Browsing by Author "Lai, Feng-Jie"

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Natural zeolite for adsorbing and release of functional materials
(2018-09-01)
Hovhannisyan, Vladimir Ararat
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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)
Rapid volumetric multiphoton imaging with the combination of an ultrasound lens and a resonant mirror
(2018-01-01)
Hsu, Chia-Wei
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Chiang, Tsung-Yen
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Lai, Feng-Jie
;
Chen, Shean-Jen
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光電學院
The combination of a tunable acoustic gradient (TAG) lens and a resonant mirror were integrated into a multiphoton excited (MPE) microscope that is rapidly and precisely controlled by an embedded field programmable gate array (FPGA) to acquire images at high frame rate.
Volumetric bioimaging based on light field microscopy with temporal focusing illumination
(2018-01-01)
Hsu, Feng-Chun
;
Sie, Yong Da
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Lai, Feng-Jie
;
Chen, Shean-Jen
;
光電學院
Light field technique at a single shot can get the whole volume image of observed sample. Therefore, the original frame rate of the optical system can be taken as the volumetric image rate. For dynamically imaging whole micron-scale biosample, a light field microscope with temporal focusing illumination has been developed. In the light field microscope, the f-number of the microlens array (MLA) is adopted to match that of the objective; hence, the subimages via adjacent lenslets do not overlay each other. A three-dimensional (3D) deconvolution algorithm is utilized to deblur the out-of-focusing part. Conventional light field microscopy (LFM) illuminates whole volume sample even non interesting parts; nevertheless, whole volume excitation causes even more damage on bio-sample and also increase the background noise from the out of range. Therefore, temporal focusing is integrated into the light field microscope for selecting the illumination volume. Herein, a slit on the back focal plane of the objective is utilized to control the axial excitation confinement for selecting the illumination volume. As a result, the developed light field microscope with the temporal focusing multiphoton illumination (TFMPI) can reconstruct 3D images within the selected volume, and the lateral resolution approaches to the theoretical value. Furthermore, the 3D Brownian motion of two-micron fluorescent beads is observed as the criterion of dynamic sample. With superior signal-to-noise ratio and less damage to tissue, the microscope is potential to provide volumetric imaging for vivo sample.