Papers by Keyword: Temperature-Responsive Surface

Abstract: PHBV ultrafine fibers were fabricated by electrospinning process. Electrospun PHBV fiber structures revealed randomly aligned fibers with average diameter of 400 nm. PIPAAm was grafted on the surface of PHBV nanofibrous mat by electron beam irradiation. PIPAAm-grafted PHBV mats were determined by ATR-FTIR and ESCA. Water contact angles were determined by a sessile drop method at 20 and 37
. To examine the tissue compatibility, human fibroblasts were evenly seeded onto PIPAAm-grafted PHBV mat and cast film, ungrafted PHBV mat and film. Attached and spread fibroblasts on nanofibrous mat were proliferated more rapidly than that of flat film surface. Initial cell attachment on PIPAAm-grafted surfaces was higher than ungrafted surfaces. The surface property changed to hydrophilic by PIPAAm graft, which increased initial cell attachment. Detachment of single cells from PIPAAm-grafted PHBV matrixes was measured by low temperature treatment after incubation at 37
. Cultured cells were rapidly detached from PIPAAm-grafted PHBV mat compared with film. With porous mats, the water molecules easily reach to grafted PIPAAm from underneath and peripheral to the attached cells, resulting in rapid hydration of grafted PIPAAm molecules and detachment of the cells.

Abstract: In order to realize true regenerative medicine, we have developed a novel technology for the reconstruction of tissues and organs by utilizing intelligent materials including temperature-responsive polymers. We developed temperature-responsive culture surfaces, on which temperature-responsive polymers are covalently immobilized. Cells are cultured on the surfaces at 37°C, and harvested as transplantable cell sheets by reducing temperature to 20°C. With these cell sheets we regenerate various kinds of tissues such as cornea and heart.

Abstract: In order to avoid several complications resulted from biodegradable scaffolds or single cell injection, we have developed “cell sheet engineering”. Our concept is novel tissue reconstruction not from single cells but from cell sheets. In order to prepare cell sheets, temperature-responsive culture dishes are utilized. Since temperature-responsive polymers are covalently grafted on the dishes, various types of cells adhere and proliferate on them at 37°C, but are spontaneously detached only by reducing temperature below 32°C without any need for proteolytic enzyme. All the confluent cells are noninvasively harvested as a single contiguous cell sheets with intact cell-cell junctions and deposited extracellular matrix. We have utilized these harvested cell sheets for various tissue reconstructions including ocular surfaces, periodontal ligament, cardiac patches as well as bladder.