Inhibitory Effects of Sulfonamide Derivatives on the β-Carbonic Anhydrase (MpaCA) from Malassezia pachydermatis,a Commensal,Pathogenic Fungus Present in Domestic Animals

Fungi are exposed to various environmental variables during their life cycle, including changes in CO₂ concentration. CO₂ has the potential to act as an activator of several cell signaling pathways. In fungi, the sensing of CO₂ triggers cell differentiation and the biosynthesis of proteins involved in the metabolism and pathogenicity of these microorganisms. The molecular machineries involved in CO₂ sensing constitute a promising target for the development of antifungals. Carbonic anhydrases (CAs, EC 4.2.1.1) are crucial enzymes in the CO₂ sensing systems of fungi, because they catalyze the reversible hydration of CO₂ to proton and HCO₃^-. Bicarbonate in turn boots a cascade of reactions triggering fungal pathogenicity and metabolism. Accordingly, CAs affect microorganism proliferation and may represent a potential therapeutic target against fungal infection. Here, the inhibition of the unique β-CA (MpaCA) encoded in the genome of Malassezia pachydermatis, a fungus with substantial relevance in veterinary and medical sciences, was investigated using a series of conventional CA inhibitors (CAIs), namely aromatic and heterocyclic sulfonamides. This study aimed to describe novel candidates that can kill this harmful fungus by inhibiting their CA, and thus lead to effective anti-dandruff and anti-seborrheic dermatitis agents. In this context, current antifungal compounds, such as the azoles and their derivatives, have been demonstrated to induce the selection of resistant fungal strains and lose therapeutic efficacy, which might be restored by the concomitant use of alternative compounds, such as the fungal CA inhibitors.     

An XPS and ToF-SIMS investigation of the outermost nanometres of a poly(vinylidene difluoride) coating

The outermost nanometres of a poly(vinylidene difluoride) (PVdF)-based coil coating have been investigated using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). A reference PVdF-based coating formulation and three variations of this formulation were characterised by XPS. The addition of flow agent and/or acrylic co-polymers induced significant changes in the elemental and chemical composition of the coating's air/coating surface. The XPS results indicate that both the flow agent and acrylic co-polymers segregate towards the coating's air/coating surface. The XPS results also suggest that in the fully formulated coating, segregation of the flow agent and co-polymers results in the formation of a surface/sub-surface acrylic layer of sufficient thickness to mask the fluorine signal originating from PVdF.     

Aliphatic hyperbranched polyesters based on 2,2-bis(methylol)propionic acid—Determination of structure, solution and bulk properties

Due to their highly branched structure and the large number of functional groups hyperbranched polymers possess unique properties that make them interesting for uses in a wide variety of applications. Some of the most widely investigated hyperbranched polymers are the polyesters based on 2,2-bis(methylol)propionic acid. In this paper we present the results of characterization studies of hyperbranched polyesters based on 2,2-bis(methylol)propionic acid which show that they are very complex products with a multidimensional distribution of various properties. The influence of the synthesis conditions on the structure and molar-mass characteristics of hyperbranched polyesters as well as the findings that allow a thorough understanding of the structure-property relationships are reviewed in detail.     

Review of autoxidation and driers

This article is an overview of the chemistry and driers used in autoxidatively cured coatings and in particular alkyds. The drying process for alkyds and other unsaturated fatty acid materials is based on a series of chemical reactions known as autoxidation. The autoxidative process is usually catalyzed by metal salts known as driers. Numerous of investigations have elucidated the catalytic activity and reaction mechanism of the drying process. Spectroscopic techniques, especially mass spectrometry, have been used to study the autoxidation process and its products. Recent investigations on the oxidative drying of alkyd coating films are presented with a focus on both metal based and more environmental friendly means of catalysis.     

Novel developments in the multidimensional characterization of segmented copolymers

Controlled radical polymerization (CRP) provides the polymer chemist with the ability to produce tailor-made polymers with controlled molar masses, molar mass distributions, chemical compositions and macromolecular architectures. Segmented copolymers can be synthesized having polymer segments arranged in a linear fashion (linear block copolymers), however, polymer segments can also be attached to pre-synthesized macromolecules or to multifunctional core molecules to produce branched (graft) copolymers, polymer stars or dendrimers. Although there are many ways to control the chain growth and the architecture of the target macromolecules, side reactions cannot be completely avoided. Accordingly, even with CRP, obtained products exhibit chemical composition and topology distributions along with the molar mass distribution.     

Dendrimer as nanocarrier for drug delivery

Dendrimers are novel three dimensional, hyperbranched globular nanopolymeric architectures. Attractive features like nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery and cavities in the interior distinguish them amongst the available polymers. Applications of dendrimers in a large variety of fields have been explored. Drug delivery scientists are especially enthusiastic about possible utility of dendrimers as drug delivery tool. Terminal functionalities provide a platform for conjugation of the drug and targeting moieties. In addition, these peripheral functional groups can be employed to tailor-make the properties of dendrimers, enhancing their versatility. The present review highlights the contribution of dendrimers in the field of nanotechnology with intent to aid the researchers in exploring dendrimers in the field of drug delivery.