Endothelialization and in-stent restenosis on the surface of glycoprotein IIIa monoclonal antibody eluting stent.

Since the percutaneous transtuminal coronary angioplasty was introduced into China in 1984, this procedure has become widely accepted as an important step in coronary revascularization. This study shows the effect of the monoclonal antibody (mAb) on the platelet glycoprotein IIIa receptor during endothelialization and in-stent restenosis by implanting the mAb-eluting stents into iliac arteries of rabbits. The hard tissue cross sections of the stent-implanted arterial segments were made by polymethylmethacrylate embedding. Arterial intima proliferation was observed and analyzed. The endothelialization of the stent surface was observed using scanning electron microscope, whereas the ultrastructure of the neointima was observed using transmission electron microscope. After one month of stent implantation, the surfaces of both groups were covered by intact endothelial layers, but the neointimal areas and the ratio of stenosis were significantly lesser in the mAb-eluting stent group (p < 0.01). After 3 months, the ratio of stenosis in the mAb-eluting stent group was 14.67 ± 0.79, whereas that of the bare stent group was 21.58 ± 1.76 (p < 0.01). Therefore, the mAb eluting from the stent surface has the potential to accelerate endothelialization, prevent thrombosis formation due to the interaction of stent with blood, and decrease the stenosis ratio by inhibiting neointima proliferation.

[In vitro study of platelet glycoprotein monoclonal antibody eluting stents].

In order to prove the feasibility of preparation of the drug-incorporated stent by immersing stent wires in the monoclonal antibody (mAb) solution, fluorescence stain and image analysis were used to evaluate the L-PLA-coated stent. Absorption was measured using a radioisotope technique after preparing the mAb-incorporated stent, and the absorption curve was determined from the absorption data. In an in vitro perfusion circuit, the antibody was eluted from the stent matrices, and the related influence factors were evaluated based on the release data.

[Development of drug coating on drug eluting stents].

Researches on drug-eluting stents are now focusing on three main aspects: the stent materials, the coating matrix material and the selection, adhesion and controlled release of the biological agents. The current development progresses of the coating materials, their characteristics, and the coating method for metallic stents are reviewed in this paper.

Deep desulfurization of hydrodesulfurization-treated diesel oil by a facultative thermophilic bacterium Mycobacterium sp. X7B.

The dibenzothiophene (DBT) desulfurization pathway of a facultative thermophilic bacterium Mycobacterium sp. X7B was investigated. Metabolites were identified by gas chromatography-mass spectrometry, and the results showed that 2-hydroxybiphenyl, the end product of the previously reported sulfur-specific pathway (also called 4S pathway), was further converted to 2-methoxybiphenyl. This is the first strain to possess this ability and therefore, an extended 4S pathway was determined. In addition, the DBT-desulfurizing bacterium Mycobacterium sp. X7B was able to grow on DBT derivatives such as 4-methylDBT and 4,6-dimethylDBT. Resting cells could desulfurize diesel oil (total sulfur, 535 ppm) after hydrodesulfurization. GC flame ionization detection and GC atomic emission detection analyses were used to qualitatively evaluate the effect of Mycobacterium sp. X7B treatment on the content of the diesel oil. The total sulfur content of the diesel oil was reduced 86% using resting cell biocatalysts for 24 h at 45 degrees C.