BIOCOMPATIBLE ELASTIC POLYMER NANOCOMPOSITES BASED ON MULTIWALLED CARBON NANOTUBES FOR APPLICATION IN CARDIOVASCULAR SURGERY

Highlights

The incorporation of multi-walled carbon nanotubes into the structure of the poly(styrene-block-isobutylene-block-styrene) polymer matrix leads to an increase in the tensile strength and Young's modulus of the nanocomposites. The resulting nanocomposites retain high biocompatibility and can be used as elements of implanted cardiovascular products.

Abstract

Aim. To synthesize and modify poly(styrene-block-isobutylene-block-styrene) (SIBS) with two types of multi-walled carbon nanotubes (MWCNTs) in different concentrations to improve its mechanical properties.

Methods. SIBS was synthesized by controlled cationic polymerization. Polymer nanocomposites were prepared using ultrasonic dispersion followed by casting films from a polymer solution. The resulting nanocomposite films were subjected to mechanical tests under uniaxial tensile conditions. Tensile strength, elastic-strain properties, and plastic deformation under cyclic loading were assessed. The structure of the nanocomposites was analyzed by scanning electron microscopy. The hydrophilicity of the surface of the materials was studied by measuring the contact angle with water. The cytotoxicity of the resulting polymer films was assessed by the viability and metabolic activity of endothelial cells cultured on the surface of the nanocomposites.

Results. Polymer nanocomposites with a uniform distribution of MWCNTs in the polymer matrix were obtained. SIBS films modified with 1% MWCNTs with a diameter of 50–90 nm showed an increase in tensile strength by 16.4% compared to SIBS polymer. Increasing the concentration of MWCNTs to 8% led to a decrease in the strength of polymer materials by 19,6%. The inclusion of nanoparticles into the polymer matrix significantly increased the Young's modulus of the studied polymers with a MWCNT content above 4%. With an increase in the content of MWCNTs in the nanocomposites, an increase in hydrophilicity was also observed, while the cytotoxicity of the samples towards endothelial cells was not noted.

Conclusion. Nanocomposites based on SIBS and MWCNTs, due to their high strength and biocompatibility, can become a promising material for the development of various medical products, in particular prosthetic heart valves.

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