SurroMed has formed a new company, Nanoplex Technologies, to develop applications for its submicrometer barcoding technology in proteomics and other fields, ProteoMonitor learned last week.
Mountain View, Calif.-based SurroMed, which had been investigating whether to use the barcoding technique as part of its in-house drug and biomarker discovery platform, decided to spin out the technology because at its early stage it could not be immediately integrated into SurroMed’s clinical experiments, and because it also had non-biological applications that lie outside of SurroMed’s sphere of interest, said Michael Natan, former chief technology officer at SurroMed and now CEO of Nanoplex.
“SurroMed is focused on technologies that are ready to use in our clinical lab today that we can do at high throughput,” said Natan. “We just couldn’t put resources both into nanobarcodes to get them to that stage — where they’re essentially a commercial product — and also do the things that we were doing inside SurroMed. So the decision was made to let them both go as fast as they can, [and to do that] they needed to have separate financing.”
Natan, who initially devised the barcoding technique while a researcher in Penn State’s department of chemistry, said Nanoplex will close its oversubscribed first round of financing sometime next month with around $12.5 million in funding. The plan, he said, is to develop applications of the technology in fields such as proteomics, and find partners to help bring them to market. “We still think at the end of the day nanobarcodes are going to be the answer to broad-scale proteomics,” he said. “Once nanobarcodes are a commercial product SurroMed will certainly adopt them.”
Notably, however, Applied Biosystems has backed out of an earlier agreement with SurroMed to help commercialize the technology for applications in genomics, Natan said, because the two companies couldn’t agree on intellectual property conditions. An ABI spokesperson declined to comment. Natan added that Nanoplex is close to signing another partner to continue the development work.
The barcodes are useful in large-scale protein assays, Natan said, because each barcode — the technology exists to create up to 1,000 — can be attached to specific proteins or antibodies as identifying markers, in a manner analogous to defining the identity of a protein on a chip-based array by its location.
In one example of how the barcodes might be useful in multiplexed sandwich immunoassays, antibodies tagged with distinct barcodes could be allowed to associate in solution with a sample, and fluorescently-labeled secondary antibodies would identify where a binding event had occurred. Reading out the identities of the complexes requires measuring the reflectivity of the barcode, a 30 nanometer cylinder shaped with alternating stripes of metals including silver, gold, and platinum.
Natan claimed the attached barcode doesn’t interfere with protein function because the metal rods are coated with glass or other protein-friendly chemistry, much like the solid support for an array. But unlike arrays, the solution-based approach has advantages in flexibility — each experiment is easily tailored to the number of proteins under investigation — and in kinetics, thereby significantly reducing the time it takes to run an experiment, he said.
In contrast to similar high-throughput solution-phase assays already on the market from companies such as Luminex, Natan said his barcoding technology can produce larger numbers of identifying tags. “If you really want to do 100 to 1,000 different proteins in solution, that’s one place where we really have a big competitive advantage,” he said.
However, other researchers involved in chip-based protein arrays expressed reservations about the ultimate utility of the barcoding technology in proteomics. “It seems interesting but I would be concerned about the time required to scan and read all the barcodes on all the little rods in a microscope image, and the precision with which an immunoassay can be read wrapped around the surface of a little rod,” said Leigh Anderson, chief scientific officer for Large Scale Biology. Anderson added that a chip-based approach would typically offer advantages in sensitivity and cost over the solution-based approach advocated by Natan.
In any case, Natan envisions just as many non-biological as biological applications for the technology, which he said justifies spinning the technology out of SurroMed. “You can imagine putting them in aircraft parts, in documents, in microchips — there are all kinds of applications, none of which we could pursue inside SurroMed.”