Onseok Lee

Influence of surface charge of gold nanorods on skin penetration

The skin plays an important role as a protective barrier against toxic environments and also is a route of drug administration. In spite of evidence for and interest in the skin penetration of nanoparticles, no study has examined the effect of nanoparticle surface charge on percutaneous absorption. In this study, we investigated the effect of surface charges of gold nanorods (GNs) on skin penetration.

A study of a method for distribution analysis of skin color

Background/aims: The objective and quantitative assessment of the skin is important in medical and cosmeceutical research. Assessment of color is an important element for analyzing the surface of the skin, which is usually determined subjectively by a doctor or using color analysis devices. These devices, however, cannot provide correct color information because color is construed from the mean value of the observation region, and analysis of color distribution is impossible. The purpose of this paper is to develop an objective analysis method to permit skin color measurement of each pixel unit of an image and analyze the distribution of skin surface color.

Effect of pedunculagin investigated by non‐invasive evaluation on atopic‐like dermatitis in NC/Nga mice

Background/purpose: Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disorder that is becoming increasingly prevalent. Experimental animal models have been an indispensable tool for studying its pathological mechanisms and for in vivo testing of novel therapeutic approaches. AD‐like lesions can be induced experimentally in NC/Nga mice. Pedunculagin, an ellagitannin purified from the Manchurian alder, Alnus hirsuta var. microphylla, Betulaceae, is a novel immunomodulator. To evaluate the effect of pedunculagin for AD‐like lesions in NC/Nga mice, using clinical and non‐invasive methods.

Prototype tactile feedback system for examination by skin touch

Diagnosis of conditions such as psoriasis and atopic dermatitis, in the case of induration, involves palpating the infected area via hands and then selecting a ratings score. However, the score is determined based on the testers experience and standards, making it subjective. To provide tactile feedback on the skin, we developed a prototype tactile feedback system to simulate skin wrinkles with PHANToM OMNI.

Phase‐contrast hard X‐ray microscopy using synchrotron radiation for the diagnosis of onychomycosis

Onychomycosis, or fungal infection of the nail, is a disease seen frequently in clinical settings. However, the rates of positive identification using potassium hydroxide preparations or fungal cultures are relatively low. Precise diagnosis is possible via histopathologic examination to monitor the existence of fungus and performance of a fungal culture for confirmation. Phase‐contrast hard X‐ray microscopy using synchrotron radiation provides 70‐nm spatial resolution and enables imaging of minute internal cellular structures. This study confirms the feasibility of diagnosing onychomycosis using a phase‐contrast hard X‐ray microscope developed at 1B2 beam line using a Pohang light source. Microsc. Res. Tech. 73:1110–1114, 2010.

In vivo assessment of the effect of taxifolin glycoside on atopic dermatitis-like skin lesions using biomedical tools in NC/Nga mice

Noninvasive methods of assessment are widely used in clinical trials. However, such methods have not been established in atopic dermatitis (AD), which is a chronic inflammatory skin disease.

Improved quantitative evaluation of atopic dermatitis by camera calibration and rectification of a stereo image.

Background/Purpose: The aim of this study was to establish a scientific assessment method to evaluate the severity of atopic dermatitis (AD) by calibrating part of a previously described stereo‐image optical topometer (SOT).

Quantitative color assessment of dermoscopy images using perceptible color regions.

Dermoscopy is a non‐invasive in vivo skin imaging technique that assists dermatologists in diagnosing melanoma. However, the use of dermoscopy for diagnosis requires extensive training since this approach often provides extremely complex and subjective information. The presence of an imperceptible color difference in dermoscopy images is one of the serious problems associated with the use of this technique. This imperceptible color difference leads to inaccurate lesion extraction at the borders and hinders the assessment of lesion features. Therefore, objective and quantitative assessment based on perceptible color differences is important for the diagnosis of melanoma using dermoscopy.

Non-invasive assessment of cutaneous wound healing using fluorescent imaging

Optical imaging is a very important technique in the biomedical sciences. The purpose of this study was to develop an in vivo optical system for fluorescent imaging and molecular imaging applications using quantum dots (QDs).

Efficacy of oregonin investigated by non‐invasive evaluation in a B16 mouse melanoma model

Oregonin has been reported to act as a mediator of antibiosis, a liver‐protective agent, an antioxidant, an anti‐inflammatory agent, and to prevent cancer outbreaks. B16 melanoma cells were separated with trypsin‐ethylenediaminetetraacetic acid, resuspended in 50 μl of phosphate‐buffered saline and transplanted into the backs of 6‐ to 8‐week‐old male Balb/c nude mice through subcutaneous injection. Treatment doses of oregonin were administered three times weekly, for 30 days from the 11th day after transplantation of the melanoma cells, in each group. The study consisted of a control group, a dacarbazine group, an oregonin group and a dacarbazine + oregonin group. Measurements were taken before treatment and on the 5th, 7th, 10th and 15th days after treatment for each group. Based on survival rates after transplantation, the control group showed less than 50% survival after 20 days, while the treatment groups showed at least 50% survival up to the 41st day.