Detection of In Vivo-like Cells by a Biosensor Chip Based on Metamaterials in Terahertz Regime.

Early diagnosis of diseases, especially cancer, is critical for effective treatment. The unique properties of terahertz technology have attracted attention in this field. However, current terahertz bio-detection methods face challenges due to differences between the test environment and the actual in vivo conditions. In this study, a novel method is proposed for detecting in vivo-like cells using a biosensor chip composed of metamaterials and a cavity. The cavity has a thickness of ~50 µm. The structure can protect cells from damage and provides a liquid environment like an in vivo state. Through simulation analysis, the metamaterials sensor exhibits a theoretical sensitivity of 0.287 THz/RIU (Refractive Index Unit) with a 50 µm thick analyte. The detection method is experimentally validated using the apoptosis of glioma cells and various cell types. The biosensor investigates the apoptosis of glioma cells under the impact of temozolomide, and the trend of the results was consistent with the Cell Counting Kit-8 method. Furthermore, at a concentration of ~5200 cells/cm2, the experimental results demonstrate that the sensor can distinguish between neurons and glioma cells with a resonance frequency difference of approximately 30 GHz. This research has significant potential for detecting glioma cells and offers an alternative approach to in vivo-like cell detection.

Distribution of interstitial cells of Cajal in Meriones unguiculatus and alterations in the development of incomplete intestinal obstruction.

The interstitial cells of Cajal (ICCs) act as pacemaker cells that are involved in gastrointestinal (GI) motility disorders, although the pathogenesis of these disorders is still unclear. The GI tract of Mongolian gerbils shares similar anatomical features with that of humans, but no investigation of ICCs has been reported in the GI tracts of this animal. In the present study, we first observed the distribution and morphological features of ICCs in the Mongolian gerbil GI tract. The ICCs were mainly distributed within the smooth muscle layers (ICC-IM), the myenteric plexus (ICC-MY), the deep muscular plexus in the small intestine (ICC-DMP) and the submucosal surface of the circular muscle layer in the colon (ICC-SM). The density of the ICC-IM gradually decreased from the stomach to the colon, whereas the density of the ICC-MY gradually increased. Second, we compared differences in the ICCs between the control and obstructed intestines, and no significant difference was observed in the number of ICCs after 7 days of obstruction. However, the numbers were reduced by approximately day 14 of obstruction. The pattern of immunoreactivity also partly differed from that of the control group, i.e., a scattered and interrupted network of ICCs was often observed. Western blotting revealed that p-Kit and SCF were significantly reduced in the dilated intestines by day 14. Our results indicate that the Mongolian gerbil may be a good animal model for studying changes in ICCs that may contribute to the pathogenesis of GI motility disorders.