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Wednesday, May 22, 2024

Smart cells

Editor’s note: This article is part one of two in a series about the human intersection of technology and medicine.

Although the body is one single entity, it is one single entity that is far greater than the sum of all of its many interconnected parts. Look at the body as a set of systems — skeletal, neuronal, muscular, digestive, respiratory, circulatory, immune, lymphatic and many many more, all working in concert to make one lean, mean, Call-of-Duty-4-playing yet socially “successful” machine.

These systems contain parts, all moving and interacting in ways that modern science is still playing catch-up to understand. While I understand that my head bone is connected to my neck bone, until a few days ago, I had no idea that taking a bite of polar bear liver could make me die of vitamin A poisoning … par exemple. Recently, medical science took a sizable leap forward in regenerative medicine, spurred by a discovery in an unassuming, unexpected field: dermatology.

Researchers at UC Davis’ stem cell research center, the Institute for Regenerative Cures, have observed that cells and cell fragments (membranous vesicles that lack organelles and DNA) migrate in response to both naturally occurring and artificially applied electrical fields.

“The research first came from looking at wounds. When there is a wound, you would notice the cells moving and dividing directionally toward it,” said Min Zhao, a lead investigator in the study.

Let’s take a step back and look at some of the ways parts of the body get along with one another. We’ll recall that all cells have a membrane, which takes on the integral role of keeping the outside out and the inside in. Some of these units managed by a cell’s membrane are ions, particles that have a positive or negative charge that create a field that acts on surrounding charged particles, otherwise known as an electric field.

Alex Mogilner, a professor in the UC Davis Math Department and another key investigator in the study, had the following to say about how cells sense fields.

“One important thing is [that] negative electric fields cannot enter the inside of the cell, [the] same [way they] cannot penetrate any good conductor. So, all sensing of the electric field has to be done on the cell surface,” he said. “We demonstrate that it is not the flows of ions, but spatial redistribution of some charged proteins in the cell membrane dragged by the electric field to the cell edge, that is the initial sensing mechanism.”

When something goes wrong in the body, like a cut or other wound, membranes are damaged and the balance of charged bodies changes. This upsets the homeostasis of the existing electric fields in play and triggers a series of events. In response to the changed ionic field, the body restores equilibrium by preferentially producing more cells and membranes in the wounded area to restore homeostasis.

The idea is that by drawing extra materials and resources to the site of the wound, the wound would heal faster than if the same task was accomplished with local materials. It’s as if one were to build a house. You would build it much quicker if you had brought in additional lumber, rather than waiting for trees to grow and cutting them into convenient 2×4 beams on-site.

This phenomenon illustrates beautifully how no system in the body is completely autonomous and operates in a vacuum. A process like cell division has the faculties to occur on its own, but when it acts without guidance from the body’s internal stimuli, we give it another name: cancer. When cell division is applied properly and plays well with others, it saves lives and helps people grow. When left to its own devices, it becomes an almost insurmountable affliction.

Through the efforts of researchers such as Zhao and his colleagues, we understand that electric fields play a role in the direction of cell motility and growth. Theoretically, if we could better understand the mechanisms by which cells interpret these fields, we could one day manipulate the way cells move and divide in the body.

Wouldn’t it be something if there was a cheap, lightweight and effective way to produce electric fields around the body on something like a bandage, augmenting the body’s natural ability to direct cell movement?

Ric Kaner, a researcher in the UCLA Department of Inorganic Chemistry, and his colleagues have recently designed a graphene microsupercapacitor. The “micro supercap” represents a cheap, organic way of storing electricity. The brilliance of this is that the device is lightweight, theoretically cheap to manufacture and has the potential to hold a charge to power a circuit.

But wait, there’s more! As a carbon-based material, it lacks any of the hazards associated with keeping heavy metals in batteries near open wounds.

“It’s cheap, highly conductive and if you give it a high surface area, you’d have the ultimate electrode,” Kaner said.

So how are tiny organic batteries and directed cell replication related? See part two in next week’s Aggie.

ALAN LIN is just filled with ions and can be reached at science@theaggie.org.


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