Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells have received extensive attention in the development of drug screening and toxicity testing. However, it has been reported that stem cell-derived HLCs showed hepatic functions that were too limited to be of use in drug screening and toxicity testing, possibly due to the lack of sufficient intercellular communication under conventional two-dimensional (2D) culture conditions. Therefore, a 3D differentiation system may overcome the in vitro limitation of 2D culture to produce stem cell-derived hepatocytes with mature metabolic functions. In this study, the feasibility of using a silicone-based spherofilm, specifically designed to produce spherical cell clusters, to generate uniformly sized 3D hepatic spheroids from hESCs was investigated. Hepatic spheroids generated on the spherofilm showed more homogenous size and shape than those generated in conventional low-attachment suspension culture dishes. Results of immunohistochemical analysis showed that expression of the mature hepatic marker albumin (ALB) increased over time during the hepatic maturation process. Furthermore, the 3D culture system mimicked the in vivo 3D microenvironment. Laminin, which is an important component of hepatic ECM, was expressed in hepatic spheroids. The results of immunohistochemical analysis indicated that the 3D culture environment is capable of generating an in vivo-like microenvironment. In addition, quantitative PCR analysis showed that the mature hepatic marker ALB and cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A7 were expressed at higher levels in 3D culture than in 2D culture. This indicates that the 3D culture system is suitable for hepatic maturation and that our size-controlled 3D culture conditions might accelerate hepatic function. These results suggest that 3D hepatic spheroids significantly enhance metabolic maturation of hepatocytes derived from hESCs

태양열 집열판을 이용한 가온재배 실태를 조사 분석하고 그에 따른 문제점을 도출하여 해결방안을 모색, 향후 자연에너지 이용 기기제작 및 사용의 기초자료를 제공하고자 태양열 집열판을 이용한 20농가를 조사한 결과, 설치 비용은 18백만원/20a정도 소요되었으며, 주 재배작목은 토마토(30%)와 화훼(40%)였고, 포도, 고추, 오이, 상추 및 딸기 등도 일부 재배하고 있었다. 태양열이용 정보는 대부분 지도기관에서 얻고 있었으며, 연료절감 효과가 20%미만이라고 응답한 농가가 75%로 지도기관에서 조사한 대부분 20%이상과는 차이가 있었다. 연료절감 효과에 비하여 시설비의 과중과 시공업체의 기술부족이 문제점으로 나타나 이의 보완이 필요하였다.