Manufacturing Bits: July 30

Scanning nanopore microscopes
ETH Zurich has developed a new microscopy technique that can detect and analyze signals between individual cells in living organisms.

The technology, called a force-controlled scanning nanopore microscope, is a new way to look at the behavior of individual cells. So far, researchers have tested the technology on rat brain tissue. It could one day be used to provide insights into various diseases in other organisms.

Cells are the basic building blocks for living organisms. Cells consist of biomolecules, including proteins and nucleic acids. “For the cells in our bodies to function as a unit, they must communicate with one another constantly,” according to ETH.

“They secrete signaling molecules – ions, proteins and nucleic acids – that are picked up by adjacent cells, which in turn pass on the signal to other cells,” according to ETH. “Our muscles, digestive system and brain are only able to function thanks to this type of communication. And this is the only way in which our immune system can recognize pathogens or infected cells and react accordingly – again, by sending out signals to mobilize the immune defenses.”

That’s why it is important to look at cells and the signals between them. Researchers have developed a way to measure these signals, but it requires hundreds or thousands of cells to accomplish this feat, according to ETH.

In response, researchers from ETH has devised a fluid force microscope, which is equipped with a special cantilever tip. It’s basically a solid-state nanopore integrated in an atomic force microscope (AFM).

A tiny sensor is placed on the tip of the AFM. The sensor is basically a silicon nitride pore, which registers when a cell releases various molecules. It monitors the ion-channel activities of single cells.

ETH’s technology can also look at ribonucleic acid (RNA) in cells. This, in turn, can provide insights “into which proteins a cell is currently producing – a key factor in the onset of many diseases.”

RNA, which is a nucleic acid, is present in living cells. It carries instructions from DNA for controlling the synthesis of proteins. Some RNA also carry genetic information. Deoxyribonucleic acid (DNA) is a molecule that carries the genetic instructions in living things. A complete set of DNA is called the genome.

“Our goal is to ultimately be able to analyze all of a cell’s signals,” said János Vörös, head of the Laboratory of Biosensors and Bioelectronics at ETH. “Our method offers biologists completely new ways of investigating the behavior of individual cells.”

Infrared microscopes
The University of Tokyo has developed a microscope that can see the molecules inside cells.

Traditional microscopes are limited and can only see the shapes of large structures inside cells. In response, researchers from the University of Tokyo have added a molecular-contrast unit to the microscope. The unit contains an infrared laser light source.
With this light source, the system does not require preparation of the cells with fluorescent dyes.

With the molecular-contrast unit, though, the microscope can locate specific molecules in a cell. This is done by searching for the vibration or heat signal of a molecule.

Researchers have tested the technique using tiny plastic, silica beads and human cells grown in a dish. “We believe the concept of upgrading existing, widespread standard optical microscopes to become molecular-sensitive will expand the research capabilities of various end users,” said Takuro Ideguchi, an associate professor from the University of Tokyo Institute for Photon Science and Technology. “Label-free and damageless molecular microscopic observation, which fulfills an important need in the biomedical field, should be useful for observation of intracellular drug delivery, quality assessment of regenerative cells and tissues, and other essential research functions.”

Biomagnifier
The Institute of Nanophotonics at Jinan University has developed a biomagnifier, a tool for optical imaging, sensing, and assembly of bionanomaterials.

Researchers presented the technology and the results in Light: Science & Applications, a scientific journal. Click here for the paper.