Marrying microfluidics and microarray technology, Gene Logics new spinoff Metrigenix is planning to market its Flow-thru Chip, a three-dimensional honeycomb of silicon microchannel probe surfaces that is designed to speed up hybridization times and increase probe sensitivity.
The Flow-thru Chip can hold your target molecule of interest in a three-dimensional space, then because its a honeycomb porous surface, you can run your fluorescent probe through it using microfluidics devices, and therefore greatly accelerate the reaction speed, said Mark Schena, a microarray pioneer and editor of the book Microarray Biochip Technology. What takes hours on glass you can do in five to ten minutes on Flow-thru Chips, Schena said.
Since microchannels offer a larger surface area than a typical probe spot on a two-dimensional array, more probe molecules can be attached to each one, increasing the overall sensitivity of each probe, and allowing for effective testing of smaller sample volumes. The Flow-thru Chips so far have been validated to detect changes as low as two-fold, and can go up three logs of expression changes, said Andrew OBeirne, the new CEO of Metrigenix. This technology can also make a very uniform and reproducible product, he said.
To launch the Flow-thru Chip, Metrigenix has garnered $15 million in financing from an all-star cast of biotech venture investors, including Oxford Bioscience Partners, Burrill Biotechnology Capital Fund, GE Capital Equity, and German semiconductor company Infineons financing arm, Infineon Ventures.
Gene Logic, which owns 54 percent of the new company, will provide the intellectual property and other proprietary technology related to the Flow-thru Chips. OBeirne, formerly Gene Logics senior vice president of new ventures, is among 14 Gene Logic employees who are moving over to Metrigenix. The company, which is temporarily housed on Gene Logics Gaithersburg, Md. campus is looking for a permanent location nearby, O Beirne said.
Infineon will use its semiconductor manufacturing prowess to manufacture the chip substrates, and Metrigenix will design and market the finished chips, in custom and prefabricated forms, for high-speed drug discovery assays.
Metrigenix is planning to market the Flow-thru Chips to pharmaceutical and biotechnology companies as a more precise second-stage microarray for drug development, avoiding direct competition with Affymetrix, to which Gene Logic has close ties. Were going to be focused in a more defined content space, said OBeirne.
The chips will have between one and 40 probes, not the tens of thousands that Affymetrix arrays have.
A pharmaceutical company interested in a particular disease or drugs can run the Affymetrix chip and identify 150 genes that look interesting for additional study. We are looking to take those 150 genes, and put them on our chip, said OBeirne. If they have 10,000 compounds they want to test against [genes], rather than running the 10,000 compounds against an Affymetrix chip, they can run them against our chip, and there will be a lot less data to wade through.
The chip has not been priced yet, but will be very cost effective, OBeirne said.
While a number of other companies have developed three-dimensional microarrays, this technology is distinctive in allowing the sample to remain in solution during hybridization. The other three-dimensional platforms, like Motorolas GelChip and Schleicher & Schuells nitrocellulose-coated FAST slides, suspend the target molecule in a three-dimensional polymer gel. This suspension can actually slow down hybridization, according to Gene Logic, rather than speeding it up as the Flow-thru Chip does.
But like the other three-dimensional microarray platforms, the Flow-thru Chip has a structure that lends itself to use as a substrate for protein probes, which function better when allowed to retain their three-dimensional shape. While Metrigenix initial product will have gene probes, Protein Flow-thru Chips are definitely in the plan, said OBeirne.
To control the flow of fluid for uniform deposition, the Flow-thru Chip contains microfluidics pumping mechanisms entirely within its structure, said OBeirne.
Additionally, the Flow-thru Chip requires an entirely different instrument for scanning than slide microarrays a feature that could present a cost barrier for researchers, especially those who have already shelled out $40,000 to $60,000 on an Axon scanner or similar model.
However, if a lab has a Microscope CCD camera, this instrument can be used to scan Flow-thru Chips, said OBeirne. The company is also developing its own CCD scanner for the chips that will cost researchers half what CCD cameras cost. The company plans to market the scanner and the arrays as a package, although customers can buy each separately as well.
Another potential disadvantage to the chip includes the fact that the honeycomb structure is somewhat physically fragile. You cant use contact printing to print the chips. You need to use a non-contact process like [Packards] inkjet, said Schena.
With these liabilities, newcomer Metrigenix faces the challenge of capturing market share from existing players, who are growing more numerous each month. But if the company is able to show that the Flow-thru Chip offers better and faster results at a lower price, this might be enough of an advantage to get pharmaceutical researchers to jump onto the Metrigenix bandwagon, said Schena. If you can do something in five minutes rather than two to four hours, he said, that presents a major advantage.