Browsing by Author "Hung, Shih-Chieh"

Now showing 1 - 5 of 5

A novel nanostructured supramolecular hydrogel self-assembled from tetraphenylethylene-capped dipeptides
(2016)
Yeh, Mei-Yu
;
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.
Effect of Peptide Sequences on Supramolecular Interactions of Naphthaleneimide/Tripeptide Conjugates
(2016-08-02)
Yeh, Mei-Yu
;
Huang, Ching-Ting
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Lai, Tsung-Sheng
;
Chen, Fang-Yi
;
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.
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
;
Cheng, Hsun
;
Huang, Yu-Tang
;
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.
Reverse thermo-responsive hydrogels prepared from Pluronic F127 and gelatin composite materials
(2017-01-01)
Yeh, Mei-Yu
;
Zhao, Jiong-Yao
;
Hsieh, Yi-Ru
;
Lin, Jhong-Hua
;
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.
Self-Assembled Peptide-Based Hydrogels as Scaffolds for Proliferation and Multi-Differentiation of Mesenchymal Stem Cells
(2017-04-01)
Wang, Yung-Li
;
Lin, Shih-Pei
;
Nelli, Srinivasa Rao
;
Zhan, Fu-Kai
;
Cheng, Hsun
Fluorenyl-9-methoxycarbonyl (Fmoc)-diphenylalanine (Fmoc-FF) and Fmoc-arginine-glycine-aspartate (Fmoc-RGD) peptides self-assemble to form a 3D network of supramolecular hydrogel (Fmoc-FF/Fmoc-RGD), which provides a nanofibrous network that uniquely presents bioactive ligands at the fiber surface for cell attachment. In the present study, mesenchymal stem cells (MSCs) in Fmoc-FF/Fmoc-RGD hydrogel increase in proliferation and survival compared to those in Fmoc-FF/Fmoc-RGE hydrogel. Moreover, MSCs encapsulated in Fmoc-FF/Fmoc-RGD hydrogel and induced in each defined induction medium undergo in vitro osteogenic, adipogenic, and chondrogenic differentiation. For in vivo differentiation, MSCs encapsulated in hydrogel are induced in each defined medium for one week, followed by injection into gelatin sponges and transplantation into immunodeficient mice for four weeks. MSCs in Fmoc-FF/Fmoc-RGD hydrogel increase in differentiation into osteogenic, adipogenic, and chondrogenic differentiation, compared to those in FmocFF/Fmoc-RGE hydrogel. This study concludes that nanofibers formed by the self-assembly of Fmoc-FF and Fmoc-RGD are suitable for the attachment, proliferation, and multi-differentiation of MSCs, and can be applied in musculoskeletal tissue engineering.