Biomedical 2017 October 16-17, 2017 Osaka, Japan

Zhi-Cheng Yao has completed his Bachelor’s degree from Zhejiang University, College of Biomedical Engineering & Instrument Science, in 2015, and is now proceeding for a Master’s degree. He has been focusing on preparing composite materials by encapsulating naturally bioactive components into biocompatible polymers via electrospinning/electrospraying technique, and evaluating the physicochemical and biological properties of the fabricated materials. He has published 2 journal articles and applied for a patent about modulating the characteristics of the electrospun fibers and preparing composite fibrous membranes for food preservation.

Micro-fibers (MFs) and micro-particles (MPs) with desirable porous structures are critical in drug delivery. In this study, surface morphologies of MFs and MPs were varied via non-solvent-based during electrohydrodynamic process. One-step control of fiber diameter and morphology is demonstrated using three liquids (ethanol, dimethyl silicone oil and mineral oil) serving as the non-solvent outer-flowing medium during the coaxial process. Poly-caprolactone (PCL) fibers with various surface morphologies (porous, rough and smooth) were prepared. The results clearly show the modified enveloping liquid coaxial electrospinning (ES) approach permits fiber size regulation, hydrophobic enhancement and surface topography (See Figure 1). Furthermore, non-solvent collection medium were used to generate porous particles hosting drug (indomethacin) and magnetic Fe3O4 nanoparticles (NPs) in single-step electrospraying technique (See Figure 2). In vitro drug release analysis for both porous and solid (non-porous) particle systems demonstrated a short drug burst period followed by a prolonged phase of dissolutive drug release, which is based on Fickian diffusion. Subsequently, with external alternating magnetic fields (AMF, 40 kHz), the release rate of drug from drug-magnetic porous microspheres was characterized, facilitating drug release over the established Fickian process. This work indicates a versatile and efficient method for preparing porous materials via non-solvent-based approach, which further enables controlled surface hydrophobic property and drug release kinetics of the fabricated drug carriers.

Shota Sasaki is in science and technology doctoral course in Gunma University. He has specialized in molecular biology of metabolism of hepatocyte. He had contributed to publish 2 papers in reputed journals.

Hepatocytes play a central role in drug metabolism in liver. In pharmacokinetics tests of new drugs, normal human hepatocytes have been used for evaluation of the drugs. However, supply of the hepatocytes is unstable and it costs expensive. Thus, development of efficient hepatocyte　differentiation system using ES and iPS cells has been desired for a long time. Previous studies showed that hepatocyte nuclear factor 4 (HNF4), an orphan member of the nuclear receptor superfamily and a master regulator in liver homeostasis, is an essential factor for differentiation of hepatocytes from hepatoblasts and iPS cells. In addition to HNF4, HNF4 family contains other isoform, HNF4 in mammals. Because hepatic HNF4 is hardly detected in normal liver, function of HNF4 remain to be clarified. We found that hepatic expression of HNF4 is markedly up-regulated in liver-specific Hnf4a-null mice. Furthermore, two HNF4 variants that have different N-terminal exon, known HNF41 and novel HNF42, are also up-regulated in the Hnf4a-null mice. Therefore, we investigated whether the HNF4 variants induce transcriptional activity and mRNA expression of the HNF4 target genes. As a result, HNF42, but not HNF41 was found to have strong transcriptional activity and induce expression of many liver-enriched genes in HCC-derived HepG2 cells when compared to HNF4, suggesting that HNF42 could be a new hepatocyte redifferentiation factor. These findings may contribute to establishment of differentiated hepatocytes using ES and iPS cells and development of HCC therapy by introducing HNF42.

Haruka Yoshie completed B.Sc in Chemistry from McGill University (Montreal, Canada) in 2012. She worked as a research assistant in Dr. James Martin’s group at Meakins-Christie Laboratory (Montreal, Canada) from 2012 to 2014. She completed her M.Eng in Dr. Allen Ehrlicher’s group in Bioengineering at McGill University. She is currently a PhD candidate in Dr. Allen Ehrlicher’s group at McGill Universtiy.

Acto-myosin contractility is an essential element of cellular biology, and manifests as traction forces that cells exert on their surroundings. The central role of these forces makes them a novel therapeutic target in diverse diseases. This requires accurate and higher capacity measurements of traction forces. To address this need, we employ traction force microscopy in a parallelized 96-well format, which we refer to as contractile force screening (CFS). We fabricate these plates using very compliant polydimethylsiloxane (PDMS) rubber, with a lower-bound Young’s modulus of approximately 0.7 kPa. We have recently demonstrated the utility and versatility of this platform by quantifying the compound and dose-dependent contractility responses of human airway smooth muscle cells and retinal pigment epithelial cells. Here I present our preliminary work using this system to understand the contractile changes associated with the Epithelial to Mesenchymal Transition (EMT) in cancer metastasis; we find that the strain energy of cells increases more than an order of magnitude during EMT; this suggests that the work exerted by cells during metastasis may be a key metric for characterizing these cells, and potentially identifying compounds to rectify their behaviour. Changes in cellular forces are not only limited to any one disease, but may play a role in the vast majority of human pathologies, from asthma to cancer. We believe that contractile force screening will be a broadly transformative technology allowing diverse quantitative biology and health science researchers to investigate biophysical and biomechanical challenges.

Lionel Zapata it’s a PhD strudent of the University of Concepcion. Obtained his master's degree in physiology in 2015. He is member of biotechnological company dedicated to the development of biotechnological solutions for the pharmaceutical area.

Many different monoclonal antibodies (Mabs) are already available for cancer, chronic infections and autoimmune diseases therapy. Over the last few years biopharmaceutical companies have experienced a huge improvement in the Mabs manufacturing process, however the antibody based therapies still remain too expensive. Because of the molecular nature of mAbs, the recombinant expression in mammalian cells can´t be replaced by less expensive alternatives such as bacteria or yeast culture. Here, we propose a molecular alternative for therapeutic mAbs, based on fragments of single chain antibodies (scFv) coupled through trimerization domain of tetranectine. Trimeric scFvs share with Mabs the domains involve in target recognition and have a similar molecular weigh. These trimeric scFv can be successful expressed in cheaper platforms as Yeasts or Bacteria culture. To obtain scFvs coupled trough trimerization domains the yeast expression vector pPSHG20-tetra was constructed by restriction cloning. This vector codes for the expression of an anti-VEGF scFv coupled by the tetranectine trimerization domain following by a poly histidine tag was added to N-terminal, to facilitate identification and subsequent purification. MP-36 yeast strain was transformed with the plasmid-tetra pPSHG20 by electroporation and transformed cells were isolated by auxotrophy selection and the and the insertion was checked by Southern blotting. Trimeric scFv expression was performed with 0.7% methanol during 4 days. Then trimeric scFvs were purified using affinity purification by IMAC. The protein expression yield and the ability to trimerize were analyzed by SDS-PAGE, Western blotting and densitometry, in reducing and non-reducing conditions. Finally, the bioactivity of trimeric scFv was confirmed by in vitro and in-vivo models. As a result, we demonstrated that the expresion of high yields of trimeric scFv fragments in yeast is possible. The estimated molecular weight of trimeric scFv was similar to the IgG antibody isotype. Furthermore, trimers of scFv fragments were obtained with high purity (95%) and remained their trimeric structure. The trimeric ati-VEGF scFv antibodys inhibits the biologic activity of human VEGF in in-vitro and in-vivo assay. This results suggests that functional scFv coupled trough trimerization domains production is possible. The trimeric scFv could be al reliable alternative to the Mabs based therapy with similar bioactivity but with a lower production cost.