3rd Annual Conference and Expo on Biomaterials March 05-06, 2018 Berlin, Germany

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:

Assoc. Prof. Vanja Kokol PhD got a PhD in area of Textile chemistry in 2001 at University of Maribor, Faculty of Mechanical Engineering (UM-FS). She have been employed at UM-FS from 1994, currently as a research counsellor with the habilitation of Assoc. Prof.. Her research work in the last decade is oriented in modification and functionalization of fibers and biopolymers, and their processing in highly-engineered materials for different applications (from technical to biomedical). Special attention is attributed to the development of biopolymeric 2D and 3D materials with targeted and biocompatible antimicrobial activity. She is author of more than 90 papers, 3 book chapters, 3 patents, was supervisor of several (seven) doctoral and post-doctoral (five) students, and have been active in research programme Textile chemistry (from 1999) and Center of Excelence (from 2010) for advanced materials and technologies, area of Soft biomaterials. She was involved (leading or collaborating) in many national (ARRS-L2-7576, ARRS-J2-7018), bilateral (SLo-CZ, Slo-IT, SLO-IND, SLO-DE), international (E!3100 CAWAB, E!3654 BIOPOLS, EraNet Manunet NANOWEL, EraNet Matera Plus ANTIMICROB PEPTIDES, E!4956 MAGNET, EraNet MNT TABANA, EraNet MNT n-POSSCOG) and EU (H2020-PILOTS-03-2017-760601-2-NanoTexSurf, FP7-NMP-2011-SMALL-5-280519-NANOSELECT, FP7-NMP-2011-LARGE-5-280759-NANOBARRIER, Erasmus-Mundus (EMA2)-2013–2540/001–EUPHRATES, Marie Curie ToK/DEV FP6-MTKD-CT-2005-029540-POLYSURF, FP6-2004-SME-COOP-032877-ENZUP) funded research projects. 

Abstract:

Magnesium (Mg) alloys have emerged as innovative orthopaedic implant materials due to their excellent degradability, which eliminates the need for a second surgery for their removal. However, rapid degradation of Mg alloys and subsequent loss of mechanical integrity before the tissue regeneration limits their application. The Mg-4Ag and Mg-5Gd binary alloys` degradation and corrosion properties were studied under in vitro conditions (in a simulated body fluid solution of pH 7.4 at 37°C) by using various analytical techniques and time-frame windows (up to 3 vs. 28 days), and compared with the pure (99.9 wt%) Mg alloy, before and after a biomimetic gelatin (GEL) coating via dopamine. Different kinetics and mechanisms of the alloys` degradation were identified, influencing their corrosion rates` dynamics. The EIS measurements of uncoated alloys, being performed for up to 3 days, revealed that the corrosion of all three alloys are under a kinetic-controlled mechanism, among which only pure Mg and Mg-4Ag show a repassivation ability in this time-frame. However, the corrosion rates of binary alloys were lower, reaching a value of around 0.33 mm/y and a release of 64 mg/L Mg²⁺ ions after 28 days of incubation, that was accompanied by a lower pH change (up to pH 8.3), compared to the pure Mg alloy, getting additionally reduced by GEL coating. The spectroscopic (FTIR, XRD, EDXS) and microscopic (SEM) studies revealed the formation of MgO products, as well as apatite formation on the pure Mg alloy surface, while thick and homogenous layers of differently-shaped and chemically secondary-phased Mg(OH)₂ products were identified on both binary alloys after 28 days. Besides, a protective interface layer between the alloy surface and SBF solution was formed on GEL-coated alloys, which further stimulates the mineralization of calcium phosphate compounds, being patterned by GEL macromolecules conformation. Among the binary alloys tested, the Mg-4Ag alloy seems to be the most appropriate biomaterial regarding the in-vitro degradation process that would lead to a suitable healing process at the implantation site, compared to the others available from the literature. 

Biography:

Jozsef Bako has his expertise in nanostructured photopolymerisable polymer system fabrications and evaluations. The main research field are the biodegradable polymer based hydrogel, nanogels and nanofibers as drug delivery systems. The research fields are connecting to scaffold creation for tissue regeneration aims by 3D printing methods, and production of different inorganic/organic composites and nanofibers by electrospinning technique.

Abstract:

Electrospinning is a versatile method for fabrication of submicron sized fibers from biopolymers, ceramics and composite materials. The dental application possibilities of these nanofibers are intensively research areas on the fields of tooth or pulp regenerations, prevention of dental caries, or drug delivery systems. Biopolymers can facilitate the elasticity of created structures, and ensure the similarities to the extracellular matrix. The tailoring of the diameters of the fibers, and pore sizes of the structures ensures the optimal conditions for the proliferation and differentiation of cells. The delivery of biological active ingredients, factors, or drugs can achieve fast and supported regeneration. Composite materials give possibly of adjusting physical, biological, or release properties. Nanofibers combined with inorganic ceramics, or polymers with nanoparticles can create functional materials for the speed up wound healing, or osseointegration processes.

Polymer solutions were created for electrospinning process from Poly-vinyl-alcohol (18-88 Ph, Eur.Merc) (PVA) in 10 w/w% and 50% precrosslinked, and 50% methacrylated-poly-γ-glutamic acid nanoparticles (MPGA-NP) in 15w/w%. Irgacure 2959 1w/w% was added to the composite as photoinitiator. Nanofiber fabrication was performed by Nanospinner NS1 electrospinning device (Inovenso). The created fiber matts were phtopolymerized by Bluehase 20i (Ivoclar Vivadent) dental lamp for 60sec, and the biocompatibility properties was investigated by SAOS-2.

The diameters of created MPGA/PVA nanofibers were between 82.1-149.2 nm with the average of 120.7±17.5 nm. The crosslinking of the fibers by post photopolymerization was successful, and the fibers not dissolved during the one week cell proliferating test. The good biocompatibility of the created electrospun nanofibers was proved by the presence and proliferation of SAOS cells.

This nanoparticles in the nanofibers construction allow and enhance the control of different drug releases. The work is supported by the GINOP-2.3.2-15--2016-00011 and GINOP-2.3.2-15-2016-00022.. project. The project is co-financed by the European Union and the European Regional Development Fund.

Biography:

Tae-il Son was awarded the degree of PhD by Tokyo Institute of Technology, Japan in 1989. He is a Professor in the Department of Systems Biotechnology, Chung-Ang University and a Visiting Scholar at RIKEN (2007). He has served as President of the Korean Society for Chitin and Chitosan. He is currently the Director of Biomaterial Field in the Korean Society of Industrial and Engineering Chemistry (KSIEC) in Korea. He has published more than 100 papers in reputed journals. 

Abstract:

Bioactive molecules such as EGF, TGF-β, BMP-2, are very important and useful materials in medical field; regenerative medicine and pharmacy. Immobilization method is one of current researching to overcome low stability and high cost of bioactive molecules. Chemical methods have been used widely for immobilization of bioactive molecules. However, there are some of drawbacks with this method. For example, chemical method may produce potential toxic by-product, and, in case of physical method, low efficiency of immobilized bioactive material is observed. To solve these problems, recently, the immobilization by photo-immobilization has been researched widely. The advantages of photo-immobilization are 1) high selectivity of chemical reactions or processes under mild conditions (ambient temperature of also much below), 2) typically no need for added catalysts or special solvents, 3) spatially addressable effects (2D and 3D structuring possible) and 4) applicable to very small and (relatively) large scales. To use for photo-immobilization, various natural polymers, such as gelatin, chitosan, hyaluronic acid reacted by irradiation to UV or visible light can be applied for medical area to increase biocompatibility and functionality, for example, coating agent for bioinert devices like stent and implant, anti-adhesive agent, wound dressing and bio-adhesive.

Biography:

Giuseppe Tronci is a Lecturer in Healthcare Materials at the University of Leeds with leading expertise in the chemistry of biopolymers, design of integrated biomimetic systems, and high-value manufacture of medical devices. He has established a bespoke platform for the fabrication of customised collagen materials with retained triple helix conformation and multiple integrated biofunctionalities. This work has led to the development of a University of Leeds patent-pending technology, whose applicability in wound healing has been successfully confirmed in diabetic mice.

Abstract:

The trends in diabetic occurrence and aging populations impose a heavy economic burden on healthcare providers worldwide [1]. Diabetic wounds suffer from delayed healing, and can soon become infected, chronic ulcers. If not treated timely, they can lead to gangrene, haemorrhage and lower-extremity amputations, potentially resulting in permanent disabilities and pain for patients. Advanced wound dressings have been commercialized to respond to the pressing needs of an increasing diabetic population. However, control of the wound microenvironment and matrix metalloproteinase (MMP) activity is still only partially accomplished, resulting in economically unaffordable healing times. Here, type I photoactive (atelo)collagen was synthesized and explored as a building block of factor-free advanced wound dressings with customisable macroscopic properties and integrated wound-regulating functionalities. Covalent functionalization of rat tail collagen with photoactive compounds, e.g. 4-vinylbenzyl chloride, was initially confirmed (by ¹H-NMR, TNBS colorimetric assay, and circular dichroism) to prompt the synthesis of UV-induced networks of collagen triple helices [2, 3]. The type and degree of collagen functionalization governed the structure-property relationships, whereby the averaged swelling ratios (SR: 707-1600 wt.%), bulk compressive (E_c: 15-129 kPa) and atomic force microscopy (AFM) elastic moduli (E_AFM: 16-387 kPa) could be adjusted [4]. Obtained network configurations proved key to control the activity of MMP-9 in vitro, with respect to a leading dressing product. This synthetic route was successfully transferred to minimally-antigenic, telopeptide-free type I collagen [5], resulting in comparable water-swollen atelocollagen networks. Preclinical investigations in a full-thickness wound model in diabetic mice proved the accelerated healing capability of this collagen system with respect to a commercial polyurethane dressing [6].

Biography:

Susanne Staehlke earned her Diploma in Genetic and Microbiology at the University of Rostock, and went on to earn her PhD at the University Medical Center Rostock, Dept of Cell Biology, Germany, studying the interaction of human osteoblasts with defined microtopographical features of titanium-cell architecture und signaling. She is now a young researcher completing her Post-doctoral training at the University Medical Center Rostock, Dept of Cell Biology. She is a Member of the German Society for Biomaterials (DGBM) and got DGBM Poster awards in 2011 and 2013. She is skilled in western blot analysis, immunofluorescence, biomedical science, flow cytometry, cell signaling and confocal microscopy. She has published over 10 papers and has given several invited presentations at international meetings around the world (Hong Kong: ICBB 2012, Minneapolis: BioInterface 2013, Oslo: ScSB 2013, Rytro: PSBM 2016 and 17, Xian: CMCB2017, Bordeaux: FiMPART 2017).

Abstract:

The first critical courses for assessing the suitability of a new biomaterial in medicine are biofunctionality and compatibility of the biosystem at the site of its effect. Topographical as well as chemical surface properties of biomaterials have a specific impact of integration and regeneration in bone tissue. The surface stimuli can affect the cell behavior, either detrimentally or favorably. So, the osteoblasts recognize their surrounding by adhesion receptors connected intracellularly with focal adhesion complexes. The associated intracellular actin cytoskeleton is in control for cell morphology, migration as well as for the transmission of signals and forces of the surroundings into the cells. External signals from physico-chemical environments finally influence the cell function (Figure 1). However, it is unclear as to which physiological processes will be affected in detail. In the previous studies, we could find out that defined geometrical micro-pillars influenced the cell architecture and the cell function of human MG-63 osteoblasts. In addition, the mobilization of intracellular calcium ions (Ca²⁺) after ATP stimulus was significantly impaired in cells growing on micro-pillars. It raises the question whether the mobilization of intracellular Ca²⁺, as “second messenger”, represents a sensitive parameter for in vitro studies of cell-biomaterial interactions. In our recent studies we examined the cell physiology and signaling on different chemical properties of biomaterials. The data indicate an increased intracellular Ca²⁺ signaling on plasma-chemically modified titanium with improved cell adhesion and spreading. The understanding of complex cellular behavior and intracellular signaling events is critical for the acceptance of new biomaterial surfaces in regenerative medicine.

Biography:

Raisa Chetcuti earned a B.Eng (Hons.) degree in Mechanical Engineering from the University of Malta in 2016. She is currently reading for an MSc in Mechanical Engineering at the same institution. Her research interests lie in the general field of biomaterials, but in her study, she is focusing on the tribocorrosion behaviour of PVD coatings to be applied to the artificial hip joint in conditions which replicate more closely the human body environment. In 2016, she has studied two novel PVD coatings for the bearings of the artificial hip joint and she was acknowledged with the best project in the mechanical engineering stream for 2016 award by the Chamber of Engineers in Malta.

Abstract:

Bone injuries coupled with a longer life expectancy necessitate the increased longevity of implanted biomaterials in patients suffering from bone diseases such as arthritis and osteoporosis. CoCrMo alloys have been widely employed as bearing surfaces in metal-on-metal (MoM) orthopaedic implants given their optimal mechanical properties and high corrosion resistance, as well as their relatively low wear rates and the post-operative stability. Loss of material by corrosion-wear of the hip joint and metal ion release into the blood stream are of prime concern as these can cause adverse reactions in the human body such as inflammation and bone erosion as well as loosening of the implant. This study aims to reduce the material loss at the bearing surfaces by the application of a multi-layer PVD coating on an ASTM F-1537 CoCrMo substrate. A 2.3 µm thick CrN coating was deposited on top of a 3.6 µm CoCrMo precipitate free supersaturated metastable solution of carbon, otherwise known as S-phase (S), by magnetron sputtered PVD. The coated samples designated as CrN/S, displayed a higher hardness and they retained their topography in nano-scratch tests relative to the uncoated CoCrMo substrate under the same conditions. Tribocorrosion tests for uncoated CoCrMo samples against uncoated CoCrMo counterfaces as well as for coated samples against coated counterfaces were conducted in Ringer’s solution as well as in diluted Foetal calf bovine serum at 37±1 °C under reciprocating sliding conditions. Results show that under all applied potentials and in both solutions, the coated tribopairs when compared to the uncoated ones exhibited a significant decrease in material loss and excellent resistance to catastrophic failure by tribocorrosion. Figure 1 outlines the improvement exhibited by the coated samples under anodic conditions; the coated samples exhibiting a smaller wear scar and mostly polishing wear as opposed to the uncoated samples, in both solutions.

Biography:

David Sustr has an expertise in polyelectrolyte multilayers, diffusion measurements, microscopy techniques and more. He gained these abilities during studies and work at Masaryk University (Czechia), University of Helsinki (Finland), University of Potsdam (Germany), and Fraunhofer IZI-BB (Germany). His motivation comes from an interest in understanding reasons of behavior and its relationships of various systems and materials. 

Abstract:

Assessment of molecular diffusion is of high importance in fields of drug delivery systems, biomaterial development, cell biology, etc. Assessment and comprehensive analysis of the diffusivity provides a deeper understanding of the diffusion phenomenon and heterogeneity of biomaterials. This insight eventually may lead to a rational control over the diffusivity. Fluorescence recovery after photobleaching (FRAP) is commonly employed to probe molecular diffusion by analysis of the recovery of fluorescence after photobleaching of fluorescently labelled molecules. Despite FRAP being a popular method, it is hard to analyze multi-fractional molecular diffusion due to limited possibilities of approaches for analysis. Here we present a novel simulation-optimization-based approach (S-approach) that significantly broadens possibilities of the analysis. In the S-approach, possible fluorescence recovery scenarios are primarily simulated and afterwards compared with a real measurement while optimizing parameters of a model until a sufficient match is achieved. This makes it possible to reveal multi-fractional molecular diffusion. The proposed S-approach is compared with a conventional, yet advanced analytical solution based approach (A-approach) which involves fitting an analytical solution of molecular diffusion to FRAP recovery profiles. The S-approach is superior for multi-fractional analysis compared to the analytical one, however, diffusion of a single population of molecules can be assessed by either of the approaches. 

Biography:

Eddy Eddy is a dentist by training, graduated from Universitas Padjadjaran, Bandung, Indonesia in 2012. He continues his study as a PhD student in the Department of Biomaterials, Faculty of Dental Science in Kyushu University, Japan until present. His main research interest is the development and fabrication of artificial bone graft to fill defects in bones then afterwards replaced to new bone. He has presented his research at many international conferences.

Abstract:

Introduction: Previously, we had proposed that beta tricalcium phosphate granular cement (β-TCPGC) is useful to prevent flowing out of the β-TCP granules from the bone defect. When the β-TCP granules were mixed with acidic calcium phosphate solution, it set to form interconnected porous structure. Although it seems promising, β-TCP granules need to be mixed with the acidic calcium phosphate solution. Calcium sulfate hemihydrate (CSH) has self-setting ability by converting to calcium sulfate dihydrate (CSD) when exposed to water. Furthermore, CSD is the component of Osteoset^®, which is a commercially available as a bone substitute. In this study, we fabricated CSH coated β-TCP granules through dissolution-precipitation method. This setting ability could inhibit the flowing out of the β-TCP granules from the bone defect.

Experimental Method: β-TCP granules were immersed in NaHSO₄ solution for 1, 3, 5 and 7 days at 70^oC. The samples were then heated at 120^oC for 4 hours. β-TCPGC was prepared by mixing the granules with saline solution at a L/P ratio of 0:3 and identified by XRD and SEM. The mechanical strength of the β-TCPGC was measured as a DTS by universal testing machine. β-TCPGC was implanted in rabbit femur for 4 weeks and the percentage of newly formed bone was calculated from histological analysis.

Results: β-TCP granules immersed in NaHSO₄ solution were coated by CSD and CSD became CSH after heating at 120ºC for 4 hours. CSH coated β-TCP granules mixed with saline solution were set and DTS value of β-TCPGC with 75 wt.% of CSH was 0.8±0.1 MPa. The percentage of newly formed bone of β-TCPGC with 75 wt.% of CSH was 28.7±0.5%. Meanwhile, β-TCP granules without coating were 19.9±1.1%.

Conclusion: CSH coated β-TCP were successfully fabricated and formed interconnected porous structure with good mechanical strength after mixing with saline solution. 

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.