Browsing by Author "Lin, Hsin-Chieh"

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A novel nanostructured supramolecular hydrogel self-assembled from tetraphenylethylene-capped dipeptides
(2016)
Yeh, Mei-Yu
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Huang, Chen-Wei
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Chang, Jui-Wen
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Huang, Yu-Tang
;
Lin, Jhong-Hua
Herein, we report a tetraphenylethylene-diglycine (TPE-GG) hydrogelator from a systematic study of TPE-capped dipeptides with various amphiphilic properties. From a chemical design, we found that the hydrogelation of TPE-GG molecules can be utilized to generate supramolecular nanostructures with a large TPE-based nanobelt width (similar to 300 nm) and lateral dimension ratio (>30 fold). In addition, TPE-GG has the lowest molecular weight and minimum number of atoms compared to any TPE-capped peptide hydrogelator reported to date. This minimal self-assembled hydrogelator can fundamentally achieve the gel features compared with other TPE-capped peptides. A combined experimental and computational study indicates the pi-pi interactions, electrostatic interactions and hydrogen-bonding interactions are the major driving forces behind the formation of self-assembled nanobelts. This study demonstrates the importance of structure-property relationships and provides new insights into the design of supramolecular nanomaterials.
A supramolecular gel based on a glycosylated amino acid derivative with the properties of gel to crystal transition
(2016-01-01)
Liu, Jie
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Xu, Fengyang
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Sun, Ziling
;
Pan, Yue
;
Tian, Jian
Here we report the generation of a novel gelator from a glycosylated amino acid derivative, which contained three structural units, an aromatic residue, a carbohydrate moiety and a tert-butyl group in a single molecule. These structural units can promote the supramolecular self-assembly of this gelator in both aprotic and protic solvents via coordinated pi-pi stacking, multiple hydrogen binding and van der Waals interactions. More importantly, due to their non-equilibrium natures, the organogels formed in DCM, chloroform and ethanol can undergo gel to crystal transition in storage, driven by unbalanced gelator-gelator and solvent-gelator interactions. In this process, the gelators were firstly trapped in a kinetically favorable gel state, and then transferred into a more thermodynamically stable crystal state upon ageing, with the generation of microcrystals in different morphologies.
A supramolecular hydrogel self-assembled from pentafluorobenzyl-dipeptide
(2015-01-01)
Hsu, Shu-Min
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Chang, Jui-Wen
;
Wu, Fang-Yi
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Lin, Yu-Chun
;
Lai, Tsung-Sheng
We report a new aromatic-capped peptide amphiphile which is able to form a supramolecular hydrogel under neutral pH. This hydrogel can also be obtained by enzymatic transformation from the hydrogelator precursor. The newly discovered hydrogel has excellent biocompatibility for four different cell lines, thus making it a potentially useful scaffolding material for biomedical applications.
AIMED - A personalized TV recommendation system
(2007)
Hsu, Shang H.
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Wen, Ming-Hui
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Lin, Hsin-Chieh
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Lee, Chun-Chia
;
Lee, Chia-Hoang
Previous personalized DTV recommendation systems focus only on viewers' historical viewing records or demographic data. This study proposes a new recommending mechanism from a user oriented perspective. The recommending mechanism is based on user properties such as Activities, Interests, Moods, Experiences, and Demographic information-AIMED. The AIMED data is fed into a neural network model to predict TV viewers' program preferences. Evaluation results indicate that the AIMED model significantly increases recommendation accuracy and decreases prediction errors compared to the conventional model.
Au@Cu2O core@shell nanocrystals as dual-functional catalysts for sustainable environmental applications
(2019-03-01)
Kuo, Ming-Yu
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Hsiao, Chih-Feng
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Chiu, Yi-Hsuan
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Lai, Ting-Hsuan
;
Fang, Mei-Jing
This work reports the synthesis of Au@Cu2O core@shell nanocrystals with controllable shell thicknesses and demonstrates their use as the dual-functional catalyst that can continuously operate under illumination and darkness conditions for efficient E. con inactivation. On account of the peroxidase mimics of the Au core and Fenton reactivity of the Cu2O shell, the Au@Cu2O nanocrystals exhibit intrinsic peroxidase-like property with the reaction kinetics in accordance with the typical Michaelis-Menten mechanism. On the other hand, time resolved photoluminescence spectra suggest the prevalence of pronounced charge separation for Au@Cu2O nanocrystals, an important advantage that is favourable for photocatalysis. By combining the photocatalytic capability with the peroxidase mimics features, Au@Cu2O nanocrystals can perform practical photocatalytic decomposition of E. coil under visible light illumination but still show vital activity towards E. coil inactivation after light illumination was turned off. The current study delivers a new catalyst configuration by exploiting the multiple functionalities of nanosized Au and Cu2O for advanced environmental and energy conversion applications.
Broad Ranges and Fast Responses of Single-Component Blue-Phase Liquid Crystals Containing Banana-Shaped 1,3,4-Oxadiazole Cores
(2014-01-08)
Chiang, I-Hung
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Long, Chun-Ji
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Lin, Hsin-Chieh
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Chuang, Wei-Tsung
;
Lee, Jey-Jau
In this study, we synthesized two novel 1,3,4-oxadiazole-based bent-core liquid crystals (OXD7*, OXD5B7F*) containing a chiral tail that display broad ranges of the blue phase III (34 and 7 K, respectively); we characterized them using polarized optical microscopy, differential scanning calorimetry, and circular dichroism. The electro-optical responses of both of these liquid crystals are much faster than those of previously reported single-component blue-phase liquid crystals. To optimize its electro-optical performance, we mixed OXD7* (the blue-phase range of which is broader than that of OXD5B7F*) with its analogue OXD6 (at weight ratios of 6:4 and 4:6). We also performed molecular modeling of single-component BPLCs (OXD7* and OXD5B7F*) to analyze the possible parameters affecting their blue phase ranges.
Construction of self-assembled nanostructure-based tetraphenylethylene dipeptides: supramolecular nanobelts as biomimetic hydrogels for cell adhesion and proliferation
(2020-09-07)
Talloj, Satish Kumar
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Mohammed, Mohiuddin
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Lin, Hsin-Chieh
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材料科學與工程學系
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Department of Materials Science and Engineering
Supramolecular fluorescent materials with aggregation-induced emission (AIE) characteristics have promising applications as fluorescent probes for bio and chemosensors. In this study, a versatile low molecular weight tetraphenylethylene dipeptide hydrogelator (TPE-YY) with efficient AIE characteristics was developed, which was able to form hydrogels in a broad pH range from 3.7 to 10.2. The self-assembly of this hydrogel is completely pH-dependent, with significant structural transitions from high to low pH. At a relatively high pH value (10.2), a weak transparent hydrogel with an entangled network of nanofibers was obtained, while upon neutralization (pH 7.2) with dilute HCl, a stable semi-transparent gel with twisted nanobelts was formed. When the pH of the hydrogel was reduced to below 5.7, a turbid viscous gel and precipitation appeared with the thickening of the nanobelts. Surprisingly, the hydrogel resulting from the glucono-delta-lactone triggered gel showed only nanofibers independent of pH. The nature of the hydrogels and the nanostructures at different pH values were thoroughly examined and discussedviaoscillatory rheology, electron microscopy and various spectroscopic techniques {(HNMR)-H-1,D-2-NMR, Fourier transform infrared (FTIR) and Circular dichroism (CD)}. Interestingly, the self-assembled hydrogel exhibited excellent biocompatibility over 95% using hydrogel leachables on two different cell lines, 3A6 (human MSCs) and L929 (mouse fibroblast cells). Moreover, the self-assembled nanobelts formed at neutral pH showed excellent cell adhesion and proliferation of 3A6 cells, whereas the nanofibers showed poor cell adhesion and proliferation. Overall, we demonstrate the importance of chemical design for the formation of self-assembled nanobelts and supramolecular hydrogels at physiological pH with selective cell adhesion and proliferation, presenting a promising applications in tissue engineering and regenerative medicine.
Effect of Peptide Sequences on Supramolecular Interactions of Naphthaleneimide/Tripeptide Conjugates
(2016-08-02)
Yeh, Mei-Yu
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Huang, Ching-Ting
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Lai, Tsung-Sheng
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Chen, Fang-Yi
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Chu, Nien-Tzu
In this study, we reported a significant difference in the supramolecular hydrogelation of newly discovered NI-GFF (NI-Gly-L-Phe-L-Phe) and NI-FFG (NI-L-Phe-L-Phe-Gly) on the basis of their phase diagrams. With a small difference in the peptide chain between NI-GFF and NI-FFG, we observed a significant difference in their self-assembly properties; NI-GFF formed a stable gel at neutral pH, whereas NI-FFG did not, under the same conditions. From spectroscopic and computational studies, intermolecular pi-pi interactions and extended hydrogen bonding interactions might reinforce the intermolecular interactions of NI-GFF, which may facilitate the formation of the self-assembled nanostructures and the hydrogel. In addition, the aggregation-induced emission (AIE)-active NI-GFF reveals relatively good biocompatibility compared with that of NI-FFG for two commonly used cell lines, suggesting that it is a promising candidate for use as a supramolecular material in biomedical applications. Our results highlight the importance of tripeptide sequences in a self-assembling hydrogel system.
Electroactive Organic Dye Incorporating Dipeptides in the Formation of Self-Assembled Nanofibrous Hydrogels
(2014-10-01)
Liu, Yu-Hao
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Hsu, Shu-Min
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Wu, Fang-Yi
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Cheng, Hsun
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Yeh, Mei-Yu
In this study, we examined the self-assembly of four dipeptides conjugated with the electroactive dye naphthalenediimide (NDI). The presence of the NDI group at the N-terminus of Phe-Phe and Phe-Gly promoted the formation of one-dimensional (1-D) nanostructures and three-dimensional (3-D) colored hydrogels under both acidic and physiological conditions. The 1-D nanostructures of these gels were stabilized through intermolecular pi pi interactions of the conjugated systems and extended hydrogen bonding of the dipeptide units.
Enzyme Instructed Self-assembly of Naphthalimide-dipeptide: Spontaneous Transformation from Nanosphere to Nanotubular Structures that Induces Hydrogelation
(1970-01-01)
Chakravarthy, Rajan Deepan
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Mohammed, Mohiuddin
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Lin, Hsin-Chieh
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材料科學與工程學系
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Department of Materials Science and Engineering
Understanding the structure-morphology relationships of self-assembled nanostructures is crucial for developing materials with the desired chemical and biological functions. Here, phosphate-based naphthalimide (NI) derivatives have been developed for the first time to study the enzyme-instructed self-assembly process. Self-assembly of simple amino acid derivativeNI-Ypresulted in non-specific amorphous aggregates in the presence of alkaline phosphatase enzyme. On the other hand,NI-FYpdipeptide forms spherical nanoparticles under aqueous conditions which slowly transformed into partially unzipped nanotubular structures during the enzymatic catalytic process through multiple stages which subsequently resulted in hydrogelation. The self-assembly is driven by the formation of beta-sheet type structures stabilized by offset aromatic stacking of NI core and hydrogen bonding interactions which is confirmed with PXRD, Congo-red staining and molecular mechanical calculations. We propose a mechanism for the self-assembly process based on TEM and spectroscopic data. The nanotubular structures ofNI-FYpprecursor exhibited higher cytotoxicity to human breast cancer cells and human cervical cancer cells when compared to the nanofiber structures of the similar Fmoc-derivative. Overall this study provides a new understanding of the supramolecular self-assembly of small-molecular-weight hydrogelators.
Fluorescent supramolecular hydrogels self-assembled from tetraphenylethene (TPE)/single amino acid conjugates
(2018-01-01)
Chu, Nien-Tzu
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Chakravarthy, Rajan Deepan
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Shih, Nai-Chia
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Lin, Yen-Hsu
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Liu, Yen-Chu
Herein, we report the synthesis of simple TPE/single amino acid conjugates, TPE-Ser and TPE-Asp with side-chains featuring functional groups that may provide an additional hydrogen bonding network for hydrogelation in aqueous medium. TPE-Ser, which has the lowest molecular weight, containing hydroxyl groups undergoes self-assembly into supramolecular hydrogels under physiological pH conditions. TPE-Asp with a carboxylic group side chain undergoes the self-assembly and hydrogelation processes under slightly acidic conditions (pH = 6.0). UV-vis, IR, PL and rheological studies clearly indicate the formation, stability and fluorescence properties of TPE-amino acid hydrogels. TEM micrographs of the hydrogels indicate that the compounds are self-assembled into a nanosheet morphology with random size and shape. Further, in vitro analysis of TPE-Ser and TPE-Asp with 3A6 cells shows that the compounds exhibit unique fluorescence signals in microcellular environments thus making them suitable candidates for bioimaging applications. Overall, these findings highlight the importance of the structure-hydrogelation relationship and provide new insights into the design of single amino-acid-based supramolecular hydrogels.
Functional Supramolecular Polymers: A Fluorescent Microfibrous Network in a Supramolecular Hydrogel for High-Contrast Live Cell-Material Imaging in 3D Environments
(2016-09-21)
Hsu, Shu-Min
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Wu, Fang-Yi
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Cheng, Hsun
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Huang, Yu-Tang
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Hsieh, Yi-Ru
A new bottom-up strategy based on aromatic peptide amphiphile is developed for a high-contrast visualization of 3D live cell-material imaging-something that has been difficult to achieve previously because of the problems associated with the diffraction of light by the nanosized peptide materials and the aggregation-caused quenching of aggregated pi-conjugated fluorophores in the nanostructures. This study reports an example of a novel supramolecular hydrogelator, naphthaleneimide-phenylalanine (NI-Phe), which forms a self-supporting hydrogel displaying a unique microfibrous network and promising aggregation-induced emission characteristics at pH 7.4. The storage modulus of the NI-Phe gel supports the mass of a cell for 3D cell culturing. This work illustrates a new dopant-free supramolecular approach, complementary to well-established doping procedures that should facilitate the development of live cell imaging in 3D scaffolding materials.
Glucosamine-Based Supramolecular Nanotubes for Human Mesenchymal Cell Therapy
(2018-05-02)
Talloj, Satish Kumar
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Cheng, Bill
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Weng, Jen-Po
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Lin, Hsin-Chieh
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材料科學與工程學系
Herein, we demonstrate an example of glucosamine-based supramolecular hydrogels that can be used for human mesenchymal cell therapy. We designed and synthesized a series of amino acid derivatives based on a strategy of capping D-glucosamine moiety at the C-terminus and fluorinated benzyl group at the N-terminus. From a systematic study on chemical structures, we discovered that the glucosamine-based supramolecular hydrogel [pentafluorobenzyl (PFB)-F-Glu] self-assembled with one-dimensional nanotubular structures at physiological pH. The self-assembly of a newly discovered PFB-F-Glu motif is attributed to the synergistic effect of pi-pi stacking and extensive intermolecular hydrogen bonding network in aqueous medium. Notably, PFB-F-Glu nanotubes are proven to be nontoxic to human mesenchymal stem cells (hMSCs) and have been shown to enhance hMSC proliferation while maintaining their pluripotency. Retaining of pluripotency capabilities provides potentially unlimited source of undifferentiated cells for the treatment of future cell therapies. Furthermore, hMSCs cultured on PFB-F-Glu are able to secrete paracrine factors that downregulate profibrotic gene expression in lipopolysaccharide-treated human skin fibroblasts, which demonstrates that PFB-F-Glu nanotubes have the potential to be used for wound healing applications. Overall, this article addresses the importance of chemical design to generate supramolecular biomaterials for stem cell therapy.
Influence of amino acid side chains on the formation of two component self-assembling nanofibrous hydrogels
(2017)
Nelli, Srinivasa Rao
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Lin, Jhong-Hua
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Thi Ngoc Anh Nguyen
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Tseng, Dion Tzu-Huan
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Talloj, Satish Kumar
Herein, we report the synthesis and optimization of an aqueous phase two-component co-assembled nanofibrous hydrogel based on charge-transfer (CT) between pyrenebutyric acid and naphthalene diimide-capped groups. This donor-acceptor CT interaction is a powerful driving force that can induce self-assembly in the aqueous phase even if the molecule contains only a single amino acid. The intermolecular CT interactions for mixed components can also be visualized in the quantum-chemical approach. This two-component supramolecular co-assembly provides a new path for the design of self-assembled nanomaterials.
Influence of amino acid side chains on the formation of two component self-assembling nanofibrous hydrogels
(2017)
Nelli, Srinivasa Rao
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Lin, Jhong-Hua
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Thi Ngoc Anh Nguyen
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Tseng, Dion Tzu-Huan
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Talloj, Satish Kumar
Herein, we report the synthesis and optimization of an aqueous phase two-component co-assembled nanofibrous hydrogel based on charge-transfer (CT) between pyrenebutyric acid and naphthalene diimide-capped groups. This donor-acceptor CT interaction is a powerful driving force that can induce self-assembly in the aqueous phase even if the molecule contains only a single amino acid. The intermolecular CT interactions for mixed components can also be visualized in the quantum-chemical approach. This two-component supramolecular co-assembly provides a new path for the design of self-assembled nanomaterials.
Intramolecular Interactions of a Phenyl/Perfluorophenyl Pair in the Formation of Supramolecular Nanofibers and Hydrogels
(2014-02-10)
Hsu, Shu-Min
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Lin, Yu-Chun
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Chang, Jui-Wen
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Liu, Yu-Hao
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Lin, Hsin-Chieh
A new system for the incorporation of a phenyl/perfluorophenyl pair in the structure of a peptide hydrogelator was developed. The strategy is based on the idea that the integration of an end-capped perfluorophenyl group and a phenylalanine with a phenyl moiety in the side chain forms an intramolecular phenyl/perfluorophenyl pair, which can be used to promote the formation of the supramolecular nanofibers and hydrogels. This work illustrates the importance of structure-hydrogelation relationship and provides new insights into the design of self-assembly nanobiomaterials.
Nanofibrous hydrogels self-assembled from naphthalene diimide (NDI)/amino acid conjugates
(2015-01-01)
Hsu, Ling-Huang
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Hsu, Shu-Min
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Wu, Fang-Yi
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Liu, Yu-Hao
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Nelli, Srinivasa Rao
The combination of a naphthalene diimide (NDI) group and a single amino-acid of serine (Ser) or lysine (Lys) can be used to promote the formation of a supramolecular hydrogel, which indicates the aromatic amino acid is not necessary to be used in the structural design of NDI-capped small molecule hydrogelators. An equimolar ratio of NDI-Ser and NDI-Lys can form a stable hydrogel under neutral conditions and its gel-to-sol transition temperature is higher than 37 degrees C. This work, as the first example of NDI-containing hydrogelators without aromatic rings in the side chains of amino acids, illustrates a new approach to design NDI-capped supramolecular hydrogels.
Peptide Glycosylation Generates Supramolecular Assemblies from Glycopeptides as Biomimetic Scaffolds for Cell Adhesion and Proliferation
(2016-03-23)
Liu, Jie
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Sun, Ziling
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Yuan, Yuqi
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Tian, Xin
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Liu, Xi
Glycopeptide-based hydrogelators with well-defined molecular structures and, varied contents of sugar moieties were prepared via in vitro peptide glycosylation reactions. With systematic glucose modification, these glycopeptide hydrogelators exhibited diverse self-assembling behaviors in water and formed supramolecular hydrogels with enhanced thermostability and biostability, in comparison with their peptide analogue. Moreover, because of high water content and similar structural morphology and composition to extracellular matrixes (ECM) in tissues, these self-assembled hydrogels also exhibited great potential to act as anew biomimetic scaffolds for mammalian cell growth. Therefore, peptide glycosylation proved to be an effective means for peptide modification and generation of novel supramolecular hydrogelators/hydrogels with improved biophysical properties (e.g., high biostability, increased thermostability, and cell adhesion) which could promise potential applications in regenerative medicine.
Remarkable influence of alkyl chain lengths on supramolecular hydrogelation of naphthalene diimide-capped dipeptides
(2015-01-01)
Zhan, Fu-Kai
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Hsu, Shu-Min
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Cheng, Hsun
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Lin, Hsin-Chieh
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材料科學與工程學系
The influence of aliphatic chain lengths on supramolecular hydrogelation of naphthalene diimide-capped dipeptides is described. The dependence of the gelation pH as a function of chain lengths reveals an inverse linear relationship and the gelation pH values cover a broad range from pH 2 to pH 9. In addition, the presence of a n-octyl tail in the hydrogelator could enhance the ability of self-assembly in dilute solution.
Reverse thermo-responsive hydrogels prepared from Pluronic F127 and gelatin composite materials
(2017-01-01)
Yeh, Mei-Yu
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Zhao, Jiong-Yao
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Hsieh, Yi-Ru
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Lin, Jhong-Hua
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Chen, Fang-Yi
Gelatin is an important hydrocolloid which has widespread applications in the pharmaceutical industry and biomedical science. However, despite its significance, clinical applications of gelatin are largely limited because of its gel-to-solution transition around human body temperature. In this work, we developed a series of F127-gelatin composite hydrogels with reverse thermo-responsive properties. The stiffness of F127-gelatin hydrogels can be adjusted by varying the types and contents of gelatin (type A, GA and type B, GB). The results of rheological data showed that F127-GA gels have higher gel strengths than those of F127-GB, which might be due to different isoelectric points between GA and GB. In addition, F127-gelatin gels showed significant cell viability and biocompatibility for human mesenchymal stem cells, indicating that these discovered hydrogels can serve as potential biomaterials and implantable scaffolds for applications in tissue engineering and regenerative medicine.