Composition and in vitro biocompatibility of corroding tungsten coils

Abstract

The purpose of the article is to evaluate composition and biocompatibility of corroding mechanically detachable spirals (MDS, Balt Extrusion, Montmorency, France). Analysis of the material composition of corroding MDS coils was assessed by inductively coupled plasma atomic emission spectroscopy, inductively coupled plasma mass spectroscopy, and wavelength-dispersive x-ray spectrometry. Toxicity assays were performed with human venous endothelial cells, venous smooth muscle cells and fibroblasts. The analyses of the MDS coils demonstrated a tungsten content of the dissolving MDS spirals of > 99.9 mas%. In vitro, human endothelial, vascular smooth muscle cells and fibroblasts were not adversely affected by markedly elevated tungsten concentrations (60,500 microg/l) after 12 days in the culture medium. The examined cells showed an extensive vital growth on the coil surface. Corrosion of tungsten coils leads to markedly elevated tungsten levels in the culture medium. However, growth and vitality of endothelial cells, fibroblasts, and vascular smooth muscle cells are not adversely affected by elevated tungsten concentrations.

Holey Tungsten Oxynitride Nanowires: Novel Anodes Efficiently Integrate Microbial Chemical Energy Conversion and Electrochemical Energy Storage

“…Such unique crystal structure enables tungsten oxynitride (WON) to have a number of attractive properties such as high hardness, excellent conductivity, good thermal stability, and high melting point . More importantly, the good biocompatibility could strengthen the enrichment of bacteria, which enables WON to have promising application as the anode in MFCs . In addition, comparing with other metal nitrides and metal oxynitrides, the extraordinary chemical inertness further gives WON great promise as a durable anode .…”

The use of tungsten as a chronically implanted material

“…Various causes for this corrosion have been proposed in the literature: Weill et al blame the metallic impurity of the MDS coils [16,63]. This was disproven by studies that spectroscopically verified the purity of the W pre-implantation (>99.9% by mass) [60][61][62]71]. Barrett et al attribute degradation due to mechanical effects of percussive systolic-diastolic blood flow on the spirals [66] but this explanation was nullified when corrosion was observed by radiography in venous fistula drainage pathways with no percussive flow [16] as well as in cannulae of the spermatic vein [66].…”

Examination of radio‐opacity enhancing additives in shape memory polyurethane foams

“…In this study, the radio‐opacity enhancing moieties tungsten (W), barium sulfate (BaSO 4 ), and zirconium oxide (ZrO 2 ) were physically added to SMP foams . The usage of these materials in medical device applications is briefly mentioned below.…”

“…However, the shape recovery properties and kinetics of W filled foams were not examined. W has been used in embolization devices in the form of embolic coils with degradation products being below cytotoxic limits …”