Attenuation of acute inlammatory responses by surface nanotopography

The interaction between biology and non-viable surfaces is crucial for many organisms and cells. For example, bacterial cells need to adhere to mineral surfaces in the soil, plants climb and adhere to walls and marine organisms produce adhesives to cling to underwater rocks etc. In the human body, tissue needs to firmly adhere to the mineral surface of bone, but also to foreign materials when for example a biomaterial is implanted. The knowledge of how biology interacts with surfaces is hence important and interesting in many aspects. Within seconds after implantation of a biomaterial, proteins from the immune complement and coagulation systems adsorbs to the surface with possible adverse consequences for the patient. To overcome this, chemical surface modifications are readily employed. However, recently the significance of surface nanotopography for the adsorption of proteins, and attachment of cells have been acknowledged. To facilitate research on the interactions between biology and nanostructured substrates novel experimental surfaces with defined nanotopography and surface chemistry were developed. The surfaces are fabricated by binding gold nanoparticles to a gold surface, using a non-lithographic method and standard laboratory equipment. The surface chemistry was evaluated using XPS and ToF-SIMS. On these surfaces, the effect of surface nanotopography on the activation of the immune complement and activation of blood platelets was studied using QCM-D, SEM and fluorescence microscopy. It was found that although nanostructured surfaces adsorbed greater amount of serum proteins, activation of the immune complement was attenuated by surface nanotopography. A suggested mechanism is that the curvature of the nanoparticles prevents interaction between complement proteins. It was also found that blood platelets were activated to a lower degree on nanostructured surfaces and were sensitive to changes in nanoparticle size and inter-particle distance. These nanostructures surfaces can hopefully facilitate research on protein/cell interactions on nanostructured surfaces

Konzeption eines Bezugsrahmens zur Analyse und Entwicklung von Geschäftsmodellen mobiler Gesundheitsdienstleistungen

Die Nachfrage nach mobil erbrachten Gesundheitsdienstleistungen steigt an. Dabei ist IT-Unterstützung verfügbar, Dienstleistungsorganisationen in der Domäne müssen aber mit knappen Budgets und einem Engpass an Fachkräften zurechtkommen. Gleichzeitig wird eine hohe Servicequalität vorausgesetzt. Es sind Hilfestellungen nötig, damit die Dienstleister die Versorgung hochwertig gestalten können. Im vorliegenden Beitrag wird hierzu ein Bezugsrahmen entwickelt, der die konfigurative Gestaltung entsprechender Geschäftsmodelle unterstützt

Antibacterial Properties of hLf1-11 Peptide onto Titanium Surfaces: A Comparison Study Between Silanization and Surface Initiated Polymerization

Dental implant failure can be associated with infections that develop into peri-implantitis. In order to reduce biofilm formation, several strategies focusing on the use of antimicrobial peptides (AMPs) have been studied. To covalently immobilize these molecules onto metallic substrates, several techniques have been developed, including silanization and polymer brush prepared by surface-initiated atom transfer radical polymerization (ATRP), with varied peptide binding yield and antibacterial performance. The aim of the present study was to compare the efficiency of these methods to immobilize the lactoferrin-derived hLf1-11 antibacterial peptide onto titanium, and evaluate their antibacterial activity in vitro. Smooth titanium samples were coated with hLf1-11 peptide under three different conditions: silanization with 3-aminopropyltriethoxysilane (APTES), and polymer brush based coatings with two different silanes. Peptide presence was determined by X-ray photoelectron spectroscopy, and the mechanical stability of the coatings was studied under ultrasonication. The LDH assays confirmed that HFFs viability and proliferation were no affected by the treatments. The in vitro antibacterial properties of the modified surfaces were tested with two oral strains (Streptococcus sanguinis and Lactobacillus salivarius) showing an outstanding reduction. A higher decrease in bacterial attachment was noticed when samples were modified by ATRP methods compared to silanization. This effect is likely due to the capacity to immobilize more peptide on the surfaces using polymer brushes and the nonfouling nature of polymer PDMA segment.Peer Reviewe