ePTFE

Expanded polytetrafluoroethylene (ePTFE) is a microporous form of the fluoropolymer PTFE (polytetrafluoroethylene) produced by the controlled expansion of extruded PTFE. The expansion creates a three‑dimensional network of nodes and fibrils that yields a porous structure. This porosity can be tuned to promote tissue ingrowth or to function as a barrier. ePTFE is valued for its chemical inertness, thermal stability, biocompatibility, and relatively low friction. The material is typically hydrophobic, but surface modification can alter tissue interaction.

Production and forms: ePTFE is made by stretching extruded PTFE under controlled conditions to generate porosity. Depending on processing, it can form small-pore membranes for filtration, or larger-pore fabrics and sheets used as implantable materials. The pore size and overall porosity determine whether the material acts primarily as a scaffold for tissue integration or as a barrier with limited permeability.

Medical applications: ePTFE is widely used in medicine. Vascular grafts and patch materials (often marketed under the Gore-Tex name) employ ePTFE for peripheral and some central vessels, with a long track record in durability and biocompatibility. It also serves as endovascular stent-graft coverings, dural substitutes, and hernia repair patches. In addition, ePTFE membranes are used as surgical barriers and in certain implantable devices, as well as in filtration membranes for sterile filtration and separation applications.

Advantages and limitations: The porous structure supports tissue in-growth and endothelialization in many implants, aiding integration. However, patency can be a concern in very small-diameter grafts, and infection risk exists with implanted devices. As a non-biodegradable fluoropolymer, ePTFE remains in the body over the long term unless removed or replaced surgically.

Regulatory and handling notes: ePTFE products undergo biocompatibility testing and sterilization requirements; common methods include steam, ethylene oxide, or gamma irradiation.