Earticle

Ligand-receptor type interactions are typical in cell signaling and inducing various changes in cell phenotypes, but it has drawn growing attention that nanostructure environment, along with 3D environment, can play important roles in cell signaling and cell phenotypic changes including cell differentiation, morphology and migration. This is critical in realization of in-vivo-like environment on in vitro platforms, with coupling of typical ligand-receptor interactions. Here, we used biocompatible, chemically flexible and optically active Au nanostructures in studying the effect of interfacing nanostructures with living cells. In mimicking cell membranes, synthetic, tailorable and fluid supported lipid bilayer or lipid vesicles are used herein.

Polymers with chain ends attached to proteins have potential applications in pharmaceuticals and biotechnology, as they can effectively improve protein stability, solubility, and biocompatibility. The plausible applications include protein delivery, enzyme immobilization, and biosensors. Recently, conjugates between natural proteins and synthetic polymers have been receiving increasing interests in material science areas with expectations of providing new routes for preparation of biologically functional structures by synergistic action from two distinctive materials. In addition, synthetic polymers attached to proteins impart new properties such as self-assembly and phase behaviour. In this study, we describe the synthesis of NTA end-functionalized polystyrenes by ATRP and their use for bioconjugation with His6-GFP to produce self-assembled structures in aqueous system.

Zinc phthalocyanine (ZnPc) is one of the most promising next generation photosensitizers that can replace FDA-approved porphyrin-based photosensitizers for the photodynamic cancer therapy (PDT), due to its favorable photophysical, photochemical properties, and strong absorption in the spectral range of 600-900 nm that guarantees maximum tissue penetration. One of the most important hurdles that ZnPc faces for the facile application in biological environments is its low solubility (or dispersibility) in water. So far, the solubility increase has been sought by introducing hydrophilic moieties into the molecular backbones of ZnPc and porphyrin-based photodynamic agents. In this presentation, I will introduce an unexpectedly increased water dispersibility of ZnPc when ZnPc molecules are self-crystallized into one-dimensional nanowires. The ZnPC nanowires have been synthesized by vaporization-condensation-recrystallization (VCR) process, a sort of solid-vapor-solid process at 550 oC using ZnPc powder as a precursor. The increased water dispersibility of ZnPc NW is attributed to the increased available water-binding sites in ZnPc molecules present in a form NW crystal structure. Different from ZnPc powder (b form) that has a strong interaction between ZnPc rings through Zn(II)-N interactions, a form ZnPc NW has a weak inter-ring interaction because a top ZnPc ring is off-staggered to a bottom ZnPc ring, so that the Zn(II) ions and all of skeleton N atoms are ligation-free to accommodate more water molecules to interact. The water solution of ZnPc NW has been tested for photodynamic cancer therapy. Interestingly, the ZnPc NW aqueous solution shows dual photodynamic and photothermal properties, by which tumor cells could be destroyed more efficiently. Such dual property-driven therapeutic effects have been examined by both in vitro and in vivo experiments. The results reveal that ZnPc NWs are internalized well into the KB tumor cells, and eradicates the tumor cells very efficiently upon the irradiation of NIR (808 nm) light for 3 min.

In nature, certain biological systems, including bacteria, plants, algae, and fungi, have evolved to preserve their species under unfavorable harsh environments by protecting their genetic information with a hard shell. Chemically-generated, spore-like structures, coined as “artificial spores”, are suggested as a new type of hybrid systems, which will be contributable to increasing the long-term stability and performance of cell-based sensors, bioreactors, microfluidic devices, etc. as well as to the fundamental studies in cell biology. The spore-like structures have been generated by encapsulating individual living yeast cells within artificial shells, such as inorganic silica and organic polydopamine. We showed that our methods endowed living cells with durability against harsh environments, controllability in cell cycles, and reactivity for cell-surface modification.

Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds composed of two or more fused aromatic rings that are important components of crude oil, creosote and coal tar. PAHs are the cause of great environmental concern because of their persistence, toxicity, mutagenicity, and carcinogenicity; they are on "priority-pollutant" lists in most countries. Bioremediation employing microorganisms that can degrade PAHs has proven to be a non-disruptive, cost-effective and highly efficient method of safely breaking down environmentally persistent compounds, including PAHs. Gaining an understanding of PAH-degrading bacteria, especially those occurring at contaminated sites, may result in clean-up strategies that can be effective in reducing PAH concentrations to below toxic levels. Sea-tidal flats are characterized by high primary production and nutrient cycling rates, which may rely upon high microbial abundance and diversity. We hypothesized that the Taean tidal flat sediments may also harbor diverse PAH-degrading microbial communities. The present study therefore aimed to investigate (i) the diversity and composition of the PAH-degrading bacterial populations enriched from the contaminated sea-tidal flat on the Taean coast; (ii) the isolation of PAH biodegrading bacteria from the enriched bacterial consortia and their PAH degradation abilities; and (iii) monitoring of the abundance of Alteromonas populations and in situ expression of Alteromonas-specific dioxygenase genes in the contaminated sea-tidal flat over time. Following the 2007 oil spill in South Korean tidal flats, we sought to identify microbial players influencing the environmental fate of released polycyclic aromatic hydrocarbons (PAHs). Two years of monitoring showed that PAH concentrations in sediments declined substantially. Enrichment cultures were established using seawater and modified minimal media containing naphthalene as sole carbon source. The enriched microbial community was characterized by 16S rRNA-based DGGE profiling; sequencing selected bands indicated Alteromonas (among others) were active. Alteromonas sp. SN2 was isolated and was able to degrade naphthalene, phenanthrene, anthracene, and pyrene in laboratory-incubated microcosm assays. PCR-based analysis of DNA extracted from the sediments revealed naphthalene dioxygenase (NDO) genes of only two bacterial groups: Alteromonas and Cycloclasticus, having gentisate and catechol metabolic pathways, respectively. However, reverse transcriptase PCR (RT-PCR)-based analysis of field-fixed mRNA revealed in situ expression of only the Alteromonas-associated NDO genes; in laboratory microcosms these NDO genes were markedly induced by naphthalene addition. Analysis by GC/MS showed that naphthalene in tidal- flat samples was metabolized predominantly via the gentisate pathway; this signature metabolite was detected (0.04 μ M) in contaminated field sediment. A qPCR-based two-year data set monitoring Alteromonas-specific 16S rRNA genes and NDO transcripts in sea-tidal flat field samples showed that the abundance of bacteria related to strain SN2 during the winter season was 20-fold higher than in the summer season. Based on the above data, we conclude that strain SN2 and its relatives are site natives-- key players in PAH degradation and adapted to winter conditions in these contaminated sea-tidal-flat sediments

Most of microorganisms tend to live in aggregates on surfaces (i.e., biofilm) rather than in planktonic state in natural, clinical, and industrial settings. In biofilm state, bacterial cells are imbedded in polymeric substances (e.g., extracelluar polymeric substance and lippopolysaccharide) secreted by bacteria themselves, which give them advantages to survive in harsh environmental conditions. Biofilm is formed on every surface including membrane filters in water purification. Biofilm formed on membrane filters is difficult to be removed by physical treatments. Chlorine is commonly used to kill bacteria and to retard biofilm formation. However, chlorine can affect not only bacterial mortality but also damage to membrane filter. In addition, organic matters and cell debris generated by the chlorine treatment can be nutrients for bacteria, which even proliferates biofilm formation on membrane filter (Baker, J.S., and Dudley, L.Y., 1998). Disturbing normal metabolic networks involved in biofilm formation in bacteria is an alternative method to reduce biofilm without damaging surface materials and stimulating biofilm formation (Balaban, N., 2008, Rasmussen et al., 2005). Previously, we reported that ginger extract was effective to reduce biofilm in borosilicate bottle. In this study, we hypothesized that ginger extract can be applied to reduce biofilm formation on membrane filter in water purification. The objective of this study was to apply ginger extract to inhibit biofilm formation on membrane filter and to investigated bacterial physiology and molecular mechanisms involved in biofilm inhibition. To this end, we investigated the effects of ginger extract on bacterial growth, biofilm formation, and protein expression using Pseudomonas aeruginosa as a model bacterium. Ginger extract was effective to reduce biofilm formation by reducing the production of extracellular polymeric substance, and appeared to be involved in iron metabolism. Ginger extract was also successful to reduce biofouling rate in a laboratory-scale reverse osmosis process. This study demonstrated the effectiveness of biofilm inhibitors in membrane filtration process.

In recent, paradigm for industrial wastewater treatment has been gradually shifting from a simple pollution control technology to energy- and resource-integrated one. Along with rapid technological advances in various types of anaerobic wastewater treatment processes, high-strength organic wastewater generated from industry is now valued as an alternative resource for energy production. In this case study, high-rate anaerobic treatment of PTA (purified terephthalic acid) wastewater, which accompanies methane biogas production, was intensively reviewed based on our own results from varied aspects encompassing microbiology, process design and performance, and systems engineering approaches as well. Complex anaerobic biodegradation mechanisms of the syntrophic mixed culture system involved in the PTA wastewater treatment were summarized first and a two-stage UASB process was proposed as an efficient process configuration to cope with these complex biodegradation mechanisms. The performance of the two-stage UASB process was also discussed especially focusing on its relationship to the microbial distribution within the granules at each stage. As for the systems engineering approaches, several mathematical modeling results for a full-scale anaerobic filter process treating real PTA wastewater were briefly highlighted regarding their potential as an efficient process monitoring tool. This review study would be able to provide some meaningful guidelines for the researchers and engineers who aim to develop an anaerobic wastewater treatment process for the purpose of energy recovery from their own target wastewaters.

Phytoremediation, the use of vegetation for the in situ treatment of contaminated soils and sediments, is an emerging technology that promises the effective and inexpensive cleanup of hazardous waste sites. In present study, we used three plant species (Brassica juncea, Sorghum vulgare, and Phaseolus mungo) for the remediation of textile effluent. The B. juncea, S. vulgare and P. mungo demonstrated decolorization of textile effluent up to 79, 57, and 53%, respectively. The shoot length of S. vulgare and shoot and root length of P. mungo was significantly affected because of textile effluent toxicity. However, B. juncea was found to be the most tolerant, effective color removing and heavy metal extracting agent as compared to other tested plant species. The B. juncea was also used to degrade exemplary dye reactive red 2 and the metabolites were identified as napthalenesufamide (m/z 372) and 2-amino-4, 6-dichlorotriazine (m/z 167). The B. juncea grown using textile effluent showed enhanced vegetative growth with respect to the height of the shoot and root up to 129 and 178%, respectively, as compared to control plants, which indicates utilization and degradation of textile dyes into less toxic products. Significant induction of intracellular laccase (266%) was observed in the case of B. juncea, indicating its crucial role for a potential metabolism and further degradation of the textile effluent.

Precious metals are widely being used in various industries because of their specific physical and chemical properties. Conventional methods for the recovery of low concentrations of dissolved precious metal ions from solution phases include solvent extraction, chemical precipitation and ion exchange. These methods have significant disadvantages, including incomplete metal recovery, high capital costs, high reagent and energy requirements, and other waste products that require disposal. In this talk, a sorption-based recovery method is proposed as an alternative separation technology to overcome such disadvantages. To make the proposed method competitive, required specification of sorbents is discussed. Especially, strategies for design of powerful sorbents are suggested with some successful application cases.

The future resources for food, fuels, and chemicals potentially come from ocean. One of the major marine resources is microalgae, which have the ability to fix carbon dioxide at a much faster rate than that of terrestrial plants. The fixed carbon dioxide is converted to microalgal biomass, which has potential applications in producing biofuels, animal feed, health food, pharmaceuticals, and other high-value products. Therefore, using microalgae to mitigate CO2 emissions is a promising strategy for CO2 storage and utilization. We have identified various indigenous microalgae strains that utilize flue gas of a steel-making factory for growth with excellent CO2 biofixation ability. We are able to adjust the composition of resulting microalgal biomass (lipid, carbohydrates, proteins, pigments, etc.) by using different cultivation strategies to meet the needs of downstream applications. To make the concept of microalgae industry a realty, many new technologies and engineering approaches should be developed (for instance, outdoor large-scale cultivation, biomass harvesting, product conversion technology, etc.). Some key technologies required for realizing commercialization of microalgae-based CO2 emission mitigation and biorefinery are introduced in this presentation.

In this study, the advanced biodiesel (namely green diesel) production from microalgal biomass is presented. Overall process consists of microalgae selection, harvesting/dewatering, lipid extraction, and green diesel conversion. Forty seven microalgal strains (Chlorella sp., Scenedesmus sp., and Nannochloris sp.) collected from Korean Collection for Type Cultures (KTCC) were tested for coal-fired flue gas application and 3 strains were selected based on volumetric biomass and lipid productivities under various cultivation conditions. The microalgae were cultivated by various transparent film photobioreactor systems with coal-fired flue gas under out-door conditions and its areal lipid productivity was estimated to be ~4.2 L lipid/m2/year. The lipid content was measured as FAME (fatty acid methyl ester) by GC. Lipid components from microalgal biomass were extracted by two-step pyrolysis process and converted into hydrocarbon (green diesel) by catalytic decarboxylation. The harvesting/dewatering from the overall microalgal green diesel production process might be a critical step in terms of cost, energy consumption and water recycling, and further investigation is under progress.

The carbon dioxide (CO2) emissions are main cause for global climate change. It becomes critical to develop novel technologies that can subside the problem. The biotechnology-based CO2 capture tool is one of the important and potential systems for solving the CO2-revoked climate problems. Carbonic anhydrase (CA, EC 4.2.1) accelerates the uptake of CO2 from air into intracellular system. Recently, we cloned several types of CAs from marine microalgae or bacteria and we constructed their sequences optimized for high-efficient expression in E. coli system. We achieved successful microbial expression of several CAs and characterized the properties of the recombinant CAs. The acquired CAs can mediate biomineralization by catalyzing the dissolved CO2 to bicarbonate (HCO3 -), which can be precipitated as CaCO3 under Ca2+ condition. In addition, HCO3 - concentrated by CAs can be converted with PEP (phosphoenolpyruvate) into four-carbon organic acid oxaloacetate (OAA) catalyzed by phosphoenolpyruvate carboxylase (PEPCase, EC 4.1.1.31). These two enzyme system can be used as novel platform technology for CO2 capture and use. These biotechnologybased approaches based on marine CA will be essentially employed for development of efficient CO2 capture/sequestration systems.

Anaplerotic carboxylation refers the linkage reactions between glycolysis and TCA cycle mediating carboxylation of C3 metabolites into C4 metabolites. The energy for carbon-carbon bondage formation derives from difference sources in the anaplerotic enzymes, and the artificial anaplerotic carboxylation was affected by intracellular modulating metabolite concentrations, cofactors(3), and the way of regulations(2). Artificial expression of anaplerotic enzymes such as phosphoenolpyruvate carboxylase(PPC), phosphoenolpyruvate carboxykinase(PCK), and NADP-dependent malic enzyme(MaeB) enhanced the carboxylation of C3 metabolites under anaerobic with surplus of CO2 source (119 mM bicarbonate) conditions(4). The availability of CO2 source for the anaplerotic enzymes were corelated to the C4 metabolite production(5). The NAD-dependent Malic enzyme(MaeA) expression mediated decarboxylation under the same conditions. Cellular energy currencies related to the anaplerotic enzyme expressions were modified depending on their chemical energy source for carboxylation, i.e., PEP for PPC, PEP and ATP for PCK, NADPH for MaeB, and NADH for MaeA, and on their modulating metabolite concentrations. The examples of cellular energy currency modifications are introduced as well as the cellular responses therefrom(1, 6).

Enzymes immobilized on nano/micro sized organic/inorganic hybrid materials have been known to be stabilized. For meeting the requirement of enzymatic processes, such as highly stabilized activity, enhanced specific activity with high enzyme loading, and easy scale up, the enzymes have been subjected to be aggregated on the surfaces of quantum dots-embedded nanofibers, entraped in calcium phosphate nanoparticles or organic-inorganic hybrid microspheres as porous support materials for good accessibility of substrate. The successful immobilization of enzymes on these enzyme-nano/micro sized organic/ inorganic hybrid materials have well been evidenced by using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Transmission electron microscopy (TEM), while physical characterizations such as like Dynamic light scattering (DLS), Elemental analysis (EDAX), particle size etc were done. As results, the immobilized enzymes have shown the good storage and recyclable stabilities retained in terms of its enzyme activity, in repeated usages for more than ten times. Therefore, considering CO2 enzymatic bioconversion into useful materials, this unique enzyme stabilization technology developed here is strongly considered to be a key tool for realizing enzymebased CO2 bioconversion. An example of enzyme-based CO2 bioconversion will be presented in this talk with clear perspectives on CO2 bioconversion.

Since the derivation of human embryonic stem cells, research in regenerative medicine has revolutionized our perspectives on the feasibility of cell-based therapies. We can hope for great advances in the treatment of major illnesses, ranging from diabetes to cardiac and neurological diseases. There is an increasing need for novel technologies to accelerate the development of stem cell science and therapeutic cell production. Cell population heterogeneity is a major obstacle to understanding and optimizing complex biological processes, such as when stem cell characteristics are obscured by average measurements of impure populations. In order to assess the heterogeneity within populations, we have developed microfluidic arrays with thousands of microbioreactors and analyzed single stem cells in nanoliter-scale clonal cultures. The differentiation of embryonic stem cells has led to the production of insulin-producing cells or their progenitors for the cellular therapy of diabetes. There is a renewed need for immobilized cell bioreactor innovation. We have developed bioreactors and processes suitable for producing therapeutic cells derived from embryonic stem cells up to ~1,000 L scales.

Stem cell therapy has been developing rapidly as a potential cure for repairing or regenerating the functions of diseased organs and tissues. Adipose-derived stromal cells (ASCs) are an attractive cell source for stem cell therapy because they can be isolated easily from fat tissue in significant numbers and exhibit multiple differentiation potential under appropriate in vitro culture conditions. However, ASCs derived from individual donors can show wide variations in differentiation potential. In addition, the regulatory mechanisms underlying stem cell differentiation remain unclear. Bone morphogenic protein 2 (BMP-2) is an important signal for up-regulation of osteogenesis and chondrogenesis of stem cells. SRY-related HMG-box gene 9 (SOX-9) has also been reported as one of the key transcription factors for chondrogenesis. Meanwhile, transforming growth factor β (TGFβ) is a well-known ASC chondrogenic differentiation factor that stimulates ASC signaling pathways by activating transmembrane type I and type II receptors. We hypothesized that co-delivery of those genes would result in improved efficiency of recovery of normal chondrogenic properties in dedifferentiated chondrocytes.

The rapid progress in stem cell research has provided several tissue sources such as embryonic stem cells, induced pluripotent stem cells or mesenchymal stem cells that can provide tissue for restaurative therapies of brain disorders. However, clinical transplantations using such tissue have been sparse. The first FDA approved clinical applications of stem or progenitor cells to the brain employed human neural progenitor cells (hNPCs). These cells may be relatively safe since there has been no tumor formation in animal experiments and no serious adverse events in the above mentioned clinical studies. On the other hand, pluripotency and self renewal may be limited in progenitor cells derived from the fetal or adult human brain. Previous reports raised concerns in respect to early senescence and chromosomal instability.Our goal was to improve stability of tissue specific fetal hNPCs with a special focus on midbrain derived cells and their conversion into dopaminergic neurons. We were able to demonstrate that low oxygen is critical for long term expansion triggering hypoxia inducible factor 1 alpha dependent and independent mechanisms. Detailed analyses show, that hNPCs remain surprisingly stable at least during the first 20 passages. Growth curves remain stable and indicate that appr. 1017 hNPCs can be generated from a single specimen over 200 days in culture. During proliferation, there is a rapid wash out of glial (GFAP, O4) and neuronal markers (Tuj1, TH, DAT) but an increase of markers for pluripotency (nestin, CD15, CD133, CD184) and cell cycle (Ki67, PCNA). Following differentiation appr. 30 – 50% of these cells convert into cells expressing neuronal markers and midbrain derived tissue gives rise to up to 20 % of cells expressing tyrosine hydroxylase. These cells release dopamine and improve motor behavior in unilateral 6-hydroxydopamine rat or primate models of Parkinson’s disease. No chromosomal abnormalities were found following long-term expansion.In addition, we have also been able to expand NPCs from fetal human striatal or spinal cord tissue for generation of medium spiny neurons or motor neurons. We hope that such cells will be relevant to better understand or treat Huntington’s disease or spinal cord lesions. We provide evidence that hNPCs can be readily expanded and that these cells preserve the potential to differentiate into functional (dopaminergic) neurons without increasing their teratogenic potential, thus fetal hNPC’s are an alternative cell source to study human brain development and search for novel therapies.

Induced conversion of cell types and targeted genetic modification have been challenging in mammalian cells including human cells. It has been recently shown that one specific cell type can be converted into another through epigenetic modification using only a handful of reprogramming factors. In addition, significant breakthroughs have been made in targeted genetic modification. We will first briefly review the recent progress in the cell fate conversions including the reprogramming of somatic cells into pluripotent stem cells and direct lineage change between differentiated cells. This induced cell type conversion is thought to occur through epigenetic modification. We will next present recent progresses on the targeted genetic modification of mammalian cells using zinc finger nucleases, especially combined with induced cell fate conversion. We have developed a surrogate reporter system which enables efficient enrichment of cells of which genomes have been edited using zinc finger nucleases. These targeted engineering of mammalian cells through epigenetic and genetic modification will greatly contribute both to the establishment of research models for human diseases and to the development of therapeutic modality for these diseases.

Tissue loss and organ failure is one of the most devastating and costly medical problems in the current health care. Regenerative medicine aims to restore lost tissue structure and function via engineering biological tissue equivalents. Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs) may have significant potential to impact regenerative medicine. These cells are attractive cell sources for tissue regeneration due to their unique capacity of self-renewal and differentiation into multiple lineages. However, methods must be developed to control stem cell commitment before they can be used clinically. My current research aims to overcome this hurdle by engineering stem cell microenvironment via extrinsic signaling. In addition, long term objective of my research is to isolate precursor cells from hESCs and iPSCs and characterize and identify the extracellular microenvironment cues, and the downstream signaling pathways, that drive the lineage specification and differentiation. Identification of appropriate biomaterials that support cellular attachment, proliferation and, most importantly in the case of pluripotent stem cells, lineage specific differentiation is also critical for tissue engineering and cellular therapy.

Stem cell implantation can be used to induce neovascularization and has been tested as a therapy for ischemia treatment. However, stem cell implantation as a therapy for ischemia treatment may have limitations for clinical applications. Since the methods of stem cell harvest are invasive, it may not be feasible to harvest autologous stem cells from aged patients or patients with cardiovascular risk. Furthermore, poor cell survival after engraftment in ischemic tissue may lower the therapeutic efficacy of stem cells. hADSCs implanted to ischemic tissues support tissue revascularization in large part through secreted angiogenic factors. The goal of this study is to demonstrate that medium collected from human adipose-derived stromal cells (hADSCs) cultured as spheroids can exhibit improved therapeutic efficacy for ischemia treatment. Conditioned medium derived from hADSC monolayer culture (M-CM) or spheroid culture (S -CM), fresh medium (FM), or hADSCs were injected intramuscularly into the muscle in the medial thigh after mouse hindlimb ischemia modeling. Due to a mild hypoxic environment formed in hADSC spheroid, spheroid culture was effective to precondition the hADSCs to upregulate hypoxia-inducible factor-1α gene expression following significant enhancement in both angiogenic and anti-apoptotic factor secretion to the culture medium compared to monolayer cultures. S-CM administration to ischemic hindlimbs in mice significantly enhanced neovasclurization, protected muscles from incipient ischemic apoptosis, and improved limb survival as compared to M-CM or FM administration or hADSC implantation. These data suggest that injection of conditioned medium obtained from hADSC spheroid culture may be more effective therapeutic option for treatment of ischemic diseases than hADSC implantation.

Exploitation of sustainable and environment-friendly energy resources is highly required to resolve energy shortage. Recently, salinity gradient power (SGP) is considered as a feasible candidate with high potential to substitute fossil fuels due to its benefits: less periodic, abundance, and no emission of carbon dioxide. In this presentation, SGP processes such as pressure retarded osmosis (PRO) Reversed Electrodialysis (RED), and Capacity Mixing (CapMix) were reviewed with its mechanism, limitations, and available applications. For instance, in a PRO system, water permeates through semi-permeable membrane from feed solution to draw solution, and energy is generated by depressurizing the permeated flow through hydro turbine. Models for understanding of its mechanism and for improving of its performance were overviewed. In addition, applications of seawater reverse osmosis (SWRO), wastewater treatment (WWT), and PRO hybrid process were introduced to develop new water-energy nexus processes. The SWRO-PRO hybrid process and SWRO-PRO-WWP hybrid process can contribute on opening an insight to reduce the total energy consumption in SWRO plant as well as to apply the SGP energy to other engineering fields.

Recently the incidence of red tide has increased in Middle East, especially in Abu Dhabi, and the number of red tide recordings jumped to five in 2006 and eight in 2008. Algal bloom has a serious effect on operation of seawater desalination plants. It clogs a filter and the plant operation is halted. Although red tide phenomenon can cause a serious problem in seawater desalination plant, very limited information concerning an effect of algal bloom on the plant operation is available. An effect of algal bloom on membrane fouling is examined in this study. The study attempts to answer to questions such as how algae cause membrane fouling and how to reduce the fouling. For this study, seawater taken from the Masan bay is spiked with dinoflagellate species such as heterosigma akashiwo and prorocentrum micans. The algae spiked seawater was then fed into the microfiltration system. While increasing the cell number, the membrane fouling was induced and how algae induce the fouling has been investigated. The HPLC-SEC analysis was conducted to pinpoint the fouling substances. Several treatment techniques were introduced to indentify the most effective method of reducing the fouling.

The issues of water shortage and depletion of fresh water supply due to climate change place a great demand on alternative water resources. The increased need to secure a high quality water supply from various sources has resulted in the emergence of advanced membrane technologies, especially seawater desalination by reverse osmosis (RO). Compared with typical thermal driven desalination processes like MSF and MED, RO process requires less energy consumption, for this reason, the global RO market has been increasing more than 10 % annually. Despite the major advancements in RO desalination technology, which resulted in significant reductions in cost and energy use, its efficiency and sustainable operation are hampered by membrane fouling and by the considerable energy consumption [1].A recently resurgent membrane process, forward osmosis (FO) is considered to be a potential, sustainable alternative to conventional pressure-driven membrane processes. The advantages of FO technology include; (i) it operates without hydraulic pressure, thus with lower energy consumption, (ii) it can achieve high rejection of a wide range of contaminants, and (iii) it may have lower fouling potential than pressure-driven membrane processes because of the absence of applied hydraulic pressure. This presentation will discuss the future of seawater desalination technologies which would overcome limitations of current RO-based desalting process. More specifically, the concept of FO-RO hybrid desalination process is first explored to improve the energy efficiency and to increase water recovery and productivity. Recent research topics and developments in FO technology are also presented with focusing on the opportunities and challenges. Fouling behavior in FO has been investigated systematically, and the governing mechanism inducing the decline in the productivity of FO process is delineated. In FO, salt reversely diffused from the draw to the feed side results in an accelerated cake-enhanced osmotic pressure (CEOP) and corresponding severe permeate flux decline. Colloidal fouling in FO is also enhanced by reverse salt diffusion because it creates salinity-rich environment near the membrane surface, which prompts particle destabilization and aggregation. Fouling reversibility was also examined by varying the cross-flow velocity during the FO fouling runs. The permeate flux during organic/colloidal fouling in FO recovered almost completely with increasing cross-flow velocity. Our results suggest that fouling in FO could be controlled effectively by optimizing the hydrodynamics in the feed stream without employing chemical cleaning [2]. As a new concept to improve the productivity of FO process, PA-FO (Pressure- added FO) is suggested and its mechanistic features are investigated. In PA-FO, in addition to the chemical osmotic pressure, a low mechanical pressure is applied to increase the driving force for the water separation and corresponding the permeate water flux. The experimentally measured water fluxes generated in PA-FO are consistently lower than those predicted by modeling equation calculating the water flux in PA-FO process which accounts for the effects of applied hydraulic pressure. This result can be explained by the effect of the permeate water flux on the severity of internal concentration polarization (ICP) within the membrane support layer. As the permeate water flux increases, draw solution within the membrane support layer becomes more diluted, which in turn, decreases the effective osmotic pressure gradient at the interface between the support layer and the active layer. Based on the results obtained, we propose new concept to interpret the process efficiency of PA-FO.

Membrane processes of electrodialys (ED) and nanofiltration (NF) are environmentally friendly tools with no secondary waste generation for the recovery of various organic acids produced by fermentation. An organic acid usually exists in the fermentation broth in a salt from. Desalting to isolate this salt from other impurities is performed first and then the conversion of the recovered salt to its acid form is done. In this talk, experimental results on the isolation of lactic acid and succinic acid by desalting ED or desalting NF, and the acidification by watersplitting ED will be discussed together with mathematical modeling of each process.

The bio-industry in Korea, which has not been fully cultivated, is being developed continuously, owing to accumulated research capabilities and enhanced technical standard. In particular, the foundation is being laid for the bio-industry in Korea, as many conglomerate companies are actively taking part in this industry.Major advanced countries (OECD countries) have established a support policy on the government level to cope with the age of the bio- economy, and are increasing their investment and support in the industry. Various market trend firms are also forecasting high growth in the bio-industry and market. The strategic importance of the bio-industry is very significant, as there is no doubt in forecasting and the prospect that the bio-industry will take the position of being a new growth engine, followed by the IT industry.However, there are numerous entry barriers in the commercialization process of biotechnologies, including the characteristic of bioresearch where, “it takes a long time and entails a high risk of failure.” There are also financial problems and a lack of experience as many bio-companies are the venture company, and there is a lack of participants and marketing capability at the value chain stage.This study reviews the technologies and prospects of the bioengineering industry, based on the mega-trend and future forecasting that have become worldwide issues recently. This study also reviews the major issues and statuses of biotechnologies in Korea, and diagnoses the status of the bio-industry at home and abroad, to analyze the characteristics and difficulties of the bio-industry and its businesses.This study will set up future development strategies that should be referred to by the bio-company, by introducing the national bio R&D status; the government’s investment plan; and the policy for bio industry promotion by area, such as R&D support, manpower development, arrangement of the support policy, international cooperation, and infrastructure establishm ent. The strategy for the successful commercialization of biotechnologies w ill also be introduced together with success stories.

This paper will consider some of the key issues relating to the manufacturing and quality of a biosimilar drug substance that arise during assessment for marketing approval in European Union (EU). Details of the manufacture of the drug substance, starting with thawing of the WBC represent an important component of the submission. The applicant needs to be aware that this represents a commitment and should allow some flexibility in this description. In-Process Controls need to be based on process development experience and defined before validation. Furthermore the action to be taken if a control parameter is out of specification is normally required. Control of starting materials need to be defined including source, history and generation of the cell substrate and the cell banking system.Before submission it is important that the entire process is fully validated and the reproducibility and robustness of the process demonstrated. The Committee on Health and Medicinal Products (CHMP) will be in interested in the development of the manufacturing process and the early studies that have shaped the current process. There is a need to particularly focus on earlier processes which were involved in generating batches used in the non-clinical and clinical program with robust comparability data included.Data on the quality and integrity of the protein forms another cornerstone of the submission and there is a need to apply state of the art methods in order to confirm the structure and understand the heterogeneity and impurity profile. These data form part of the justification of the specifications for release of the drug substance. Stability studies form another important aspect of the EU application requiring data from batches produced by the final production process. This presentation will cover the key Quality issues relating to the drug substance that EU regulators focus on in granting market authorisation approval.

The recent entry into force of the KORUS FTA, the ongoing public pressures to reduce healthcare costs and the impending expiration of brand name drug patents and exclusivities are expected to spur significant growth of the US and global biosimilars industry through the end of the decade. However, USFDA concerns about the safety, efficacy and purity of these complex and variable molecules persist. The recently promulgated draft proposed guidelines intended to implement the BPCIA’s provisions and which reflect these concerns would, if adopted, likely raise regulatory uncertainties and result in delayed development of biosimilars and interchangeables, overall higher development, manufacturing, data generation and testing costs, reduced product profit margins, and lower than anticipated patient cost savings. The BPCIA’s mandatory patent settlement procedure, furthermore, is likely to raise additional litigation uncertainties, risks and costs for biosimilar applicants due to the difficulty of undertaking ‘freedom-to-operate’ clearances (including prior art searches) given the biotechnology-jurisprudence lag, USFDA Orange Book exclusion of process patents, pending non-published (provisional) patent risk, and broad and nested platform patents. These risks and uncertainties notwithstanding, many biopharma companies have endeavored to capitalize on the perceived biologics trend by pursuing various individual, alternative and/or collaborative business strategies, focusing on, among other things, the development of new innovative biologics, biosimilars and/or bio-betters, and the entering into of domestic and cross-border out-licensing arrangements, and marketing, distribution and/or joint manufacturing ventures.

Twin-Arginine translocation (Tat) pathway has been known with a unique cellular protein folding quality control mechanism in gram negative bacteria, which exports only correctly folded proteins across cytoplasmic membrane. Recently, we identified for the first time that a certain type of translocation intermediate of the recombinant Tat substrate is stably displayed on the surface of Escherichia coli. Furthermore, it was revealed that this display is dependent on a functional signal sequence and a folding efficiency of substrate. Taking advantage of the features of the display, a new protein engineering technology permitting simultaneous engineering of in vivo folding and affinity of proteins was exploited. This display technology should accelerate screening and engineering processes for the development of therapeutically valuable proteins such as single-chain variable fragment (scFv) and alternative binding scaffolds readily expressed in bacteria.

The N-linked glycan on the Fc (fragment crystallizable) domain of IgG antibody is indispensable for binding to effector Fc gamma receptors (FcγRs) expressed on various immune cells and hence for the clearance of abnormal target cells. In IgG molecules, removal of the invariant glycan at Asn297 abolishes binding to FcγRs and effector functions. Recently, we have engineered aglycosylated IgG Fc variants that showed binding to FcγRI with affinity nearly identical to that of glycosylated antibodies. Interestingly, the engineered aglycosylated antibodies were able to potentiate tumor cell killing with dendritic cells (DCs) as effectors, while the glycosylated antibodies did not induce the DC-mediated ADCC (antibody dependent cell-mediated cytotoxicity). Additionally, we have isolated an aglycosylated antibody with selectivity towards activating FcγRIIa over inhibitory FcγRIIb and with superior macrophage-mediated ADCP (antibody dependent cell-mediated phagocytosis) when compared with a clinical grade glycosylated antibody. A set of Fc engineered versions of aglycosylated antibody with various receptor selectivities and unique effector functions have been generated and will be discussed.

Despite all the technical progress in protein engineering, our ability to rationally manipulate the structures and functions of proteins is quite limited, because the genetic code specifies the same 20 amino acids building blocks. The development of a method that makes possible the systematic expansion of the genetic code can enable the evolution of proteins with new or enhanced properties. Recent advances in engineering of translation machinery have made it possible to add over 60 novel amino acids to the genetic code, but the repertoire of unnatural functional groups is still limited and their application is quite restricted. In an effort to overcome these major obstacles, newly discovered aminoacyl tRNA synthetase and tRNA were characterized in terms of structure and biochemical properties. Based on these studies, the cellular translation system was redesigned and evolved to site-specifically incorporate novel unnatural amino acids. Direct incorporation of unnatural amino acids can make considerable contribution to biotechnology and bioenergy research areas such as protein engineering, click chemistry, and nanobiotechnology, and bioenergy production. Detailed experimental design and results will be presented and application of synthetic biology technology will be discussed.