Comparison of the capacity of enamel matrix derivative gel and enamel matrix derivative in liquid formulation to adsorb to bone grafting materials.

Background: The use of an enamel matrix derivative (EMD) has been shown to enhance periodontal regeneration (e.g., formation of root cementum, periodontal ligament, and alveolar bone).

Alkali treatment of microrough titanium surfaces affects macrophage/monocyte adhesion, platelet activation and architecture of blood clot formation.

Titanium implants are most commonly used for bone augmentation and replacement due to their favorable osseointegration properties. Here, hyperhydrophilic sand-blasted and acid-etched (SBA) titanium surfaces were produced by alkali treatment and their responses to partially heparinized whole human blood were analyzed. Blood clot formation, platelet activation and activation of the complement system was analyzed revealing that exposure time between blood and the material surface is crucial as increasing exposure time results in higher amount of activated platelets, more blood clots formed and stronger complement activation.

Preparation of superhydrophilic microrough titanium implant surfaces by alkali treatment.

A new strategy to render intrinsically hydrophobic microrough titanium implant surfaces superhydrophilic is reported, which is based on a rapid treatment with diluted aqueous sodium hydroxide solutions. The physicochemical characterization and protein interaction of the resulting superhydrophilic implant surfaces are presented. The superhydrophilicity of alkali treated microrough titanium substrates was mainly attributed to deprotonation and ion exchange processes in combination with a strong enhancement of wettability due to the roughness of the used substrates.

Stability and nonfouling properties of poly(poly(ethylene glycol) methacrylate) brushes under cell culture conditions.

This paper investigates the stability and nonfouling properties of poly(poly(ethylene glycol) methacrylate) (PPEGMA) brushes prepared by surface-initiated atom transfer radical polymerization from SiO(x) substrates modified with a trimethoxysilane-based ATRP initiator. At high chain densities, PPEGMA brushes were found to detach rapidly from glass or silicon substrates. Detachment of the PPEGMA brushes could be monitored with contact angle measurements, which indicated a decrease in the receding water contact angle upon detachment.

RGD-Functionalized polymer brushes as substrates for the integrin specific adhesion of human umbilical vein endothelial cells.

This report demonstrates the feasibility of surface-initiated atom transfer radical polymerization to prepare thin polymer layers ("brushes") that can be functionalized with short peptide ligands and which may be of use as coatings to promote endothelialization of blood-contacting biomaterials. The brushes are composed of poly(2-hydroxyethyl methacrylate) (PHEMA) or poly(poly(ethylene glycol) methacrylate) (PPEGMA), which do not only suppress non-specific adhesion of proteins and cells but also contain hydroxyl groups that can be used to introduce small peptide ligands. A protocol has been developed that allows functionalization of the brushes with RGD containing peptide ligands resulting in surface concentrations ranging from approximately 0.

Protein function microarrays based on self-immobilizing and self-labeling fusion proteins.

Protein microarrays are an attractive approach for the high-throughput analysis of protein function, but their impact on proteomics has been limited by the technical difficulties associated with their generation. Here we demonstrate that fusion proteins of O6-alkylguanine-DNA alkyltransferase (AGT) can be used for the simple and reliable generation of protein microarrays for the analysis of protein function. Important features of the approach are the selectivity of the covalent immobilization; this allows for direct immobilization of proteins out of cell extracts, and the option both to label and to immobilize AGT fusion proteins, which allows for direct screening for protein-protein interactions between different AGT fusion proteins.

A novel star PEG-derived surface coating for specific cell adhesion.

In this study a novel approach for the coating and functionalization of substrates for cell culture and tissue engineering is presented. Glass, silicon, and titanium panes were coated with an ultrathin film (30 +/- 5 nm) of reactive star-shaped poly(ethylene glycol) prepolymers (Star PEG). Homogeneity of the films was checked by optical microscopy and scanning force microscopy.

Protein-functionalized polymer brushes.

A new strategy for the preparation of protein-functionalized polymer brushes is reported, which is based on a combination of surface-initiated atom transfer radical polymerization (ATRP), p-nitrophenyl chloroformate activation of the surface hydroxyl groups, and subsequent O(6)-benzylguanine (BG) functionalization. The BG-functionalized brushes are used to chemoselectively immobilize O(6)-alkylguanine-DNA-alkyltransferase (AGT) fusion proteins with a defined orientation and surface density. These protein-modified polymer brushes are attractive candidates for the development of protein microarrays.