Titanium Culture Vessel Presenting Temperature Gradation for the Thermotolerance Estimation of Cells

Hyperthermia can be induced to exploit the thermal intolerance of cancer cells,which is worse than that of normal cells,as a potential noninvasive cancer treatment.To develop an effective hyperthermia treatment,thermal cytotoxicity of cells should be comprehensively investigated.However,to conduct such investigations,the culture temperature must be accurately regulated.We previously reported a culture system in which the culture temperature could be accurately regulated by employing metallic culture vessels.However,appropriate temperature conditions for hyperthermia depend on the cell species.Consequently,several experiments need to be conducted,which is a bottleneck of inducing hyperthermia.Hence,we developed a cell culture system with temperature gradation on a metallic culture surface.Michigan Cancer Foundation-7 cells and normal human dermal fibroblasts were used as cancer and normal cell models,respectively.Normal cells showed stronger thermal tolerance;this was because the novel system immediately exhibited a temperature gradation.Thus,the developed culture system can be used to investigate the optimum thermal conditions for effective hyperthermia treatment.Furthermore,as the reactions of cultured cells can be effectively assessed with the present results,further research involving the thermal stimulation of cells is possible.

Cell-Based Microfluidic Device Utilizing Cell Sheet Technology

The developmentof microelectromechanical systems hasresulted in the rapid development of polydimethylpolysiloxane(PDMS)microfluidic devices for drug screening models.Various cell functions,such as the response of endothelial cells to fluids,have beenelucdated using microuidic devices.Additionlly,organon-achip systems that includeorgans that are importantfor biologicalcirculation,such as the heart,liver,pancreas,kidneys,and brain,have been developed.These organs realize the biologicalcirculation system in a manner that cannot be reproduced by artificial organs;however,the flow channels between the organsare often artifically created by PDMS.In this study,we developeda microfluidic device consisting only of cels,by combiningcell sheet technology with microtitanium wires.Microwires were placed between stacked fibroblast cellsheets,and the celisheets adhered to each other,afer which the microwires were removed leaving a luminal structure with a size approximatelyequal to the arteriolar size.The lumen structure was constructed using wires with diameters of 50,100,150,and 200μm,which were approximations of the arteriole diameters.Furthermore using a perfusion device,we successfully perfused theluminal structure created inside the celsheets.The results revealed that a aulture solution can be supplied toa cellsheet witha very high cell density.The biofabrication technology proposed in this study can contribute to the development of organ-on-a-chip systems.