Surface-immobilized PAMAM-dendrimers modified with cationic or anionic terminal functions: physicochemical surface properties and conformational changes after application of liquid interface stress.

Functionalization of surfaces with highly branched dendrimer molecules has gained attractiveness for various applications because the number of functional groups exceeds those of surfaces functionalized with self-assembled monolayers. So far, little is known about the physicochemical properties of dendrimer functionalized surfaces, especially if the flexibility of dendrimer structure remains after covalent immobilization. Therefore, the purpose of this study was to covalently immobilize polyamidoamine (PAMAM) dendrimer molecules exhibiting terminal amine and carboxyl groups to silicon model surfaces and to explore their properties and structure at the solid-air and solid-liquid interface.

The impact of dendrimer-grafted modifications to model silicon surfaces on protein adsorption and bacterial adhesion.

In the oral cavity, omnipresent salivary protein films (pellicle) mediate bacterial adhesion and biofilm formation on natural tissues as well as on artificial implant surfaces, which may cause serious infectious diseases like periimplantitis. The purpose of this in vitro study was to investigate the adsorption/desorption behaviour of human saliva on model surfaces grafted with polyamidoamine (PAMAM) dendrimer molecules compared to self-assembled monolayers (SAMs) exhibiting the same terminal functions (-NH(2), -COOH) by two complementary analytical methods. Furthermore, the role of saliva conditioning of PAMAM and analogous SAM modifications on the adhesion of Streptococcus gordonii DL1, an early oral colonizer, was investigated.

Hydroxide nanoparticles for deacidification and concomitant inhibition of iron-gall ink corrosion of paper.

This Article reports an investigation on the use of magnesium hydroxide nanoparticles dispersed in alcohols to inhibit two different and synergistic degradation processes usually affecting historically valuable manuscripts and, more generally, paper documents. We show that the preservation of paper from acid hydrolysis and oxidative ink corrosion can be achieved by stabilizing the final pH of deacidified paper around 6.5 to 7.

Influences of protein films on antibacterial or bacteria-repellent surface coatings in a model system using silicon wafers.

Immobilization of defined chemical functionalities to biomaterial surfaces is employed to optimize them not only for tissue compatibility but also for prevention of bacterial infection. Grafting surfaces with chains of poly(ethylene glycol) (PEG) results in bacterial repellence whereas modification with cationic groups conveys them with bactericidal properties. Since biomaterials in situ will become exposed to a protein-rich environment, it is necessary to investigate the influence of prior protein adsorption on the antibacterial activity of this type of chemical surface modification.