Application of Hydrogel Nanoparticles for the Capture, Concentration, and Preservation of Low-Abundance Biomarkers

Abstract

In the recent years, a lot of emphasis has been placed on the discovery and detection of clinically relevant biomarkers. Biomarkers are crucial for the early detection of several diseases, and they play an important role in the improvement of current treatments, thus reducing patient mortality rate. Because biofluids account to 60% of the body mass, they represent a goldmine of significant biomarkers. Unfortunately, because of their low concentration in body fluids, their lability, and the presence of high abundance proteins (i.e., albumin and immunoglobulins), low abundance biomarkers are difficult to detect with mass spectrometry or immunoassays. Nanoparticles made of poly(N-isopropylacrylamide) (NIPAm) and functionalized with affinity reactive baits allow researchers to overcome these physiological barriers and in one single step capture, concentrate, and preserve labile biomarkers in complex body fluids (i.e. urine, blood, sweat, CSF). Although hydrogel nanoparticles have been largely studied and used as a drug delivery tool, our application focuses on their capturing abilities instead of the releasing of specific drug molecules. Once the functionalized nanoparticles are incubated with a biological fluid, small biomarkers are captured by the affinity baits while unwanted high abundance analytes are excluded. The potentially relevant biomarkers are then concentrated into small volumes. The concentration factor (up to 10,000-fold) successfully enhances the detection sensitivity of mass spectrometry and immunoassays allowing the detection of previously invisible proteins.

Towards Addressing the Body Electrolyte Environment via Sweat Analysis:Pilocarpine Iontophoresis Supports Assessment of Plasma Potassium Concentration

“…Many efforts are therefore ongoing to design fast, reliable and user-friendly methods to access the body’s biochemical status via sweat, and hence to directly address pathophysiological conditions. One such attempt is development of alternative approaches of non-invasive collection and manipulation of metabolites released in sweat by skin via the use of osmotic properties of hydrogels contained in micropatches 12 – 14 . These approaches are based on nanosized hydrogel particles functionalized with affinity reactive baits and are designed to investigate complex body fluids such as sweat.…”

“…These approaches are based on nanosized hydrogel particles functionalized with affinity reactive baits and are designed to investigate complex body fluids such as sweat. Those formats can concentrate up to 10 4 -fold and isolate in one single step low abundance biomarkers prior to analysis whereas unwanted high abundance analytes are excluded concomitantly 12 – 14 .…”

Strategies for Characterization of Low-Abundant Intact or Truncated Low-Molecular-Weight Proteins From Human Plasma

“…In addition, specialized affinity bait-containing hydrogel particles, which simultaneously conduct molecular sieve chromatography and affinity chromatography in one step, have shown great promise for LMW proteins harvesting. Cumulative evidence shows that hydrogel particles can conduct enrichment and encapsulation of selected classes of proteins and peptides from complex mixtures of biomolecules such as native human serum and urine, purify them from endogenous high-abundance proteins such as albumin, and protect them from degradation during subsequent sample handling [45,50,51].…”