Tailored cell sheet engineering using microstereolithography and electrochemical cell transfer.

Postoperative adhesion and occlusion remain a serious issue associated with various surgeries, including endoscopic surgery, in which proliferated fibrous tissues stick to adjacent tissues and often cause severe complications. Cell sheet engineering has emerged as an effective approach not only for cell transplantation but also for the treatment of postoperative adhesion and occlusion. However, as the tissues in the body, such as middle ear and small intestine, and typical operative sites are non-flat and spatially complicated, tailored cell sheets with three-dimensional (3D) configurations may lead to widespread use of this approach. In the present study, we used microstereolithography, biocompatible gold plating, and electrochemical cell detachment to achieve this purpose. Various objects with dimensions ranging from millimeter- to micrometer-scale were fabricated with photocurable resin using lab-made equipment for microstereolithography. To coat the fabricated objects with a thin gold layer, conventional cyanide-based gold plating was unusable because it severely damaged almost all cells. Electroless non-cyanide gold plating we prepared was cytocompatible and suitable for electrochemical cell detachment. Cell sheets on the gold-plated substrate could be directly transplanted into a mouse intraperitoneally using electrochemical cell detachment. We further demonstrated that cell sheets grown on gold-coated 3D objects were rapidly detached along with the desorption of electroactive-oligopeptide monolayer and transferred to a surrounding hydrogel. This approach may provide a promising strategy to prepare and directly transplant tailor-made cell sheets with suitable configurations.