• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.397-397
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• 2010

Bone is considered as hierarchically organized biocomposites of organic (collagen) and inorganic (hydroxyapatite) materials. The precise structural dependence between hydroxyapatite (HAp, $Ca_{10}(PO_4)_6(OH)_2)$ crystals and collagen fibril is critical to unique characteristics of bone. To meet those conditions and obtain optimal properties, it is essential to understand and control the initial growth mechanisms of hydroxyapatite at the molecular level, such as other nano-structured materials. In this study, collagen fibrils were prepared by adsorbing native type I collagen molecules onto hydrophobic surface. Hydrophobicity was introduced on the Si wafer surface by using PECVD (plasma enhanced chemical vapor deposition) method and cyclohexane as a precursor. Biomimetic nucleation and growth of HAp on the self-assembled collagen nanofibrils were occurred through incubation of the sample in SBF (simulated body fluid). Chemical and morphological evolution of HAp nanocrystals was investigated by surface-sensitive analytical techniques such as ToF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) and AFM (Atomic Force Microscopy) in the early growth stages (< 24 hrs). The very initial stages (< 12 hrs) of mineralization could be clearly demonstrated by ToF-SIMS chemical mapping of surface. In addition to ToF-SIMS and AFM measurement, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction analysis were conducted to characterize the HAp layer in the late stages. This study is of great importance in the growth of real bone-like materials with a structure analogous to that of natural bones and the development of biomimetic nanomaterials.

• Applied Microscopy
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• v.40 no.3
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• pp.155-162
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• 2010

Bone is a hierarchically structured composite material which has been well studied by the materials engineering community because of its unique structure and mechanical properties. Bone is a laminated organic-inorganic composite composed of primarily hydroxyapatite, collagen and water. The main mineral that gives bone's hardness is calcium phosphate, which is also known as hydroxyapatite. Light microscopy (LM) and transmission electron microscopy (TEM) were used to study the structure of femurs from chicken and rabbit. The elemental analysis was used to search variation in the distribution of calcium, potassium and oxygen in the femur. Current investigation focused on two structural scales: micro scale (arrangement of compact bone) and nano scale (collagen fibril and apatite crystals). At micro scale, distinct difference was found in microstructures of chicken femur and rabbit femur. At nano scale, we analyzed the shape and size of apatite crystals and the arrangement of collagen fibril. Consequently, femurs of chicken and rabbit had very similar chemical property and structures at nano scale despite of their different species.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.265-284
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• 2007

Introduction : There are three major forms of Epidermolysis Bullosa(EB) - EB Simplex(EBS), Junctional EB(JEB) and Dystrophic EB(DEB). DEB is divided into two groups that Dominant DEB(DDEB) and Recessive DEB(RDEB). RDEB has two types that Hallopeau-Siemens(generalized type) and mitis(localized type). Objects : This study was carried out to observe the progress of Recessive Dystrophic Epidermolysis Bullosa-mitis(RDEB-mitis) disease and find effective remedy. Methods: Both diagnosis and treatment were divided into three groups voluntarily. l. diagnosis - dermatic symptoms, mucosal symptoms, general symptoms 2. treatment - herbal medications, moxibustion, medicines used extemally(外用藥) Results : After treating 9 months, the condition of the patient grew better and the grades of severity of ROEB-mitis disease were lower at each diagnosis item. Conclusions : As above results, oriental medical treatments were very effective for this disease. But more case studies are necessary for establishing more effective diagnosis and treatment methods.

• Journal of the Korean Chemical Society
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• v.60 no.3
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• pp.187-193
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• 2016

In this study, preparation of positively and negatively charged carbon nanotube (CNT)-collagen (CG) hydrogels with pH sensitive characteristic was reported. The positive and negative characteristics of the prepared hydrogels were created by introduction of positively functionalized CNT-NH₂ and negatively functionalized CNT-COOH, respectively, into the collagen hydrogel. The surface charge of CNTs (CNT-NH₂ and CNT-COOH), CG and CNTs/CG hydrogels was measured by Zetasizer. The swelling ratios of CNT-NH₂/CG and CNT-COOH/CG hydrogels in aqueous solution were checked by measuring of weight changes of the hydrogels in the range of pH 2~10. In detail, the positively charged CNT-NH₂/CG hydrogel swelled up to 5% at pH 4 in comparison to the weight at pH 7, while the negatively charged CNT-COOH/CG hydrogel swelled up to 10% at pH 10. The prepared CNT-NH₂/CG and CNT-COOH/CG hydrogels will be very useful as pH sensitive oral drug-delivering systems for gastrointestine (pH ~2) and small intestine (pH ~9), respectively.

• The Korea Journal of Herbology
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• v.32 no.5
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• pp.1-6
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• 2017

Objectives : Corni Fructus (CF) is traditional herbal medicine used on polyuria, low back pain, and tinnitus. This study aimed to evaluate inhibits skin wrinkle formation effect of CF. Methods : To evaluate the produce inhibition effect of CF, SD-rats were distributed into four groups; normal rats (Nor), AGEs (advenced glycation end product)-induced rats (Con), AGEs-induced rats treated with 100mg/kg CF (CF). To induce AGEs, streptozotocin (50mg/kg) was administered intraperitoneally and after 3 days oral administrated 100mM methyl glyoxal for 3 weeks. Results : The oral administration of CF suppressed the reactive oxygen specis (ROS) in serum. The AGEs in skin tissues was significantly reduced through treatment of CF. Furthermore, the expressions of AGEs related proteins such as polyclonal anti-$N^e$-(carboxymethyl)lysine (CML), anti-$N^e$-(carboxyethyl)lysine (CEL), AGE receptors (RAGE) were decreased in CF treated group compared with the control group in skin tissues. Inflammation-related proteins such as Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) reduced in CF treatment group than control group. AGE-induced rats exhibited that the significant decreased collagen however, CF treatment (100mg/kg of body weight) up regulated collagen by improved the expression levels of skin fibril-related genes such as Matrix metalloproteinase (MMP-1). Conclusion : Taken together, our study suggests that CF regulates ROS to prevent accumulation of AGEs and inhibits skin wrinkles. Our finding indicate that CF may be an effective agent for inhibits AGEs formation, and improved skin wrinkle.

• Applied Microscopy
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• v.3 no.1
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• pp.29-38
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• 1973

Introduction. The human cutaneous scars manifest themselves many ways in different types according to the factors such as the age, sex, race of the patient as well as the location,. kind and heal ing process of the wound. Among the scars it is quiet difficult to verify the clinical course of the hypertrophic or keloidal scars from the true keloids. However, clinical observations indicate that stress, either mechanical or in the forms of chronic infections, can induce a functional change in the fibroblasts causing an excessive production of collagenous matrix. In this study, we preliminary attempt to justify any difference of the cellular structure between keloids and hypertrophic scars by using electron microscope. Material and Methods. A total of 23 cases: 2 scars, 2 hypertrophic scars and 19 keloids are examined. Immediately, the biopsy tissue was fixed in 10% neutral formalin and 4% glutaraldehyde solution in phosphate buffer for 4 hours, post fixed in 1 % osmium tetraoxide for two hours, dehydrated with graded alcohol, and embedded in Epon 812. Thick sections were stained with hematoxylin eosin, periodic acid-Schiff(PAS) and Van Gieson stain. Thin sections were cut and uranyle acetate, lead citratestain and examined with the electron microscope. Result. The morphologic features of keloid showed thick, homogenously eosinophilic bands of collagen and numberous large active fibroblasts. The hypertrophic scar and soft scar are more cellular than keloid and composed thinner collagenous fiber. For this paper in the etiology of keloids can not as be defined, but and interesting keloidal tissue fibroblast showed irregular nucleus with irregular shape dense bodies and fibril materials contained in to the cytoplasm.

• BMB Reports
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• v.57 no.5
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• pp.232-237
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• 2024

This study investigated how adipose tissue-derived mesenchymal stem cells (AT-MSCs) respond to chondrogenic induction using droplet-based single-cell RNA sequencing (scRNA-seq). We analyzed 37,219 high-quality transcripts from control cells and cells induced for 1 week (1W) and 2 weeks (2W). Four distinct cell clusters (0-3), undetectable by bulk analysis, exhibited varying proportions. Cluster 1 dominated in control and 1W cells, whereas clusters (3, 2, and 0) exclusively dominated in control, 1W, and 2W cells, respectively. Furthermore, heterogeneous chondrogenic markers expression within clusters emerged. Gene ontology (GO) enrichment analysis of differentially expressed genes unveiled cluster-specific variations in key biological processes (BP): (1) Cluster 1 exhibited up-regulation of GO-BP terms related to ribosome biogenesis and translational control, crucial for maintaining stem cell properties and homeostasis; (2) Additionally, cluster 1 showed up-regulation of GO-BP terms associated with mitochondrial oxidative metabolism; (3) Cluster 3 displayed up-regulation of GO-BP terms related to cell proliferation; (4) Clusters 0 and 2 demonstrated similar up-regulation of GO-BP terms linked to collagen fibril organization and supramolecular fiber organization. However, only cluster 0 showed a significant decrease in GO-BP terms related to ribosome production, implying a potential correlation between ribosome regulation and the differentiation stages of AT-MSCs. Overall, our findings highlight heterogeneous cell clusters with varying balances between proliferation and differentiation before, and after, chondrogenic stimulation. This provides enhanced insights into the single-cell dynamics of AT-MSCs during chondrogenic differentiation.