Inkjet printing-based β-secretase fluorescence resonance energy transfer (FRET) assay for screening of potential β-secretase inhibitors of Alzheimer's disease

Lee, Jungmi,Samson, Annie Agnes Suganya,Song, Joon Myong Elsevier 2018 Analytica chimica acta Vol.1022 No.-

<P><B>Abstract</B></P> <P>Amyloid-β (Aβ) is generated by proteolytic processing of amyloid precursor protein (APP) by beta-secretase (BACE-1) and gamma-secretase. Amyloid-β is responsible for the formation of senile plaques in Alzheimer's disease (AD). Consequently, inhibition of β-secretase (BACE-1), a rate-limiting enzyme in the production of Aβ, constitutes an attractive therapeutic approach to the treatment of AD. This paper reports an inkjet printing-based fluorescence assay for high throughput screening of β-secretase inhibitors achieved by employing a BACE-1 FRET substrate (Rh-Glu-Val-Asn-Leu-Asp-Ala-Glu-Phe-Lys-Quencher). This peptide substrate is known to be a readily available and suitable substrate for proteolytic activity, and it has high affinity to BACE-1. The BACE-1 peptide substrate printed on parchment paper was effectively cleaved by BACE-1, which was printed on the same spot. The amount of enzyme and substrate required for this inkjet printing-based BACE-1 assay can be less than 1.4ⅹ10<SUP>3</SUP>, permitting the evaluation of inhibitor activity with femtomolar potency. The inkjet-printing-based BACE-1 inhibitory assay revealed inhibitory effects of inhibitor IV and STA on BACE-1 with an IM<SUB>50</SUB> of 1.00 × 10<SUP>−15</SUP> mol and 1.01 × 10<SUP>−14</SUP> mol, respectively. These data confirm that both BACE-1 inhibitors (inhibitor IV and STA) actively inhibited the BACE-1 proteolysis of BACE-1 substrate on parchment paper. It important to note that the number of mole of BACE-1-substrate and enzyme utilized in the printing-based enzymatic assay are 1.4ⅹ10<SUP>3</SUP> smaller than the amount used in the conventional well-plate assay. The inkjet printing-based inhibitory assay constitutes a versatile high throughput technique and the IM<SUB>50</SUB> values of the inhibitors were obtained with satisfactory reproducibility, suggesting that this inkjet-printing BACE-1 inhibitory assay could be quite suitable for the screening of new potential BACE-1 inhibitors for AD.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An inkjet printing-based fluorescence assay was developed for high throughput screening of β-secretase inhibitors using FRET peptide substrate. </LI> <LI> The BACE-1 peptide substrate printed on parchment paper was effectively cleaved by BACE-1 which printed on the same spot. </LI> <LI> The inkjet-printing-based BACE-1 inhibitory assay revealed inhibitory effects of inhibitor IV and STA on BACE-1. </LI> <LI> The inkjet printing-BACE-1 inhibitory assay revealed that the consumed amount of the sample was reduced by 1.4 × 10<SUP>3</SUP> times. </LI> <LI> The inkjet printing-based inhibitory assay enabled in a high throughput format, and it is a reliable for BACE-1 inhibitor screening. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

All-inkjet-printed flexible piezoelectric generator made of solvent evaporation assisted BaTiO₃ hybrid material

Lim, Jongwoo,Jung, Hyunsung,Baek, Changyeon,Hwang, Geon-Tae,Ryu, Jungho,Yoon, Daeho,Yoo, Jibeom,Park, Kwi-Il,Kim, Jong Hee Elsevier 2017 Nano energy Vol.41 No.-

<P><B>Abstract</B></P> <P>Attractive approaches based on flexible piezoelectric energy harvesting technology that convert ambient mechanical energies into electrical energy have attracted attention in response to recent progress in the field of flexible electronics technology. Although the harvesters on plastic substrates has shown the feasibility of the piezoelectric energy generation from the repetitive and tiny bending deformations, the complicated fabrication process and size limitations hinder the commercialization of piezoelectric self-powered technology. In this study, all-inkjet-printed flexible piezoelectric energy harvester based on a BaTiO<SUB>3</SUB> hybrid film is demonstrated by adopting only a simple and facile inkjet-printing process. Flexible/large-area piezoelectric hybrid film and Ag electrode layers are printed onto a flexible substrate by only non-contact inkjet process without high temperature annealing and complicated transfer processes. All-inkjet-printed energy harvester converts the periodically mechanical deformations into an open-circuit voltage (V<SUB>oc</SUB>) of ~ 7V, a short-circuit current (I<SUB>sc</SUB>) of 2.5 μA (corresponding to a current density of 0.21 μA·cm<SUP>−2</SUP>), and an effective output power of around 5 μW (corresponding to a power density of 0.42 μW·cm<SUP>−2</SUP>). This novel approach provides an innovative platform for self-powered system and inorganic-based flexible electronics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> All-inkjet-printed f-PEH was fabricated by using a practical inkjet-printing process. </LI> <LI> Piezoelectric BaTiO<SUB>3</SUB> nanoparticles and resin were inkjet-printed onto a plastic substrate. </LI> <LI> The fabricated f-PEH generates the output voltage of ~ 7 V and current of 2.5 μA. </LI> <LI> The flexible energy harvester showed mechanically stable under periodic bendings. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>All-inkjet-printed flexible energy harvester made of BaTiO<SUB>3</SUB> - resin hybrid film has been demonstrated by introducing a simple, facial, and scalable inkjet-printing process. Flexible piezoelectric BaTiO<SUB>3</SUB> - resin hybrid film and conductive layers are printed onto a plastic substrate by only non-contact inkjet process without high temperature annealing and complicated transfer processes.</P> <P>[DISPLAY OMISSION]</P>

Polymer Inkjet Printing: Construction of Three-Dimensional Structures at Micro-Scale by Repeated Lamination

Yun, Yeon-Hee,Kim, Jae-Dong,Lee, Byung-Kook,Cho, Yong-Woo,Lee, Hee-Young The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.3

Solution-based, direct-write patterning by an automated, computer-controlled, inkjet technique is of particular interest in a wide variety of industrial fields. We report the construction of three-dimensional (3D), micro-patterned structures by polymer inkjet printing. A piezoelectric, drop-on-demand (DOD) inkjet printing system and a common polymer, PVA (poly(vinyl alcohol)), were explored for 3D construction. After a systematic preliminary study with different solvent systems, a mixture of water and DMSO was chosen as an appropriate solvent for PVA inks. The use of water as a single solvent resulted in frequent PVA clogging when the nozzles were undisturbed. Among the tested polymer ink compositions, the PVA inks in a water/DMSO mixture (4/1 v/v) with concentrations of 3 to 5 g/dL proved to be appropriate for piezoelectric DOD inkjet printing because they were well within the proper viscosity and surface tension range. When a dot was printed, the so-called 'coffee-ring effect' was significant, but its appearance was not prominent in line printing. The optimal polymer inkjet printing process was repeated slice after slice up to 200 times, which produced a well-defined, 3 D micro-patterned surface. The overall results implied that piezoelectric DOD polymer inkjet printing could be a powerful, solid-freeform, fabrication technology to create a controlled 3D architecture.

Inkjet-Printed Biofunctional Thermo-Plasmonic Interfaces for Patterned Neuromodulation

Kang, Hongki,Lee, Gu-Haeng,Jung, Hyunjun,Lee, Jee Woong,Nam, Yoonkey American Chemical Society 2018 ACS NANO Vol.12 No.2

<P>Localized heat generation by the thermo-plasmonic effect of metal nanoparticles has great potential in biomedical engineering research. Precise patterning of the nanoparticles using inkjet printing can enable the application of the thermo-plasmonic effect in a well-controlled way (shape and intensity). However, a universally applicable inkjet printing process that allows good control in patterning and assembly of nanoparticles with good biocompatibility is missing. Here we developed inkjet-printing-based biofunctional thermo-plasmonic interfaces that can modulate biological activities. We found that inkjet printing of plasmonic nanoparticles on a polyelectrolyte layer-by-layer substrate coating enables high-quality, biocompatible thermo-plasmonic interfaces across various substrates (rigid/flexible, hydrophobic/hydrophilic) by induced contact line pinning and electrostatically assisted nanoparticle assembly. We experimentally confirmed that the generated heat from the inkjet-printed thermo-plasmonic patterns can be applied in micrometer resolution over a large area. Lastly, we demonstrated that the patterned thermo-plasmonic effect from the inkjet-printed gold nanorods can selectively modulate neuronal network activities. This inkjet printing process therefore can be a universal method for biofunctional thermo-plasmonic interfaces in various bioengineering applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2018/ancac3.2018.12.issue-2/acsnano.7b06617/production/images/medium/nn-2017-06617n_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn7b06617'>ACS Electronic Supporting Info</A></P>

Polymer Inkjet Printing: Construction of Three-Dimensional Structures at Micro-Scale by Repeated Lamination

윤연희,김재동,이병국,이희영,조용우 한국고분자학회 2009 Macromolecular Research Vol.17 No.3

Solution-based, direct-write patterning by an automated, computer-controlled, inkjet technique is of particular interest in a wide variety of industrial fields. We report the construction of three-dimensional (3D), micropatterned structures by polymer inkjet printing. A piezoelectric, drop-on-demand (DOD) inkjet printing system and a common polymer, PVA (poly(vinyl alcohol)), were explored for 3D construction. After a systematic preliminary study with different solvent systems, a mixture of water and DMSO was chosen as an appropriate solvent for PVA inks. The use of water as a single solvent resulted in frequent PVA clogging when the nozzles were undisturbed. Among the tested polymer ink compositions, the PVA inks in a water/DMSO mixture (4/1 v/v) with concentrations of 3 to 5 g/dL proved to be appropriate for piezoelectric DOD inkjet printing because they were well within the proper viscosity and surface tension range. When a dot was printed, the so-called ‘coffee-ring effect’ was significant, but its appearance was not prominent in line printing. The optimal polymer inkjet printing process was repeated slice after slice up to 200 times, which produced a well-defined, 3D micro-patterned surface. The overall results implied that piezoelectric DOD polymer inkjet printing could be a powerful, solid-freeform, fabrication technology to create a controlled 3D architecture.

잉크젯 인쇄 기술을 이용하여 상대적으로 낮은 온도에서 리튬이 도핑 된 인듐-아연-산화물 트랜지스터의 제작

최운섭 대한금속·재료학회 2021 대한금속·재료학회지 Vol.59 No.5

Inkjet printing is a very attractive technology for printed electronics and a potential alternative to current high cost and multi-chemical lithography processes, for display and other applications in the electronics field. Inkjet technology can be employed to fabricate organic light emitting diodes (OLED), quantum dots displays, and thin-film transistors (TFTs). Among potential applications, metal oxide TFTs, which have good properties and moderate processing methods, could be prepared using inkjet printing in the display industry. One effective method of improving their electrical properties is via doping. Lithium doping an oxide TFT is a very delicate process, and difficult to get good results. In this study, lithium was added to indium-zinc oxide (IZO) for inkjet printing to make oxide TFTs. Electrical properties, transfer and output curves, were achieved using inkjet printing even at the relatively low annealing temperature of 200 oC. After optimizing the inkjet process parameters, a 0.01 M Li-doped IZO TFT at 400 oC showed a mobility of 9.08 ± 0.7 cm2/V s, a sub-threshold slope of 0.62 V/dec, a threshold voltage of 2.66 V, and an on-to-off current ratio of 2.83 × 108. Improved bias stability and hysteresis behavior of the inkjet-printed IZO TFT were also achieved by lithium doping.

Influence of the Physical Properties of Digital Printing Paper on the Printing Quality

Young-Baeck Ha,박정윤,Hyoung-Jin Kim 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.2

Present-day commercial printing is often accompanied with less quantity and more customization, as a response to the corresponding consumer demand of high quality and differentiation. One of the printing methods dealing with such features is the digital press, whose current trend greatly differs from that of traditional printing methods using liquid inkjet and solid toner. In this study, the correlation between the characteristics of the digital printing paper and the color density of the printed material was analyzed through a comparison of the physical and optical characteristics and printability of five different digital printing paper samples. With respect to the printing quality of the five samples, the color density of printout influenced by color inks was confirmed to be related to their air permeability and roughness characteristics. Specifically, the color density was directly influenced by surface irregularities caused by paper roughness, for the same amount of ink applied. The same result was shown in the status of ink transfer, obtained by the optical image analysis. In terms of printability, toner ink was better than inkjet, which could be explained with the amount of ink remaining on the surface of the printing paper: more ink remains on the surface of the paper using the inkjet than the solid-type (toner), due to wetting and capillary penetration into the porous digital printing paper. Additionally, the printthrough more often occurred on the liquid-type inkjet-based printout, due to the influence of density and air permeability of the paper. The trapping of printout was found to be related to adhesion between the ink molecules, and was rather irrelevant to the properties of the digital paper. Dot reproduction of the ink was better materialized when less liquid penetrates into the surface and when the internal structure of the paper was considered, as the amount of ink remains on the surface of the paper increased. The dot gain was seemingly due to wetting caused by the dispersion of the ink, when the amount of ink remaining on the surface of the paper was large enough.

Influence of substrate temperature and overlap condition on the evaporation behavior of inkjet-printed semiconductor layers in organic thin film transistors

Kang, Byung Ju,Oh, Je Hoon Elsevier 2016 THIN SOLID FILMS - Vol.598 No.-

<P><B>Abstract</B></P> <P>In this study, we investigate the evaporation behavior of inkjet-printed semiconductor layers of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) to obtain well-oriented crystalline structures for the fabrication of high-performance organic thin film transistors (OTFTs). Variations in overlap and substrate temperature are considered to control the evaporation behavior and the resulting crystalline structures of the layers. The internal flow and corresponding contact line movement can be controlled via three representative inkjet-printing regimes. For inkjet-printing regimes that induce outward convective flow (the coffee stain effect), randomly-oriented TIPS pentacene crystalline structures are produced by irregular contact line receding. With an optimized inkjet-printing regime, uniform bottom contact line movement is generated by the unidirectional internal flow, resulting in well-oriented crystalline structures. All-inkjet-printed OTFTs with semiconductor layers inkjet-printed using the optimized regime exhibit a high field effect mobility of ~0.13cm<SUP>2</SUP>/Vs, due to the one-dimensionally-oriented TIPS pentacene crystal arrays.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crystal structure of inkjet-printed semiconductor layers was controlled. </LI> <LI> Crystal growth is determined by evaporation behavior of drying semiconductor layers. </LI> <LI> The evaporation behavior is affected by overlap condition and substrate temperature. </LI> <LI> Well-oriented crystal structure can be obtained by uniform contact line movement. </LI> <LI> OTFTs with well-oriented crystal structures show good electrical performance. </LI> </UL> </P>

프린팅 전자소자용 잉크젯 기술과 소재

류병환(Beyong-Hwan Ryu),최영민(Youngmin Choi) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

It is strongly expected that inkjet printing method will be play an important role on printable electronics such as 3D integration of embedded ceramic devices (capacitor, resistor, inductor and electrode or circuit), Si-TFT and organic TFT including display C/F, RFID, FPCB, and etc. A inkjet printing method has been center of attention to strengthen the competitiveness of flat panel display on market and to open the new world of manufacturing process of printable electronics. We will survey the industrial tendency of printable electronics and flat panel display including some examples of inkjet printing and present the considerable points of inkjet printing method and some role of materials for successful inkjet printing.

전자 인쇄를 위한 잉크젯 프린팅 시스템 개발

권계시(Kye-Si Kwon),고정국(Jung-Kook Go),김진원(Jin-Won Kim) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.10

전자 인쇄 분야에 활용이 가능한 잉크젯 프린팅 시스템을 개발하였다. 목표한 위치에 정확하게 이미지를 패터닝 하기 위한 프린팅 시스템의 하드웨어 및 소프트웨어를 개발 하였다. 이를 위하여 패턴 카메라와 선택된 노즐 간의 거리를 구할 수 있는 소프트웨어 알고리즘을 개발하였다. 또한 AutoCAD 의 dxf 파일을 이용하여 XY 스테이지를 동시에 움직여서 프린팅할 수 있는 벡터 프린팅 방법을 개발하였다. 또 다른 프린팅 방법으로 비트맵 이미지를 이용하여 복잡한 이미지를 출력할 수 있는 래스터 프린팅 방법을 개발하였고, CAD 를 이용한 래스터 프린팅 방법과 그 때 생기는 기술적인 문제들을 기술하였다. An inkjet printing system for printed electronics was developed. In this study, a printing algorithm was mainly discussed. In order to print a pattern image at a target location, we developed a hardware and software algorithm for determining the distances between a substrate camera and the selected nozzles. We implemented a vector-printing algorithm where AutoCAD dxf file was used for XY motion control and for printing. We also developed printing method using bitmap images. The technical issues in using CAD drawings and bitmap images were discussed.