• 한국정밀공학회지
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• 제26권1호
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• pp.146-154
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• 2009

In recent tissue engineering field, it is being reported that the fabrication of 3D scaffolds having high porous and controlled internal/external architectures can give potential contributions in cell adhesion, proliferation and differentiation. To fabricate these scaffolds, various solid free-form fabrication technologies are being applied. The solid free-form fabrication technology has made it possible to fabricate solid free-form 3D microstructures in layer-by-layer manner. In this research, we developed a multi-head deposition system (MHDS) and used design of experiment (DOE) to fabricate 3D scaffold having an optimized internal/external shape, Through the organization of experimental approach using DOE, the fabrication process of scaffold, which is composed of blended poly-caprolactone (PCL), poly-lactic-co-glycolic acid (PLGA) and tricalcium phosphate (TCP), is established to get uniform line width, line height and porosity efficiently Moreover, the feasibility of application to the tissue engineering of MHDS is demonstrated by human bone marrow stromal cells (hBMSCs) proliferation test.

• 혜화의학회지
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• 제19권2호
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• pp.145-151
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• 2011

Backgrounds: Multidisciplinary approaches including surgery, chemotherapy, and radiation therapy are currently being performed to target various cancers in Western Medicine. However, some cancers still remain difficult to battle, which has long attracted many scientists for the discovery of new agents to fight cancers. Ginseng is one of the herbs used in Oriental Medicine including Korea, China and Japan. We have further investigated ginseng for its anticancer effect. Objective: This is a comprehensive review summary of anticancer effect of ginseng and ginsenoids as a possible agent for future cancer treatment. Methods: Data were retrieved from two web sites; www.pubmed.com and www.riss.kr, and authorized texts concerning anticancer effects of ginseng. From collected data, information on anticancer effect of ginseng was thoroughly sorted, restructured, then assessed. Results: Panax Ginseng C.A. Meyer belongs to Araliaceae Panax family, a perennial prairie plant with its root known as Ginseng Radix. Ginseng induces anticancer effect through cell cycle arrest, acceleration of apoptosis, anti-angiogenesis, and suppression of metastasis. Anticancer effect of ginseng may be due to single compound or multi-compound actions. Many studies report involvement of immune mechanisms of cytokines, Natural Killer (NK) cells, macrophages and some antibodies in enhancing anticancer effect of ginseng. In near future, possibility of applying these mechanisms into clinical trials is convinced. There were some important findings on saponin in ginsenoids in reviewing for this article; First, eradication of metastatic tumors were influenced by macrophage activation. Second, suppression of malignant melanoma cell metastasis to lung were induced by macrophage and NK cell activation in spleen with red ginseng acidic polysaccharide (RGAP). Third, final metabolites of M1, M4 had exerted anticancer effect of ginseng. Conclusion: Unknown anticancer mechanisms of ginseng have been studied for many years up until now. Ginseng is comprised of multiple bio-chemical compounds that create complex pharmaceutical interactions. Therefore, for its proper usage and safe prescription, studies on different types of ginseng and patients' susceptibility to ginseng according to their constitution and stages of the disease should be further pursued. More efforts are needed to understand the anticancer mechanisms of ginseng as well.

• Journal of Periodontal and Implant Science
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• 제47권3호
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• pp.165-173
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• 2017

Purpose: The aim of this study was to radiographically and clinically compare the effect of extracellular matrix (ECM) membranes on dimensional alterations following a ridge preservation procedure. Methods: One of 2 different ECM membranes was applied during a ridge preservation procedure. A widely used ECM membrane (WEM; Bio-Gide, Geistlich Biomaterials, Wolhusen, Switzerland) was applied in the treatment group and a newly developed ECM membrane (NEM; Lyso-Gide, Oscotec Inc., Seongnam, Korea) was applied in the control group. Cone-beam computed tomography (CBCT) scans and alginate impressions were obtained 1 week and 6 months after the ridge preservation procedure. Results were analyzed using the independent t-test and the nonparametric Mann-Whitney U test. Results: There were no significant differences between the ECM membranes in the changes in the dimension, width, and height of the extraction socket or the quantity of bone tissue. Conclusions: The NEM showed comparable clinical and radiographic results to the WEM following the ridge preservation procedure.

• 대한본초학회지
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• 제35권6호
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• pp.43-53
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• 2020

Objective : Reflux esophagitis is a disease caused by reflux of stomach contents, stomach acid, and pepsin into the esophagus, and is currently increasing worldwide. This study was conducted to evaluate the effect of a mixture of Rhei Rhizoma and Scutellariae Radix (RS) extract on acute reflux esophagitis in rats. Methods : Rats were divided into five groups for examination: Normal group (Nor, n=8), water-treated acute reflux esophagitis rats (Con, n=8), tocopherol 30 mg/kg body weight/day-treated acute reflux esophagitis rats (Toco, n=8), RS 100 mg/kg body weight/day-treated acute reflux esophagitis rats (RS100, n=8), RS 200 mg/kg body weight/day-treated acute reflux esophagitis rats (RS200, n=8). All rats fasted for 18 h and then were derived by linking the metastatic junction between pylorus and forestomach and corpus. And rats were sacrificed 5 h after surgery. We analyzed the expression of NADPH, MAPK, inflammatory, anti-inflammatory, and tight junction related proteins by western blot in esophageal tissue and observed the level of reactive oxygen species (ROS), alanine aminotransferanse (ALT), and aspartate aminotransferase (AST) in serum. Results : RS administration significantly protected the esophageal mucosal damage of reflux esophagitis, and ROS, AST, and ALT levels were significantly reduced in RS administration compared to Con group. In addition, RS administration effectively suppressed MAPK and NF-κB pathways and upregulated protein expressions of tight junction protein. Conclusions : These results suggest that RS protected the esophageal mucosa by inhibiting the MAPK and NF-κB pathways and upregulating tight junctions.

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.323-335
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• 2000

The purpose of this study was to examine the frequency of dehiscence bone defect on peri-implant and to compare the difference between resorbable membrane and nonresorbable membrane in bone regeneration on peri-implant. Amomg the patients, 22 patientswho have recieved an implant surgery at the department of Periodontics in Dankook University Dental Hospital showed implant exposure due to the dehiscence defect and 27 implants of these 22 patients were the target of the treatment. $Gore-Tex^{(R)}$ and $Bio-mesh^{(R)}$ were applied to the patients and treated them with antibiotics for five days both preoperatively and postoperatively. Reentry period was 26 weeks on average in maxilla and 14 weeks on average in mandible. The results were as follows : 1. Dehiscence bone defect frequently appeared in premolar in mandible and anterior teeth in maxilla respectively. 2. Among 27 cases, 2 membrane exposures were observed and in these two cases, regenerated area was decreased. 3. In non-resorbable membrane, bone surface area $9.25{\pm}4.84$ preoperatively and significantly increased to $11.48{\pm}7.52$ postoperatively.(P<0.05) 4. In resorbable membrane, bone surface area was $14.80{\pm}8.25$ preoperatively and meaningfully widened to $17.61{\pm}10.67$ postoperatively.(P<0.05) 5 . The increase of bone surface area in non-resorbable membrane was $2.23{\pm}3.38$ and the increase of bone surface area in resorbable membrane was $2.80{\pm}3.00$ ;therefore, there was no significant difference between these two membranes(P<0.05). This study implies that the surgical method using DFDB and membrane on peri-implant bone defect is effective in bone regeneration regardless the kind of the membrane, and a similar result was shown when a resorbable membrane was used.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.159-160
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• 2006

A novel approach to the manufacture of biocompatible ceramic scaffold for tissue engineering using micro-stereolithography system is introduced. Micro-stereolithography is a newly proposed technology that enables to make a 3D micro structure. The 3D micro structures made by this technology can have accurate and complex shape within a few micron error. Therefore, the application based on this technology can vary greatly in nano-bio fields. Recently, tissue-engineering techniques have been regarded as alternative candidate to treat patients with serious bone defects. So many techniques to design and fabricate 3D scaffolds have been developed. But the imperfection of scaffold such as random pore size and porosity causes a limitation in developing optimum scaffold. So scaffold development with controllable pore size and fully interconnected shape have been needed for a more progress in tissue engineering. In this paper, bone scaffold was developed by applying the micro-stereolithography to the mold technology. The scaffold material used was HA(Hydroxyapatite) nano powder. HA is a type of calcium phosphate ceramic with similar characteristic to human inorganic bone component. The bone scaffold made by HA is expected, in the near future, to be an efficient therapy for bone defect.

• 한국정밀공학회지
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• 제24권4호
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• pp.138-146
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• 2007

Some biodegradable polymers and other materials such as hydrogels have shown the promising potential for surgical applications. Post surgical adhesion caused by the natural consequence of surgical wound healing results in repeated surgery and harmful effects. Recently, scientists have developed absorbable anti-adhesion barriers that can protect a tissue from adhesion in case they are in use; however, they are dissolved when no longer needed. Although these approaches have been attempted to fulfill the criteria for adhesion prevention, none can perfectly prevent adhesions in all situations. Overall, we developed a new method to fabricate an anti-adhesion membrane using biodegradable polymer and hydrogel. It employed a highly accurate three-dimensional positioning system with pressure-controlled syringe to deposit biopolymer solution. The pressure-activated microsyringe was equipped with fine-bore nozzles of various inner-diameters. This process allowed that inner and outer shapes could be controlled arbitrarily when it was applied to a surgical region with arbitrary shapes. In order to fulfill the properties of the ideal barriers f3r preventing postoperative adhesion, we adopted the pre-mentioned method combined with surface modification with the hydrogel coating by which anti-adhesion property was improved.

• Journal of Periodontal and Implant Science
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• 제28권1호
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• pp.87-102
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• 1998

The purpose of this stuffy was to assess and compare the osseous responses to implanted particles of porous synthetic HA (Interpore $200^{(R)}$, Interpore International, U.S.A.), resorbable natural bovine derived HA (Bio-$oss^{(R)}$, Gestlich Pharma, Switzerland) and calcium carbonate(Biocoral $450^{(R)}$, Inoteb, France) in bone defects. Four calvarial defects of 2.5mm diameter were created in earth of 16 Sprague-Dawley rats. The experimental materials were subsequently implanted hi three defects, leaving the fourth defect for control purpose. Four animals were earth sacrificed at 3 days, 1week, 2weeks and 4 weeks after surgery. The tissue response was evaluated under light microscope. Overall, histologic responses showed that all the particles were well tolerated and caused no aberrent tissue responses. There were difference in the amount of newly formed bone at the experimental sites and control site. There was more new bone formation associated with calcium carbonate site. In addition, the calcium carbonate site displayed multinucleated giant cells surrounding calcium carbonate particles after the 1st week, and osteoid tissue within the particle after the 2nd week. After 4 weeks, calcium carbonate particles were resorbed and replaced with new bone. The healing of the natural bovine derived HA site was similar to that of porous synthetic HA, except that new bone growth between the two particles have progressed more in the former site after the 2nd week. In the natural bovine derived HA site, the particle was surrounded by newly formed bone after the 4th week. After 4 weeks, the control site showed more mature bone than other sites. In conclusion, the grafted site were better in new bone formation than non-grafted sites. In particular the calcium Carbonate site showed the ability of osteoinduction and natural bovine denver HA showed osteoconduction in rat calvarial defects. This suggest that calcium carbonate and natural bovine derived HA could enhance the regenerative potential in periodontal defects.

• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.493-502
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• 2008

Purpose: The purpose of this study is to investigate on the regenerative capacity by using different size of graft materials around bony defect around implant. Material and Methods: Dental implant fixtures(Bio-TIS, Korea) were placed into the tibia of 8 rabbits. After placement of implant, artificial defects were created for each group, and the size of bone graft materials were used according to each designated group. 4 weeks after surgery, 8 rabbits were sacrificed. The histologic and histomorphometrical study were done for comparison of the regenerative capacity using $80-90{\mu}m$ and $200{\sim}1000{\mu}m$ size of grafting materials of OCS-$B^{(R)}$. Result: Matured bone formation was significantly increased more in Group E1($80-90{\mu}m$) than in Group E2($200{\sim}1000{\mu}m$). Group E1($80-90{\mu}m$) showed more significant augmentation in marginal length of graft material per unit area than Group E2($200{\sim}1000{\mu}m$). Group E1($80-90{\mu}m$) showed more interspace in graft material than Group E2($200{\sim}1000{\mu}m$). Control group showed no new bone formation around and inside of implanted fixture. Conclusion: Small grafting material size has great influence on bone regeneration.

• 폴리머
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• 제33권4호
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• pp.307-312
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• 2009

전기방사법으로 식물성 폴리페놀을 함유하는 PHBV 나노섬유를 제조하였으며, 얻어진 나노섬유의 평균직경은 340-450 nm였다. 폴리페놀의 첨가에 의해 나노섬유의 직경이 증가하였으며 폴리페놀의 첨가량도 나노섬유의 직경 변화에 영향을 미쳤다. 이는 PHBV와 폴리페놀 사이의 수소결합에 기인하는 것으로 확인되었다. 제조된 나노섬유를 이용한 ATR-FTIR 분석 결과 PHBV와 폴리페놀 사이에 수소결합이 존재하는 것을 확인할 수 있었고, XRD 분석 결과 폴리페놀의 첨가에 의해 PHBV 나노섬유의 결정성이 높아졌다. 이들 폴리페놀을 함유하는 나노섬유는 우수한 항균특성을 보였다.