Enabling Point-of-Care Diagnostics - Interview with Speakers
Holger Becker of the microfluidic ChipShop will be chairing the session next month on Novel Tools for Point-Of-Care at the 8th Annual Enabling Point-of-Care Diagnostics conference. He asked the speakers in his session, Aydogan Ozcan of UCLA, David Erickson of Cornell University, Ian White of the University of Maryland and Aaron Wheeler of the University of Toronto, for their thoughts on technologies and issues pertinent to the field. Here is a preview of the session.
1. What would be the most pressing medical/diagnostic need which could be solved with new technologies?
Aydogan Ozcan: There are so many needs - each of which would be crucial for different parts of the world and for different populations, age groups etc. For infectious diseases, diagnosis, treatment and monitoring of HIV, TB and malaria are very important as they collectively cause several million deaths each year.
David Erickson: The most pressing need (as opposed to say market potential) is likely diagnostics in the remote parts lower and middle income countries. In particular, infectious diseases (which if diagnosed early can limit larger outbreaks) and malnutrition (which has lifelong consequences). The opportunity is that smartphone technology is widely available in many of these areas and thus it makes sense to develop synergistic technologies.
Ian White: Accurate, affordable, and rapid diagnostics. Bloodstream infections represent one of many examples. Bloodstream infections don't present with obvious signs. If a bloodstream infection is suspected, blood is drawn for culture. Cultures may take more than two days, and the identification of drug-resistant species adds additional time. The patient's health can deteriorate significantly during this time, and broad spectrum antibiotics must be used (which further promotes the emergence of drug resistant pathogens). Furthermore, blood cultures are infamously inaccurate. It is necessary to develop a tool that can rapidly diagnose bloodstream infections, and that is simple enough that the test can be performed for low cost in the clinic.
Aaron Wheeler: A symptom-based multiplexed panel for pediatric respiratory illness.
2. What are the current technological bottlenecks for realizing a solution to 1)?
Aydogan Ozcan: Most existing solutions depend on surface functionalization and surface chemistry. Cost, shelf-time, quality control and storage requirements are barriers for success. In the case of malaria, fragmentation of the market is also an issue.
David Erickson: I think in many of these cases there are very few technological bottlenecks and most of the challenge lies in developing successful business models that allow for deployment.
Ian White: The primary difficulty is sample preparation. Polymerase chain reaction can be used to identify pathogens, but the sample preparation steps to convert whole blood into a sample ready for PCR are too complicated and time consuming to be performed for low cost in the clinic.
Aaron Wheeler: Sample prep is the biggest problem—in particular bridging the gap from the macro-scale of clinical specimens to the micro-scale of efficient fluidics/detection.
3. Lab-on-a-chip technologies have been around for quite some time. Where do you see the biggest hurdles for the uptake into diagnostic/clinical practice?
Aydogan Ozcan: The answer to this question depends on the medical application and the setting, location that it is implemented. Generally, I see hype generating spin-off companies as a major threat to the eco-system as they, with their hypes, mislead the community as a whole with false expectations.
David Erickson: Lab-on-chip type technology is used in some clinical practices now. One thing that limits the larger uptake at the consumer level is cost of developing and purchasing a test-instrument system for measurements that are only done occasionally (e.g. cholesterol monitoring).
Ian White: The interface between the microfluidic chip and the sample is still a problem, as is raw sample prep.
Aaron Wheeler: Most systems that I see are either (a) very simple, with modest capability to integrate sophisticated sample processing protocols, or (b) require extensive off-chip ancillary equipment to operate (pumps, valves, tubes, interconnects, etc.). For POC, we need true “chip-scale” solutions that can perform all of the common lab protocols of a clinical assay in a fully automated and inexpensive manner. Whoever solves this wins.
4. Which application or technology is emerging as a hot topic in a 2-5 year time-frame?
Aydogan Ozcan: Whole genome sequencing for a few hundred dollars.
David Erickson: Nutrition
Ian White: Diagnostics in low resource settings.
Aaron Wheeler: I am biased, but I believe that digital microfluidics (DMF) is an emerging solution of the future for true POC Dx that is CLIA waived.
5. What was your biggest disappointment with regards to a technology which did not take off as you would have expected?
Aydogan Ozcan: Meta-material based microscopy and nanoscopy.
David Erickson: There is so much potential in personalized diagnostics. I'm not sure I'm disappointed that it hasn't take off yet, but perhaps if it doesn’t take off in a few years I will be.
Ian White: Microfluidic PCR is a perfect example of an excellent microfluidic technology that has not realized its potential because of a lack of sample/chip interface and the lack of automated sample preparation.
Aaron Wheeler: Interestingly, I think it is digital microfluidics (DMF). Several groups have tried, but none, in my opinion, have addressed the complete solution as described above. I recently helped spin out a company, Kapplex, Inc., to address this opportunity.
To learn more and connect with this faculty, make plans to attend Enabling Point-of-Care Diagnostics, taking place at the 2014 Next Generation Dx Summit, August 19-20 in Washington, DC.