BioSpan® segmented polyether urethane (SPU) is a critical biomedical polymer used in the majority of clinical ventricular assist devices and artificial heart cases worldwide. It is one of the most extensively tested biomedical polymers on the market, backed by a comprehensive FDA Master File. BioSpan® is among the most elastomeric biomaterials available that simultaneously exhibits an impressive combination of physical and mechanical properties together with biological compatibility, characterized by:

• Excellent Flex Life
• Low Modulus
• High Strength
• High Elongation
• Biostability

PTG developed BioSpan® segmented polyurethane in response to the crisis created by the withdrawal of Biomer™1 by Ethicon Inc. Although BioSpan® was designed as a direct replacement for Biomer, PTG made several improvements to the manufacturing process, including scaling up the reaction from 5 to 100 gallons, using glass-lined reaction vessels and depth filters that minimize contamination and implementing rigorous quality control and documentation of the manufacturing procedures. As a result, PTG consistently produces BioSpan® batches of precise molecular structure. This consistency, combined with an extensive FDA Master File, has facilitated the approval process for clinical applications of BioSpan.

For device components that require high strength, flexibility, and fatigue resistance, BioSpan® should be considered as a candidate biomaterial*. Whereas typical urethanes lose stability with increasing soft segment concentration, BioSpan® SPU has excellent physical properties at nominal 70A Shore hardness.

PTG has also developed and patented a new generation of BioSpan® that incorporates silicone into the soft segment, thus delivering the biocompatibility and stability of silicone to an extremely soft biomaterial with unique bulk properties. Processing

BioSpan® materials are available in dimethylacetamide (DMAc) solution, suitable for fabrication processes such as casting, dipping, spinning, and spraying. When preparing films or components from BioSpan® solution, PTG recommends heating the immediate work area to 30-35 °C (86-95 °F) with HEPA-filtered air and adequate ventilation. The elevated temperature is required because DMAc is a hygroscopic solvent and will pick up moisture at room temperature, resulting in a poor quality part. Dry the part in an oven at 60 °C (140 °F) to remove the remaining solvent after the bulk of the solvent has evaporated (20-60 minutes). The oven drying time will vary depending on the dimensions of the part. A final water extraction or multiple extractions may remove trace DMAc. Perform this water extraction at 60 °C for 24 hours or longer, depending on sample thickness. If possible, the entire contents of a container should be used at one time. If less than the entire contents of a container are used, make sure the solution is handled in a clean environment and the remainder is stored properly after each usage. The remainder should be stored in a sealed container at < 4°C and could be reused.

Alternatively, PTG has the clean room facilities to fabricate devices and device components from BioSpan, according to your specifications.