By Ben Butkus
Carpegen, a German company providing real-time PCR-based periodontal testing services to dental practices, has developed a prototype microfluidic cartridge and benchtop instrument to enable practitioners to perform such testing at the point of care.
In addition, the company believes that its platform can be used for a wide variety of point-of-need testing in the diagnostic, food safety, and environmental markets, among others, and is seeking partners to help further develop the technology for those applications, company officials said.
Carpegen, based in Muenster, was founded in September 2001. Since that time, it has focused on developing molecular testing platforms based on real-time PCR and DNA chip technology for detecting and diagnosing periodontal pathogens.
The company has always operated under a service model, providing kits to dental practices for sample collection and testing the samples in house. Beginning in 2003, Carpegen forged a partnership with GABA International, a business unit of Colgate-Palmolive, to market its testing service and distribute kits to customers.
However, last year Carpegen split from GABA, finding that it was "much more effective to have direct contact with our customers," Carpegen CEO Antje Roetger told PCR Insider last week.
Even before the split with GABA, based on feedback it received from clients, Carpegen was considering the development of a point-of-care system that would allow dentists to conduct testing for periodontal pathogens in their clinics. Like any diagnostic testing, Roetger said, it made much more sense for dentists to be able to receive relatively fast results compared to the days or even weeks it might take to send a test to a central laboratory for testing.
Carpegen won an unspecified amount of funding from the German Federal Ministry of Education and Research to explore the development of such a system under a program entitled "Integrated Microsystems for Biotechnological Applications."
Because Carpegen's expertise was primarily in DNA testing and PCR, it enlisted another small local company called Systec Elektronik to work on the microelectromechanical and microfluidics development necessary to create a point-of-care testing system.
"We started this in 2007, and now we have a prototype that works quite well," Roetger said. "We worked very well together with Systec to develop a new system based on fluidic cicruits." In fact, the system has worked so well in internal tests that Carpegen decided that it would be suitable for other point-of-testing applications, she said.
"It could be used for detecting hospital infections such as MRSA; or for respiratory infections," Roetger said. "It's also interesting for non-medical applications such as environmental and food testing. We would like to distribute the system ourselves to dentists; but for other applications we are looking for partners with access to these other markets."
The prototype system uses a circular cartridge built from three molded plastic discs containing microfluidic circuits. The discs are stacked on one another but each can rotate independently of the other, allowing various microfluidic channels to be formed for sample processing and detection.
The cartridge is placed into a bench-top instrument about the size of a computer printer, which runs the assay by rotating the various components and performing sample processing, nucleic acid extraction, PCR setup, fluorescence-based data acquisition, and raw data analysis. From start to finish a test would likely take less than an hour, according to the company.
One of the system's strengths is that it is "a completely closed device," Krzysztof Siemieniewicz, Carpegen's senior project manager in R&D, told PCR Insider. "Once the sample enters the device, the PCR product never leaves," thus eliminating potential contamination of the sample or the platform, he added.
"It's also very flexible, because you basically create collection areas between chambers on this disc by rotating them," Siemieniewicz said. "It was basically developed for DNA diagnostics or nucleic acid testing, but I also can imagine doing immunology or other testing on it."
In addition, Carpegen said that the system is easy enough to be used by trained healthcare or semi-skilled personnel, further making it suitable for point-of-care testing.
The platform will likely use a specific TaqMan-based real-time PCR reaction since that is what Carpegen currently uses for its testing services. For sample preparation, Carpegen employs magnetic beads combined with its own lysis buffers and reagents.
Carpegen is still testing and validating the platform, and plans to use it to process periodontal assays through its in-house testing service. "This is very practical for us because we have our own test for periodontal pathogens," Roetger said. "This is a very well-evaluated and -validated method. It has been used in many clinical studies for periodontology, is considered a gold standard in the dental diagnostics market, and it's perfect for validating the system."
Carpegen has also signed on a clinical partner in the Center of Dentistry of the University Hospital of Bonn, which has "provided samples for optimizing the system and specifications for everything that is important from the view of the dentist," Roetger said.
The company would like to directly sell the platform to the periodontal testing market, which comprises "more than 40,000 dental offices in Germany alone," not to mention other European countries. Many of these dental offices currently use molecular diagnostics, "and we are quite sure that many of them will buy a device if it's available," she added.
In order to market to dental practices, however, Carpegen will likely need to secure some sort of financing, Roetger said, without specifying how much. In the meantime, "the next step for us is to approach companies in the diagnostic and pharma industries and try to make some interesting licensing deals," she said.
Carpegen has filed an international patent application covering its technology, Roetger said.