Nanoscopic insights into the surface conformation of neurotoxic amyloid β oligomers

Unraveling characteristic structural determinants at the basis of Aβ42 oligomers' neurotoxicity by a sub-molecular SERS investigation of their surface.

Comparative Analysis of the Chemical Composition and Microstructure Conformation Between Different Dental Implant Bone Drills

Background: Hardness is considered an important parameter for evaluating the clinical performance of dental implant bone drills. It is connected to the chemical composition, microstructure conformation and manufacture of the surgical drills. Methods: Microstructure of five dental implant drills using scanning electronic microscopy (SEM) integrated with energy dispersive X-ray spectrometry. Vickers microhardness was measured using a CV 2000 microhardness tester with an indentation force of 500 g. Results: Composition of the implant drills was typical of martensitic stainless steel (MSS). The drills contained 13%–17% of Cr; Mo, Si and Mn were present as minor ligands. The examined bone drills showed different external surface conformation and hardness in relation to the different industrial production processes. A rougher external surface and a higher hardness value are characteristics of the surgical bone drills produced by hot forming; the implant drills produced by machining showed mailing lines on their external surface and a lower hardness. Conclusions: Different compositions and treatments were used by the manufacturers to improve the hardness of the external layer of the dental implant drills making them prone to a diverse heat generation during the implant site preparation.

Electrochemical modulation of plasma fibronectin surface conformation enables filament formation and control of endothelial cell–surface interactions

Electrochemical modulation of a gold surface charge induces conformational changes in fibronectin when immobilized on the surface. A negatively-charged surface yields an open and filamentous fibronectin which significantly improves endothelial cell adhesion.

Improvement of Hydroxyapatite Deposition on Titanium Dental Implant Using ArF Laser Ablation: Effect on Osteoblast Biocompatibility In Vitro

To develop a better surface conformation of titanium dental implants, we examined the in vitro biocompatibility of a thin natural apatite (NA) film deposited by laser ablation. Thin (2000-Å) hydroxyapatite (HA) and NA films were deposited on titanium discs using an ArF excimer laser operating at a repletion rate of 10 Hz and annealed by heating at 360°C for 1 h. Energy dispersive analysis of the NA film revealed peaks of Na and Mg in addition Ca and P. X-ray diffraction showed that crystalline HA was present in the HA and NA films. Primary mouse osteoblast grew faster and had higher alkaline phosphatase activity when grown in NA films than on HA films or a bare titanium surface. In addition, osteocalsin production by these cells was higher on HA and NA than bare titanium, but there was no significant difference between cells grown on HA and NA. Thus surface modification with NA film may contribute to successful osteoblast function and differentiation at titanium interface.