Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Hydrogel Skin-Covered Neurons Self-Assembled with Gustatory Cells for Selective Taste Stimulation

Many technical challenges exist in the co-culture of multiple types of cells, including medium optimization, cell-to-cell connection, and selective data acquisition of cellular responses. Particularly, mixed cellular responses limit the precise interpretation of intercellular signal transduction. Here, we report the formation of an agarose gel skin on neurons closely assembled with gustatory cells to selectively stimulate gustatory cells by retarding the diffusion of tastants to neurons. The signal transmission, triggered by denatonium benzoate, from gustatory cells to neurons was monitored using intracellular calcium ion concentrations. The agarose gel skin efficiently suppressed the direct transfer of tastants to neurons, decreasing the number of responsive neurons from 56 to 13% and the number of calcium ion signals per neuron from multiple to single. The assembly of neurons with gustatory cells induced the high level of neuronal responses through taste signal transduction from gustatory cells to neurons. However, the calcium ion signal peaks of free neurons coated with agarose gel were much shorter and weaker than those of neurons closely assembled with gustatory cells. This work demonstrated that agarose gel skin is a simple, fast, and effective means to increase the signal selectivity of cellular responses in the co-culture of multiple types of cells

Highly Robust Multilamellar Lipid Vesicles Generated through Intervesicular Self-Assembly Mediated by Hydrolyzed Collagen Peptides

Despite the well-known advantages of lipid vesicles for drug and gene delivery, structural instability limits their practical applications and requires strictly regulated conditions for transport and storage. Chemical crosslinking and in situ polymerization have been suggested to increase the membrane rigidity and dispersion stability of lipid vesicles. However, such chemically modified lipids sacrifice the dynamic nature of lipid vesicles and obfuscate their in vivo metabolic fates. Here, we present highly robust multilamellar lipid vesicles through the self-assembly of preformed, cationic large unilamellar vesicles (LUVs) with hydrolyzed collagen peptides (HCPs). The cationic LUVs undergo vesicle-to-vesicle attachment and structural reorganization through polyionic complexation with HCPs, resulting in the formation of multilamellar collagen-lipid vesicles (MCLVs). The resulting MCLVs exhibit excellent structural stability against variations in pH and ionic strength and the addition of surfactants. Particularly, the MCLVs maintain their structural stability against repeated freeze–thaw stresses, proving the unprecedented stabilization effect of biological macromolecules on lipid lamellar structures. This work provides a practically attractive technique for the simple and quick fabrication of structurally robust lipid nanovesicles without covalent crosslinkers, organic solvents, and specialized instruments

Tannin–Titanium Oxide Multilayer as a Photochemically Suppressed Ultraviolet Filter

UV filters can initiate redox reactions of oxygen and water when exposed to sunlight, generating reactive oxygen species (ROS) that deteriorate the products containing them and cause biological damages. This photochemical reactivity originates from the high chemical potential of UV filters, which also determines the optical properties desirable for sunscreen applications. We hypothesize that this dilemma can be alleviated if the photochemical pathway of UV filters is altered to coupling with redox active molecules. Here, we employ tannic acid (TA) as a key molecule for controlling the photochemical properties of titanium dioxide nanoparticles (TiO₂ NPs). TA provides an unusual way for layer-by-layer assembly of TiO₂ NPs by the formation of a ligand-to-metal charge transfer complex that alters the nature of UV absorption of TiO₂ NPs. The galloyl moieties of TA efficiently scavenge ROS due to the stabilization of ROS by intramolecular hydrogen bonding while facilitating UV screening through direct charge injection from TA to the conduction band of TiO₂. The TiO₂–TA multilayers assembled in open porous polymer microspheres substantially increased sun protection while dramatically reducing ROS under UV exposure. The assembled structure exhibits excellent in vivo anti-UV skin protection against epidermal hyperplasia, inflammation, and keratinocyte apoptosis without long-term toxicity