Bio-Sensing Chip Inspired by Mammalian Cells

Innovation: Academia

University of Cambridge

2020

Image: Komsan Loonprom / Shutterstock / CC BY NC ND - Creative Commons Attribution + Noncommercial + NoDerivatives

Respond to Signals

To interact with its environment, a living system must not only sense a variety of signals, but also respond to them. To be energy- and material-efficient, those responses must be appropriate to the signal. This generally requires sensing thresholds to trigger an appropriate level of response (for example, hiding under a shrub versus running away to avoid a predator). Response strategies are tied to a specific signal and often have a response threshold, which determines how strong a signal must be to warrant expending energy to respond. One example is a plant that lives in arid regions in South Africa. Its seed capsules remain closed until rainfall triggers them to open to release the seeds. But the plant only responds to a second rainfall, thus protecting against releasing its seeds before there is enough sustained water for them to grow.

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Sense Chemicals (Odor, Taste, etc.) From the Environment

Chemicals are important for signaling and communication among living systems, either intentionally (such as when two living systems try to find one another) or unintentionally (such as when a plant emits a chemical signal that an herbivore can use to find a tasty bite). They are also important for other uses, such as navigating or finding sources for minerals. But chemical signals are often relatively weak and disperse when moving through water or gases. Therefore, detecting them requires specialized abilities, including a way to determine where they are coming from. A well known example of sensing chemicals can be seen in ants following a pheromone trail laid down by others in their colony to locate a quality and abundant food source.

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Send Chemical Signals (Odor, Taste, Etc.)

Tastes, odors, and hormones are all chemical signals that can float through the air or water, or be applied to solid surfaces. Chemicals are important for signaling and communication; even humans, with our underdeveloped sense of smell, are influenced by chemicals more than we realize. Chemical signals are often specific to the living system intended to receive them, and are often relatively weak, dispersing upon moving through liquids or gases. To ensure that chemical signals reach their target, living systems create unique chemical signals and methods of dispersal. One example is an orchid that is pollinated by dung beetles, and therefore distributes a dung-smelling aroma to attract them.

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Physically Assemble Structure

Living systems use physical materials to create structures to serve as protection, insulation, and other purposes. These structures can be internal (within or attached to the system itself), such as cell membranes, shells, and fur. They can also be external (detached), such as nests, burrows, cocoons, or webs. Because physical materials are limited and the energy required to gather and create new structures is costly, living systems must use both conservatively. Therefore, they optimize the structures’ size, weight, and density. For example, weaver birds use two types of vegetation to create their nests: strong, a few stiff fibers and numerous thin fibers. Combined, they make a strong, yet flexible, nest. An example of an internal structure is a bird’s bone. The bone is comprised of a mineral matrix assembled to create strong cross-supports and a tubular outer surface filled with air to minimize weight.

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Electronic chip from University of Cambridge contains a mammalian cell membrane that behaves like a natural cell membrane, giving insight into the effects of viruses.

Benefits

Reduced cost
Ease-of-use
Increased efficiency

Applications

Disease control
Medical treatments
Pharmaceuticals

UN Sustainable Development Goals Addressed

Goal 3: Good Health & Wellbeing

Bioutilization

Mammalian cells

The Challenge

Keeping cells alive in the laboratory can be expensive, time consuming, and requires a lot of specialized equipment. In addition, if researchers are working with harmful pathogens, they risk exposure which could prove fatal. Developing a technique that mimics live cells without using them directly could prove beneficial.

Innovation Details

Cell membranes play a critical role in biological signaling, controlling everything from pain relief to viral infection by acting as a gatekeeper between a cell and the outside world. The bio-sensing chip retains all the important features of the cell membrane, including structure and ion flow, without the additional steps that are usually required to keep a cell alive. To make the bio-sensor, cell membranes were first taken from live cells and then combined with electrodes. This allows researchers to measure any changes happening in the cell in real time, while also safely monitoring how the cell is interacting with other cells such as viruses. If a virus is introduced onto the chip, the reaction and behavior of the membrane can be monitored though electrical signals. The device is the size of a human cell and allows for multiple measurements to be taken simultaneously. It can also be modified to mimic additional cell types, such as bacterial or plant.

Biological Model

The cell membrane contains specialized proteins called ion channels where an ionic current flows. The current is the flow of charged ions which gives an electrical signal, notifying the cell with important information.

See Related Strategy

Biological Strategy

Membranes Sensitive to Voltage

Common to all organisms

Channels within cell membranes control movement of ions due to a voltage-sensitive sensor consisting of four proteins.

References

Journal article

Self-Assembly of Mammalian-Cell Membranes on Bioelectronic Devices with Functional Transmembrane Proteins

Langmuir

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