Abstract
BackgroundThe blood proteome is thought to represent a rich source of biomarkers for early stage disease detection. Nevertheless, three major challenges have hindered biomarker discovery: a) candidate biomarkers exist at extremely low concentrations in blood; b) high abundance resident proteins such as albumin mask the rare biomarkers; c) biomarkers are rapidly degraded by endogenous and exogenous proteinases.Methodology and Principal FindingsHydrogel nanoparticles created with a N-isopropylacrylamide based core (365 nm)-shell (167 nm) and functionalized with a charged based bait (acrylic acid) were studied as a technology for addressing all these biomarker discovery problems, in one step, in solution. These harvesting core-shell nanoparticles are designed to simultaneously conduct size exclusion and affinity chromatography in solution. Platelet derived growth factor (PDGF), a clinically relevant, highly labile, and very low abundance biomarker, was chosen as a model. PDGF, spiked in human serum, was completely sequestered from its carrier protein albumin, concentrated, and fully preserved, within minutes by the particles. Particle sequestered PDGF was fully protected from exogenously added tryptic degradation. When the nanoparticles were added to a 1 mL dilute solution of PDGF at non detectable levels (less than 20 picograms per mL) the concentration of the PDGF released from the polymeric matrix of the particles increased within the detection range of ELISA and mass spectrometry. Beyond PDGF, the sequestration and protection from degradation for a series of additional very low abundance and very labile cytokines were verified.Conclusions and SignificanceWe envision the application of harvesting core-shell nanoparticles to whole blood for concentration and immediate preservation of low abundance and labile analytes at the time of venipuncture.
Highlights
The peptidome/metabolome, populated by small circulating proteins, nucleic acids or metabolites, represents a valuable source of biomarker information reflecting the biologic state of the organism [1,2]
We envision the application of harvesting core-shell nanoparticles to whole blood for concentration and immediate preservation of low abundance and labile analytes at the time of venipuncture
Despite the recent progress in proteomics discovery and measurement technologies, identification of clinically useful biomarkers has been painfully slow. While this lack of progress is partly due to the inherent analytical difficulties associated with an extraordinarily complex sample matrix such as blood, there are three fundamental and serious physiologic barriers thwarting biomarker discovery and measurement: 1. The foremost problem in biomarker measurement is the extremely low abundance of candidate markers in blood, which exist below the detection limits of mass spectrometry and conventional immunoassays
Summary
The peptidome/metabolome, populated by small circulating proteins, nucleic acids or metabolites, represents a valuable source of biomarker information reflecting the biologic state of the organism [1,2]. Tissue-derived proteins, that are too large to passively enter the blood stream, can be represented in the circulation as peptides or protein fragments This LMW region of the proteome is amenable to biomarker discovery based approaches using current mass spectrometry technology. The foremost problem in biomarker measurement is the extremely low abundance (concentration) of candidate markers in blood, which exist below the detection limits of mass spectrometry and conventional immunoassays. Such a low abundance would be expected for early stage disease since the diseased tissue constitutes a small proportion of the patient’s tissue volume. Three major challenges have hindered biomarker discovery: a) candidate biomarkers exist at extremely low concentrations in blood; b) high abundance resident proteins such as albumin mask the rare biomarkers; c) biomarkers are rapidly degraded by endogenous and exogenous proteinases
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
