicon (mc-Si) has been widely used in the fabrication of solar cells due its reasonable performance and low cost that came from the high contamination by transition metals such as iron, which is presented during the module fabrication. At certain point, the high impurities will degrade the performance of solar cell by exhibiting high resistivity preventing the material to be a valid solution for this application. In this work, we will attempt to exploit the drawbacks heavily doped (contaminated) mc-Si by iron to design low-cost feasible nano-antennas for various applications. These antennas can be used in harvesting infrared energy from solar radiation or waste heat using nano-rectennas. In addition, nano-rectennas can replace batteries in low-power wearable devices by drawing energy generated from body heat, or ambient radiation. Moreover, these nano-antennas can be used in gas sensing arrays in hostile environment and extreme conditions (high temperature and radiation). When the concentration of iron goes high (i.e around 1020 cm-3), the resistivity will be in the order of 0.001 Ω.cm will results in a conductivity of 105 S/m. This conductivity leads to a reasonable antenna resonance at THz frequencies. Several antenna configurations will be presented in this work based on the new conductivity of the heavily doped mc-Si.

Salvador Aznar-Cervantes works as a Researcher in the Department of Biotechnology, in the R&D Center in Biotechnology and Biomedicine, IMIDA (Murcia). He\r\nobtained his degree in Biology from the University of Murcia (2006), and then he completed his Doctoral thesis, working as a grant holder (FPI-INIA), under the\r\ndirection of Dr. José Luis Cenis Anadón, in January 2013. During the course of his PhD, he researched on biotechnological and biomedical applications of the silk\r\nworm (Bombyx mori). This period was complemented with 3 successive visits (2010, 2011, and 2012) to the Department of Chemical Engineering of Massachusetts\r\nInstitute of Technology (MIT), where he also collaborated with Tufts University (Professor David L. Kaplan) and the Massachusetts General Hospital (Professor\r\nRobert Redmond).

Graphene based materials are being studied as emerging scaffolds for tissue engineering applications due to their excellent\r\nproperties in terms of biocompatibility. Numerous reports have noted the optimal adhesion and proliferation of diverse\r\ntype of cells growing on graphene oxide (GO) materials, moreover the chemical nature of graphene seems to act also on the\r\ndifferentiation of stem cells. In this work we explored the possibility to produce electrospun silk fibroin (SF) scaffolds with GO\r\nin order to combine the excellent properties of both biomaterials. The GO was added by two different procedures; absorption\r\nof GO on the surface of the fibers and incorporation of GO in the electrospinning solution. The first one was performed by\r\nmeans of one dipping cycle of the SF electrospun mats in GO aqueous suspension (1mg.mL-1) and the second through the\r\nelectrospinning of a 18% (w/v) SF aqueous solution (containing SF:GO in 1000:1 ratio). Adhesion and proliferation of L929\r\nfibroblasts growing onto these materials were studied by SEM and MTT assay, respectively. Both materials showed a significant\r\nstimulatory effect in the proliferation of L929 cell cultures 4 days after the seeding (Tukey, p<0.05). Considering pure SF\r\nelectrospun mats (SF) as negative controls the proliferation increased by 64.7% in meshes with GO adsorbed (SF/GOab) and\r\nby 30.3% in meshes with GO incorporated in the electrospinning solution (SF:GO1000:1). Therefore, this work suggests the\r\npotential use of electrospun SF-GO scaffolds for applications in biomedicine.

Ana Pagán obtained her degree in Biology from University of Murcia. She has completed her PhD from the same University, with a research stay at the Division\r\nof Nutrition and Metabolic Diseases, LMU University, Munich, Germany. She works as a Postdoctoral researcher in the Instituto Murciano de Investigación y\r\nDesarrollo Agrario y Alimentario (IMIDA, Murcia, Spain), in the Department of Biotechnology, with premier biomaterials in tissue engineering.

Introduction: Silk fibroin and graphene are both promising biomaterials. Hybrid scaffolds combining their properties could\r\nbe attractive for tissue engineering applications. Specifically, reduced graphene oxide (rGO) is biocompatible and electrical\r\nconductor, which is an interesting property for nervous tissue regeneration. PC12 cells further differentiate into nerve cells\r\nwhen stimulated by nerve growth factor (NGF). The aim of this assay was to induce neurite formation on Bombyx mori silk\r\nfibroin (SF) based biomaterials and in combination with rGO.\r\nMaterials & Methods: The PC12 cell line was seeded onto electrospun mats from SF aqueous solutions and electrospun SF\r\nmats coated with rGO. The treatment with NGF at 50 ng/ml was used as positive control. Neurite formation and its length were\r\nevaluated after 7 days in culture by image analysis.\r\nResults: Cells growing on SF mats showed no differentiation (0%), nevertheless, PC12 cells on SF+rGO mats showed 55.5%\r\n(±2.3) of neurite differentiation and statistically similar to 61.1% (±2.1) obtained with NGF stimulation. Although, neurite\r\nlength of cells growing on SF+rGO mats was lower than those stimulated with NGF.\r\nConclusion: rGO coating of SF electrospun mats induce per se neurite differentiation of PC12 cells, similar to neurite\r\ndifferentiation under stimulation with NGF, while nude SF mats induce no cell differentiation. Thus, the combination of SF\r\nwith rGO seems to be an interesting biomaterial for nervous tissue engineering.

Kranthi Kumar Guduru is a Assistant Professor in Mechanical Engineering department at Chtistu Jyothi Intitute of Technology and Science-Warangal, India. He\r\nhas a PhD degree along with a Master of Technology in CAD/CAM. He also has 5 years of teaching experiance, is life member of Indian society for technical\r\neducation, published 10 papers in international conferences and journals including IIT-Roorkee and IIT-Madaras in the area of materials and metallurgy, designed\r\none experiment in thermal engineering and has the knowledge of computer programming used in his research work. His research work is mostly on natural fiber\r\ncomposite which are eco friendly and easily biodegradable in manufacturing.

Hybrid composites typically have a fiber or particle phase that is stiffer and stronger than the continuous matrix phase and\r\nserve as the principal load carrying members. The matrix acts as a load transfer medium between fibers, and in less ideal\r\ncases where the loads are complex, the matrix may even have to bear loads transversed to the fiber axis. In this research, the\r\ncomparative synthesis and analysis of kenaf fiber and polymer fibers are treated with NaOH solution and the fibers are properly\r\nreinforced with polypropylene resin and epoxy resin respectively in a matrix form to prepare hybrid composite laminates of\r\n6 mm thicknesses. Thereafter work is done to determine the mechanical properties like flexural strength or flexural modulus,\r\ntensile strength, tensile modulus and compressive strength with suitable specimens with ASTM standards. The anylysis is done\r\nin the Ansys 10.0 for various load and result factors. So the matrix also serves to protect the fibers from environmental damage\r\nbefore, during and after composite processing. When designed properly, the new combined material exhibits better strength\r\nthan each individual material. Composites are used not only for their structural properties, but also for electrical, thermal, and\r\neco-friendly environmental applications.