One approach to the engineering of functional cardiac tissue for basic studies and potential clinical use involves bioreactor cultivation of dissociated cells on a biomaterial scaffold. Our objective was to develop a scaffold that is (1) highly porous with large interconnected pores (to facilitate mass transport), (2) hydrophilic (to enhance cell attachment), (3) structurally stable (to withstand the shearing forces during bioreactor cultivation), (4) degradable (to provide ultimate biocompatibility of the tissue graft), and (5) elastic (to enable transmission of contractile forces). The scaffold of choice was made as a composite of poly(dl-lactide-co-caprolactone), poly(dl-lactide-co-glycolide) (PLGA), and type I collagen, with open interconnected pores and the average void volume of 80 +/- 5%. Neonatal rat heart cells suspended in Matrigel were seeded into the scaffold at a physiologically high density (1.35 x 10(8) cells/cm(3)) and cultivated for 8 d in cartridges perfused with culture medium or in orbitally mixed dishes (25 rpm); collagen sponge (Ultrafoam) and PLGA sponge served as controls. Construct cellularity, presence of cardiac markers, and contractile properties were markedly improved in composite scaffolds as compared with both controls.

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Purpose:Kyungpook National University School of Medicine has been implementing hybrid problem-based learning (PBL) since 1999. The aim of this study was to investigate the changes in the students’ perceptions and satisfaction levels of hybrid PBL.Methods:The target period of our study was from 1999 to 2014, and target subjects were second-year medical students in Kyungpook National University School of Medicine. The survey was conducted at the end of semester. We had a focused interview with group leaders and some volunteer students.Results:As for the scores regarding students’ overall satisfaction with PBL, there was significant improvement in 2005 compared to 2002, but the scores decreased and no differences between the survey years noted after 2005. The students’ preference ratio for the once a week PBL sessions, tutor presence, synchronization of contents, and arrangement of PBL sessions and related lectures was 60%–80%, 50%–90%, 52%–96%, and 78%–93%, respectively.Conclusion:In order to increase students’ satisfaction with hybrid PBL and to improve the perception of it, firstly, it is necessary to arrange the date and the time of PBL sessions so that students can concentrate on PBL. Secondly, PBL cases should be selected and arranged to be well synchronized with the ongoing lectures. Finally, it is important to create a safe atmosphere so that students can engage actively in PBL sessions.

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PurposeThis study aims to identify how problem-based learning (PBL) has been implemented in Korean medical education, and how it is evaluated by each medical school.MethodsFor this study, a total of 40 medical schools in Korea were surveyed via e-mail. The survey tool was a questionnaire consisting of 22 questions which was developed independently by the researchers.ResultsOf the 40 medical schools, 35 schools were implementing PBL programs in their medical curriculum, while five were found not currently to be running the program. A large number of the schools which introduced PBL (30 schools, 85.7%) used a hybrid PBL model. In over 70% of the medical schools surveyed, professors evaluated the effects of PBL as positive. Most medical schools (85.7%) stated they would maintain or expand their use of PBL. However, the lack of understanding and skeptical attitude of the faculty on PBL, the lack of self-study time and passive attitude of students, insufficiency of good PBL cases, and the perfunctory PBL introduction for school accreditation interfere with the successful PBL.ConclusionPBL has been incorporated in Korean medical curriculum as hybrid PBL type. It is analyzed that intensive tutor training and good PBL case development are necessary for the success and effective operation of PBL.