Analytical performance of a standardized kit for mass spectrometry-based measurements of human glycosaminoglycans.

Glycosaminoglycans (GAGs) are long linear sulfated polysaccharides implicated in processes linked to disease development such as mucopolysaccharidosis, respiratory failure, cancer, and viral infections, thereby serving as potential biomarkers. A successful clinical translation of GAGs as biomarkers depends on the availability of standardized GAG measurements. However, owing to the analytical complexity associated with the quantification of GAG concentration and structural composition, a standardized method to simultaneously measure multiple GAGs is missing.

Shotgun proteomics coupled to nanoparticle-based biomarker enrichment reveals a novel panel of extracellular matrix proteins as candidate serum protein biomarkers for early-stage breast cancer detection.

Background: The lack of specificity and high degree of false positive and false negative rates when using mammographic screening for detecting early-stage breast cancer is a critical issue. Blood-based molecular assays that could be used in adjunct with mammography for increased specificity and sensitivity could have profound clinical impact. Our objective was to discover and independently verify a panel of candidate blood-based biomarkers that could identify the earliest stages of breast cancer and complement current mammographic screening approaches.

Identification of novel candidate circulating biomarkers for malignant soft tissue sarcomas: Correlation with metastatic progression.

Soft tissue sarcomas (STS) are a heterogeneous group of rare tumors for which identification and validation of biological markers may improve clinical management. The fraction of low-molecular-weight (LMW) circulating proteins and fragments of proteins is a rich source of new potential biomarkers. To identify circulating biomarkers useful for STS early diagnosis and prognosis, we analyzed 53 high-grade STS sera using hydrogel core-shell nanoparticles that selectively entrap LMW proteins by size exclusion and affinity chromatography, protect them from degradation and amplify their concentration for mass spectrometry detection.

Immunocapture strategies in translational proteomics.

Aiming at clinical studies of human diseases, antibody-assisted assays have been applied to biomarker discovery and toward a streamlined translation from patient profiling to assays supporting personalized treatments. In recent years, integrated strategies to couple and combine antibodies with mass spectrometry-based proteomic efforts have emerged, allowing for novel possibilities in basic and clinical research. Described in this review are some of the field's current and emerging immunocapture approaches from an affinity proteomics perspective.

Analysis of urinary human growth hormone (hGH) using hydrogel nanoparticles and isoform differential immunoassays after short recombinant hGH treatment: preliminary results.

Successful application clinical-grade human growth hormone (hGH) immunoassays to the discovery of illegal doping cases has been rare. Indeed, the preferred biological matrix in doping control is urine, where the estimated baseline concentration of hGH falls well below the linear range and sensitivity threshold of all commercially available immunoassays, including hGH isoform differential immunoassays which can discriminate pituitary endogenous hGH from recombinant hGH. We employed hydrogel nanoparticles as a pre-processing step that concentrate urinary hGH into the linear range of isoform differential immunoassays.

Application of Analyte Harvesting Nanoparticle Technology to the Measurement of Urinary HGH in Healthy Individuals.

Urine represents a valuable biofluid for noninvasive measurement of Human Growth Hormone (HGH) secretion. Unfortunately, currently available commercial HGH immunoassays do not achieve the sensitivity needed for urinary HGH measurement in the low picogram per milliliter range, the expected normal concentration range of HGH in urine. A nanotechnology based sample preprocessing step was used to extract and concentrate HGH in urine so that urinary HGH could be measured with a clinical grade standard immunoassay designed for serum (Immulite 1000, Siemens).

Multifunctional core-shell nanoparticles: discovery of previously invisible biomarkers.

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.

Mass spectrometry-based characterization of the vitreous phosphoproteome.

Purpose: the vitreous gel is a highly hydrated extracellular matrix containing many proteins. These proteins are likely accumulated in the vitreous by local secretion, filtration from the blood, or diffusion from the surrounding tissues and vasculature, and may be altered in disease state. In the last several years, several reports of large-scale profiling of vitreous proteins have been published; however, there is little information on the characterization of the phosphoproteome of vitreous.

The use of hydrogel microparticles to sequester and concentrate bacterial antigens in a urine test for Lyme disease.

Hydrogel biomarker capturing microparticles were evaluated as a biomaterial to amplify the sensitivity of urine testing for infectious disease proteins. Lyme disease is a bacterial infection transmitted by ticks. Early diagnosis and prompt treatment of Lyme disease reduces complications including arthritis and cardiac involvement.

Nanoparticle technology: amplifying the effective sensitivity of biomarker detection to create a urine test for hGH.

Several clinical-grade immunoassays exist for the specific measurement of hGH or its isoforms in blood but there is an urgent need to apply these same reliable assays to the measurement of hGH in urine as a preferred 'non-invasive' biofluid. Unfortunately, conventional hGH immunoassays cannot attain the sensitivity required to detect the low concentrations of hGH in urine. The lowest limit of sensitivity for existing hGH immunoassays is >50 pg/mL, while the estimated concentration of urinary hGH is about 1 pg/m-50 times lower than the sensitivity threshold.

Air sampling with Empore solid phase extraction membranes and online single-channel desorption/liquid chromatography/mass spectrometry analysis: determination of volatile and semi-volatile organophosphate esters.

A method for determining organophosphate esters in air samples using C8 Empore solid phase extraction (SPE) membranes has been developed. After the sampling the analytes trapped in the membrane are completely desorbed with methanol, using an extraction cell connected online to the organic modifier channel of a HPLC gradient pump. The addition of water to the mobile phase prior to analytical chromatography ensures that the analytes are refocused and efficiently separated.

A simple and rapid assay for analyzing residues of carbamate insecticides in vegetables and fruits: hot water extraction followed by liquid chromatography-mass spectrometry.

A simple, specific, and rapid analytical method for determining seven largely used carbamate insecticides in tomato, spinach, lettuce, zucchini, pear, and apple is here presented. This method is based on the matrix solid-phase dispersion technique, with heated water as extractant followed by liquid chromatography (LC)-mass spectrometry (MS) equipped with a single quadrupole and an electrospray ion source. Target compounds were extracted from the vegetal matrixes by water heated at 50 degrees C.