PixelEXX Systems, a nanotechnology shop founded by scientists at Washington University in St. Louis, last week announced that it had received $250,000 in private equity seed financing to help it develop a nanoarray platform for cell imaging.
According to Stuart Solin, co-founder and co-president of PixelEXX, the cash will help the firm develop a prototype array that can survey cells for information that could be useful in high-throughput drug screening and diagnostics.
“Drug screening is a major possible application for this technology,” Solin told Cell-Based Assay News this week. However, Solin stressed that “we don’t know what kinds of applications will be developed with this technology. One cannot predict what will be discovered, and there is uncertainty there of course.”
Part of that uncertainty is the nature of PixelEXX’s platform. The market for cell arrays is extremely nascent, and only a few companies, such as Boston’s Molecular Cytomics, have debuted products. Furthermore, those companies and researchers that have developed cell arrays have relied on microarray imaging or other optical-imaging techniques to look at biological processes in cells.
PixelEXX, on the other hand, will use phenomena discovered in the lab of Solin, a physicist, to measure the physical properties of cells and capture images of those cells via an array of pixels. The technology is based on the premise that by altering the geometric properties of a solid — in this case a cell — one can create optimal properties for cellular assays.
“We are perhaps the first to use geometrical contributions to enhance the impact of desirable properties, and we are trying to make a prototype to make this technology work as an imaging device,” Solin said.
“The idea is to have a nanosensor element or pixel that is very sensitive, configure multiple pixels into an array to sense perturbations in a massively parallel way, and to get an image,” he added. “Ultimately, we are going to produce with super-high resolution what amounts to a contact image. You won’t have to stain cells and go through procedures related to optical processes.”
This technology will allow scientists to do direct imaging of cellular machinery that operates at the nanoscale, said Samuel Wickline, a cofounder of PixelEXX. “You will be able to see [cellular] machinery moving around and doing things in real time, with very high spatial and temporal resolution.”
In addition, the device will enable researchers to register many different kinds of cellular activities at once “instead of using one microscope to look at one thing at one time,” Wickline told CBA News this week.
“You will be able to see [cellular] machinery moving around and doing things in real time, with very high spatial and temporal resolution.”
Wickline also pointed out that the device will be connected to scientists’ PCs where they will obtain an image of the experiment, and will not have to adjust any lenses. He said that the image acquisition will all work via software.
To date, PixelEXX’s founders have been able to develop single-pixel semiconductors to measure the physical properties of a cell. Solin said that much of that development work was supported by a $17 million National Institutes of Health grant awarded to WUSTL’s Center of Materials Innovation in 2005.
In addition to being a cofounder of PixelEXX, Solin also founded the Center for Materials Innovation when he came to WUSTL in 2002.
Solin said that there are a number of extraordinary transport phenomena that PixelEXX can study using its proposed nanoarray devices. The first phenomenon that PixelEXX has selected for use in its assays is extraordinary electroconductance, or measuring electric impulses in a solid, which could have applications in oncology.
According to Solin, PixelEXX aims to make an array capable of imaging EEC in cells within the next 12 to 18 months. “We hope to be able to manufacture these EEC arrays and to use them to study the surface charge density on cancer cells,” he said.
Solin added that, “With EEC, the cell itself is a source because its surface charge density creates an electric field. We will have to build the market, and that is what makes it a bit dicier, but the EEC doesn’t require an external source, and it isn’t difficult to manufacture.”
Accept No Substitute?
Solin explained that the company decided to focus on measuring EEC because it is easier to manufacture and sell than a device for measuring other phenomena, such as extraordinary optoconductance, which measures optical signals, usually by illumination, rather than electronic signals.
Solin said that that PixelEXX had considered building EOC arrays. Such arrays would require an external light source, like a light-emitting diode. And because EOC is already measured in some part by charge-coupled device cameras, PixelEXX would be able to play in an established imaging market.
However, PixelEXX decided that EOC arrays would be too difficult to manufacture as an initial product, and settled on the less-charted course of selling arrays that measure EEC.
Still, Solin said that the next commercial focus of PixelEXX would be on EOC, where users would have the option to study several properties in a cell, including the transmission, absorption, and reflection of light, as well as fluorescence emission.
Although the addition of an external light source complicates the fabrication of an EOC array, a built-in market would already exist for PixelEXX, because it “obviates the need for certain kinds of optical microscopes or other technology that is already in use.”
Wickline agreed, saying that it is a substitute for some microscopic techniques. As he explained, “We put the microscope in the incubator, and in fact, grow the cells on top of the microscope. So you could obtain an image of the cells without having to move anything.”
PixelEXX received the $250,000 seed capital from BioGenerator, a venture-capital group that supports biotechnology entrepreneurial activity in the St. Louis area. As PixelEXX develops its EEC array prototype, the company is also looking to seek further investments to help it commercialize the technology.
So far, the company comprises Solin and Wickline, who is also a professor of internal medicine, biomedical engineering, physics, and cell biology and physiology at WUSTL.
Rounding out the team are Kirk Wallace and Michael Hughes, researchers affiliated with WUSTL who will work as senior scientists at the company. Solin said that PixelEXX is actively seeking other employees, especially with managerial experience, who can help to grow the company.
“We are looking to attract others to work with the company and are in active consultation,” he said. He added that WUSTL has already licensed the patents connected to PixelEXX’s technology to the company, and that the firm believes its IP position to be secure.
In addition, “We are aggressively [developing] our business plan over the next three months,” Wickline said.
— Charlotte LoBuono contributed additional reporting to this article.
A version of this article appears in the current issue of BioArray News, a Cell-Based Assay News sister publication.