XPS characterization of surface films formed on surface-modified implant materials after cell culture

Nitrogen ion-implanted Ti–6Al–4V, Ti–5Al–2.5Fe and 316 L stainless steel and nitrogen or carbon sputter-coated samples were inoculated with rat bone marrow. The interface between the cell layer and the substrata was studied by X-ray photo-electron spectrometry and observed by scanning electron microscopy (SEM). Ca and P were detected on all materials after in vitro cell culture. Titanium appears to be present mainly in the form of TiO2.     

A simple method to prepare calcium phosphate coatings on Ti6Al4V

A two-step chemical treatment followed by immersion in a supersaturated calcification solution (SCS) was found to be a simple way to prepare calcium phosphate (Ca–P) coatings on Ti6Al4V. The Ca–P deposition on the treated metallic surfaces could be accelerated by employing a pre-calcification (Pre-Ca) procedure prior to immersion in SCS. The two-step treatment was performed by etching the metallic plates with a mixture of HCl and H2SO4 followed by ageing in boiling diluted NaOH solution at 140°C. Pre-Ca was carried out by incubating the two-step treated plates in Na2HPO4 solution and then in saturated Ca(OH)2 solution. The formation of a bioactive microporous surface oxide layer on Ti6Al4V by the two-step treatment was most probably responsible for the induction of Ca–P precipitation. The deposition rates and compositions of Ca–P coatings in two different SCSs were investigated by means of scanning electron microscopy, X-ray diffraction and infrared spectrophotometry.     

Calcium phosphate formation induced on silica in bamboo

The effect of in vitro induction of calcium phosphate on bamboo surfaces is reported for the first time. Bamboo is studied for biomaterial application due to its elasticity modulus being closer to human bone than other biomaterials. Following an earlier study of cytotoxicity and precipitation of apatite on ground tissue and vascular bundles of bamboo, the composition and function of the minerals in bamboo, especially silica, are considered in the present work. It is found that in both outer and inner surfaces of bamboo culm, there exists some silica. Bamboo elicits an inert response when soaked directly in calcification solution. After the rind of bamboo is treated with sodium hydroxide solution, the silica underneath can induce precipitation of calcium phosphate in an ambient environment. Furthermore, by subsequent grafting with polyethylene glycol (PEG 1000), calcium phosphate induction of bamboo rind can be improved, depending on the concentration of NaOH solution and treatment time. Heat treatment of bamboo can remove the organic materials around the minerals in bamboo, allowing the calcification behaviour of the silica-containing inorganic phase of bamboo in aqueous solution to be studied.     

Routine patch testing with the preservative system Kathon CG

Of 1620 patients routinely patch tested with Kathon CG 100 p.p.m. aqua for suspected allergic contact dermatitis, 81 (5.0%) had a positive reaction. Sixty-two reactions (3.8%) were relevant for the dermatitis for which the patient consulted the dermatologist. Most patients were females who presented with dermatitis of the hands and/or face. Forty-six per cent of the patients had become sensitized by using cosmetic products on healthy skin. The other 54% had pre-existing dermatitis, especially atopic dermatitis and irritant dermatitis. Most reactions were caused by moisturizing creams.     

Triple-layer artificial skin: Porous 50/50 copoly (L-lactide/epsilon-caprolactone) template for neodermis regeneration

Abstracts are not published in this journal     

A novel method for fabrication of biodegradable scaffolds with high compression moduli

It has been previously shown that, when used for meniscal reconstruction, porous copoly(L-lactide/-caprolactone) implants enhanced healing of meniscal lesions owing to their excellent adhesive properties. However, it appeared that the materials had an insufficient compression modulus to accomplish 100% fibrocartilage formation. In addition, to be used for meniscal prosthesis, the compression modulus of the porous materials should be larger than 150 kPa in order to protect the articular cartilage. A technique was developed to prepare stiff porous materials of a high molecular weight 50/50 copoly(L-lactide/-caprolactone) suitable for fibrocartilage regeneration in meniscal implants and meniscal prosthesis. Porous microspheres (50–250 m) were agglutinated in the presence of NaCl crystals (250–300 m). The microspheres were mixed with solid solvent in order to obtain a homogeneous distribution of solvent over the spheres. By changing the amount of solvent and crystals, the density and the compression modulus could be varied over a range of 0.07 g ml-1 to 0.5 g dl-1 and 40–1100 kPa, respectively.     

In-vitro apatite formation on phosphorylated bamboo

Natural self-reinforced composite, bamboo, was surface modified by phosphorylation with urea–H3PO4 and NaOH–H3PO4 methods; then precalcification was performed by immersing samples in saturated Ca(OH)2 solution. After that, calcium phosphate can be formed on the surface of bamboo samples in calcification media: simulated body fluid (1.5 SBF) and accelerated calcification solution (ACS). Experimental results reveal that pre-calcification is an inevitable step for the formation of calcium phosphate. The calcium phosphate formed in 1.5 SBF was identified by thin-film X-ray diffraction as apatite which was not well crystallized. Compared with the urea–H3PO4 method, the NaOH–H3PO4 method has the advantages of quicker and continuous apatite formation and stronger adhesive between apatite and bamboo.     

Towards Viable Personal Networks and FedNets -- a Value-Web Perspective

The concepts of Personal Networks (PNs) and Federated Networks (FedNets) have been introduced before, but there are no studies published yet about migration strategies towards viable solutions in the market. One of the main reasons is the lack of a clear vision about the different values that various parties involved in achieving PNs and FedNets have to offer to each other and the end user. In fixed broadband communication such value chains and business models are already commonly used for rolling out complex service offering based on fiber-to-the-home and broadband home networks. In this paper we use the knowledge from these business domains to approach the problem of PNs and FedNets.     

ELECTROPHORESIS AND ASSAY OF TRYPSIN INHIBITORS IN DIFFERENT STAGES OF TEMPE PRODUCTION

Tempe was made according to a laboratory method giving the Indonesian product. At several stages samples were taken, trypsin inhibitors were extracted with different procedures (high pH, salt) and purified with affinity chromatography. A standard assay method for trypsin inhibitors showed large differences in the activity of the extracts. The purified samples were subjected to isoelectric focusing and sodium dodecyl sulfate-electrophoresis, with which mainly Kunitz inhibitors were found. Utilisation of 2-mercaptoethanol in sodium dodecyl sulfate-electrophoresis proved that Kunitz inhibitors had been modified by affinity chromatography.     

Preparation of High-Strength Calcium Phosphate Glass-Ceramics by Unidirectional Crystallization

Unidirectionally crystallized CaO-P₂O₅ glass-ceramics were produced by reheating glass rods between 450° and 580°C (glass transition temperature ∼500°C) under a temperature gradient of 30°C/cm. These glass-ceramics exhibit high bending strength (∼650MN/m²) and toughness. Sample preparation is described and compared with conventional unidirectional solidification of melts. The characteristic mechanical properties are discussed in terms of the texture of the glass-ceramics.