Anti-SELP monoclonal antibody, clone BL5 Functional Grade

The objectives of this study were to evaluate: (i) the influences of hydrogel geometry, DNA molecular weight, and DNA conformation on DNA release from a silk-elastinlike protein polymer (SELP) hydrogel, (ii) the bioactivity and transfection efficiency of encapsulated DNA over time in vitro, (iii) the delivery and transfection of a reporter gene in a murine model of human breast cancer in vivo, and (iv) the in vitro release and bioactivity of adenovirus containing the green fluorescent protein (gfp) gene as a marker of gene transfer. Plasmid DNA was released from SELP hydrogels in a size-dependent manner, with the average effective diffiisivity ranging from 1.70 +/- 0.52 x 10(-12) cm(2)/s for a larger plasmid (11 kbp) to 2.55 +/- 0.51 x 10(-10) cm(2)/s for a smaller plasmid (2.6 kbp). Plasmid conformation also influenced the rate of release, with the rank order linear>supercoiled>open-circular. DNA retained bioactivity in vitro, after encapsulation in a SELP hydrogel for up to 28 days. Delivery of pRL-CMV from a SELP hydrogel resulted in increased transfection in a murine model of human breast cancer by 1-3 orders of magnitude, as compared to naked DNA. The release of a bioactive adenoviral vector was related to the concentration of the polymer in the hydrogel. These studies indicate that genetically engineered SELP hydrogels have potential as matrices for controlled nonviral and viral gene delivery. (C) 2003 Elsevier B.V. All rights reserved.

Accurate determination of selenium (Se) species in biological samples is a critical issue because Se commonly occurs at low levels and in diverse species. The method for the full quantification of Se species in serum samples was proposed through combined ion-pair reverse-phase (RP) chromatography and affinity chromatography (AF) hyphenated to inductively coupled plasma( quadrupole) mass spectrometry (ICP-qMS) with post-column isotope dilution analysis (IDA) and a collision cell technique (CCT). Different Se species like inorganic Se (Se4+ and Se6+), selenocystine (SeCys), selenomethionine (SeMet), selenoprotein P (SelP), selenoalbumin (SeAlb) and glutathione peroxidase (GPx) can be separated and quantified. The proposed methodology was used to qualitatively and quantitatively study the dynamic distribution of Se species in human serum samples from the Hg-contaminated area after supplementation with 100 mu g of Se daily as Se-enriched yeast for 180 days. SelP takes up almost half and even more of the total Se and increases with the Se administration. The repeatability in terms of relative standard deviation (R. S. D. %, n = 10) is 6% for GPx and SelP and 5% for SeAlb. The detection limits are 0.1 mu g Se L-1 for GPx and other non-retained Se compounds, 1.0 mu g Se L-1 for SelP and 1.2 mu g Se L-1 for SeAlb, 1.3 mu g Se L-1 for inorganic Se; 1.2 mu g Se L-1 for SeCys; 1.1 mu g Se L-1 for SeMet, respectively.