Biocompatible stents
A new method of manufacturing polymer tubes has been developed in Russia
Scientists of the Siberian Federal University (SFU) and the Siberian State University of Science and Technology (SibGU) named after Academician M.F. Reshetnev have developed a new technology for manufacturing tubes from biocompatible biodegradable polymers. According to the authors, the developed products can be used as coronary and urological stents due to the high level of compatibility with the human body, non-toxicity and durability. The results of the study are published in the journal Materials Letters (Boyandin et al., A novel method of fabricating polymer tubes using the casting solution technique).
One of the methods of treating patients with atherosclerosis, heart failure, pathologies of the upper urinary tract is stenting – a surgical operation by which a patient is fitted with a stent (ed. – a frame of stretchable wire or a porous tube) into the lumen of a hollow organ to expand it to the required size. According to the researchers, metals and polymers are most often used to create modern stents. Metal stents, despite their thermal stability and the ability to expand independently, can be toxic. Polymers are safer, and stents made of them are much cheaper than metal ones, but they are inferior in strength and ease of installation.
Scientists of SFU and SibGU named after M.F. Reshetnev have developed a technology for designing polymer stents that are safe for humans, which have increased strength in comparison with other samples.
"As a material, we used biocompatible polyesters – polyhydroxyalkanoates of microbiological origin and polylactides. Made by pouring a polymer solution into silicone molds with subsequent evaporation of the solvent, these tubes can have different lengths and diameters from 2 to 6 mm," Anna Sukhanova, a biotechnologist at SFU, said.
As a result of the research, it was found that a biopolymer solution placed inside a vertically fixed silicone tube forms a biopolymer tube on its inner walls during evaporation, said Anatoly Boyandin, senior researcher at the scientific laboratory "Intelligent Materials and Structures" of the M.F. Reshetnev SibSU.
"A serious obstacle to the formation of high-quality polymer tubes was the increase in the wall thickness of the resulting tubes as the solution evaporated from top to bottom. The aim of the work was, among other things, the selection of such conditions under which the tubes are as homogeneous as possible along their entire length," the scientist stressed.
According to the authors, the developed tubes are biodegradable. For example, when using coronary or urological stents, the walls of the duct itself are restored over time, and the stent decomposes at the same time, without requiring removal and without irritating the surrounding tissues.
In the future, new polymer tubes will probably be able to help patients with the new SARS-CoV-2 coronavirus who have acquired complications from the genitourinary and cardiovascular systems, the scientists noted.
The developed biopolymer tubes were tested on laboratory animals at the Krasnoyarsk State Medical University named after Professor V.F. Voino-Yasenetsky, where their applicability as urological stents was shown.
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