Study and Evaluation of non- neural cells for Biosensing

For many years, researchers have used parts of animals, tissues and cells to observe physical and chemical responses. Cosmetic industries have used the human nose for analytical detection; security services use dogs and tests with bees for drug and explosive detection. Some research has focussed on disease recognition using smell, linked to that, engineering and medicine have studied using different species of animals, tissue or cell types, as potential biosensors. Insect tissues are supposedly robust in this respect and could produce signals over extended periods of time without the necessity for temperature and environmental control. Animals are useful for studies of anatomy and physiology, discovering molecules, vaccines, pest control and many other purposes.
The base of this thesis originated with the theory and application of Electroantennography and added to these, the knowledge of insect anatomy and its accurated ability to survival in the environment. The work was designed to develop a pathway to comprehend cell behaviour passing through the chance to build a novel biosensor to detect the presence of chemical substances (chemosensor).
The work compares cell survival without supplement changes followed by Trypan Blue exclusion protocol, and chemical resistance among the cells using MTT assay to assess the cellular metabolic activity. The cells alive during incubation and showed a high survival rate for both experiments. In sequence, the cells were analysed regarding their electrical properties compared to pituitary tumour of mouse cells (AtT-20). The intrinsic characteristic of AtT-20 is spontaneous electrical activity. Insect and acari cells (Sf21 and BME/CTVM) do not have this essential property for our purpose, but our interest was to trigger electrical signals by adding chemical solutions. Drosophila cells (ML-DmBG2) are from the brain and ventral ganglia cells and can form weak attachment to the surfaces (polystyrene or glass). They were seen to modify their shape from spherical to elongated cells- alike neurons and form into clusters- neurites. The electrophysiology assays employed calcium imaging, patch clamp and multielectrode array assay, are challenging for all these cell lines. The work here reports the progress and the obstacles in assessing the behaviour of diversified cell lines. Indeed, the evaluation of cellular responses towards the assays intensified the questioning about cell biology (targeting the electrophysiology), chemical biology (pathway and signals of released proteins) and highly specific cells to apply in a biosensor.