Browsing by Author "Dong, Chen-Yuan"

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Multiphoton and confocal imaging of precisely cut oral cancer tumor sections for personalized medicine
(2020-01-01)
Chiang, Shu-Jen
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Tseng, Po-Hang
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Huang, Hsu-Cheng
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Chen, Shi-Chi
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Chen, Shean-Jen
Traditionally, testing of therapeutic agents uses two-dimensional cell cultures which does not recapitulate the complex, three-dimensional architecture of tissues. In the case of cancer drug development, immunotherapy (IT) emerged as an effective treatment strategy for the patients who respond to therapy. However, the overall patient response rate for immunotherapy is around 25%. Therefore, there is a need to develop more effective drug testing platform for cancer patients. In this work, we develop three-dimensional tissue cultures of human oral cancer slices. We observed the growth dynamics of the tissue sections for up to 28 days. Their viability over extended periods suggest that the tissue sections may be used for personalized drug testing.
Multiphoton imaging of dye penetration dynamics in tissue sections
(2020-01-01)
Tseng, Po-Hang
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Chiang, Shu-Jen
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Chen, Shean-Jen
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Dong, Chen-Yuan
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光電學院
Rapid and in-depth labeling biological tissue samples is invaluable for studying tissue organization in three-dimensions. The current strategy in finding optimal labeling parameters for dye molecules through tissues often requires trial and error testing. Difficulty in establishing a standard approach is due to lack of information on the diffusion parameters of dye through tissues. In this study, we investigate the temporal progression of dye penetration in different tissue types. By the combination of multiphoton imaging of labeled tissues and application of the theoretical model of diffusion with well-defined boundary conditions, we aim to arrive at systematic parameters for optimizing dye penetration. Determination of the effective diffusion coefficient of the dyes used will then be useful for further application.
Natural zeolite for adsorbing and release of functional materials
(2018-09-01)
Hovhannisyan, Vladimir Ararat
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Dong, Chen-Yuan
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Lai, Feng-Jie
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Chang, Nan-Shan
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Chen, Shean-Jen
Using multiphoton microscopy (MPM), we demonstrated that effective inducing of two-photon excited luminescence and second-harmonic generation signals in nano/microparticles of clinoptilolite type of zeolite (CZ) by femtosecond near-infrared laser excitation can be successfully utilized in multiphoton imaging of the drug adsorption processes. Adsorption of photodynamic active dyes (hypericin, chlorin e(6), methylene blue, and fluorescein) and their release from CZ pores in the presence of biomolecules, such as collagen from bovine Achilles tendon, albumin, and hemoglobin, were investigated by absorption and fluorescence spectrometry. To quantify the experimental results on hypericin release, here we use a kinetic curves fitting approach and calculate hypericin release rates in different environments. This approach allows to compare various mathematical models and uses more parameters to better characterize drug release profiles. In addition, magnetic CZ particles were fabricated and proposed as a promising material for drug delivery and controlled release in biological systems. Optical spectrometry and MPM are effective approaches that may reveal potential of natural zeolites in controlled drug delivery and biomedical imaging. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Photodynamic dye adsorption and release performance of natural zeolite
(2017-03-31)
Hovhannisyan, Vladimir
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Dong, Chen-Yuan
;
Chen, Shean-Jen
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光電學院
;
College of Photonics
Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and methylene blue. Furthermore, the release of hypericin from CZ pores in the presence of biomolecules is shown, and CZ can be considered as an effective material for drug delivery and controlled release in biological systems. The results may open new perspectives in application of CZ in biomedical imaging, and introducing of the optical approaches into the clinical environment.