Surface modification of polyaniline nanorods with thiol-terminated poly(ethylene oxide)

Electrochemically grown polyaniline (PAni) thin films have been shown to react efficiently with thiols, which can dramatically change the surface properties of the material without significantly impacting bulk conductivity. Such films, however, are difficult to process and are unsuitable for many applications. Here, we demonstrate the grafting of thiol-terminated poly(ethylene oxide) (PEG-SH) of various molecular weights onto PAni nanorods. The resulting materials are characterized by spectroscopic, microscopic, and thermal analytical methods to demonstrate the covalent attachment of the PEG polymers to the nanorods. The derivatized nanorods are water dispersible and maintain their original morphology and electroactivity. The number of thiols bound to the nanoparticles under a given set of conditions decreases as the size increases, but the total mass of PEG increases with increasing size. The reaction proceeds at room temperature, but is much faster at higher temperature and greater PEG density is observed

Drug Interactions with Levothyroxine Therapy in Patients with Hypothyroidism: Observational Study in General Practice

Background and Objectives : Several drugs may interact with levothyroxine and reduce its bioavailability. The aim of this study was to analyse the Italian general practice patients with hypothyroidism from 2002â2011, in terms of variation of thyroid-stimulating hormone (TSH) levels, number of levothyroxine prescriptions and dose of levothyroxine before and during potential drugâdrug interactions (DDIs).Methods: Data were extracted from the Italian general practice Health Search CSD Longitudinal Patient Database (HSD). Analysis was limited to individuals aged 18 years and older with at least one levothyroxine prescription from 2002 to 2011 and at least one year of clinical history recorded in HSD. A quasi-experimental pre-post analysis was carried out using a self-controlled study design, on an intention-to-treat basis.Results: Overall, 5,426 levothyroxine users (7.5 % of population in HSD) were included in the study. The incidence rate ratio comparing the TSH trend before and during the period of exposure to potential DDI showed a significant increase of TSH levels during initial exposure to potential DDI, which decreased over time. The number of prescriptions and dose of levothyroxine decreased before the potential DDI and increased symmetrically during the period of exposure to potential DDI.Conclusions: The co-prescription of levothyroxine and potentially interacting drugs results in an increased use of levothyroxine. Clinicians should carefully consider adjusting levothyroxine therapy in presence of concomitant drugs, such as proton-pump inhibitors, which may reduce levothyroxine bioavailability

Light induced functionalization of PCL-PEG block copolymers for the covalent immobilization of biomolecules

Functionalized poly-ε-caprolactone-block-polyethyleneglycol (PCL-PEG) amphiphilic copolymers were prepared to be constituents of nanocarriers used for the targeting of specific cells. Hence, we conceived a smooth and simple photografting methodology on these copolymers using a bifunctional molecular clip (O-succinimidyl-4-(p-azido-phenyl)butanoate). We prepared PCL-PEGs with pendent N-hydroxysuccinimide esters and studied the grafting with 3H-lysine, which radioactivity was counted by LSC. Several parameters were investigated, such as behavior of homopolymers, initial concentrations, irradiation, and incubation durations. Evidences of a “PEG directed photografting” are discussed and this selectivity could be improved by a selective solvent technique. The photografting on different PCL-PEGs revealed a dependency of the rates to the crystallinity of the copolymers. Several controls by SEC, DLS, and TEM of the treated copolymers were realized. Lastly, the coupling of α-d-mannopyranoside ligand was performed, reaching amounts of 5400 nmol/g of PCL-PEG. This derivatized PCL-PEG enters in the preparation of nanocarriers used for the targeting of antigen presenting cells