Korea Research Institute of Bioscience and Biotechnology
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Porous structures prepared by a novel route: combination of digital light processing 3D printing and leaching method
No full textWe present a route to prepare porous structures by combining digital light processing (DLP) 3D printing with a leaching process. Porous structures with different pore-size distributions were successfully fabricated via the combined route. Specifically, the porous structures were directly prepared on the mount by adopting a bottom-up DLP 3D printing method. To apply the leaching process, NaCl salts were adopted and the size distribution of the salts was adjusted to control the pore size in the porous structures. Two different size distributions of the salts, in the range of 25？75 μm and 95？135 μm, respectively, were adopted to print the porous structures, which were successfully achieved with a solid loading of 60 vol.% of NaCl salts. In actuality, the morphological and microstructural characteristics of the porous structures were determined by the size distribution of NaCl salts and the relative quantity of salts. The role of NaCl salts in the printing process was demonstrated, and the novel route was successfully applied to fabricate a biocompatible porous structure.
Targeting HSF1 as a therapeutic strategy for multiple mechanisms of EGFR inhibitor resistance in EGFR mutant non-small-cell lung cancer
No full textAlthough EGFR-TKI treatment of NSCLC (non-small-cell lung cancer) patients often achieves profound initial responses, the efficacy is transient due to acquired resistance. Multiple receptor tyrosine kinase (RTK) pathways contribute to the resistance of NSCLC to first- and third-generation EGFR-TKIs, such as erlotinib and osimertinib. To identify potential targets for overcoming EGFR-TKI resistance, we performed a gene expression signature-based strategy using connectivity map (CMap) analysis. We generated erlotinib-resistant HCC827-ErlR cells, which showed resistance to erlotinib, gefitinib, osimertinib, and doxorubicin. A list of differentially expressed genes (DEGs) in HCC827-ErlR cells was generated and queried using CMap analysis. Analysis of the top 4 compounds from the CMap list suggested HSF1 as a potential target to overcome EGFR-TKI resistance. HSF1 inhibition by using HSF1 shRNAs or KRIBB11 decreased the expression of HSF1 downstream proteins, such as HSP70 and HSP27, and also decreased the expression of HSP90/HSP70/BAG3 client proteins, such as BCL2, MCL1, EGFR, MET, and AXL, causing apoptosis of EGFR-TKI-resistant cancer cells. Finally, we demonstrated the efficacy of the HSF1 inhibitor on PC9-ErlR cells expressing mutant EGFR (T790M) in vivo. Collectively, these findings support a targetable HSF1-(HSP90/HSP70/BAG3)-(BCL2/MCL1/EGFR/MET/AXL) pathway to overcome multiple mechanisms of EGFR-TKI resistance.
Building consensus on definition and nomenclature of hepatic, pancreatic, and biliary organoids
No full textHepatic, pancreatic, and biliary (HPB) organoids are powerful tools for studying development, disease, and regeneration. As organoid research expands, the need for clear definitions and nomenclature describing these systems also grows. To facilitate scientific communication and consistent interpretation, we revisit the concept of an organoid and introduce an intuitive classification system and nomenclature for describing these 3D structures through the consensus of experts in the field. To promote the standardization and validation of HPB organoids, we propose guidelines for establishing, characterizing, and benchmarking future systems. Finally, we address some of the major challenges to the clinical application of organoids.
C4 bacterial volatiles improve plant health
No full textPlant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.
Production of porpyra-334 in transgenic lines of Nannochloropsis salina by the expression of mycosporine-like amino acid biosynthetic genes of P. yezoensis
No full textMycosporine-like amino acids (MAAs) are small secondary metabolites produced by some marine species. These compounds absorb ultraviolet (UV) light, typically between 310 and 362 nm, and protect the producers from UV-associated damage. They also have anti-photoaging, anticancer, and anti-inflammatory properties, which has generated considerable interest in the cosmetic, pharmaceutical, biotechnology, and materials fields. Commercial use has been limited due to its reliance marine organisms for production, resulting in low and inconsistent yields. This study was undertaken to increase production of MAAs. We generated transgenic lines of the Nannochloropsis salina that carry and express the MAA biosynthesis genes from red alga Pyropia yezoensis. We characterized their MAA yield and the properties of MAAs produced by these lines. When exposed to UV light, the transgenic lines generated fewer reactive oxygen species compared to wild-type. The yield of porphyra-334 in one of the transgenic lines was 25 mg g？1 dry cell weight, the greatest reported. We hope these results will support the use of MAAs in numerous applications and increase our understanding of their biosynthetic pathways.
Real-time neurotransmitter monitoring in brain using 3D nanostructures
No full text3D 나노 구조체 기반 신경전달물질 실시간 모니터링 기술 개발NGC001212
Biodegradable films based on chitosan and defatted Chlorella biomass: functional and physical characterization
No full textBiodegradable films based on chitosan, glycerol, and defatted Chlorella biomass (DCB) were prepared and characterized in terms of thermal stability, mechanical, water barrier, and optical properties. Increasing DCB content from 5 to 25 wt% increased tensile strength of chitosan films by 235%. The incorporation of DCB decreased both moisture content and swelling degree of chitosan/defatted Chlorella biomass (Cs/DCB) films. Furthermore, increasing the content of defatted algal biomass decreased light transmission and reduced water vapor permeability of composite films by more than 60%. As confirmed by scanning electron microscopy and Fourier transform infrared analysis, such improvement in functional and physical properties is mainly due to the homogeneous and uniform distribution of DCB into the polymeric matrix along with the establishment of strong hydrogen bond interactions between chitosan and algal biomass constituents. Moreover, Cs/DCB composite films showed more than 50% of degradation in 60 days soil burial test.
Amplification of EBNA-1 through a single-plasmid vector-based gene amplification system in HEK293 cells as an efficient transient gene expression system
No full textOur previous work showed that there is a limitation in the use of dihydrofolate reductase (dhfr)/methotrexate (MTX)-mediated gene amplification systems in dhfr-non-deficient HEK293 cells, as endogenous dhfr may interfere with the amplification process. In the present study, we successfully generated Epstein-Barr virus nuclear antigen-1 (EBNA-1)-amplified HEK293 cells in a dhfr-non-deficient HEK293 cell background using a single-plasmid vector-based gene amplification system with shRNA targeting the 3′-UTR of endogenous dhfr. The introduction of this shRNA efficiently downregulated the expression of endogenous dhfr in the HEK293 cells without affecting exogenous dhfr expression. The downregulation of endogenous dhfr improved the efficiency of EBNA-1 amplification, as evidenced by a comparison with the amplification extent in cells lacking shRNA expression at the same MTX concentration. The EBNA-1 expression levels from the EBNA-1-amplified clones selected in this study were higher than those obtained from EBNA-1-amplified clones that were generated using the conventional amplification in our previous study. Consistent with previous studies, EBNA-1 amplification improved the production of the Fc-fusion protein through a specific protein productivity (qp)-enhancing effect, rather than by improving cell growth or transfection efficiency. In addition, the N-glycan profiles in the Fc-fusion protein produced using this transient gene expression (TGE) system were not affected by EBNA-1 amplification. These results indicate the potential utility of EBNA-1-amplified mammalian cells, developed using a single-plasmid vector-based gene amplification system, for efficient protein production.
Practical studies of Russian dandelion new variety for its transfer to company
No full text식물유래 유용 산업소재 생산하는 러시아민들레 신품종의 기업체 이전을 위한 실용화연구ABM437201