Comprehensive and Systematic Analysis of the Immunocompatibility of Polyelectrolyte Capsules.

The immunocompability of polyelectrolyte capsules synthesized by layer-by-layer deposition has been investigated. Capsules of different architecture and composed of either non-degradable or biodegradable polymers, with either positively or negatively charged outer surface, and with micrometer size, have been used, and the capsule uptake by different cell lines has been studied and quantified. Immunocompatibility studies were performed with peripheral blood mononuclear cells (PBMCs). Data demonstrate that incubation with capsules, at concentrations relevant for practical applications, did not result in a reduced viability of cells, as it did not show an increased apoptosis. Presence of capsules also did not result in an increased expression of TNF-α, as detected with antibody staining, as well as at mRNA level. It also did not result in increased expression of IL-6, as detected at mRNA level. These results indicate that the polyelectrolyte capsules used in this study are immunocompatible.

Development of new methodologies for on-line determination of the bromate ion in samples of water subjected to ozonation treatment.

The bromate ion has been identified as an inorganic disinfection by-product (DPB) in water subjected to purification treatment. Its presence arises from the application of oxidation processes to water containing bromide through the action of oxidant agents such as the ozone used in ozonation processes. This ion has been identified as a possible carcinogen by the U.S. Environmental Protection Agency, which recommends a maximum concentration of 10 microgL(-1). The literature reports a broad range of methods for the analysis of bromate in water, among which ion chromatography is the one most widely used, with different detection systems. However, most of the methods described to date require state-of-the-art technology and costly instrumentation, such that they are not readily adaptable to routine analyses. The present work reports a procedure for the spectrophotometric determination of bromate based on the bromination reaction of 3-3' dimethoxybenzidine, o-dianisidine (ODA). The reaction is based on the formation of Br2 in the presence of excess bromide and the later bromination of ODA, generating a product that absorbs at 450 nm. The procedure was set up with Flow Injection Analysis and allows the determination of the analyte in the 8 microg L(-1)-3.3 mg L(-1) range, with a detection limit of 6.0 microg L(-1) and relative standard deviations (n=12, [BrO3-]=8.0 and 30.0 microg L(-1)) of 4.8% and 2.9%, respectively. The determination rate was 10-11 samples/hour.

Functional insights into the cellular response triggered by a bile-acid platinum compound conjugated to biocompatible ferric nanoparticles using quantitative proteomic approaches.

At present, bioferrofluids are employed as powerful multifunctional tools for biomedical applications such as drug delivery, among others. The present study explores the cellular response evoked when bile-acid platinum derivatives are conjugated with bioferrofluids by testing the biological activity in osteosarcoma (MG-63) and T-cell leukemia (Jurkat) cells. The aim of this work is to evaluate the biocompatibility of a bile-acid platinum derivative conjugated with multi-functional polymer coated bioferrofluids by observing the effects on the protein expression profiles and in intracellular pathways of nanoparticle-stimulated cells. To this end, a mass spectrometry-based approach termed SILAC has been applied to determine in a high-throughput manner the key proteins involved in the cellular response process (including specific quantitatively identified proteins related to the vesicular transport, cellular structure, cell cycle, biosynthetic process, apoptosis and regulation of the cell cycle). Finally, biocompatibility was evaluated and validated by conventional strategies also (such as flow cytometry, MTT, etc.).