Biography:

S E Rodil has bachelor and master degrees in physics from the National Autonomous University of Mexico (UNAM) and PhD degree from the University of Cambridge, UK. Her expertise in the development of surface modifications of metallic implants in order to improve the biological response. She has been particularly interested in the development of coatings to improve the osseointegration of metallic dental and orthopedic implants, aiming to find a solution that might also decrease the cost of the implants for their use in third world countries. She is a Professor at the National Autonomous University of Mexico, where she is involved in research and the preparation of the new generation of materials research students.

Abstract:

Titanium oxide (TiO₂) has been recognized as the active layer responsible for the good biocompatibility and osteogenic properties of the Ti-based medical alloys used for dental and orthopedic applications. Meanwhile, magnesium (Mg) and its alloys are currently widely researched for orthopedic applications, since their mechanical properties are more adequate to balance load transfer between bone and implant, but also due to its biodegradability. Extensive mechanical, in vitro and in vivo studies have been done to improve the biomedical performance of Mg alloys through alloying, processing conditions and surface modifications, including coatings deposition. The main purpose of such modifications is to extend the degradation rate of the alloy in order to match it with bone self-healing time. In this work, we are investigating the use of titanium oxide coatings deposited by physical vapor deposition techniques on high purity Mg alloys. These TiO₂ coatings have been extensively evaluated to demonstrate that independent of the substrate into which they are deposited, the coatings have the ability to promote the differentiation of mesenchymal stem cells into the osteoblast lineage, while improving the corrosion resistance of the uncoated metallic substrate and inhibiting bacterial adhesion. Here, we present the preliminary results of the corrosion resistance of the coated Mg-alloys in physiological fluids, their cell biocompatibility and weight loss kinetics.

Biography:

Je-Ken Chang is an Orthopedic Surgeon at the Kaohsiung Medical University. His research work focuses on Regenerative Medicine, especially Tissue Engineering of articular cartilage and bone, as well as degenerative diseases like osteoarthritis and osteoporosis. He has published his study results in journals including Biomaterials, Acta Biomaterialia, Journal of Tissue Engineering and Regenerative Medicine and Journal of Applied Physiology

Abstract:

Simvastatin (Sim) is a clinically used lipid lowing agent, which has been indicated to increase bone morphogenetic protein-2 (BMP-2) expression. BMP-2 has been demonstrated to play a critical role in cartilage development, and is applied to promote chondrogenic differentiation of mesenchymal stem cells (MSCs). However, BMP-2 was also used for osteogenic differentiation of MSCs. Hyaluronan (HA) is one of the main extra cellular matrices during the early stage of chondrogenesis, and we previously found that HA microenvironment initiates and promotes chondrogenesis of adipose derived stem cells (ADSCs). In this study, we hypothesize that HA enhances the chondrogenic effect and prevents osteogenic effect of Sim on ADSCs, and this can be applied for cartilage regeneration. The ADSCs were cultured in vitro in HA-coating, well treated with Sim, and the BMP-2 expression, chondrogenesis as well as osteogenesis of ADSCs were analyzed. The result showed that HA microenvironment enhances Sim-induced BMP-2 expression and chondrogenesis of ADSCs. The real-time PCR results showed that the BMP-2 and chondrogenic genes (SOX-9, Collagen type II and Aggrecan) expressions induced by Sim in ADSCs were enhanced when cultured in HA-coated well (Figure. 1). The result from sGAG synthesis of ADSCs also shows HA microenvironment enhances more pronounced sulfated glycosaminoglycan (sGAG) synthesis of ADSCs that is induced by Sim (Figure. 2). HA microenvironment also reduces osteogenic genes expressions (osteocalcin and alkaline phosphatase) and calcium deposition of ADSCs that is induced by Sim (Figure. 3). The synergic effect of HA with Sim can promote chondrogenesis and prevent osteogenesis of ADSCs, and may be applied for articular cartilage defect regeneration. This result shows the local cue on affecting chondrogenesis and osteogenesis of BMP-2 in ADSCs induced by Sim.

Biography:

Dr. Lee has extensive expertise in performance improvement and innovation in metal corrosion and abrasion. His researches include innovative biomaterials reaction mode, the establishment of the nano-reaction mechanism based on the combination of biopolymer biomaterials, the applications of various researches of many scholars: the combination of improved and innovative adsorption method.

(1) Author’s educational qualifications:

A. The Director of Career Training Center at Dayeh University (2012-08-01~2014-07-31)

B. The Director of Engineering Research and Development Center at Dayeh University (2006-08-01~2007-07-31)

C. The Associate Professor of Department of Materials Science and Engineering at Dayeh University (2013-08-01~so far)

D. The Assistant Professor of Department of Materials Science and Engineering at Dayeh University (2010-08-01~2013-07-31)

E. PhD in Materials Science and Engineering of Chung Hsing University (2004-08-01~2010-06-31)

(2) Awards achieved:

A. 2017 Platinum Award from Hong Kong Innovation & Technology International Invention Exhibition, Chung Hwa Innovation & Invention Association, and Taiwan International Invention Award Association (2017/12/08)

B. 2017 Good Work Award from Light Metal Innovation Application Contest Masterpiece of Bureau of Industry, Ministry of Economic Affairs (2017/11/10)

(3) Papers published: Please Refer to the Section of Recent Publications.

(4) Area of research interest:

    A. Surface Science and Modification

  B. Corrosion and Material Warranty

Abstract:

In this study, chitosan (Cs) and xanthan gum (XG) were made to react in a weight ratio of 1:1 to form a cross-linking polymer. Xanthan gum-chitosan/nanowire Ni(XG-Cs/-Ni) was prepared by the addition of nickel nanowire (NiNW) onto the XG-Cs to form the nano polymerization colloid. Field emission scanning electron microscope (FE-SEM) showed that the diameter of nickel nanowires was about 80 nm and the length was about 11 μm, with high density and high aspect ratio. The crystal planes (111) (200) and (220) [They  are the growing directions of crystal planes (x,y,z)] were analyzed by X-ray diffraction (XRD). The results showed that the nanowires were fine nickel grains and had the characteristics of the crystal dislocation structure and the twin crystal structure which were observed by transmission electron microscopy (TEM). The melting points of XG-Cs/-Ni were measured by differential scanning calorimetry (DSC), they were 59.0-197.3/695.5°C. Analysis of XG-Cs/-Ni by the thermogravimetric analyzer (TGA) revealed three weight loss points.

Biography:

Monika Jenko completed her PhD in Material Science at the University of Ljubljana. For 11 years she was the Director and Initiator at the Institute of Metals and Technologies (IMT) and later joined the Jožef Stefan International Postgraduate School with Advanced Metallic Materials in the frame of the Nanoscience and Nanotechnology study program. She has worked in different national and international projects in the field of Material Science, Applied Surface Science, Surface Engineering, and Nanoscience and has been very active in the field of Biocompatible Materials since the last five years. She has published several papers in reputed journals and is a member of different international working groups.

Abstract:

Statement of the Problem: The endoprosthetics of hip- and knee-joint replacements is currently the most common and successful methods in advanced surgery to treat degenerative joint disease for relieving pain and for correcting deformities. While these surgeries have positive outcomes, approximately 10% of the implants fail prematurely. The most common causes for revision surgeries are aseptic loosening and implant infection.

Orientation: Microstructure is a neglected factor in implant design, and a detailed microstructure characterization is required to determine the role of prematurely failed implants that determine the biological responses, such as the composition and structure of the surface oxide film, the surface contamination and the surface topography. The release of metal ions and the lack of the wear resistance of biomaterials result in implant loosening, which leads to implant failure. The release of metal nanoparticles and polyethylene debris into the soft tissue at the site of the implants is decisive for osteolysis and the implants’ longevity.

Findings: The surface chemistry of Ti alloys (Ti6Al4V, Ti6Al7Nb) and the CoCrMo alloy of (retrieved and new) hip and knee endoprostheses components were studied in detail using advanced electron spectroscopy techniques FE-SEM, EDS, EBSD, AES and XPS. We will present the findings from the clinical and materials sciences point of view. All the retrieved implants were sent for sonication in Ringer’s solution for cleaning and pathology analysis. Later, they were dried and stored in special sterile Wipak medical Steriking bags. All the X-ray images of implants in the patients are stored in the database of the UMC.

Conclusion & Significance: The surface chemistry results showed that thin oxide films on the Ti alloys prevent further corrosion, improve the biocompatibility, and affect the osseointegration. It is obvious that we need to keep an optimal microstructure with regards to the corrosion and mechanical properties, which can be controlled through processing parameters and be standardized in the near future.

Biography:

Mei-Ling Ho has focused her study on Regenerative Medicine, especially Tissue Engineering of articular cartilage and bone, as well as degenerative diseases like osteoarthritis and osteoporosis, in the recent 20 years. In the field of research, she has published her study results in high ranking journals including Biomaterials, Acta Biomaterialia, Journal of Tissue Engineering and Regenerative Medicine and as well as Journal of Applied Physiology. Besides, she has also studied the stem cell biology for searching effect mechanism of drugs, nature products and physical agents, magnetic field and laser therapy. She also studied the novel gene effects on bone and cartilage by gene knock animals for searching the new drugs in future.

Abstract:

Regenerating the damaged articular cartilage to be a functional hyaline cartilage has been a clinically unmet need. Although several current treatment methods, micro-fracture, osteo-chondral grafting and autologous chondrocytes implantation, have been used to repair the damaged cartilage, the most concerned issue is the formation of unwanted fibrous cartilage rather than hyaline cartilage in the repaired tissue. The most difficult challenge in cartilage regeneration is that the tissue mainly possesses differentiated chondrocytes to maintain extra-cellular matrix homeostasis, which lacks of in situ and circulatory stem cells. One of the current approaches to solve this clinically unmet need is the stem cell-based tissue engineering. Adipose-derived stem cells (ADSCs) have been thought to be beneficial for use because of easy harvest, higher yield numbers and multi-potent differentiation. To make it possible for ADSCs-based articular cartilage regeneration, the most important thing to be solved is the in situ chondral-induction for ADSCs. We have conducted a series of studies to develop biomaterials that can provide the extra-cellular micro-environment, including chemical and physical cues, to optimize the ADSC chondrogenesis in the repair site of articular cartilage. We found that hyaluronan (HA) enriched micro-environment can initiate and enhance ADSC chondrogenesis via CD44 mediation. On the other hand, matrix stiffness has been indicated to direct stem cell differentiation into different tissues. We further developed the chondral-induction biomaterials by ways of adjusting chemical and physical cues. We found that the modified cross-linked HA products can be optimized by tuning the HA molecular weight and matrix stiffness. Most importantly, the cartilage regeneration effect of the newly developed HA-modified hydrogel product has been confirmed in an osteo-chondral defect rabbit model (Fig.1). The findings and biomaterial development from these studies provide the important information to persuade the possibility for the future clinical use of ADSCs-based articular cartilage regeneration.

Biography:

Alexandre Morel’s research interests are focused on applied tissue engineering to be highly interdisciplinary. He gained expertise in bio-microfluidics and cell culture working on the development of a cyclically-stretchable 3D-vascular network during his Master’s thesis in ARTORG center in Bern (Switzerland).  He worked on the development of a 3D-kidney model using bioprinting technologies during an internship at the University of Applied Sciences in Wädenswil (Switzerland).  In addition to bio-microfluidics and bioprinting, expertise in electrospinning enables him to tackle tissue development with suitable solutions. During his PhD thesis, he acquired abilities to investigate mechanical aspects at different scale levels and could deepen his knowledge in mechanobiology. These new skills help to design scaffolds with appropriate mechanical properties for tissue engineering application.

Education:

Bachelor’s degree in Biomedical Sciences (insigni cum laude), University of Fribourg (CH) Master’s degree in Biomedical Engineering (insigni cum laude), University of Bern (CH)

Currently PhD candidate for ETH Zurich, working at Empa St. Gallen (CH)

Abstract:

Introduction: Electrospun membranes are increasingly investigated for tissue engineering application due to their structure mimicking the extracellular matrix architecture. As one important parameter, implants should mimic the mechanical properties of the host tissue in order to achieve a successful integration. E-spun fibers can be tailored in terms of diameter, mechanical properties as well as their geometrical arrangement that alters membrane porosity. However, influences of these factors on mechanical properties of the whole membrane and their interdependence are still poorly understood. This project aims to bridge the gap between microscopic single fiber and macroscopic membrane mechanical properties as well as fiber-to-fiber interaction. For this purpose, influences of fiber diameter and of fiber-to-fiber cross-linkage are investigated at different mechanical scale levels.

Methodology: Poly-(lactic acid) as a prominent biodegradable polymer is focused for fiber development. Membranes are produced with the nanospider (Elmarco), a pilot plant for industrial fiber volume production by needleless electrospinning. Mechanical behavior of isolated single fibers is measured by 3-point-bending testing by atomic force microscopy and axial tensile testing with a nanomechanical testing system. Polymer structure of fibers is assessed by different methods e.g. wide-angle x-ray scattering and selective amorphous phase dissolution. Geometrical deformation of fiber networks during uniaxial testing is investigated by in-situ scanning electron microscopy- and in-situ small-angle x-ray scattering tensile testing.

Findings: Thinner fibers have higher crystallinity level and higher molecular orientation leading to greater young’s modulus. Also, higher fiber alignment during uniaxial deformation is found in membranes made out of thinner fibers. These factors lead to a stiffer response of those membranes in the direction of loading.

Outlook & Significance: Cells cultured onto mechanically tailored membranes under cyclic stretching will help to understand the performances of e-spun scaffolds for regenerative medicine application. Furthermore, we are currently developing a 3D-numerical model of membrane formation and structure informed by experimental data.

Biography:

Qianqian Cui is studying for doctor degree in the Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology. She has been studying the subject for nearly one year. She is very interested in the research on the fabrication of materials which prevent inherently biofilm formation by physical methods. They have produced the nanocone surfaces and firmly believe that the project will contribute to the development for bioactive materials.

Abstract:

Statement of the Problem: The bacterial adhesion to the solid surfaces and subsequent formation of biofilm are greatly harmful for the efficiency of material application and related processes. It is of important significance for protecting the environment and life health to study the formation mechanism of biofilm and the way of preventing the formation of biofilm. At present, we are working on fabricating the thermo-responsive material surfaces with nanocone array to regulate the bacterial adhesion and prevent biofilm formation, i.e. Bacterial cells are penetrated and killed by nanocone structures and thermo-responsive poly (N-isopropylacrylamide) (PNIPAAm) detaches and releases the dead cells and debrises through the change of temperature.

Method & Technology: We have prepared hexagonally packed ordered alumina inverse taper-nanopores by using one-step hard anodizing and etching peeling of high purity aluminum foils followed by multistep mild anodizing and etching pore-widening. Then adopting template-based hot embossing copies the shapes of anodic aluminum oxide template onto the polymer surfaces on which the nononipple structures can be attained. These nononipples were transformed to nanocones by chemical dissolution. According to the type of substrate materials, suitable methods of grafting thermo-responsive poly (N-isopropylacrylamide) (PNIPAAm) were chosen to obtain the thermo-responsive materials with nanocone array. For example, the glass surface and polymer surface with nanocone array were grafted with PNIPAAm by the method of ARGET-ATRP and ultraviolet irrigation, respectively.

Conclusion & Significance: Modulating the structural parameters of the thermo-responsive nanocone surfaces will realize the target of regulating bacterial adhesion, killing bacteria and releasing dead cells and their cell fragments. The material that is able to regulate bacterial adhesion and prevent biofilm formation belongs to physical environmental friendly materials, which provides new mentality for the control of bacterial adhesion and biofilm formation.

Biography:

M Helena Gil is currently Professor at Chemical Engineering Department, University of Coimbra. She has a large experience in the preparation and characterization of polymeric materials to be applied in biomedical or industry fields. Research in polymer chemistry within her group includes also preparation and characterization of hydrogels, immobilization of biological compounds, biosensors and drug delivery systems. She is author or co-author of more than 200 scientific papers on international reviews and of more of 10 book chapters.    M Helena Gil have supervised more than 60 MSc students and more than 20 PhD students, with 30 research fellows under the framework of several national and international projects. 

Abstract:

Nowadays, both synthetic and natural polymeric materials have been applied in the ophthalmologic area. In our group some work has been done on the development of intraocular lenses (IOLs) as well as on soft contact lenses (SCLs) for endophthalmitis prophylaxis in cataract surgery and implantable disks for glaucoma treatment. The use of ocular controlled drug delivery systems after ocular surgery is being used as an alternative to the usual eye drop administration. The development of SCLs based on acrylic monomers for this purpose is the subject of our more recent study. Some membranes were prepared by bulk polymerization using different monomers, such as ethylhexyl methacrylate, methyl methacrylic acid and a crosslinking agent, and were characterized physical and chemically. To increase their performance as drug delivery systems, the surface membranes were also modified by using either graft copolymerization or plasma treatment. All the copolymers were loaded with several ophthalmologic drugs and used for drug release studies.

Biography:

Melinda Szalóki has her expertise in investigation of polymeric restorative materials and 3D printable biocompatible polymers. The phage display analysis of dental materials creates new approach for analyzing of molecular mechanism of allergy. She is involved in analysis of biomolecular interaction by Fourier Transformed Surface Plasmon Resonance (FT-SPR) measurements. 

Abstract:

Biocompatible MED620 and MED610 polymers are 3D printable materials used mainly in oral surgery and orthodontics. Researchers have reported that MED610 significantly reduced the cell numbers of keratinocytes, even in non-direct contact. The purpose of this study is to investigate the effect of different surface manipulations on cell proliferation, surface specific oligopeptides regarding MED610 and to compare to MED 620 and MED610 regarding degree of conversion (DC), polymerization shrinkage (PS) (Stratasys, USA). The MED610 and MED620 samples were printed by Objet30 OrthoDesk (Stratasys, USA) 3D printer. In cell proliferation study osteosarcoma (SAOS-2) and dental pulp stem cells (DPSC) were used. The surface manipulation was done by two methods of support material removal. 7-mer oligopeptides was used to determine surface specific peptides based on New England Biolabs protocol. The PS of polymers was measured based on Archimedes’ principle by an analytical balance (Adam PW 254, UK). A Nicolet 6700 Fourier Transform Infrared spectroscope (FTIR) (Thermo Electron Co. USA) in attenuated total reflectance (ATR) mode was used for DC measuring. The surface treatment has an effect on cell proliferation and surface specific oligopeptides. The PS of MED620 and MED610 photopolymers were 7.56 V/V% ± 0.12 and 8.17 V/V % ± 0.24, respectively. The DC of MED620 and MED610 samples 93.34 % ± 2.66 and 97.76 % ± 1.31, respectively. Based on the results of the study it was found that the chemical modification of polymer surface influence the numbers of the attached cells, sequence of surface specific peptides and the physical properties i.e. polymerization shrinkage and degree of conversion that can be related to the different application and composition of the 3D printable biocompatible orthodontic polymers. The work is supported by the GINOP-2.3.2-15-2016-00011 and GINOP-2.3.2-15-2016-00022 projects. The projects are co-financed by the European Union and the European Regional Development Fund.

Biography:

Tzong-Yuan Juang is an Assistant Professor in the Department of Cosmeceutics, China Medical University, Taiwan. His research interests are focused on developing water-soluble dendritic macromolecules including dendrimers and hyperbranched macromolecules, and studying their supramolecular chemistry in solution and the relationship and applications at organic/inorganic interfaces. Potential application areas such as molecular exfoliation for 2D layered graphene and natural clay, fluorescent carrier molecules for container and drug delivery for biomedical applications.

Abstract:

In this study, we intend to used self-condensation of an AB₂ monomer to prepare fluorescent hyperbranched poly (amido acids) (HBPAAs) featuring wholly aliphatic backbones, multiple terminal CO₂H units, and many internal tertiary amino and amido moieties. Because tertiary amino groups are known to behave as fluorescent centers in dendritic structures, in this study we wish to prepared AB₂ monomer through an efficient synthetic scheme, involving blocking and deblocking processes, in high yield. Visible blue photoluminescence self-emissions would be generated from the non-conjugated HBPAAs in aqueous solution; that is, bright blue fluorescence behavior, with emission peaks at 395 nm and fluorescence QYs of up to 23%, appeared when the branching tertiary amino moieties were embedded in a self-polymerized globular confinement. These amphiphilic HBPAAs also have potential for use as tracing nanocarriers and molecular-level containers. Self-condensation of this AB₂ building block to construct water-soluble globular architectures with desired fluorescence properties appears to be a facile approach toward dendritic macromolecules with labeling-delivery applications.

Biography:

Filipa A M M Goncalves has her expertise in Polymer Synthesis and Characterization. She is currently finishing her PhD in the Chemical Engineering Department at University of Coimbra. She graduated from Évora University in 2007 with a degree on Chemistry and in 2010 she finished her master’s degree on Industrial Polymer Applications. Her research interest is focused on the development of biodegradable and biocompatible polymer based on renewable resources. She co-authored 11 papers and her PhD is focused on the synthesis of biodegradable and biocompatible polyesters for applications in tissue engineering. 

Abstract:

In recent years, various studies have focused on producing and improving treatments for skin regeneration. Polymers are the most important components of these systems in terms of release characteristics and permeation of drugs as well as mechanical properties of the formulations of these systems. The biopolymer films have become a very popular choice since they are biodegradable and biocompatible. In our group we have developed some hydrogels based on gelatin, pectin, starch and alginate to be applied as drug delivery systems. Here we wish to report the preparation of new wound dressings based on chitosan and dicarboxylic acids from renewable sources. Membranes based on pectin and chitosan were also developed. The films were physically, chemically and biologically characterized. Finally, they were loaded with polyhexanide (PHMB) which works as an antiseptic. The hydrophilic properties were evaluated. The effects of the sterilization by gamma irradiation and by heat treatment were accessed and the effect on the final properties of the films was evaluated. 

Biography:

Alexandre Hardy obtained his Engineering Degree in Materials from Polytech’Paris-University Pierre and Marie Curie (Paris, France) in 2015. Passionate about Biomaterials, he is currently a PhD student in the field of polymeric biomaterials in the Laboratory of Conception and Evaluation of Bioactive Molecules – Team BioVectorology, UMR 7199 CNRS/University of Strasbourg (France).

Abstract:

Statement of the Problem: Nowadays, the development of functional biomaterials able to contain and release drugs is of increasing interest for the treatment of various diseases and inflammation states. Synthetic Compact Polyelectrolyte Complexes (CoPECs), have shown interesting properties such as self-healing and stretching abilities or capacity to immobilize and protect enzymes. Very recently, alginate and chitosan natural polyelectrolytes, in the form of CoPECs, have been described as promising candidates for the development of high-performance biomaterials.

Purpose: The purpose of the current study is to functionalize this new natural CoPEC and to evaluate its potential as anti-inflammatory functional biomaterial. Indeed, one of its constituents, chitosan, is already known to have anti-inflammatory effects.

Methodology & Technical Orientation: Chitosan was chemically modified with b–cyclodextrin and mixed with alginate to make a final CoPEC able to trap and release drugs. The ratio between the two constituents of the material was determined by titration of the fluorescently labeled alginate. The intrinsic anti-inflammatory potential of the functionalized material, as well as its effect on cell viability, were assessed through in vitro assays.

Findings: Functionalized CoPEC is non-cytotoxic and causes a decrease of the production of NO and of pro-inflammatory cytokine TNF-a by macrophages previously activated with LPS. In addition, the biomaterial attenuates the differentiation of macrophages, which corroborates its anti-inflammatory action.

Conclusion & Significance: Given its anti-inflammatory efficacy and the multitude of final shapes it can take (crude material, membrane, micro- and nanoparticles), b-cyclodextrin-linked chitosan/alginate CoPEC could be used as anti-inflammatory biomaterial with the ability to deliver additional drug for combined treatment of severe chronic diseases such as Crohn’s disease, arthritis or cancer.