근적외선과 PLSR/SVR을 이용한 비알콜성 지방간질환 진단 (Nonalcoholic fatty liver disease )

근적외선 흡수를 이용하여 마우스 별로 지방에 포함된 지방의 양을 측정하였는데, 측정시 partial least square regression 및 support vector regression을 사용하였음

SWIR을 이용하여 쉽게 진단이 가능한 분야

심방세동의 RF세동시 발생하는 병변의 lesion의 광학적 진단

근적외선 파장영역에서 adipose tissue를 검출하는 광학적 신호 영역을 추출함. (910-960 nm)

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자체형광(생체형광)을 이용한 lesion의 광학적 진단

조직 구조에 따른 형광의 변이 및 이를 이용한 lesion의 크기 및 두께 측정

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종양조직의 특성

  1. Acidity (low pH)

  2. Higher levels of reactive oxygen species (ROS)

3. Overexpressed enzymes: MMPs, HAase

4. Overexpressed glutathione (GSH)

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상피세포의 Autofluorescence

305 - 473 nm까지의 다양한 종류의 레이저를 조사해서 얻은 상피 및 케라틴 류의 autofluorescence 측정

The keratin signal created interference in the assessment of the endogenous fluorescence signals NADH/FAD fluorescence in epithelium and collagen fluorescence in stroma associated with the development of epithelial precancer.

The autofluorescence of columnar epithelium was found to be dominated by NADH and FAD signals....

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Articles from J. Biophoton.

Raman spectroscopy investigation of biochemical changes in tumor spheroids with aging and after treatment with staurosporine

There has been increasing use of in vitro cell culture models that more realistically replicate the three‐dimensional (3D) environment found in vivo. Multicellular tumor spheroids (MTS) using cell lines or patient‐derived organoids have become an important in vitro drug development tool, where cells are grown in a 3D “sphere” that exhibits many of the characteristics found in vivo. Significantly, MTS develop gradients in nutrients and oxygen, commonly found in tumors that contribute to therapy resistance. While MTS show promise as a more realistic in vitro culture model, there is a massive need to improve imaging technologies for assessing biochemical characteristics and drug response in such models to maximize their translation into useful applications such as high throughput screening (HTS). In this study, we investigate the potential for Raman spectroscopy to unveil biochemical information in MTS and have investigated how spheroid age influences drug response, shedding light on increased therapy resistance in developing tumors. The wealth of molecular level information delivered by Raman spectroscopy in a noninvasive manner, could aid translation of these 3D models into HTS applications.

Simultaneous photoreduction and Raman spectroscopy of red blood cells to investigate the effects of organophosphate exposure

Simultaneous photoreduction and Raman spectroscopy with 532 nm laser has been used to study the effects of organophosphate (chlorpyrifos [CPF]) exposure on human red blood cells (RBCs). Since in RBCs, auto‐oxidation causes oxidative stress, which, in turn, is balanced by the cellular detoxicants, any possible negative effect of CPF on this balance should results in an increased level of damaged (permanently oxygenated) hemoglobin. Therefore, when 532 nm laser, at a suitable power, was applied to photoreduce the cells, only common oxygenated form of hemoglobin got photoreduced leaving the permanently oxygenated hemoglobin detectable in the Raman spectra simultaneously excited by the same laser. Using the technique effects of CPF to build up oxidative stress on RBCs could be detected at concentrations as low as 10 ppb from a comparison of relative strengths of different Raman bands. Experiments performed using simultaneously exposing the cells, along with CPF, to H2O2 (oxidative agent) and/or 3‐Aminotriazole (inhibitor of anti‐oxidant catalase), suggested role of CPF to suppress the cellular anti‐oxidant mechanism. Since the high level of damaged hemoglobin produced by the action of CPF (at concentrations >100 ppm) is expected to cause membrane damage, atomic force microscopy (AFM) was used to identify such damages.Upper panel: Raman spectra of normal, photoreduced CPF exposed and unexposed RBCs. Lower panel: The weak Fe‐O2 Raman band for CPF exposed cells shown on the left. The AFM images of unexposed and exposed cells are shown on the right. Scale bar, 2.5 μm.