• Title/Summary/Keyword: Biomedical materials

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Development of New Materials of Ginseng by Nanoparticles

  • Yang, Deok Chun;Mathiyalagan, Ramya;Yang, Dong Uk;Perez, Zuly Elizabeth Jimenez;Hurh, Joon;Ahn, Jong Chan
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.04a
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    • pp.3-3
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    • 2018
  • For centuries, Panax ginseng Meyer (Korean ginseng) has been widely used as a medicinal herb in Korea, China, and Japan. Ginsenosides are a class of triterpene saponins and recognized as the bioactive components in Korean ginseng. Ginsenosides, which can be classified broadly as protopanaxadiols (PPD), protopanaxatriols (PPT), and oleanolic acids, have been shown to flaunt a vast array of pharmacological activities such as immune-modulatory, anti-inflammatory, anti-tumor, anti-diabetic, and antioxidant effects. In recent years, a number of ginseng and ginsenoside researches have increasingly gained wide attention owing to its unique pharmacological properties. Although good efficacies of ginsenosides have been reported, lack of target specific delivery into tumor sites, low solubility, and low bioavailability due to modifications in gastro-intestinal environments limit their biomedical application in clinical trials. As a result to this major challenge, nanotechnology and drug delivery techniques play a significant role to solve this problematic issue. Thus, we reported the preparation of poly-ethylene glycol (PEG) and glycol chitosan (GC) functionalized to ginsenoside (Compound K and PPD) conjugates via hydrolysable ester bonds with improved aqueous solubility and pH-dependent drug release. In vitro cytotoxicity assays revealed that PEG-CK, and PPD-CK conjugates exhibited lower cytotoxicity compared to bare CK and PPD in HT29 cells. However, GC-CK conjugates exhibited higher and similar cytotoxicity in HT29 and HepG2 cells. Furthermore, GC-CK-treated RAW264.7 cells did not exhibit significant cell death at higher concentration of treatment which supports the biocompatibility of the polymer conjugates. They also inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW64.7 cells. In addition to polymer-ginsenoside conjugates, silver (AgNps) and gold nanoparticles (AuNps) have been successfully synthesized by green chemistry using different m. The biosynthesized nanoparticles demonstrated antimicrobial efficacy, anticancer, anti-inflammatory, antioxidant activity, biofilm inhibition, and anticoagulant effect. Special interest on the effective delivery methods of ginsenoside to treatment sites is the focus of metal nanoparticle research.In short, nano-sizing of ginsenoside results in an increased water solubility and bioavailability. The use of nano-sized ginsenoside and P. ginseng mediated metallic nanoparticles is expected to be effective on medical platform against various diseases in the future.

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A Study on the Aspects of the Relationships and Hardships on a 'Sijipsali' Narratives in Korean Women's Married Life (여성 화자의 시집살이담에 나타난 관계와 고난의 양상)

  • Kim, Kyung-Seop;Kim, Jeong-Lae
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.409-417
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    • 2020
  • Oral-Performance in itself, which successfully narrates one's life, constitutes a kind of decent Verbal arts. The term 'Sijipsali-Narrative' refers to oral narratives portraying a series of events in the course of Women's Life-Story which arise from family life and socio-cultural issues through marriage. As a result, Sijipsali-Narrative belongs to a subcategory of Women's Life-Story. Sijipsali-Narrative can be divided into two categories as follow. One type of Sijipsali-Narrative is the 'Family-Connection sijipsali-narrative,' which results from the relationship between a daughter-in-law and the rest members of the family. Among the 'Family-Connection sijipsali-narratives,' including several forms of Sijipsali such as that of father-in-law and that of husband and that of children, Sijipsali of the mother-in-law is most distinctive. The other type of Sijipsali-Narrative is 'Sociocultural-Connection Sijipsali-narrative', which comes not from human relationship but from general issues a narrator is suffering from as a daughter-in-law in a family. The most universal narrative comes from Sijipsali connected with poverty and historical events, and family history, appearance, attitude of the daughter-in-law and so on can be materials for the narratives. Actually, the two types of Sijipsali narrative is not so much distinguished from each other as intermingled with each other. Sijipsali arising from family relationship can inevitably be related with poverty and some events, which result in conflicts among family members and so harass daughter-in-laws. This thesis has a clear-cut orientation to overview the aspects of the Relationships and Hardships on a 'Sijipsali' Narratives in Korean Women's Married Life.

Changes in surface roughness of bracket and wire after experimental sliding - preliminary study using an atomic force microscopy (브라켓과 탄선 간의 마찰 전후 표면 변화 분석 - 원자현미경을 이용한 예비연구)

  • Lee, Tae-Hee;Park, Ki-Ho;Jeon, Ji-Yun;Kim, Su-Jung;Park, Hun-Kuk;Park, Young-Guk
    • The korean journal of orthodontics
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    • v.40 no.3
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    • pp.156-166
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    • 2010
  • Objective: The surface roughness of orthodontic materials is an essential factor that determines the coefficient of friction and the effectiveness of tooth movement. The aim of this study is to evaluate the surface roughness change of the brackets and wires after experimental sliding quantitatively. Methods: Before and after experimental sliding tests, the surface roughness of stainless steel brackets, ceramic brackets, stainless steel wires, and beta-titanium (TMA) wires were investigated and compared using atomic force microscopy (AFM). Results: After sliding tests, changes in the surface of the wire were greater than changes in the bracket slot surface. The surface roughness of the stainless steel bracket was not significantly increased after sliding test, whereas the roughness of ceramic brackets was decreased. Both the surface roughness of stainless steel and TMA wires were increased after sliding test. More changes were observed on the ceramic bracket than the stainless steel bracket. Conclusions: AFM is a valuable research tool when analyzing the surface roughness of the brackets and wires quantitatively.

Role of the periosteum on bone regeneration in rabbit calvarial defects (가토의 두개골 결손부에서 골재생에 끼치는 골막의 역할)

  • Jang, Hyun-Seon;Kim, Sang-Mok;Park, Joo-Cheol;Kim, Byung-Ock
    • Journal of Periodontal and Implant Science
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    • v.35 no.4
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    • pp.939-948
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    • 2005
  • The role of the periosteum on osteointegration of $Bio-Oss^{(R)}$(Geistlich, Wolhusen/Switzerland) was studied in rabbit calvarial defect. 12 New Zealand white male rabbits between 2.8 and 4 kg were included in this randomized, blinded, prospective study. Each rabbit was anesthetized with Ketamine HCl(5 mg/kg) and Xylazine HCl(1.5 ml/kg). An incision was made to the bony cranium and the periosteum was reflected. Using a 6-mm trephine bur(3i. USA), four 8-mm defects were created with copious irrigation. The defects were classified into barrier membrane($Tefgen^{(R)}$, Lifecore Biomedical. Inc, U.S.A.) only group as a control, $Bio-Oss^{(R)}$ with barrier membrane group, $Bio-Oss^{(R)}$ with periosteum covering group, and $Bio-Oss^{(R)}$ without periosteum covering group. There were 2 rabbits in each group. The wound was closed with resorbable suture materials. Rabbits were sacrificed using phentobarbital(100 mg/kg) intravenously at 1, 2, and 4 weeks after surgery. The samples were fixed in 4% paraformaldehyde, and decalcified in hydrochloric acid decalcifying solution(Fisher Scientific, Tustin, CA) at $4^{\circ}C$ for 2-4 weeks. It was embedded in paraffin and cut into 6 ${\mu}m$ thickness. The sections were stained with H & E and observed by optical microscope. The results were as follows; 1. The periosteum played an important role in osteointegration of $Bio-Oss^{(R)}$ in bone defects. 2. When the periosteum remained intact and $Bio-Oss^{(R)}$ was placed on the defect, $Bio-Oss^{(R)}$ with periosteum covering has been incorporated into the newly formed bone from 2-week postoperatively. 3. When the periosteum was removed at the surgical procedure, invasion of connective tissue took place among the granules, and new bone formation was delayed compared to periosteum covering group. Therefore, when the bone grafting was performed with periosteal incision procedure to achieve tension-free suture, the integrity of the overlying periosteum should be maintained to avoid fibrous tissue ingrowth.

Effect of a Proton Pump Inhibitor on Tumor Bleeding Prevention in Unresectable Gastric Cancer Patients: a Double-Blind, Randomized, Placebo-Controlled Trial

  • Kim, Young-Il;Kim, Mi-Jung;Park, Sook Ryun;Kim, Hark Kyun;Cho, Soo-Jeong;Lee, Jong Yeul;Kim, Chan Gyoo;Kim, Gwang Ha;Park, Moo In;Nam, Byung-Ho;Park, Young Iee;Choi, Il Ju
    • Journal of Gastric Cancer
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    • v.17 no.2
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    • pp.120-131
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    • 2017
  • Purpose: Tumor bleeding is a major complication in inoperable gastric cancer. The study aim was to investigate the effects of proton pump inhibitor (PPI) treatment for the prevention of gastric tumor bleeding. Materials and Methods: This study was a prospective double-blind, randomized, placebo-controlled trial. Patients with inoperable gastric cancer were randomly assigned to receive oral lansoprazole (30 mg) or placebo daily. The primary endpoint was the occurrence of tumor bleeding, and the secondary endpoints were transfusion requirement and overall survival (OS). Results: This study initially planned to enroll 394 patients, but prematurely ended due to low recruitment rate. Overall, 127 patients were included in the analyses: 64 in the lansoprazole group and 63 in the placebo group. During the median follow-up of 6.4 months, tumor bleeding rates were 7.8% and 9.5%, in the lansoprazole and placebo groups, respectively, with the cumulative bleeding incidence not statistically different between the groups (P=0.515, Gray's test). However, during the initial 4 months, 4 placebo-treated patients developed tumor bleeding, whereas there were no bleeding events in the lansoprazole-treated patients (P=0.041, Gray's test). There was no difference in the proportion of patients who required transfusion between the groups. The OS between the lansoprazole (11.7 months) and the placebo (11.0 months) groups was not statistically different (P=0.610). Study drug-related serious adverse event or bleeding-related death did not occur. Conclusions: Treating patients with inoperable gastric cancer with lansoprazole did not significantly reduce the incidence of tumor bleeding. However, further studies are needed to evaluate whether lansoprazole can prevent tumor bleeding during earlier phases of chemotherapy (ClinicalTrial.gov, identifier No. NCT02150447).

Software development for the visualization of brain fiber tract by using 24-bit color coding in diffusion tensor image

  • Oh, Jung-Su;Song, In-Chan;Ik hwan Cho;Kim, Jong-Hyo;Chang, Kee-Hyun;Park, Kwang-Suk
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.133-133
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    • 2002
  • Purpose: The purpose of paper is to implement software to visualize brain fiber tract using a 24-bit color coding scheme and to test its feasibility. Materials and Methods: MR imaging was performed on GE 1.5 T Signa scanner. For diffusion tensor image, we used a single shot spin-echo EPI sequence with 7 non-colinear pulsed-field gradient directions: (x, y, z):(1,1,0),(-1,1,0),(1,0,1),(-1,0,1),(0,1,1),(0,1,-1) and without diffusion gradient. B-factor was 500 sec/$\textrm{mm}^2$. Acquisition parameters are as follows: TUTE=10000ms/99ms, FOV=240mm, matrix=128${\times}$128, slice thickness/gap=6mm/0mm, total slice number=30. Subjects consisted of 10 normal young volunteers (age:21∼26 yrs, 5 men, 5 women). All DTI images were smoothed with Gaussian kernel with the FWHM of 2 pixels. Color coding schemes for visualization of directional information was as follows. HSV(Hue, Saturation, Value) color system is appropriate for assigning RGB(Red, Green, and Blue) value for every different directions because of its volumetric directional expression. Each of HSV are assigned due to (r,$\theta$,${\Phi}$) in spherical coordinate. HSV calculated by this way can be transformed into RGB color system by general HSV to RGB conversion formula. Symmetry schemes: It is natural to code the antipodal direction to be same color(antipodal symmetry). So even with no symmetry scheme, the antipodal symmetry must be included. With no symmetry scheme, we can assign every different colors for every different orientation.(H =${\Phi}$, S=2$\theta$/$\pi$, V=λw, where λw is anisotropy). But that may assign very discontinuous color even between adjacent yokels. On the other hand, Full symmetry or absolute value scheme includes symmetry for 180$^{\circ}$ rotation about xy-plane of color coordinate (rotational symmetry) and for both hemisphere (mirror symmetry). In absolute value scheme, each of RGB value can be expressed as follows. R=λw|Vx|, G=λw|Vy|, B=λw|Vz|, where (Vx, Vy, Vz) is eigenvector corresponding to the largest eigenvalue of diffusion tensor. With applying full symmetry or absolute value scheme, we can get more continuous color coding at the expense of coding same color for symmetric direction. For better visualization of fiber tract directions, Gamma and brightness correction had done. All of these implementations were done on the IDL 5.4 platform.

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Metabolic Abnormalities in Patients with Mitochondrial Myopathy Evaluated by In Vivo $^{31}$P Magnetic Resonance Spectroscopy (인($^{31}$P) 자기공명분광법을 사용하여 사립체 근질병환자와 정상인과의 대사물질 비교조사)

  • Bo-Young Choe
    • Investigative Magnetic Resonance Imaging
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    • v.2 no.1
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    • pp.89-95
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    • 1998
  • Purpose : To investigate the phosphorus metabolic abnormalities in skeletal muscle of patients with mitochondrial myopathy using in vivo $^{31}P$ magnetic resonance spectroscopy(MRS). Materials and Methods : Patients with mitochondrial myopathy(N=10) and normal control subjects (N=10) participated. All in vivo $^{31}P$ MRS examinations were performed on 1.5T whole-body MRI/MRS system by using an image selected in vivo spectroscopy (ISIS) pulse sequence that provided a $4{\times}4{\times}4{\;}cm^{3}$ volume of interest (VOI) in the right thigh muscle tissue. Peak areas for each phophorus methabolite were measured using a Marquart algorithm. Results : The specific features in patients with mitochondrial myopathy were a significant increase of Pi/PCr ratio (p=0.003) and a significant decrease of ATP/PCr ratio (p=0.004) as compared with normal controls. In particular, the ${\beta}-ATP/PCr$ ratio between controls and patients with mitochondrial myopathy was predominantly altered. Conclusions : In vivo $^{31}P$ MRS may be a useful modality in the clinical evaluation of patients with mitochondrial myopathy based on ATP/PCr and Pi/PCr ratios in skeletal muscle tissue and provides a valuable information in further understanding disorders of muscle metabolism.

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THE mRNA EXPRESSION OF MMP-1, TIMP-1, $TGF-{\beta}_1$ IN GINGIVAL KERATOCYTES FROM GINGIVAL HYPERPLASIA INDUCED BY CYCLOSPORINE A (정상 치은 조직에서 배양된 각화세포에서 Cyclosporine A에 의한 MMP-1, TIMP-1, $TGF-{\beta}_1$의 발현에 관한 연구)

  • Kang, Hag-Soo;Lee, Jae-Sun;Bing, Jung-Ho;Park, Chang-Joo;Im, Jae-Jung;Hwang, Kyung-Gyun;Shim, Kwang-Sup
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.4
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    • pp.405-411
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    • 2008
  • Purpose : Cyclosporine A (CsA) is a versatile immunosuppresive agent used to prevent graft rejection syndrome and treat autoimmune disease. One of the major side effects associated with CsA is the abnormal gingival hyperplasia. The purpose of this study was to investigate the relationship between the mRNA expression of the MMP-1, TIMP-1, and $TGF-{\beta}_1$ and the concentration of CsA in cultured human gingival keratinocytes. Materials & Methods : Gingival keratocytes were obtained from gingival tissues of 4 healthy donors. The cultured gingival keratocytes were incubated with increasing concentrations of CsA (0-2000 ng/ml) for 24 hours and the expression of MMP-1, TIMP-1, and $TGF-{\beta}_1$ were determined by reverse transcription-polymerase chain reaction (RT-PCR). Results : The expressions of MMP-1 and $TGF-{\beta}_1$ were not significantly different according to the concentrations of CsA. The expression of TIMP-1 was significantly increased at the CsA concentration of 500 ng/ml. Conclusion : We concluded that the gingival hyperplasia induced by CsA was more related with TIMP-1 than MMP-1 or $TGF-{\beta}_1$ on gingival collagen metabolism in patients treated with CsA.

Effect of microgrooves and fibronectin conjugation on the osteoblast marker gene expression and differentiation

  • Park, Su-Jung;Leesungbok, Richard;Ahn, Su-Jin;Im, Byung-Jin;Lee, Do Yun;Jee, Yu-Jin;Yoon, Joon-Ho;Cui, Taixing;Lee, Sang Cheon;Lee, Suk Won
    • The Journal of Advanced Prosthodontics
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    • v.7 no.6
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    • pp.496-505
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    • 2015
  • PURPOSE. To determine the effect of fibronectin (FN)-conjugated, microgrooved titanium (Ti) on osteoblast differentiation and gene expression in human bone marrow-derived mesenchymal stem cells (MSCs). MATERIALS AND METHODS. Photolithography was used to fabricate the microgrooved Ti, and amine functionalization (silanization) was used to immobilize fibronectin on the titanium surfaces. Osteoblast differentiation and osteoblast marker gene expression were analyzed by means of alkaline phosphatase activity assay, extracellular calcium deposition assay, and quantitative real-time PCR. RESULTS. The conjugation of fibronectin on Ti significantly increased osteoblast differentiation in MSCs compared with non-conjugated Ti substrates. On the extracellular calcium deposition assays of MSCs at 21 days, an approximately two-fold increase in calcium concentration was observed on the etched 60-${\mu}m$-wide/10-${\mu}m$-deep microgrooved surface with fibronectin (E60/10FN) compared with the same surface without fibronectin (E60/10), and a more than four-fold increase in calcium concentration was observed on E60/10FN compared with the non-etched control (NE0) and etched control (E0) surfaces. Through a series of analyses to determine the expression of osteoblast marker genes, a significant increase in all the marker genes except type I collagen ${\alpha}1$ mRNA was seen with E60/10FN more than with any of the other groups, as compared with NE0. CONCLUSION. The FN-conjugated, microgrooved Ti substrate can provide an effective surface to promote osteoblast differentiation and osteoblast marker gene expression in MSCs.

Antimicrobial activity of dental polishing bur material with fluoride ion (불소이온을 함유한 연마용 버 재료의 항균력 연구)

  • Jeong, Insun;Kim, Ji-Hyun;Yun, Kwi-Dug
    • The Journal of Korean Academy of Prosthodontics
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    • v.58 no.3
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    • pp.201-206
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    • 2020
  • Purpose: The purpose of this study is to evaluate the antimicrobial activity on the dental bur with fluoride for S. mutans. Materials and methods: 0 ppm, 300 ppm, 500 ppm, 1,000 ppm, 1,450 ppm fluoride ion is added to a specimen. S. mutans was incubated for 24 hours, the number of S. mutans were counted. Kruskal-Wallis and MannWhitney analysis were used SPSS 25.0 (IBM SPSS 25.0, Chicago, IL, USA). Results: The mean S. mutans counts of 0 ppm, 300 ppm, 500 ppm, 1,000 ppm, and 1,450 ppm were 374.0 ± 12.6, 251.0 ± 66.7, 111.4 ± 35.6, 41.6 ± 11.7 and 13.2 ± 4.6, respectively. All groups except the control and 300 ppm showed statistically significant. Conclusion: Thus, more than 500 ppm fluoride ion showed the statistically significant antimicrobial activity. 1,450 ppm group showed the highest antimicrobial activity. This study showed the clinical possibility for dental caries protection and antimicrobial activity of dental bur.