2^nd Annual Conference and Expo on Biomaterials March 27-28, 2017 Madrid, Spain

José Manuel Baena, MSc is a Research Associate. He is the Founder of BRECA Health Care, pioneer in 3D printed custom made implants for orthopedic surgery, and REGEMAT 3D, the first Spanish bioprinting company. He is an expert in innovation, business development and internationalization. He is a Lecturer in some business schools, and is passionate about Biomedicine and Technology. In his free time, he also works as a Researcher at the Biopathology and Regenerative Medicine Institute (IBIMER).

Statement of the Problem: Regenerative medicine refers to methods to regenerate or replace human cells, tissues or organs in order to restore or establish normal function. The clinical use of stem cells, genes and tissues constitutes a new range of advanced therapy medicinal products (ATMPs) such as gene therapy medicinal products, somatic cell therapy medicinal products, tissue engineered products and combined advanced therapies’ products. Each of them can be formulated with different types of biomaterials to provide greater cell viability, such as release systems, scaffolds, etc. The purpose of this study is to describe the different products with stem cells and scaffolds that should be considered ATMPs for clinical application, to classify the different types of medicinal products and meet the legal requirements for their marketing authorisation. Methodology & Theoretical Orientation: The aim of this study was to define the main biomaterials used in ATMPs and medical devices, and the regulatory aspects for their clinical application. Thus, we searched the main available databases up to September 2016. Findings: Major advances in advanced therapies focus on the development of matrices made of natural or synthetic origin biomaterials such as collagen, alginate, hyaluronic acid, polyethylene glycol, etc. All of them should be considered medical devices by themselves, but if each scaffold is combined with stem cells, tissues or genes, they will be considered medicinal products. Conclusion & Significance: The ability to combine cells, tissues and genes with biomaterial manufactured structures to develop medicinal products, opens up new prospects in the administration of these ATMPs in the area of regenerative medicine.

Marco Consumi is a Research Scientist at Department of Biotechnology, Chemistry and Pharmacy in University of Siena, Italy. He has received his PhD in Biomaterials from University of Trento and studied polymers and polymer based materials for controlled release of active substances in pharmaceutical and nutraceutical field. As a Postdoctoral Fellow, he was focused on understanding the correlation between the chemical composition of materials and their biological activity. He has broad expertise in synthesis modification and characterization of polymers (naturals and synthetics) and materials for biomedical applications. Actually, he is involved in 2 EU ITN projects in bacterial infection topic to fundamentally better understand the biology, chemistry and physical properties of biofilms and 2 Toscany Region funded projects on nutraceutical filed.

Monascus fermented red rice (RYR) has been demonstrated to lower cholesterol in blood and sold over-the-counter as an alternative to cholesterol-lowering statin drugs, especially for who stopped statin drugs due to their side effects. The goal of this work is to develop an extended-release formulation, able to maintain the activity effect against the cholesterol, obtaining a constant release of statins present in RYR throughout the staying of the tablets inside the intestine. This study focus on the analysis of different carriers for controlled release systems composed by polysaccharide-based matrices by two different formulations based on K-Carrageenan and Gellan gum (ranging from 10-90% in weight). Samples as cylindrical tablets have been physicochemical characterized by FTIR, DSC, TGA, Rheometer and TOF-SIMS, water uptake, water bond, water diffusion and mesoporosity. The Monacolin K release has been monitored until 48 hours in simulated intestinal fluid SIF. HMG-CoA reductase activity has been measured to determine the formulation influence on statin activities against the Lovastatin activity used as control. The selected formulation enhances the statins release respect to the RYR matrix alone and in addition, the preliminary biological results suggest that the activity of these samples is associated with the inhibition of HMG-CoA reductase. Release tests pointed out that formulations obtained combining polymers in a ratio close to 1 (i.e., 40/60 and 50/50) guaranteed a potentiated release of Lovastatin from RYR inducing also a superior hypocholesterolemizing action both in terms of hepatocytes cholesterol production and inhibitory activity towards 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA). The most effective one, in hypocholesterolemizing activity, in terms of inhibitory activity versus HMG-CoA reductase and hepatocytes cholesterol production, was the formulation obtained combining 40% of K-Carrageenan and 60% of Gellan gum.

Richard M Hall is a Member of the University of Leeds with an interest in motion preservation devices as well as research in to spinal cord injury and augmentation procedures such as vertebroplasty. He currently coordinates the LifeLongJoints project and is the Director of Postgraduate Research Studies in Engineering.

Background: We have developed a single method using 3D agarose gels that is suitable to test the biocompatibility of all three types of wear debris (Polyethylene, Ceramic and Metal) simultaneously. Methodology & Theoretical Orientation: Clinically relevant sterile UHMWPE and CoCr wear particles were generated using methodologies described previously. Commercially available nanoscale and micron-sized silicon nitride (SiN) particles (<50 nm and <1 μm, Sigma UK) were sterilized by heat treatment for 4 hours at 180 °C. Agarose-particle suspensions were prepared by mixing warm 2% (w/v) low-melting-point agarose solution with the particles dispersed by sonication in DMEM culture media. The suspensions were then allowed to set at room temperature for 10 min in 96 well culture plates. Sub-confluent L929 murine fibroblasts were cultured on the prepared gels for up to 6 days in 5% (v/v) CO2 at 37 °C. After incubation, the viability of cells was measured using the ATP-lite assay; the results were expressed as mean±95% confidence limits and the data was analyzed using one-way ANOVA and Tukey-Kramer post-hoc analysis. Findings: The gels were observed to ensure uniform distribution of particles and migration of cells into the gel. No significant reductions in viability were observed for nanoscale and microscale SiN particles at low doses (0.5 μm3 per cell) and high doses (50 μm per cell) or for UHMWPE wear debris at high doses (100 μm3 per cell). Moreover, the viability was significantly reduced for high doses of CoCr wear debris (50 μm3 per cell) and the positive control, Camptothecin (2 μg.ml-1) at day 6. These results are consistent with the literature and therefore validate our 3D agarose cell culture method. Conclusion & Significance: Biocompatibility of polymer, metal and ceramic wear debris can be tested simultaneously by using 3D particle embedded agarose gels.

Na Keum Jang received her BS degree in Animal Biotechnology and MS degree at the Department of BIN Fusion Technology, Chonbuk National University, Republic of Korea. Her research interest includes synthesis of polymeric biomaterials for regenerative medicine and sensors applications. Now she is studying microneedle patch for transdermal drug delivery system at Raphas Co. Ltd.

The microneedle-mediated transdermal delivery system has been developed to provide minimal invasive self-administration method with patient friendly manner. Especially, dissolving microneedles, which deliver the target drugs as the drug-loaded microneedle dissolves into the skin, have been spotlighted recently. Droplet-born air blowing (DAB) fabrication method has advantages in stability with precise dose control because DAB provides quick manufacturing process with ambient temperature. The purpose of this study is to show the characteristics of dissolving microneedles, which were manufactured in our mass production system. Microneedle was fabricated by DAB method. The loaded amount of vitamin C and vitamin B3 was analyzed by HPLC/UV system was used to assay the loaded amount within microneedles; and delivered amount of drug into the skin was analyzed using Franz diffusion cell (Logan, FDC-6T). We optimized the DAB process parameters and scaled up. 350 μm and 500 μm length of HA microneedles were fabricated and dried within 10 min without applying any heat. The stability of EGF within HA microneedle was investigated during 2 months at 25, 45°C and was confirmed. The anti-oxidant was stable within HA microneedle during 2 months at 25°C and 45°C. In vitro and ex vivo studies using Franz diffusion cell showed excellent delivery efficiency compared to topical solution. Most of the loaded anti-oxidants was delivered through the skin after 24 hr (98.0±2.0%, n=3). The microneedles dissolution in skin was confirmed, so the drugs within microneedle should be delivered into the intradermal region. Based on the method, we loaded lots of active ingredients with precise dose control, and confirmed the stability of labile drugs such as peptide drugs and antioxidants within microneedles. We are investigating the formulations for biopharmaceutics using this platform technology.

Patricia Mazón studied Chemistry at the University of Alicante, and pursued her PhD about aminoacids synthesis. She started her adventure in Biomaterials field in 2012 at the University Miguel Hernández. Currently, she is a Professor at the Department of Materials Science, Optic and Electronic Technology and Researcher at the Biomaterials area of Bioengineering Institute.

Alternatives to natural bone grafts are needed in a society that progressively prolonged life expectancy, and it should address the health problems of an aging population. In this context calcium silicophosphate scaffolds are promising candidates. Composition belongs to subsystem Nurse’s A-phase-Silicocarnotite was selected for the ceramic scaffolds that were prepared by the polymer replication method. An interconnected porous structure with a striking similarity to human cancellous bone tissue was obtained. Response to ceramic scaffolds was evaluated by implantation in New Zealand tibia rabbits in periods of 3 and 6 months. Radiological studies showed correct integration and partial resorption of the scaffold. Histological results presented no evidence for inflammation or infection at the implantation sites. Colonization process of the scaffold started in the periphery and then penetrated throughout implant porosity. Scaffolds degraded over time and that degradation happened according to the tissue in-growth rate. Histomorphometric analysis gave high BIC values (67.30% ± 1.41) opposite to control samples, where newly formed bone in the cortical defect increased in a smaller amount than in the grafted defects. After six months of implantation SEM studies reveal that the whole ceramic implant surface was covered by a newly formed bone tissue. The new bone layer was composed of Ca-P, mainly with traces of Si due to the gradual diffusion of Si ions from the scaffolds into the newly forming bone, which formed part of the biomaterial’s resorption process. The results indicate that this material provides an optimal microenvironment for the osteogenic differentiation of the undifferentiated osteoblastic precursor cells contained in hematopoietic bone marrow.

Anna Arvidsson has her expertise in biomaterials and medical device surfaces, with a specific interest related to infection. She has an interdisciplinary background within engineering biology, directed towards biomaterials. During years at Göteborg University with research on surface mediated interactions at the bone/soft tissue implant interface, she has gained experience in surface modifications, surface characterization, and in vitro and in vivo models. Based on this knowledge, she is now creating and exploring new innovations at Dentsply Sirona Implants with purpose to further improve dental implant treatments and tissue regeneration.

Statement of the Problem: Biomaterial associated infections are challenging to treat due to bacterial biofilm formation. Infections around dental implants (so called peri-implantitis) may occur both shortly after implantation as well as after several years. Some risk factors are patient related, such as a prior history of periodontitis, poor oral hygiene, and smoking. However, product properties have also been indicated to influence the risk, progression, and resolution of peri-implantitis. It is hypothesized that anti-biofilm surface modifications may have a counteracting effect in the progress of infection and thereby reducing the risk of infection. Titanium nitride (TiN) coatings are used for dental abutments due to its golden color, but have also been found to accumulate less amounts of plaque. However, there is limited knowledge on possible mode of action. The purpose of this study is to characterize the surface properties of TiN and to investigate biofilm formation on TiN in comparison with Ti. Methodology: Pre-conditioned specimens were incubated with a co-culture of different oral bacterial species for up to four days. Biofilm formation was evaluated with plate counts, qPCR, live/dead, and crystal violet. Ti and TiN specimens were also characterized using a set of different surface analytical techniques. Findings: After 24 h, plate counts showed a log 2 reduction of bacterial load on TiN compared to Ti, while qPCR failed to show a difference. Live/dead indicated that the biofilm is thinner on TiN than on Ti. Conclusion & Significance: TiN was found to have a certain degree of anti-biofilm properties in vitro. However, any conclusions on clinical significance need data from randomized clinical studies.

Richard M Hall is a Member of the University of Leeds with an interest in motion preservation devices as well as research in to spinal cord injury and augmentation procedures such as vertebroplasty. He currently coordinates the LifeLongJoints project and is the Director of Postgraduate Research Studies in Engineering.

Adverse biological responses to wear debris generated by total hip replacements (THRs) limit the lifetime of such devices. This has led to the development of biocompatible coatings for prostheses. Silicon nitride (SiN) coatings are highly wear resistant and any resultant wear debris is soluble, reducing the possibility of a chronic inflammatory reaction. SiN wear debris produced from coatings has not been characterized in vivo. The aim of this research is to develop a sensitive method for isolating low volumes of SiN wear debris from periprosthetic tissue. Commercial silicon nitride particles of <50 nm (Sigma Aldrich) were incubated with formalin fixed sheep synovium at a volume of 0.01 mm3/g of tissue (n=3). The tissue was digested with papain (1.56 mg/ml) and proteinase K (1 mg/ml) and samples were subjected to density gradient ultracentrifugation using sodium polytungstate (SPT) to remove protein from the particles. Control tissue samples, to which no particles were added, were also subjected to the procedure. Particles were washed to remove residual SPT and filtered onto 15 nm filters. The filtered particles were imaged by scanning electron microscopy and positively identified by elemental analysis before and after the isolation procedure. To validate whether the isolation method affected particle size or morphology, imaging software (imageJ) was used to determine size distributions and morphological parameters of the particles. A Kolmogorov-Smirnov test was used to statistically analyze the data. The particle size distributions of isolated and nonisolated particles were similar. Morphology in terms of roundness and aspect ratio was unchanged by the procedure. Future work aims to test the method on titanium and cobalt chrome wear debris generated by a pin-on-plate wear simulator. The method will then be applied to isolate and characterize particles from in vivo studies of novel SiN coated prostheses in a rabbit and sheep model.

The microneedle-mediated transdermal delivery system has been developed to provide minimal invasive self-administration method with patient friendly manner. Especially, dissolving microneedles, which deliver the target drugs as the drug-loaded microneedle dissolves into the skin, have been spotlighted recently. Droplet-born air blowing (DAB) fabrication method has advantages in stability with precise dose control because DAB provides quick manufacturing process with ambient temperature. The purpose of this study is to show the characteristics of dissolving microneedles, which were manufactured in our mass production system. Microneedle was fabricated by DAB method. The loaded amount of vitamin C and vitamin B3 was analyzed by HPLC/UV system was used to assay the loaded amount within microneedles; and delivered amount of drug into the skin was analyzed using Franz diffusion cell (Logan, FDC-6T). We optimized the DAB process parameters and scaled up. 350 μm and 500 μm length of HA microneedles were fabricated and dried within 10 min without applying any heat. The stability of EGF within HA microneedle was investigated during 2 months at 25, 45°C and was confirmed. The anti-oxidant was stable within HA microneedle during 2 months at 25°C and 45°C. In vitro and ex vivo studies using Franz diffusion cell showed excellent delivery efficiency compared to topical solution. Most of the loaded anti-oxidants was delivered through the skin after 24 hr (98.0±2.0%, n=3). The microneedles dissolution in skin was confirmed, so the drugs within microneedle should be delivered into the intradermal region. Based on the method, we loaded lots of active ingredients with precise dose control, and confirmed the stability of labile drugs such as peptide drugs and antioxidants within microneedles. We are investigating the formulations for biopharmaceutics using this platform technology.

Eloisa Gonzalez-Lavado is a PhD student in the Nanomedicine Group of the University of Cantabria (Spain). I did a chemistry Bachelor’s degree at the University of Extremadura (Spain).I have an european interuniversity master’s degree in theoretical chemistry and computational modelling. Currently I am working with carbon nanotubes and their biomedical aplications, especially in Cancer, studying their biocompatibility, their capability as nanocarriers and their own antitumoral effect.

Our laboratory has focused on the intrinsic anti-proliferative, anti- migratory and cytotoxic effects of carbon nanotubes (CNTs). We have shown how MWCNTs interact with microtubules assembling biosynthetic polymers triggering serious biomechanical cellular defects that lead to cancer cell death. These properties of CNTs produce antitumoral effects in solid melanoma tumors in vivo. The huge surface area of CNTs maximizes their ability to interact with many biological components and different chemicals, constituting their biocorona. Taking into account these surface properties, we aimed to increase these intrinsic antitumoral effects of CNTs functionalizing these nanomaterials with a well-known anti-tumoral drug (5-fluoracil) in vitro in melanoma cells and in vivo in solid malignant melanomas produced by allograft transplantation in murine recipients. We have double-coated CNTs with an internal chemical layer surrounded by a second coat of proteins. The first layer carrying chemicals, either a dye (as a proof-ofconcept) or a drug (5-fluoracil) and the second being a serum protein coating layer, both assembling the biocorona. The protein coating serves for (1) CNTs recognition by cellular receptors, (2) endocytosis, (3) protection of the chemical component attached to the nanotube surface until protein degradation that takes place at the lysosome, and (4) the release of the transported drug during the first 5-9 hours next to the internalization process. CNTs loaded with 5-fluoracil double coated with serum proteins display a significantly enhanced antitumoral effect in vitro and in vivo in mice bearing solid melanoma tumors.

Iordana Neamtu is a Senior Scientific Researcher at “Petru Poni” Institute of Macromolecular Chemistry in Iasi - Romania. Her expertise is in synthesis of polymer materials with potential biomedical applications. She has published more than 50 papers in reputed journals and participated in more than 15 Romanian Projects.

Nanogels are cross-linked polymeric particles, which can be considered as hydrogels if they are composed of water soluble/ swellable polymer chains. Their applications for polymer-based bioactives’ delivery systems require biodegradability, controlled particle size with uniform diameter, large surface areas for multivalent bioconjugation and interior network for the incorporation of different therapeutics, environmental-stimuli responsive capability, dispersibility in biological fluids, sustained release in time of bioactives and facile removal of the devices after the bioactives delivery, etc. This study describes the synthesis and characterization of a stimuli-responsive nanogel performed by crosslinking poly(itaconic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane) with 1,12 dodecandiol. The copolymer with different ratios between the two comonomers is able for network formation, binding properties, amphilicity, and good oxidative and thermal stability. At the same time the new nanogel structure has high functionality, biocompatibility, temperature and pH responsivity, and is designed to have potential biomedical applications. The chemical structure is explored utilizing common spectroscopic analyses, while the dual pH and temperature sensitivity is evaluated by determining the hydrodynamic radius and zeta potential by dynamic light scattering technique. The analysis of the thermal stability by thermogravimetric analysis supports the new covalent bonds realized by the crosslinking reaction between the copolymer and diol. The acute toxicity of the nanogel is estimated after mice oral administration. Accordingly, analysis of histological evaluation of liver tissues does not reveal substantial pathological modifications. The results propose that the nanogel may be suitable for in vivo use as bioactives’ delivery system.

Tiago Monteiro is a second year PhD student at the Doctoral Program in Sustainable Chemistry at Faculdade de Ciências e Tecnlogia, Universidade Nova de Lisboa, Portugal. He has previously obtained a MSc degree in Biotechnology (2013) and a BSc degree in Molecular and Cellular Biology (2011) at the same institution.

Real world application of reductase-based electrochemical biosensing devices is limited by the need of anaerobic working conditions. Molecular oxygen is a main interferent because (a) it can react with many redox mediators in their reduced form, and (b) the reduction of oxygen at the working electrode surface generates an intense background noise that can mask important redox processes occurring between -200 and -800 mV (vs SHE). Standard laboratorial oxygen removal strategies, such as argon purging or vacuum degassing, are incompatible with on-site monitoring. Alternatively, a bi-enzymatic scavenging system that efficiently reduces the soluble oxygen content in small volume samples, and can maintain anaerobic conditions in an open-air environment for extended periods of time, was adapted for biosensing purposes. The scavenging system is composed by glucose oxidase (GOx) and catalase (Cat) in solution and uses the glucose as main substrate, removing oxygen in a two-step cycle. This strategy was successfully employed with a miniaturized reductase-based biosensing tool to monitor nitrite in real samples. We now aim at making the scavenging system an integral part of the biosensors, simplifying operating procedures and reducing costs. Therefore, we have immobilized GOx and Cat on pyrolytic graphite electrodes, using a silica sol-gel matrix, and tested the system’s ability to provide local anaerobic conditions. Several combinations of GOx/Cat in solution and in the immobilized state were prepared and the electrochemical response, in non-deareated solutions containing glucose, was monitored by cyclic voltammetry. Our results showed that although the scavenging system was more effective when in solution, the co-immobilized GOx and Cat were still able to provide a satisfactory anaerobic environment. Additionally, the configurations containing either immobilized GOx or Cat were explored as biosensing tools to monitor glucose and hydrogen peroxide, respectively. The GOx-based bioelectrode responded linearly to glucose concentrations from 1.2 – 7 mM.

Aurica P Chiriac has completed her PhD in 1994. She has published more than 100 papers in reputed journals and is an Editorial Board Member of some reputed journals. She participated in more than 15 Romanian Projects and 5 European Projects.

The study is devoted to investigating the possibility of using an alternating magnetic field (AMF) for deposition and covering a stent surface and improve its functionalities with a new magnetic composite (MC). MC was prepared in situ during functionalization of poly(maleic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane) copolymer by opening the anhydride ring with erythritol and introducing magnetic nanoparticles into the polymer matrix. Ten different solvents were used to evidence the dependence between AMF presence, the reaction medium characteristics and the kinetic deposition. Interdependence among the viscosity, density and molar polarization of the solvents and the yield of deposition was registered. The covering of stent with MC is also analyzed by microscopy and the new magnetization values are estimated.

Statement of the Problem: Biomaterial associated infections are challenging to treat due to bacterial biofilm formation. Infections around dental implants (so called peri-implantitis) may occur both shortly after implantation as well as after several years. Some risk factors are patient related, such as a prior history of periodontitis, poor oral hygiene, and smoking. However, product properties have also been indicated to influence the risk, progression, and resolution of peri-implantitis. It is hypothesized that anti-biofilm surface modifications may have a counteracting effect in the progress of infection and thereby reducing the risk of infection. Titanium nitride (TiN) coatings are used for dental abutments due to its golden color, but have also been found to accumulate less amounts of plaque. However, there is limited knowledge on possible mode of action. The purpose of this study is to characterize the surface properties of TiN and to investigate biofilm formation on TiN in comparison with Ti. Methodology: Pre-conditioned specimens were incubated with a co-culture of different oral bacterial species for up to four days. Biofilm formation was evaluated with plate counts, qPCR, live/dead, and crystal violet. Ti and TiN specimens were also characterized using a set of different surface analytical techniques. Findings: After 24 h, plate counts showed a log 2 reduction of bacterial load on TiN compared to Ti, while qPCR failed to show a difference. Live/dead indicated that the biofilm is thinner on TiN than on Ti. Conclusion & Significance: TiN was found to have a certain degree of anti-biofilm properties in vitro. However, any conclusions on clinical significance need data from randomized clinical studies.

Zeynep Orman has graduated from Chemical Engineering department and currently studying Bioceramics for her Master’s studies in Yildiz Technical University. She is experienced in polymers research and has conducted a project about solar cell studies.

The regeneration potential of human bone to repair large bone defects often requires biomaterials, such as those associated with comminuted fractures or bone tumor resection. The need for bone substitutes is rapidly increasing and many researches have been done to improve their performance. Calcium phosphate based bioceramics have been used due to their high bio-compatibility and their successful use of orthopedic and dental applications. Calcium phosphate bioceramics are similar to bone and tooth minerals due to their chemical and crystallographic properties; hence it is particular interest for bone grafting, augmentation in maxillofacial surgery and in orthopedics as a filling material. Many marine structures are composed of calcium carbonate (aragonite or calcite) and can be converted to calcium phosphate materials by chemical exchange. In this study structural and chemical properties of Clinocardium ciliatum based bio ceramic materials (TCP, B-TCP and other phases) were produced by using mechano-chemical (hot-plate) conversion method. At three varying temperature of 450°C, 850°C and 1200°C the materials were transformed to various bioceramic phases. For complete characterization of the bioceramics produced Fourier Transform Infrared Spectroscopy (FTIR), x-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and differential thermal analysis (TG/DTA) analyses were carried out.

Loredana E Nita is currently a Senior Researcher at Petru Poni Institute of Macromolecular Chemistry, Romania. She has completed her PhD in Chemistry in 2007 at Petru Poni Institute of Macromolecular Chemistry. She has published more than 100 papers in reputed journals and is a member in Editorial Board of some reputed journals. She participated in more than 15 Romanian Projects and 5 European Projects.

In the last decades, considerable attention has been dedicated to study of interactions between polymer-polymer pair and interpolymer complexes. In this contest, the self-assembling procedure for preparation of functional nanostructure based on linear polyampholyte polypeptide, poly(aspartic acid) (PAS) and a globular protein, bovine serum albumin (BSA), have been studied. The main interest was to identify the formation of an interpenetrated complex between a natural protein and a synthetic polymer in order to design materials suitable for biomedical applications, such as carriers for drug delivery. From the viscometric investigation of PAS/BSA/water ternary systems, it was observed that, for x* value near 0.5, the maximum of intermolecular interactions among the two polymeric partners take place. This statement is sustained by the strong raise of the hydrodynamic radius in the same area of composition. Dielectric spectroscopy data also provide the higher compatibility of PAS with BSA protein molecules and confirm the best conditions for a stable interpolymer complex formation by self-assembling at the PAS/BSA molar ratio x* of 0.542 in aqueous solution. Thus, it is quite important for having desired properties - chemical and biological - the setting and fulfillment of the conditions for achieving the non-covalent forces to make highly functional nanoscale compounds.

Shghayageh Javadi did her Master’s degree in Biomedical Engineering. Her thesis is about biomaterial coating and focused on best coating method of biomaterials. She has researched on different pretreatment for surface modification of titanium. She has used anodizing process with combination of alkali treatment for surface modification of titanium. The result of her search and experiments showed that the anodized titanium at high voltages may be suitable substrate for biomimetic coating procedure.

Biomimetic coating procedure was used to deposit a bioactive layer of hydroxyapatite (HA) on the surface – modified titanium by anodization process. The anodization was performed on the clean surface of titanium under three different voltages of 80, 100 and 130v using HF as the electrolyte. The morphology, structure and topography of the anodized substrates were evaluated by Scaning Electron Microscopy (SEM) or Field Emission Scanning Electron Microscopy (FE-SEM), X ray Diffraction (XRD) and Atomic Force Microscopy (AFM), respectively. Biomimetic coatings were deposited on the surface of anodized titanium using a twostage procedure by immersion in two concentrated Simulated Body Fluids (SBF) with different concentration of Mg+2 and HCO3 -2 ions under physiological conditions. The results showed that an increase in anodization voltage tends to produce a porous surface with circular pores toward a columnar layer of rutile. The surface roughness of anodized surfaces was increased by increasing voltage. Biomimetic coating procedure was caused to form a HA layer which was proved by XRD, FTIR and SEM. The HA layer formed on the anodized titanium surface has a whisker-like morphology. The crystallinity of HA layer was increased by an increase in voltage. The findings indicate that the anodized titanium at high voltages may be suitable substrate for biomimetic coating procedure.