Noble metal coating reduces acute stent thrombosis

Swedish medtech company Bactiguard has developed infection prevention technology based on a thin noble metal coating that prevents bacterial adhesion and biofilm formation on medical devices. Researchers from Bactiguard, the KTH Royal Institute of Technology and Karolinska Institute have now confirmed in a new study that, when adding the coating to implant materials, the body’s reaction to foreign objects is significantly reduced.

Any medical device that is inserted into the blood stream will cause a so-called thrombo-inflammatory reaction. This includes activation of the coagulation system, which potentially can result in a thrombosis. A stent is a metal net designed to open a blood vessel that is obstructed. Activation of the coagulation system and build-up of a thrombosis within a stent is a very serious complication that may lead to injury or death.

Bactiguard’s noble metal coating has the benefit of reducing microbial adhesion on the surface of a medical device, with previous studies suggesting that the coating can also reduce the thrombo-inflammatory reaction. The latest study on the impact of using the coating to reduce thrombo-inflammatory reactions and acute stent thrombosis was performed to gather even more clinical data and proof points of the coating’s efficacy, with the results published in the journal Scientific Reports.

Two versions of the coating were applied to the stents in the study — Bactiguard’s standard coating consisting of gold, silver and palladium, and a modified version including neodymium. The research methods used were both in vivo (in pigs) and in vitro (through blood marker analysis which also included human samples).

The pigs underwent implantation of coated and non-coated stents in a blinded fashion, where the interventionist did not know which stents were coated and which were not. The experiment was terminated after two hours, representing the acute phase of the implantation. The stents were placed in the lingual artery with one coated and one uncoated on each side. The volume of the stent was analysed using CT-scan data and performed by a treatment blinded assessor. The researchers also conducted laboratory tests using both human and pig blood.

The measurements showed that the coated stent group had a notable decrease in blood clot volume compared to the control group. This effect was observed as early as one hour after the stent was implanted and became even more accentuated after two hours. The in vitro data, using both human and pig blood, showed a significant decrease in markers of coagulation and inflammation in the coated group compared to the control group.

“The finding of this study is promising and yet another set of important data supporting the efficacy of Bactiguard’s coating,” said Stefan Grass, Chief Medical Officer at Bactiguard. “The combination of infection prevention without increased risk of thrombosis is very appealing and unique for a coated intravascular device.”

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