Individual 3D-Printed Implants Made from a Copolymer of Vinylidene Fluoride with Tetrafluoroethylene: Studies of the Effects of Steam Sterilization on Structure and Toxicity

Surgical intervention for the treatment of oncological pathologies requires the use of individual implants to replace the affected tissues. This article presents the results of studies on the use of a Russian-originated polymer material — a copolymer of vinylidene fluoride with tetrafluoroethylene (VDF-TeFE) - for the manufacture of individual implants by 3D printing using layer-by-layer deposition technology (fused deposition modeling, FDM). The influences of the steam sterilization process on the crystal structure, geometric dimensions, and cytotoxicity of implants were studied. Sterilization was found to lead to an increase in crystallite size in the electrically active (ferroelectric) crystalline phase in the polymer material from which the implant is made but not to produce significant changes in implant shape, while maintaining high implant functionality. Studies using 3T3L1 fibroblast cell cultures showed that the steam sterilization process did not cause the formation of toxic compounds and can be used to sterilize individual implants made from VDF-TeFE copolymer by FDM 3D printing.