Browsing by Author "Chang, Nan-Shan"

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Fast and improved bioimaging via temporal focusing multiphoton excitation microscopy with binary digital-micromirror-device holography
(2018-11-01)
Sie, Yong Da
;
Chang, Chia-Yuan
;
Lin, Chun-Yu
;
Chang, Nan-Shan
;
Campagnola, Paul J.
Conventional temporal focusing-based multiphoton excitation microscopy (TFMPEM) can offer wide-field optical sectioning with an axial excitation confinement of a few microns. To improve the axial confinement of TFMPEM, a binary computer-generated Fourier hologram (CGFH) via a digital-micromirror-device (DMD) was implemented to intrinsically improve the axial confinement by filling the back-focal aperture of the objective lens. Experimental results show that the excitation focal volume can be condensed and the axial confinement improved about 24% according to the DMD holography. In addition, pseudouniform MPE can be achieved using two complementary CGFHs with rapid pulse-width modulation switching via the DMD. Furthermore, bioimaging of CV-1 in origin with SV40 genes-7 cells demonstrates that the TFMPEM with binary DMD holography can improve image quality by enhancing axial excitation confinement and rejecting out-of-focus excitation. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Natural zeolite for adsorbing and release of functional materials
(2018-09-01)
Hovhannisyan, Vladimir Ararat
;
Dong, Chen-Yuan
;
Lai, Feng-Jie
;
Chang, Nan-Shan
;
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)