Scientists at Washington University in St. Louis have developed a method to preserve protein biomarkers in clinical samples, without the need for refrigeration. The technique relies on growing molecules called metal-organic frameworks around the proteins in the sample, potentially enabling clinicians in remote and low-resource settings to send patient samples long distances for analysis, using the regular mail service.
In many places around the world, taking blood samples to search for protein biomarkers is pointless without refrigerated courier services to transport the samples long distances to the nearest clinical lab. For many, these services are too expensive, or not available.
This problem inspired the Washington University group of researchers to devise a low-cost alternative. Their solution involves “shrink wrapping” the proteins in blood or urine samples for protection by adding nanoporous materials called metal-organic frameworks. The researchers then allow the sample to dry onto standard laboratory filter paper before mailing it to a clinical lab for analysis. The technique is simple enough for clinicians to perform it in the field.
“Once you are ready to analyze the sample, you extract everything from the paper back into liquid,” said Srikanth Singamaneni, one of the researchers involved in the study. “We showed that this method maintains the integrity of the biospecimens.”
The team validated their approach using urine samples they had spiked with a protein biomarker of kidney injury. By adding a nanoporous metal-organic framework to the samples, and then drying them onto filter paper, the team was later able to determine that the technique preserved up to 95% of the protein biomarker in the samples.
The preserved samples also stood up to a real-world test. Using the regular mail service, the research team mailed the loaded filter paper samples to a colleague, who then sent them back, for a total round trip of ten days. After this journey, up to 90% of the protein biomarker was intact, meaning the samples could still provide meaningful clinical information.
“One of our next steps is to take the technology out of the laboratory and commercialize it so that it can work to the greatest good for the greatest number of people,” said Evan D. Kharasch, another researcher involved in the study. “This would make it widely available in both first-world countries as well as emerging countries and in emergency situations or environmental disasters where we need to deploy people and have scarce resources.”
Study in Chemistry of Materials: Metal–Organic Framework Encapsulation for Biospecimen Preservation…
