Stat strip xp2

Fibroblasts (5.0 × 10⁵ cells/mL) in 2 mL of the culture medium were seeded on the oligopeptide-modified membrane substrate. The cells were then cultured for 14 days and changes in the number of cells were determined by extracting DNA using a commercial kit (QIAmp DNA Mini Kit, Qiagen). For histological staining, cell sheets were fixed with 3.7% formaldehyde in PBS, embedded in paraffin, and sectioned. Hematoxylin and eosin (H&E) staining was performed following standard procedures. Images were acquired using a digital microscope (BZ-X710, Keyence, Osaka, Japan). To evaluate the respiration activity of cell sheets, the consumption of glucose and the production of lactate were quantified using electrochemical glucose (Nipro Stat StripXP2; NIPRO, Osaka-Shi, Japan) and lactate (Lactate Pro; ARKRAY, Inc., Edina, MN, USA) sensors.
To evaluate changes in a metabolic activity during the formation of thick cell sheets, fibroblasts in 2 mL culture medium were seeded on the substrate and conventional culture dishes at a density of 2.0 × 10⁵ cells/cm². The culture medium was sampled every 24 h for 14 days of culture. The secretion of VEGF was quantified using an ELISA kit according to the manufacturer's instructions. All assays were conducted in duplicate and the concentrations were calculated using a standard curve obtained for recombinant VEGF.