Camouflaged angiogenic BMP-2 functions exposed by pico-paracrine biohybrids.

The constant release of human bone morphogenetic protein 2 (rhBMP-2) in the picomolar range (Pico-Stat) from PDLLA-biohybrids led to the detection of intrinsic novel pro- and anti-angiogenic functions of this cytokine. As integrant part in this perspective of previous work, first evidence for the binding of rhBMP-2, as an , to allosteric angiogenic receptors in cocultures of human endothelial cells is reported.

Intrasurgical Protein Layer on Titanium Arthroplasty Explants: From the Big Twelve to the Implant Proteome.

Purpose: Aseptic loosening in total joint replacement due to insufficient osteointegration is an unsolved problem in orthopaedics. The purpose of the study is to obtain a picture of the initial protein adsorption layer on femoral endoprosthetic surfaces as the key to the initiation of osseointegration.

Experimental Design: The paper describes the first study of femoral stem explants from patients for proteome analysis of the primary protein layer.

Antimicrobial and Osseointegration Properties of Nanostructured Titanium Orthopaedic Implants.

The surface design of titanium implants influences not only the local biological reactions but also affects at least the clinical result in orthopaedic application. During the last decades, strong efforts have been made to improve osteointegration and prevent bacterial adhesion to these surfaces. Following the rule of "smaller, faster, cheaper", nanotechnology has encountered clinical application.

Chick ex ovo culture and ex ovo CAM assay: how it really works.

Chicken eggs in the early phase of breeding are between in vitro and in vivo systems and provide a vascular test environment not only to study angiogenesis but also to study tumorigenesis. After the chick chorioallantoic membrane (CAM) has developed, its blood vessel network can be easily accessed, manipulated and observed and therefore provides an optimal setting for angiogenesis assays. Since the lymphoid system is not fully developed until late stages of incubation, the chick embryo serves as a naturally immunodeficient host capable of sustaining grafted tissues and cells without species-specific restrictions.

Polyethylenimine-coated albumin nanoparticles for BMP-2 delivery.

Nanoparticle (NP)-based delivery has gained importance for improving the potency of therapeutic agents. The bovine serum albumin (BSA) NPs, obtained by a coacervation process, was modified by electrostatic adsorption of cationic polyethylenimine (PEI) to NP surfaces for delivery of bone-inducing growth factor, bone morphogenetic protein-2 (BMP-2). Different concentrations of PEI were utilized for coating BSA NPs to stabilize the colloidal system and to control the release of BMP-2.

Extracellular proteasome in the human alveolar space: a new housekeeping enzyme?

We hypothesized that 20S proteasome is present and functional in the extracellular alveolar space in humans. Proteasomal activity was measured in bronchoalveolar lavage (BAL) supernatant from eight humans using specific proteasomal fluorogenic substrates and I(125)-albumin with and without specific proteasome inhibitors. Furthermore, gelfiltration, Western blot technique, and mass spectrometry were applied for proteasome characterization.

Bone apposition to titanium implants biocoated with recombinant human bone morphogenetic protein-2 (rhBMP-2). A pilot study in dogs.

The aim of the present study was to investigate bone formation to recombinant human bone morphogenetic protein-2 (rhBMP-2)-biocoated and rhBMP-2-nonbiocoated titanium implants after implantation in dogs. Implantation of sand-blasted and acid-etched (C), chromosulfuric acid surface-enhanced (CSA), and rhBMP-2-biocoated CSA [BMP-A: noncovalently immobilized rhBMP-2 (596 ng/cm(2)), BMP-B: covalently immobilized rhBMP-2 (819 ng/cm(2))] implants was performed in both the mandible and tibia of dogs. After 4 weeks of healing, the percentage of direct bone to implant contact (BIC) and the induced bone density (BD) at a distance of less than and greater than 1 mm adjacent to each implant was assessed.

Interaction of fibrinogen with n-alkylagaroses and its purification by critical hydrophobicity hydrophobic interaction chromatograpy.

A rational application of hydrophobic interaction chromatography (HIC) to the purification of proteins has remained an enigma in spite of over 30 years of research. The critical hydrophobicity parameter, which can be determined from a concentration series of n-alkyl Sepharose 4B (Seph-Cn) offers the possibility of adapting the HIC gel to the needs of purification. To this end a library of HIC gels (Seph-C4 to Seph-C6) of different immobilized alkyl residue concentrations was synthesized and tested with purified bovine fibrinogen.

Hydrophobic interaction chromatography: harnessing multivalent protein-surface interactions for purification procedures.

Hydrophobic interaction chromatography (HIC) is one of the basic purification procedures in the biosciences. However, because of its complexity, it has not gained the same foothold in the methodological repertoire of protein chemistry as has affinity chromatography or ion exchange chromatography. This is mainly a result of the lack of a general optimization procedure for the reversible adsorption and elution of a novel protein to be purified.

Accelerated and improved osteointegration of implants biocoated with bone morphogenetic protein 2 (BMP-2).

A concept and methodology are presented for the direct biocoating of implantable metals like titanium and stainless steel with bone morphogenetic protein 2 (BMP-2) for future applications as cementless bone or dental prostheses. Such bioactive surfaces can influence cells and tissues by chemotactic as well as juxtacrine mechanisms. Reference is made to first experiments in sheep and rabbits in which BMP-2 coatings impressively increased the osteoinductive potential of titanium implants.