Biomimetic Taste Sensors And Their Applications In Taste Detection And Personalized Drug Evaluation

Mammals have a sensitive taste perception system,which can rapidly and specifically identify and detect various taste substances.Taste receptors,are usually expressed in taste buds of the oral cavity and are therefore able to recognize five tastes:sour,sweet,bitter,salty and umami.Recently,significant progress has been made in the distribution and physiological functions of taste receptors in non-taste tissues.They are expressed in respiratory tract,digestive tract,heart,brain and other tissues,and their roles are not limited to taste perception.Studies have shown that taste receptors may become new targets for disease treatment.In this dissertation,tissues or cells expressing taste receptors were used as sensing elements,and micro-nano sensors were used as secondary transducers to convert response signals into electrical signals.Four bionic taste sensors were designed for taste detection and personalized drug evaluation.Firstly,a bionic taste sensor based on tongue epithelium was constructed using taste receptors expressed in the oral cavity to achieve quantitative detection of food additives and sensory evaluation of sour and sweet interactions.Secondly,based on the characteristic of heterotopic expression of taste receptors in non-taste tissues,cells from respiratory tract and heart were used as sensing elements.The bionic taste sensors of personalized drug screening for asthma and tachycardia disease was constructed respectively.Finally,combined with the cell co-culture technology,two novel taste sensors were proposed,and their application in taste detection was preliminarily explored.On the one hand,taste sensor based on the hypothalamus neuron-glial cell co-culture network was developed to detect sweet substances and explore the important role of sweet receptors in maintaining the balance of sugar metabolism.On the other hand,SH-SY5 Y cells and Caco-2 cells expressing different bitter receptors endogenously were co-cultured on the sensor chip in different proportions,which provided a new platform for the detection of bitter ligands and isothiocyanate drugs.The main content and innovations of this dissertation are given as follows:1.A bionic taste sensor based on mammalian tongue epithelium and microelectrode array was proposed to achieve quantitative detection of food additives and evaluation of sour and sweet interaction,which was consistent with human sensory evaluation resultsA bionic taste sensor was constructed using mammalian tongue epithelium as sening elements and microelectrode array as a transducer.Firstly,the tongue epithelium was characterized by immunofluorescence and scanning electron microscopy,which retained the natural state of taste buds and the natural network of various taste receptor cells.The taste quality and intensity information was coded in time-frequency patterns of local field potential.Different response patterns evoked by sweet and sour stimuli are observed,and the response is dose-dependent.Then,interaction effects of sourness against sweetness are quantified.The results indicate that suppression of sweetness by sourness occurs by increasing sourness concentrations.Finally,comparison was made with human sensory evaluation.2.A design method of biomimetic taste sensor based on airway smooth muscle cells was proposed,which realized the detection and quantitative evaluation of potential anti-asthma traditional Chinese medicinesRT-PCR was carried out for the first time to demonstrate that several m TAS2 Rs were expressed in mouse airway smooth muscle(ASM)cells,which was characterized by immunofluorescence staining.A biomimetic taste sensor based on primary ASM cells and the electric cell-substrate impedance sensor(ECIS)was developed.The activation of TAS2 Rs caused membrane hyperpolarization through a series of cell cascade reactions,leading to ASM cell relaxation and bronchiectasis Thus TAS2 Rs were used as emerging anti-asthma drug targets.ECIS can detect the morphological changes of ASM cells caused by contraction and relaxation,and reflected by the changes of cell impedance.The acetylcholine-mediated “contraction” can be effectively dilated by quinine,nobiletin,and picfeltarraenin IA,showing potential value as novel anti-asthma drugs.Besides,the effective screening of anti-asthma drugs was realized based on 3D ASM cell arrays and gel imaging.3.A design method of taste and smell compound sensor based on HL-1cardiomyocyte was proposed,which realized the detection and quantitative evaluation of potential tachycardia drugsRT-PCR was used to explore the endogenous expression of bitter and olfactory receptors in mouse HL-1 cardiomyocytes.By taking advantage of their mediating the negative inotropic effect of cardiomyocytes,they were used as a new drug target for the treatment of tachycardia.MEA sensor can detect the extracellular field potential(EFP)signal of HL-1 cells and reflect the systolic and diastolic properties.The inhibitory effect of salicin,artemisinin,xanthotoxin and azelaic acid on HL-1 cells contraction were investigated and quantitatively evaluated by normalization of EFP frequency.Meanwhile,CCK8 colorimetry was used to investigate the cardiotoxicity of these drugs.4.The design methods of two novel biomimetic taste sensors combined with cell co-culture technology was proposed to realize the preliminary quantitative evaluation of taste detectionTwo novel biomimetic taste sensors were proposed based on cell co-culture technology.On the one hand,using the properties of hypothalamic neuronal cells expressing sweet taste receptors,a hypothalamic neurons and glial cells co-cultured network taste sensor was constructed.The quantitative detection of sweeteners was achieved through neuroelectrophysiological signal acquisition and analysis.Besides,glucose excitatory neurons and glucose inhibitory neurons could be successfully detected,which is important for exploring the role of sweet receptors in the brain in maintaining the balance of glucose metabolism.On the other hand,a taste sensor using different proportions of SH-SY5 Y and Caco-2 cells co-cultured on ECIS chips was proposed,which realized the detection and pattern recognition of TAS2R16 and TAS2R38 bitter ligands.In addition,the system can be applied to the screening of isothiocyanate drugs against Helicobacter pylori,which was expected to be used for the treatment of gastritis and gastric ulcer caused by H.pylori infection.