Mechanical tissue optical clearing technique increases imaging resolution and contrast through Ex vivo porcine skin

Our previous studies demonstrated the ultrasound-induced skin optical clearing enhancement with topical application of optical clearing agents on in vitro porcine skin and in vivohuman skin. The objective of this study was to investigate the possible mechanisms of the enhanced skin optical clearing by ultrasound medications. Optical clearing effects of ex vivo guinea pig abdomen skin topically applied with 60% glycerol or the combination of 60% glycerol and ultrasound were studied by optical coherence tomography (OCT). Microstructure of skin surface was examined by scanning electron microscopy (SEM). Ultrasound with a frequency of 1 MHz and a power of 0.75 W over a 3-cm probe was simultaneously applied with glycerol solution for 15 min. The combination of 60% glycerol and ultrasound results in a 19% increase in OCT 1/e light penetration depth after 30 min, which is much better than 60% glycerol alone. SEM images demonstrated that changes in skin microstructure due to the tight order of the lipid bilayers in the stratum corneum disrupted and the separation of keratinocytes by the application of ultrasound contribute to the ultrasound-enhanced intact skin optical clearing effects.

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Mechanical tissue optical clearing devices: evaluation of enhanced light penetration in skin using optical coherence tomography

Journal of Biomedical Optics ◽

10.1117/1.3268441 ◽

2009 ◽

Vol 14 (6) ◽

pp. 064019 ◽

Cited By ~ 31

Author(s):

Christopher Drew ◽

Thomas E. Milner ◽

Christopher G. Rylander

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence ◽

Light Penetration ◽

Optical Clearing ◽

Tissue Optical Clearing ◽

Mechanical Tissue

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Tissue Optical Clearing Devices: Effects of Water Content on the Hyperelastic Mechanical Properties of Ex Vivo Porcine Skin

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19478 ◽

2010 ◽

Author(s):

William Vogt ◽

Alondra Izquierdo-Roman ◽

Christopher G. Rylander

Keyword(s):

Near Infrared ◽

Light Transmission ◽

Ex Vivo ◽

Imaging Techniques ◽

Complex Structure ◽

Heterogeneous Material ◽

Index Of Refraction ◽

Water Displacement ◽

Optical Clearing ◽

Tissue Optical Clearing

Skin is a highly anisotropic and heterogeneous material composed of water, proteins, and various cells arranged in several different layers. Because of this complex structure, there is a large mismatch in index of refraction between the tissue constituents, creating a highly scattering medium for near-infrared and visible light. “Tissue optical clearing” methods can improve light transmission through tissues, potentially improving optical imaging techniques and photoirradiative treatments [1]. Dehydration has been suggested as a possible mechanism of optical clearing [2], and previous work has demonstrated mechanical loading as a method of creating reversible localized water displacement in skin using novel tissue optical clearing devices (TOCDs) [3–4]. These TOCDs were hypothesized to increase light transmission by displacing water locally in the tissue, causing local dehydration. A model of the mechanical behavior of skin will enable improvement of current TOCDs that utilize local mechanical compression.

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QUANTITATIVE CONTROL OF OPTICAL CLEARING EFFECTS STUDIED WITH TISSUE-LIKE PHANTOM

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545810001003 ◽

2010 ◽

Vol 03 (03) ◽

pp. 195-202 ◽

Cited By ~ 2

Author(s):

JINGYING JIANG ◽

WEI CHEN ◽

QILIANG GONG ◽

KEXIN XU

Keyword(s):

Optical Properties ◽

Biological Tissues ◽

Porcine Skin ◽

Tissue Samples ◽

Optical Clearing ◽

Tissue Optical Properties ◽

Application Potential ◽

The Difference ◽

Tissue Optical Clearing

Tissue optical clearing by use of optical clearing agents (OCAs) has been proven to have potential to reduce the highly scattering effect of biological tissues in optical techniques. However, the difference in tissue samples could lead to unreliable results, making it difficult to quantitatively control the dose of OCAs during the course of tissue optical clearing. In this work, in order to study the effects of optical clearing, we customized tissue-like phantoms with optical properties of some biological tissue. Diffuse reflectance and total transmittance of tissue-like phantoms with different OCAs (DMSO or glycerol) and porcine skin tissues were measured. Then optical property parameters were calculated by inverse adding-doubling (IAD) algorithm. Results showed that OCAs could lead to a reduction in scattering of tissue-like phantoms as it did to porcine skin tissue in vitro. Furthermore, a series of relational expressions could be fit to quantitatively describe the relationship between the doses of OCAs and the reduction of scattering effects. Therefore, proper tissue-like phantom could facilitate optical clearing to be used in quantitative control of tissue optical properties, and further promote the application potential of optical clearing to light-based noninvasive diagnostic and therapeutic techniques.

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ALTERATIONS IN AUTOFLUORESCENCE SIGNAL FROM RAT SKIN EX VIVO UNDER OPTICAL IMMERSION CLEARING

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545810001027 ◽

2010 ◽

Vol 03 (03) ◽

pp. 147-152 ◽

Cited By ~ 7

Author(s):

E. V. MIGACHEVA ◽

A. B. PRAVDIN ◽

V. V. TUCHIN

Keyword(s):

Fluorescence Spectroscopy ◽

Ex Vivo ◽

Rat Skin ◽

Optical Clearing ◽

Spectral Curves ◽

The Common ◽

First Time ◽

Tissue Optical Clearing ◽

Optical Immersion

For the first time, the changes in autofluorescence spectra of ex vivo rat skin have been experimentally investigated using the combination of fluorescence spectroscopy and optical immersion clearing. The glucose, glycerol and propylene glycol solutions were used as clearing agents. The optical clearing was performed from the dermal side of skin imitating the in vivo injection of clearing agent under the dermal layers. In this contribution, the common properties of autofluorescence variation during optical immersion clearing were determined. The tendency of autofluorescence signal to decrease with reduction of scattering in tissue was noticed and discussed in detail. However, the differences in the shape of spectral curves under application of different clearing agents showed that optical clearing affects the autofluorescence properties of tissue differently depending on the type of clearing liquid. The results obtained are useful for the understanding of tissue optical clearing mechanisms and for improving techniques such as fluorescence spectroscopy.

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Ex-vivo confocal Raman microspectroscopy of porcine skin with 633/785-NM laser excitation and optical clearing with glycerol/water/DMSO solution

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545821420037 ◽

2021 ◽

pp. 2142003

Author(s):

Ali Jaafar ◽

Malik H. Mahmood ◽

Roman Holomb ◽

László Himics ◽

Tamás Váczi ◽

...

Keyword(s):

Ex Vivo ◽

Raman Microspectroscopy ◽

Penetration Enhancer ◽

Type I ◽

Distilled Water ◽

Porcine Skin ◽

Glycerol Water ◽

Optical Clearing ◽

Confocal Raman Microspectroscopy ◽

Confocal Raman

Confocal Raman microspectroscopy (CRM) with 633- and 785-nm excitation wavelengths combined with optical clearing (OC) technique was used for ex-vivo study of porcine skin in the Raman fingerprint region. The optical clearing has been performed on the skin samples by applying a mixture of glycerol and distilled water and a mixture of glycerol, distilled water and chemical penetration enhancer dimethyl sulfoxide (DMSO) during 30[Formula: see text]min and 60[Formula: see text]min of treatment. It was shown that the combined use of the optical clearing technique and CRM at 633[Formula: see text]nm allowed one to preserve the high probing depth, signal-to-noise ratio and spectral resolution simultaneously. Comparing the effect of different optical clearing agents on porcine skin showed that an optical clearing agent containing chemical penetration enhancer provides higher optical clearing efficiency. Also, an increase in treatment time allows to improve the optical clearing efficiency of both optical clearing agents. As a result of optical clearing, the detection of the amide-III spectral region indicating well-distinguishable structural differences between the type-I and type-IV collagens has been improved.

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