title: Multifunctional core-shell nanoparticles: discovery of previously invisible biomarkers.
abstract: Many low-abundance biomarkers for early detection of cancer and other diseases are invisible to mass spectrometry because they exist in body fluids in very low concentrations, are masked by high-abundance proteins such as albumin and immunoglobulins, and are very labile. To overcome these barriers, we created porous, buoyant, core-shell hydrogel nanoparticles containing novel high affinity reactive chemical baits for protein and peptide harvesting, concentration, and preservation in body fluids. Poly(N-isopropylacrylamide-co-acrylic acid) nanoparticles were functionalized with amino-containing dyes via zero-length cross-linking amidation reactions. Nanoparticles functionalized in the core with 17 different (12 chemically novel) molecular baits showed preferential high affinities (K(D) < 10(-11) M) for specific low-abundance protein analytes. A poly(N-isopropylacrylamide-co-vinylsulfonic acid) shell was added to the core particles. This shell chemistry selectively prevented unwanted entry of all size peptides derived from albumin without hindering the penetration of non-albumin small proteins and peptides. Proteins and peptides entered the core to be captured with high affinity by baits immobilized in the core. Nanoparticles effectively protected interleukin-6 from enzymatic degradation in sweat and increased the effective detection sensitivity of human growth hormone in human urine using multiple reaction monitoring analysis. Used in whole blood as a one-step, in-solution preprocessing step, the nanoparticles greatly enriched the concentration of low-molecular weight proteins and peptides while excluding albumin and other proteins above 30 kDa; this achieved a 10,000-fold effective amplification of the analyte concentration, enabling mass spectrometry (MS) discovery of candidate biomarkers that were previously undetectable.
authors: Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia 20110, USA.
authors: Davide
authors: D
authors: Tamburro
authors: Claudia
authors: C
authors: Fredolini
authors: Virginia
authors: V
authors: Espina
authors: Temple A
authors: TA
authors: Douglas
authors: Adarsh
authors: A
authors: Ranganathan
authors: Leopold
authors: L
authors: Ilag
authors: Weidong
authors: W
authors: Zhou
authors: Paul
authors: P
authors: Russo
authors: Benjamin H
authors: BH
authors: Espina
authors: Giovanni
authors: G
authors: Muto
authors: Emanuel F
authors: EF
authors: Petricoin
authors: Lance A
authors: LA
authors: Liotta
authors: Alessandra
authors: A
authors: Luchini
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis / Q000737:chemistry*; D014408:Biomarkers, Tumor / Q000097:blood / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry; D013006:Growth Hormone / Q000652:urine; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D011506:Proteins / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000178:Acrylamides; D014408:Biomarkers, Tumor; D004396:Coloring Agents; C090629:N-isopropylacrylamide-acrylic acid copolymer; D010455:Peptides; D011108:Polymers; D011506:Proteins; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D013006:Growth Hormone