Poly (ε-caprolactone)/Equine Bone Film for Guided Bone Regeneration

( Sangbae Park ),( Kyoung-je Jang ),( Myungchul Lee ),( Jae Woon Lim ),( Jae Eun Kim ),( Jong Hoon Chung ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.2

For the dental implant to support the functional load, adequate quality of alveolar bone is necessary. Alveolar bone defects make it difficult for a dental implant to be grafted and function. The guided bone regeneration is a surgical procedure that is mainly used to treat bone defects. Various barrier membranes such as titanium, polymer, and bioactive materials are used to prevent the formation of connective tissue into the defect site. In this study, Poly (ε-caprolactone)/Equine bone (PCL/EB) films were fabricated as a barrier membrane for guided bone regeneration. PCL/EB solution was prepared incorporating equine bone into 10% (w/v) PCL/acetone solution. The PCL/EB films were made by evaporating the solution on a flat plate. The surface property of the PCL/EB film was evaluated using Fourier transform infrared (FT-IR) and water contact angle analysis. The in vitro behavior of the PCL/EB film was investigated using dental pulp stem cells (DPSCs). Cell proliferation and osteogenic differentiation of DPSCs on PCL/EB film were discussed using water soluble tetrazolium salt (WST-1) assay, Alizarin Red Staining (ARS), Immunocytochemistry (ICC), and Western Blotting method. The result of this study shows that PCL/EB film is a suitable candidate for guided bone regeneration membrane.

Engineering considerations of iPSC-based personalized medicine

Sangbae Park,권용현,Shahidul Ahmed Khan,Kyoung‑Je Jang,김장호 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Personalized medicine aims to provide tailored medical treatment that considers the clinical, genetic, and environ‑ mental characteristics of patients. iPSCs have attracted considerable attention in the feld of personalized medicine; however, the inherent limitations of iPSCs prevent their widespread use in clinical applications. That is, it would be important to develop notable engineering strategies to overcome the current limitations of iPSCs. Such engineering approaches could lead to signifcant advances in iPSC-based personalized therapy by ofering innovative solutions to existing challenges, from iPSC preparation to clinical applications. In this review, we summarize how engineering strategies have been used to advance iPSC-based personalized medicine by categorizing the development process into three distinctive steps: 1) the production of therapeutic iPSCs; 2) engineering of therapeutic iPSCs; and 3) clinical applications of engineered iPSCs. Specifcally, we focus on engineering strategies and their implications for each step in the development of iPSC-based personalized medicine.

Association between Coaches` Social Network and Their Performance Outcome: Korean Olympic Soccer Team

( Sangbae Jun ),( Han J. Lee ),( Kyunghwa Lee ),( Narae Son ),( Juhyun Kwak ) 한국체육학회 2016 국제스포츠과학 학술대회 Vol.2016 No.1

Purpose: Coaches are presented with the opportunity to interact with their athletes as well as other coaches, which makes their social networks. Previous work (Burt, 1992) has found links between network positions and individual performance. We tested Burt’s (1992) theory using a Korean Olympic Soccer team. Coaches and their athletes are situated in the unique network where coaches are tied to athletes’ performance. There has been limited research examining the nature of these social networks with athletes and other coaches (Trudel and Gilbert 2004). Thus, the purpose of this study was to examine associations between the social networks and performance outcomes of Korea national soccer team coaches. Method: The study surveyed coaches’ social networks of Korea Olympic soccer team in the periods from 1992 to 2012. Their performance in the international games (e.g., the World Cups, the Olympics, Asian games, Asian Cups, FIFA-U20, and FIFA-U17) was measured using winning rate of career records. The data was analyzed with UCINET6 and NetDraw, and descriptive statistics for analyzing the relationships. Result: Findings of the study indicated Hong Myung-Bo and Huh Jung-Moo had the biggest and various social networks, and the highest scores in centrality measures. Homophily was found that most of head coaches and assistant coaches were graduates of Yonsei or Korea university. Findings did not show statistically significant relationship between coaches’ social network and their performance outcome. Conclusion: Evolution of coaches’ social networks and homophily had been discovered in a vast array of network studies were discussed.

Enhanced Osteogenic Differentiation of Dental Pulp Stem Cells on Hydrolyzed Poly (ε-caprolactone)/Equine Bone 3D Printed Scaffold

( Sangbae Park ),( Kyoung-je Jang ),( Myungchul Lee ),( Jae Woon Lim ),( Jae Eun Kim ),( Jiyong Park ),( Hyun Mok Son ),( Jong Hoon Chung ) 한국농업기계학회 2019 한국농업기계학회 학술발표논문집 Vol.24 No.2

For the dental implant to support the functional load, adequate quality of alveolar bone is necessary. Alveolar bone defects make it difficult for a dental implant to be grafted and function. The 3D printed bioactive ceramic incorporated Poly(ε-caprolactone) (PCL) scaffolds hold great promise to be used as synthetic bone graft substitutes. However, 3D printed scaffolds still lack adequate surface properties for cells to be attached to it. In this study, Poly(ε-caprolactone)/Equine bone (PCL/EB) scaffolds were fabricated using microextrusion based 3D printing technique. PCL/EB scaffolds were then hydrolyzed using sodium hydroxide solution. The mechanical strength and the surface property of the hydrolyzed PCL/EB scaffolds were evaluated using a universal testing machine (UTM) and water contact angle analysis respectively. The in vitro behavior of the hydrolyzed PCL/EB scaffold was investigated using dental pulp stem cells (DPSCs). Cell proliferation of DPSCs on hydrolyzed PCL/EB scaffold was discussed using water soluble tetrazolium salt (WST-1) assay. And osteogenic differentiation of DPSCs on the scaffold was further investigated using Alizarin Red Staining (ARS), and western blot method. The result of this study shows that hydrolyzed PCL/EB scaffold is a suitable implant material for regeneration of bone defect.

Pharmacophore Models of Paclitaxel- and Epothilone-Based Microtubule Stabilizing Agents

Sangbae Lee,이유노,James M. Briggs,이근우 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.7

Microtubules play an important role in intracellular transport, mobility, and particularly mitosis. Paclitaxel (TaxolTM) and paclitaxel-like compounds have been shown to be anti-tumor agents useful for various human tumors. Paclitaxel-like compounds operate by stabilizing microtubules through interface binding at the interface between two β-tubulin monomers in adjacent protofilaments. In this paper we present the elucidation of the structural features of paclitaxel and paclitaxel-like compounds (e.g., epothilones) with microtubule stabilizing activities, and relate their activities to spatial and chemical features of the molecules. CATALYST program was used to generate three-dimensional quantitative structure activity relationships (3D-QSARs) resulting in 3D pharmacophore models of epothilone- and paclitaxel-derivatives. Pharmacophore models were generated from diverse conformers of these compounds resulting in a high correlation between experimental and predicted biological activities (r = 0.83 and 0.91 for epothilone and paclitaxel derivatives, respectively). On the basis of biological activities of the training sets, five- and four-feature pharmacophore hypotheses were generated in the epothilone and paclitaxel series. The validation of generated hypotheses was achieved by using twelve epothilones and ten paclitaxels, respectively, which are not in the training sets. The clustering (grouping) and merging techniques were used in order to supplement spatial restrictions of each of hypothesis and to develop more comprehensive models. This approach may be of use in developing novel inhibitor candidates as well as contributing a better understanding of structural characters of many compounds useful as anticancer agents targeting microtubules.

Cyber Security and Middle Power Diplomacy

Sangbae Kim 한국국제정치학회 KJIS 2014 The Korean Journal of International Studies Vol.12 No.2

A Novel Microfluidic Platform for Evaluation of Bioengineered Implants

( Sangbae Park ),( Jae Eun Kim ),( Jae Woon Lim ),( Byeongjoo Park ),( Jong Hoon Chung ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.2

A dental implant is defined as an artificial tooth root that is usually made of a special metal and surgically implanted in the region of a missing tooth. A highly osseointegrative dental implant surrounded by reconstructed periodontium is a promising tooth replacement option that mimics the structure and physiological functions of natural teeth. However, there is a shortage of in vitro models to effectively evaluate the bioengineered implants (bioimplants) as well as their integration with reconstructed tissues. In this study, a bioimplant-on-a-chip (BoC) platform was developed and applied to investigate the cellular responses of bioimplants. The cell culture conditions on BoC were optimized using Live/Dead assay, WST-1 assay, and immunostaining. To evaluate the osseointegration of PDL-like tissues on the implants, the expression of cementum protein-1 (CEMP-1) was observed using immunofluorescence imaging. As a result, this platform successfully mimicked the structure of the natural periodontium tissue. The induced PDL-like tissues showed enhanced collagen and periostin expression. Furthermore, the osseointegration of PDL-like tissues on the bioimplants was evaluated using BoCs. The results showed that the distribution of expressed CEMP-1 was not observed around the CPCs, whereas it was very high around the bioimplant. This finding indicates that this platform can effectively assess the osseointegration of bioimplants. As most studies on implants rely on in vivo tests, this platform holds significant promise for the development and evaluation of novel dental implants.

Equine Bone-derived Biomaterials for Bioengineering Applications

( Sangbae Park ),( Juo Lee ),( Hoon Seonwoo ),( Jangho Kim ),( Jong Hoon Chung ) 한국농업기계학회 2023 한국농업기계학회 학술발표논문집 Vol.28 No.1

Although technological advances in agriculture and livestock subsector have brought sufficient amount and quality of food to humans, the growing demand in livestock products comes with environmental challenges. Therefore, the bioprocessing of agricultural by-products such as animal bone is of great interest to researchers in biosystems engineering. Here, we propose strategies to engineer hydroxyapatite (HA) from equine bones for biological engineering applications. Hydroxyapatite derived from equine bones (EBs) has acquired focus because it is free from foot-and-mouth disease and has a low production cost. Furthermore, the biocompatibility and osteogenic differentiation ability of EBs are better than those of synthetic HA. Throughout this work, we developed bioengineered implants using EBs and established an organ-on-a-chip platform to effectively evaluate the bioengineered implants. In conclusion, given platforms and techniques would surely provide significant insight in providing advanced platforms for biological engineering applications.

Hardware Institutions for Software Technologies - The Japanese Model of Industrial Development in the Personal Computer Industry

Sangbae Kim 서울대학교 국제학연구소 2002 Journal of International and Area Studies Vol.9 No.1

  This paper attempts to explain why Japan has largely failed to meet unique technological challenges in the field of computer software while it has achieved remarkable success in its technological counterpart-s-computer hardware. What makes this research question puzzling is the fact that Japan has employed pretty much the same industrial policies and institutions for promoting both sectors, nevertheless producing divergent results. Existing neo-institutional approaches to industrial competitiveness are inadequate for explaining this puzzle with respect to “sectoral variation” in the effectiveness of industrial policies and institutions. I suggest that the theory of “technological fitness” is more useful for helping us to understand the relevance of industrial institutions-and further institutional adjustment strategies-in relation to the underlying technological conditions of industrial sectors. In this view, Japan has largely failed in computer software because it has continued to rely on its “hardware institutions” in competing for software technologies.

A Novel Microfluidic Platform for Evaluation of Bioengineered Implants

( Sangbae Park ),( Jae Eun Kim ),( Jae Woon Lim ),( Byeongjoo Park ),( Jong Hoon Chung ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.2

A dental implant is defined as an artificial tooth root that is usually made of a special metal and surgically implanted in the region of a missing tooth. A highly osseointegrative dental implant surrounded by reconstructed periodontium is a promising tooth replacement option that mimics the structure and physiological functions of natural teeth. However, there is a shortage of in vitro models to effectively evaluate the bioengineered implants (bioimplants) as well as their integration with reconstructed tissues. In this study, a bioimplant-on-a-chip (BoC) platform was developed and applied to investigate the cellular responses of bioimplants. The cell culture conditions on BoC were optimized using Live/Dead assay, WST-1 assay, and immunostaining. To evaluate the osseointegration of PDL-like tissues on the implants, the expression of cementum protein-1 (CEMP-1) was observed using immunofluorescence imaging. As a result, this platform successfully mimicked the structure of the natural periodontium tissue. The induced PDL-like tissues showed enhanced collagen and periostin expression. Furthermore, the osseointegration of PDL-like tissues on the bioimplants was evaluated using BoCs. The results showed that the distribution of expressed CEMP-1 was not observed around the CPCs, whereas it was very high around the bioimplant. This finding indicates that this platform can effectively assess the osseointegration of bioimplants. As most studies on implants rely on in vivo tests, this platform holds significant promise for the development and evaluation of novel dental implants.