Drs. Kobayashi and Nakayama visited Kyushu University at Fukuoka from April 26 to 28, 2017. During the stay, Prof. Katayama and Assoc. Prof. Mori provided technical advices and discussion about transfecting nucleotides using non-viral vectors. This is collaboration work with Assist. Prof. Hyukjin Lee, Ewha Womans University, for accelerating vascularization within cell sheet-based tissues.