Biography:

Syed Hadi Hasan is a full time Professor in the Department of Chemistry, Indian Institute of Technology (BHU), Varanasi, India. He has guided 6 PhDs and 20 MTech dissertations and published approximately 100 papers in international journals. He has also published several book chapters and monographs and delivered talks in many national and international conferences. He has expertise in the field of removal of heavy metals from water, Nanotechnology, Enzyme technology, colorimetric sensing of heavy metals.

Abstract:

Although, the presence of fluoride in the drinking water under a certain limit (<1 mg/L) is beneficial for normal human health, fluoride concentration above 1 mg/L in drinking water can cause deleterious effects leading to dental and skeletal fluorosis, brittle bones, osteoporosis and arthritis. Therefore the removal of excess fluoride from drinking water is a matter of scientific concern. In connection to this, the potential use of rGO/ZrO₂ nanocomposite for the removal of fluoride from water was investigated. The rGO/ZrO₂ nanocomposite was prepared by hydrothermal method and characterized by various instrumental techniques such as FT-IR, XRD, SEM, EDX, TGA, XPS, Raman spectroscopy and BET surface area measurement. Then rGO/ZrO₂ was used as an adsorbent for the removal of fluoride from water. The process variables viz. rGO/ZrO₂ dose, initial fluoride concentration, temperature and pH were optimized using response surface methodology (RSM) in which the multiple regression analysis was conducted with the help of central composite design. The regression analysis showed good agreement with the experimental data having R²=0.94. Maximum percentage removal of fluoride was found to be 97% at predicted optimum values of process variables viz, rGO/ZrO₂ dose 0.63 g/L, initial fluoride concentration 37.6 mg/L, temperature 33°C and pH 5.8. The Langmuir isotherm was found suitable which predicted the uptake capacity to be 59.62 mg/g. The experimental data followed the pseudo-second-order kinetic model and the process was found thermodynamically spontaneous and endothermic in nature.

Biography:

Alexis Bordet performed his PhD at the LPCNO (University of Toulouse, France) under the supervision of Dr. Bruno Chaudret and Dr. Katerina Soulantika from November 2013 to December 2016. His project concerned the synthesis of magnetic nanoparticles for the magnetically induced catalytic hydrogenation of CO₂ to CH₄. He joined the group of Prof. Walter Leitner (ITMC, RWTH Aachen, Germany) as A Post-Doctorate Researcher in February 2017, and holds a position of sub-group Leader since August 2017. His research focuses on the synthesis and characterization of complex nano-catalysts for the chemical storage of energy and the conversion of biomass to biofuels.

Abstract:

Statement of the Problem: To limit global warming and decrease the carbon footprint in the energy mix, electricity is increasingly produced from intermittent renewable resources. As a result, large scale and long term energy storage is required to face the unavoidable variations in electricity production. From this perspective, the chemical storage of energy through the Sabatier reaction (power to gas) is especially promising. Our group recently evidenced the interest of magnetic induction to thermally activate suitable heterogeneous catalysts. We present here the hydrogenation of CO₂ catalyzed by iron based nanoparticles through magnetically induced heating. The challenge of synthesizing nano-objects displaying both catalytic activity and appropriate magnetic properties was taken up by designing specific iron carbide nanoparticles. Based on an organometallic approach, the synthesis developed gives access to highly monodisperse and finely tunable iron carbide nanoparticles. The size, carbon content and crystallographic organization of the NPs were proven to be critical parameters to obtain high specific absorption rates (SAR). In optimal conditions, SAR as high as 3000 W/g were measured (100 kHz, 47.4 mT). To our knowledge, this value is by far the highest ever reported for such mild conditions. Subjected to an alternating magnetic field in a dedicated flow reactor, suitable iron carbide based nanoparticles were proven to be catalytically active for the hydrogenation of CO₂ to hydrocarbons. Interestingly, the catalytic activity of iron carbide nanoparticles can be tuned by functionalizing the NPs surface with different metals such as nickel and ruthenium.

Biography:

Nina Kostevšek has her expertise in preparation of multifunctional nanomaterials based on magnetic (FePt, different ferrites) and optically active components (Au) for bioapplications such as magnetic resonance imaging, magnetic hyperthermia, photo-thermal therapy and sensing. Her research involves as well formation of smart drug nanocarriers made of SiO₂, biopolymers (chitosan, gelatine, etc.) and thermo-responsive liposomes. Reliable characterization is of vital importance for the optimization of new materials, therefore she uses advanced “state of the art” techniques such as liquid cell transmission electron microscopy for visualization of nucleation and growth of nanoparticles in their “natural” aqueous environment.

Abstract:

We have produced an innovative, theranostic material based on FePt/SiO₂/Au hybrid nanoparticles (NPs) for both, photo-thermal therapy and magnetic resonance imaging (MRI). Furthermore, a new synthesis approach, i.e., Au double seeding, for the preparation of the Au nanoshells around the FePt/SiO₂ cores, is proposed. The photo-thermal and the MRI response were first demonstrated on an aqueous suspension of hybrid FePt/SiO₂/Au NPs. The cytotoxicity together with the internalization mechanism and the intracellular fate of the hybrid NPs were evaluated in vitro on normal (NPU) and a half-differentiated cancerous cell line (RT4). The control samples as well as the normal cell line incubated with the NPs showed no significant temperature increase during the in vitro photo-thermal treatment (ΔT < 0.8°C) and thus the cell viability remained high (~90%). On the contrary, due to the high NPs uptake by the cancerous RT4 cell line, significant heating of the sample was observed (ΔT = 4°C) and, consequently, after the laser irradiation cell viability dropped significantly to ~60%. These results further confirm that the hybrid FePt/SiO₂/Au NPs developed in the scope of this work were not only efficient but also highly selective photo-thermal agents. Furthermore, the improvement in the contrast and the easier distinction between the healthy and the cancerous tissues were clearly demonstrated with the in vitro MRI experiments, proving that hybrid NPs have an excellent potential to be used as the contrast agent.

Biography:

Seham S. ALTERARY is Saudi chemistry Professor who was born in Riyadh KSA. In 1994 she earned a B.S. in chemistry from the University of King Abdul-Aziz in Jeddah, where she accepted a position of demonstrator in Faculty of Science Chemistry Department in same University. In 2003, she earned Master degree of Science with Excellent grade at the University of King Abdul-Aziz in Jeddah. In 2003, she received her PhD from University of Paris Didrot 7 in Spectroscopic Methods & Nano-technology Applications in France. She enrolled in King Saud University as Assistant Professor of Organic Chemistry since 2011 till now. In 2014, she became the Vice-Head of the Department of Physics & Astronomy in Collage of Science King Saud University. She carried out many undergraduate and graduate researches. In 2016, she became supervisor of nanotechnology unit in girls University City. She is the co-editor of “Heterocyclic chemistry and biomolecules through practice problems "book.

Abstract:

In the present work, two types of magnetic-nanostructure catalysts were synthesized for highly efficient methodologies in organic chemistry processes [1]. The vital motivation for synthesizing nano-catalyst is to promote sustainability, enhance catalysis properties and provide great advantage to catalytic applications. The unique properties of magnetic nano-catalyst such as; easy separation methodology by external applied magnetic field and the recyclability expands these class of nano-catalysts to wide area of applications. In fact, the combination between sustainable catalysis and magnetic properties yields an extremely powerful and environmentally green organic processes [2]. synthesis of both nano- catalyst -in the current work- includes the metal ferrite oxide in nano- measurements. The silica supported nano-catalyst afford functionalization options to metal ferrite oxide nano-catalyst. At the first, nano-catalyst made of copper ferrite components (CuFe₂O₄ NP) was synthesized by co- precipitation (CPT) method. Subsequently, the sol-gel method was applied to synthesized the silica coated copper ferrite magnetic nanoparticles CuFe₂O₄@SiO₂. A selection of characterization techniques were chosen to understand and investigate the changes occur in physical properties in both types of nano-catalysts. The study focuses on their structural, morphological and physical properties. Depending on the following techniques; transmission electron microscopes TEM, scanning electron microscopes       SEM,

X-ray diffraction XRD, Energy-dispersive X-ray EDX, fourier transform infrared spectroscopy FTIR and the Zeta potential which may be a useful indication for catalytic performance of hetero nano-catalysts [3].

Biography:

Thomas Maurer is an Assistant Professor at the University of Technology of Troyes. He has been developing a research activity at the interface of nanotechnology, mechanics and optics, which can be designed as mechanoplasmonics. In parallel, he is a member of the Action Laboratory of Excellence Executive Committee and responsible of the ‘Smart Sensors’ scientific work group whose aim is to integrate sensing functionalities into matter.

Abstract:

For the past twenty years, nano-optics has emerged as a promising research field; thanks to huge progress in nanofabrication and offers great technological potential for applications in fields such as biology, medicine or chemistry. Coupling between plasmonic nanoparticles (NPs), well-known as the plasmon ruler equation, was recently investigated by fabricating arrays of NP dimers with various inter-particle distances using e-beam lithography. In this talk, we aim to illustrate how it should be possible to break through frontiers between mechanics and plasmonics in the next future by showing our first results on the use of gold nanogauges for strain investigation as well as recent advances published in the literature. We will first illustrate how SEM tracking of Au NP displacements allows mapping strain tensor components at the nanoscale and bring information which is not currently achievable by other conventional techniques. Then we will expose advances which have been recently achieved in the literature concerning the potential of plasmonic NPs to develop color-changing materials and strain sensors integrated into matter.  In particular, we will focus on two inherently disordered systems made either of Au NPs or Au nanorods (NRs) grown onto PDMS substrates which exhibit material coloration due to the Au NPs strong light absorption. Thanks to an optical extinction set-up with implemented traction micromachine, plasmonic coupling between the gold nanoparticle assemblies may be observed and compared to nanoparticle displacements (see Figure 1). The long-term objective of such work is the development of a new generation of plasmonic strain sensors. Finally, we will propose perspectives of research axis in this field in order to seize the opportunity of this talk to build up collaborations. In particular, we will focus on the need of ability to develop nanofabrication routes of NP ordered arrays or nanorings onto elastomeric substrates.

Biography:

Masih Darbandi received his PhD in 2007 from Freiburg University, Germany, where he worked on semiconductor nanoparticles (QDs). Thereafter, he spent several years as a Postdoctoral Scientist in Bochum, Duisburg-Essen (Germany) and Uppsala (Sweden) universities working on different topics from MOF to Magnetic Nanoparticles. In 2012, he moved to USA as Senior Scientist (Staff) working at Vanderbilt and Brown Universities. His research area was ceramic nanoparticles, fabrication and the characterization of freestanding films of ceramic nanoparticles via electrophoretic deposition. Right now he holds a position as Faculty Member in University of Tabriz, Iran.

Abstract:

With surging the environmental problem and global energy crisis, the demands for clean, regenerative, and sustainable energy supplements are increasing in recent years. Co(OH)₂ NPs have been attractive since the beginning of the nanotechnology due to their characteristics such as additive in batteries, supercapacitor, catalysis, etc. We have developed a route toward the synthesis of Co(OH)₂ NPs, which does not require any template or surfactant, with enhanced electrochemical energy storage performance with high capacitance retention capability. The physicochemical features of the as-prepared Co(OH)₂ nanorings were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen absorption–desorption. Structural characterizations represents an excellent mesoporous structure for the as-prepared Co(OH)₂. Due to its especial structure, the as prepared Co(OH)₂ NPs posing a high porosity for better electrolyte accessibility along with large surface area for higher electrochemical reaction rates. As a result, the NPs exhibited an excellent electrochemical capacitor performance. Moreover, this simple, low cost, reproducible friendly synthesis process, reported herein, could be extended to the controlled synthesis of other functional hydroxide NPs with well-defined morphologies and shapes. The ease of the precipitation production of these NPs could be scaled up to industrial-scale manufacture for the aforementioned real-world commercial applications.

Biography:

Vladimer T Mikelashvili, PhD, Physicist has his expertise in evaluation and technology of magnetite particles containing nanofluids. He has participated in several (14) international scientific conferences, published 7 scientific articles and is a member of Georgian Scientific Group. The research objective of scientific group of Magnetic Nanofluids of Biomedical Use at Vladimir Chavchanidze Institute of Cybernetics of the Georgian Technical University is synthesis of magnetic nano suspensions, their subsequent modifications and study of the physical and chemical properties. 

Abstract:

In recent years, much attention is paid to study nanoscale magnetic nanoparticles (MNPs), such as Fe₃O₄, γ-Fe₂O₃, CоFe₂O₄, ZnFe₂O₄, BaFe₁₂O₁₉. Among these, superparamagnetic iron oxide nanoparticles (SPIONs) of magnetite (Fe₃O₄) and maghemite (γ-Fe₂O₃) are very popular candidates with their biocompatibility and can be used by encapsulation of the particles with a suitable coating substance for controlled drug delivery of therapeutic agents in “in-vivo” applications. Besides, the other applications found in the area of magnetic resonance imaging are tissue repair, immune analysis, biological fluids detoxification, magnetic hyperthermia and cell separation. In fact, although various types of techniques are used for the synthesis of magnetic nanomaterials like chemical precipitation technique, thermal decomposition of organic iron precursors, hydrothermal synthesis, and microemulsion-based technique, etc., unfortunately, at the state-of-the-art, imperfections in the final materials are still usually present. They are due to difficulties in controlling both temperature and mixing process during the synthesis, which result in a procedure-dependent nanoparticle size polydispersion due to the NPs instability towards growing processes. We propose electrohydraulic discharges assisted chemical co-precipitation technique in order to develop a simple, cost-effective, large-scale manufacturing of bio-applicable iron oxide nanoparticles involving plasma arc discharges in base solution. By this method, as preliminary experiments shows, we obtain better dispersing the formed nanoparticles at the initial stage, process their surface (static stabilization, H and OH radical addition for better absorbance) by pulsed discharges and add to the fluid the bactericidal properties. After that, the covering (stabilizing) of the monodisperse nanoparticles with surfactant is relatively easy to follow, with bioactive molecules (dextran, polyvinyl alcohol, polyethylene glycol, etc.), followed by washing from chemical reaction residuals, additional ultrasound homogenization and centrifugation. Transition electron microscopy, vibrating sample magnetometer, VIS spectrophotometry and bactericidal research was used to characterize obtaining samples. 

Biography:

Ho-Jin Moon is a Postdoctoral Research Fellow at School of Dentistry and Oral Health, Griffith University in Australia. He is an emerging Bone Immunologist with a keen interest in interactions and signalling mechanisms between osteoblast and macrophage (osteoclast) on biomaterial surfaces. He firstly started from molecular biology interest and have developed to cell response on multi-functional scaffolds for bone healing. He was awarded his Master’s and PhD degree in South Korea and then joined Tissue Engineering and Regenerative Medicine group in MenziesHIQ of Griffith University. His research interests include regenerative medicine and tissue engineering based on molecular biology to characterize the molecular basis of bone healing. He was awarded Griffith University Postdoctoral Fellowship (2016-2017) in Australia and Fostering Next-generation Researchers Program for Postdoc from the National Research Foundation of Korea (2017-2018). 

Abstract:

Statement of the Problem: Macrophages are vital modulators of inflammation, and their relationship with bone cells enables dynamic crosstalk between inflammatory M1 macrophage and regenerative M2 macrophage. It is important to modulate immune response as the first stage for tissue regeneration, wound healing at the bone, dental implant micro-environment, and hence studies have aimed at achieving tailored immune responses on Ti implants by means of surface modification. More recently, nano-engineered titanium with titania nanostructures: nanotubes or nanopores (TNS) have been suggested as favourable bone implant surfaces.

Methodology & Theoretical Orientation: Nanopores (50 nm and 70 nm diameter, TNS-50 and TNS-70) on Ti surfaces were fabricated by anodization process and characterized by SEM imaging. Then, we investigated the effect of TNS in Mo macrophage differentiation and also examined macrophage phenotype switching from M1 and M2 macrophage using immunofluorescence staining, cytokine levels and gene expression. In addition, we elucidated osteogenic effect of macrophages indirectly co-cultured with pre-osteoblasts (MC3T3-E1 cell) on these surfaces using ALP activity and Alizarin red staining.

Findings: Our results showed that TNS increased M2 macrophage phenotype expression from Mo and M1-induced macrophage. In particular, TNS-70 significantly upregulated M2 macrophage marker expression. Also, we found that co-cultured with macrophage subtypes on TNTs increased the osteogenic ability of pre-osteoblasts.

Conclusion & Significance: TNS modified Ti enhanced the M2 macrophage phenotype and promoted  osteogenesis, which has implications for bone healing in the implant micro-environment. This study will help to optimize and understand a potential underlying cellular mechanism responsible for improved bone healing for nano-engineered Ti implants. These results will thus facilitate the development of immune-responsive implantable Ti prostheses towards bone regeneration.

Biography:

Eduardo D. Martínez is an assistant researcher of CONICET working at the Low Physics Division of the Bariloche Atomic Center (CAB), a national research facility located in the city of San Carlos de Bariloche, Río Negro, Argentina. He has a materials engineering degree with a PhD in chemistry at the University of San Martín, Argentina. He performed a postdoctoral research at CAB-Argentina developing nanocomposite materials for microfabrication. At the moment, he is running a postdoc project in the physics department at the Universidad Estadual de Campinas, (UNICAMP), Brazil. His expertise is in the field of nanomaterials and nanocomposites, mostly applied to plasmonics and photonics. Specifically, he works in the chemical synthesis of nanoparticles and their assembly into nanostructures and devices by applying techniques of self-assembly and combining bottom-up and top-down methods.

Abstract:

Photon upconversion (UC) is a non-linear optical anti-Stokes process by which low energy photons stimulate the emission of higher energy photons. The hexagonal phase (P63/m) b-NaYF₄ doped with rare-earths elements stands as one of the most efficient UC materials, finding applications in bioimaging, solar-cells and displays. However, many of these applications operate in fluctuating temperature conditions affecting each emission line of the UC spectra in a different manner. In this work, we develop a functional device to study in situ the thermal effects on UC nanoparticles (UCNPs) of different size and composition by using a percolating network of silver nanowires (AgNWs) as a highly transparent heating element. The electrical power dissipated by Joule effect allows for the electrothermal control. This device was successfully applied to characterize the thermal dependence of UC in large (>100 nm) b-NaYF₄:Yb:Er(Tm,Ce-Ho) and small (<20 nm) core-shell b-NaGd₄:Yb:Er(Tm,Ce-Ho)@NaYF₄ UCNPs in the 20 °C-140 °C interval. Just the presence of AgNWs was enough to produce an enhancement of 20-30% in the intensity of UC emissions. We find that an increment in temperature can enhance or partially quench the emission lines selectively on each UCNPs system. The most temperature-sensitive case was that of Er doped UCNPs, in which the optical transitions ²H_11/2→⁴H_15/2 (H transition) and ⁴S_3/2→⁴H_15/2 (S transition), were found to reversible change in a different manner. For the case of bigger NaYF₄ UCNPs, the S transition is quenched while the H transition was barely constant. For the small-sized UCNPs, the S transition remained unaffected while the H transition was sturdily enhanced. Time-resolved spectroscopy at different temperatures revealed further insights on the mechanisms involved. A rate-equation model was proposed to unravel the underlying mechanism. Finally, we take advantage of the electrothermal device to analyze in-situ other relevant chemical processes.

Biography:

Martina Datteo graduated in Chemistry in 2016 at the University of Milano Bicocca, with a thesis on the graphene/anatase (101) interface. Her work of bachelor and master thesis has been included in two international peer- reviewed articles. She has received ‘Fondazione Grazioli’ prize for her master thesis. She is now pursing her PhD degree under the supervisor of Prof. Cristiana Di Valentin. The topic of the thesis is “Computational study of smart bioinorganic hybrids for nanomedicine”.

Abstract:

The “catalysis under cover” involves chemical processes which take place in the confined zone between a 2D material, such as graphene, h-BN, or MoS2, and the surface of an underlying support, such as a metal or a semiconducting oxide [1,2]. The hybrid interface between graphene and anatase TiO2 is extremely important for photocatalytic and catalytic applications because of the excellent and complementary properties of the two materials [3]. We investigate and discuss the reactivity of O2 and H2O on top and at the interface of this hybrid system by means of a wide set of dispersion-corrected hybrid density functional calculations [4]. Both pure and boron- or nitrogen-doped graphene are interfaced with the most  stable (101) anatase surface of TiO2 in order to improve the chemical activity of the C-layer. Especially in the case of boron, an enhanced reactivity toward O2 dissociation is observed as a result of both the contribution of the dopant and of the confinement effect in the bidimensional area between the two surfaces. Extremely stable dissociation products are observed where the boron atom bridges the two systems by forming very stable B-O covalent bonds. Interestingly, the B defect in graphene could also act as the transfer channel of oxygen  atoms from the top side across the C atomic layer into the G/TiO2 interface. On the contrary, the same conditions are not found to favor water dissociation, proving that the “catalysis under cover” is not a general effect, but rather highly depends on the interfacing material properties, on the presence of defects and impurities and on the specific reaction involved [5].

Biography:

Thaiskang Jamatia is a PhD student in the Faculty of Technology, Tomas Bata University, Czech Republic, under the supervision of Dr. Ivo Kuritka. He obtained his Master’s degree in Nanoscience and Technology from Karunya University, India. His research involves preparation and characterization of nanocomposite thin films for polymer electronics. 

Abstract:

ZnO is a semiconductor material widely used in versatile applications in optoelectronic and piezoelectric devices. The doping of ZnO with transition metals like Fe, Co, Mn, Ni, Cr or V opens a new research topic leading to materials with completely different behavior towards magnetic and optical properties. Fe_xZn_1-xO nanoparticles were synthesized with varying Fe doping concentrations (x = 0, 0.01, 0.05, 0.10, 0.15) by microwave assisted solvothermal method. The microwave synthesis is based on high temperature decomposition of zinc acetate dihydrate and iron (III) acetylacetonate in diethyleneglycol with the presence of oleic acid as a capping agent. Obtained nanoparticles formed stable colloidal solutions in toluene. These nanocolloids can be furthermore used as precursors for nanocomposites with conductive polymers and for deposition of thin films resulting in utilization in optoelectronic devices. The phase purity and crystal structure of Fe_xZn_1-xO was observed in X-ray diffraction (XRD) patterns. Elemental analysis of the dopant Fe was examined by energy-dispersive X-ray spectroscopy (EDS). The morphological studies were done in scanning electron microscope (SEM) and transmission electron microscope (TEM). Optical properties were studied by ultraviolet-visible absorption spectroscopy (UV-Vis) and photoluminescence spectroscopy (PL). Changes in band-gap were observed with different doping concentrations. The experiment results show that the optical properties of ZnO have been successfully tuned by the addition of the Fe dopant.

Biography:

Hyunseung Lee received his BE in Nanoscience & Engineering from Inje University. He is currently studying for a Master degree in the Department of Nanoscience & Engineering, Inje University, Korea.

Abstract:

MWNT-grafting-polyisoprene (PI) nanocomposites were prepared by an activators regenerated by electron transfer for atom transfer radical polymerization (ARGET-ATRP) process using isoprene end MWNT-Br. MWNT-Br intermediates were prepared by carrying out the MWNT surface treatment processes in several steps and used as an initiator of ARGET-ATRP process. The preparation process flow of MWNT-grafting-PI nanocomposites conducted in this study is presented in Figure 1. MWNT-Br intermediates with different Br element content were prepared by controlling the amount of α-bromoisobutyryl bromide (BiB) which is used as a reactant in order to convert MWNT-OH intermediates into the MWNT-Br. The Br content of MWNT-Br was quantitatively analyzed by the application of peak analysis (total Br element content (%) and C-Br element content (%)) using X-ray photoelectron spectroscopy (XPS) spectrum. Four kinds of MWNT-Br samples with different Br element contents were subjected to the ARGET-ATRP process under the same reaction conditions to produce four types of nanocomposites having different PI contents in MWNT-grafting-PI nanocomposites. The four MWNT-grafting-PI were analyzed for viscosity changes by oscillational viscometer and PI content changes by TGA and reaction yield. To compare with the above results, the changes in the atom (%) values of the C-Br groups on the MWNT surface were analyzed by the application of XPS quantitative analysis. Figure 2 shows the change of viscosity (figure 2-(a)) depending on BiB/MWNT-OH values for the four MWNT-grafting-PI nanocomposites and the change of C-Br atom% (figure 2-(b)) depending on BiB/MWNT-OH values for the four MWNT-Br intermediates. In this study, we successfully prepared the MWNT-grafting-PI nanocomposites with PI content of 70% or more and developed how to maximize the PI content of MWNT-grafting-PI nanocomposites. 

Biography:

Estefanía Martinez C is a Registered Nurse from the Universidad de Antioquia. At present, she is advancing in her undergraduate studies in Nanotechnology Engineering at the Universidad Pontificia Bolivariana, where she starts to work in the New Materials Research Group (GINUMA) in the evaluation of wound dressings and biomaterials based on bacterial nanocellulose in the biomedical field. Her interest is on the future applications of nanomaterials in tissue regeneration applying a multidisciplinary focus between engineering and nursing.

Abstract:

Statement of the Problem: Bacterial nanocellulose (BNC) is a multifunctional nanomaterial with applications in diverse fields, including scaffolds for tissue engineering and cell regeneration. In these fields, there is a gap in the knowledge regarding its blood response. This work aimed at studying the influence of material drying method and its microporosities on the material hemocompatibility response.

Methodology & Theoretical Orientation: BNC was produced using Komagataeibacter medellinensis, following the protocols by Castro et al. (2013). For the evaluation of drying effect, the biomaterials were dried by freeze drying and oven, never-dried BNC was used to comparative propose. To determine the effect of three-dimensional microporosities, BNC was synthetized using porogens and never-dried. The biomaterials were characterized by Scanning Electron Microscopy (SEM) to observe the biomaterial interaction with blood cells and fibrin. Hemolysis and thrombogenicity tests to evaluate the response of red blood cells and clotting time, respectively. These studies were performed under ISO 10993 and ASTM F756, respectively.

Findings: BNC biomaterials are conformed by nanoribbons network and interconnected micropores. Regarding this, drying processes was found that freeze-drying biomaterials present hemolytic behavior (hemolysis percentage over 2%) and a clotting time under 5 minutes. This behavior is related to friction of red blood cells with BNC nanoribbons and a quick adsorption of fibrin, which trigger the clotting cascade. The best result was found with never-dried cellulose, related to its natural water content that reduce the friction of blood cells and adsorption of fibrin (Figure). Respecting the three-dimensional microporosities, there was no statistically difference in hemolytic and clotting time; however, according to SEM images, microporosities promotes the interaction of blood cells with the biomaterial.

Conclusion & Significance: Never-dried cellulose was found to perform an appropriate blood response compared with freeze and oven dried. Furthermore, never-dried BNC allows the conformation of hemocompatible three-dimensional biomaterials, which are useful for the development of cell interactive scaffolds. In prospective these biomaterials are appropriate for future development of new implantable biomedical devices based on BNC for blood contact, taking advantage of nanotechnology.

Biography:

Ashu Jain, after completing undergraduate course in Electrical Engineering, has done her Master’s in Nanotechnology. At present she is pursuing her PhD work from Indian Institute of Technology Delhi, India, on the topic “Kinetics of Formation of Silver Nanoparticles using Leaf Extract as Reducing and Stabilizing Agent”. She is also currently working on a project sponsored by Department of Science and Technology, Government of India, under the Women Scientist A scheme. 

Abstract:

Statement of the Problem: Silver nanoparticles (SNP) synthesized using a variety of plant extracts have been widely reported. Phytochemicals present within the extract act as reducing agents and capping agents for SNP formed by reduction of Ag cations from AgNO₃ to Ag atoms. Inspite of the synthesis being energy efficient, low cost, easy and environmentally benign-without use of toxic chemicals; it has not been commercially adopted so far because the SNP synthesized using plant extracts are of varying sizes and shapes. The properties of nanoparticles are highly shape and size specific; which implies that commercial applicability of a synthesis process depends on its ability to synthesize nanoparticles of uniform shape and size. The vast applicability of SNP various fields such as biomedical applications, catalysis, sensors, electronics, energy justifies optimization of their green synthesis keeping in view the environmental concerns.

Methodology & Theoretical Orientation: Synthesis of SNP using Azadirachta Indica leaf extract was done by reacting AgNO₃ solution of known concentration with leaf extract prepared boiling finely chopped fresh leaves in water. The synthesis has been carried out at room temperature at pH of 12. The SNP synthesis was monitored using UV absorbance spectra and TEM imaging and DLS were used for characterizing shape and size.

Findings: The reduction reaction is extremely fast under the optimized conditions. The conversion of Ag cations to Ag atoms is almost 100% resulting in a high yield of SNP. The SNP synthesized by this method are spherical, of a narrow size range and highly stable.

Conclusion & Significance: Uniformity in shape and size of the green-synthesized spherical SNP holds promise for their commercial application. We however need to work towards synthesizing SNP with precise size; tailored for specific applications. This would enable commercialization of the Green synthesis of SNP using plant extracts. 

Biography:

Ali Reza Mahjoub received his MS degree in Organic Chemistry in 1988 and his PhD in Inorganic Chemistry in 1993 from University of Berlin, Germany. He is Professor at Tarbiat Modares University (TMU) now. His research activity covers many aspects of the synthesis, characterization and chemical-physics of metal oxides and nano oxides with particular emphasis to catalytic and photo degradation properties. His two other main interests are polyoxometalate and mesoporous silica. He has authored and co-authored more than 150 journal papers. The total citation is 2200 times and the H-index is 29.

Abstract:

Glycerol found in animal fat, vegetable oil, and crude oil is used as a raw material in various applications such as using in cosmetics, pharmaceuticals and food industries. In spite of such a wide range of applications, the price of glycerol is decreasing noticeably. This is due to commercialization of biodiesel which lead to large amount production of glycerol as a byproduct. So, Glycerol can be counted as biomass. Because of having three hydroxyl groups, Glycerol can be converted to many value added products via chemical reactions. Among all, one of the most interesting approaches is acetylation of glycerol by acetic acid. During this reaction di- (DAG) and tri- (TAG) acetyl glycerol are produced as valuable additives for biodiesel. It has been reported that solid acid catalysts promote the acetylation reaction of glycerol. In this study, we synthesized zirconium-modified mesoporous silica (Zr-SBA) and then immobilized tungestophosphoric acid into it (Zr-SBA-PWA). Both catalysts are used in acetylation reaction of glycerol by acetic acid at 100^°C. DAG and TAG are characterized as main products of the reaction. Comparison of two catalysts showed our result is unlike of many reports which explain by increasing the acidity of the catalyst the conversion efficiency of glycerol to DAG and TAG is improved. While the NH₃-TPD analysis showed weaker acid properties for Zr-SBA, it exhibited better performance than Zr-SBA-PWA in acetylation of glycerol. Zr-SBA converted 100% of total glycerol, while the selectivity of reaction to DAG and TAG is nearly 90% which is an impressive achievement. 

Biography:

Maryam Kamalipourazad has completed her PhD at the age of 30 years from Tarbiat Modares University. She has published more than 5 papers in international journals. She experiences in Medicinal plants and Natural products, Plant Cell Cultures, Biochemistry (HPLC, Enzyme activity measurement, protein electrophoresis,..), Plant physiology and Plant Environmental Stress Physiology (Anti-oxidant activities, measurement of Flavonoids, carbohydrates, amino acids, reactive oxygen species (ROS) contents), Molecular techniques: Extraction DNA and RNA from plant, bacteria, mitochondria and chloroplast, cDNA synthesis, primer designing, identification of gene expression levels by qRT-PCR analysis, extraction of plasmid, cloning, transformation (transgenic hairy root and callus), Green Nano.

Abstract:

Biochemical interactions result in various nanostructures in both intra and extracellular environments. Design of nanostructures in vitro and study of biochemical assemblies in vivo need an understanding of their formation mechanisms and their structural characteristics. Diphenylalanine self-assembly in a synthetic media and lipid aggregation inside algal cells are two examples of the biochemical interactions. Microscopic techniques give us the capability to predict the behavior of these self-assembled nanostructures and to identify their characteristics in different media.

The kinetics of self-assembly can be well investigated by online monitoring the organization phenomena. The dissolution process of a given nanostructure can also be monitored by observing the solvation phenomena so as to find the relevant factors which would influence the dissolution process. For example, different solvents would dissolve nanostructures in a chain type reaction or in a power law nucleation with consequent interface advance. Dissolution of diphenylalanine nanostructures in water and in methanol are instances of these reaction types, respectively, Figure 1.

The size and shape characteristics of the nanostructures are strongly influenced by the surrounding environment. Electron microscopy techniques provide us with the information on crystal habit modification. For example, the morphological evolution of diphenylalanine nanostructures makes possible the identification of ion types in the solution of the dipeptide.

In addition, staining of assembled biochemicals and their cellular localization are of the other activities carried out in our investigations. Monitoring the aggregation of lipids and their location in living cells using fluorescent dyes e.g., Nile red, can be mentioned as an example, Figure 2. This would help us to implement correct action for cell treatment.