FDA Approval for Polymer Molding in Medical Devices 101
The recent FDA approval of Abbott’s Absorb GT1 Bioresorbable Vascular Scaffold (BVS) System is designed with a poly(L-lactide) polymer to fully dissolve in the patient’s body over about three years. Another FDA-approved offering in the coronary stent market is Boston Scientific’s Synergy bioabsorbable polymer drug-eluting stent, which has a drug coating and polymer used to elute the drug that are fully absorbed about three months after implant.
These products underscore the growing popularity of resorbable polymers in medical devices. What potential does this class of material hold for new medical devices and what do manufacturers need to know about designing with and molding it?
We asked experts from MTD Micro Molding to tell us more about the challenges, equipment, and new advances in molding resorbable polymers for medical devices.
Editor’s note: This Q&A has been edited slightly.
MD+DI: What are the most common types of resorbable polymer used in medical devices?
Dennis Tully, MTD Micro Molding president: Commercially available standard absorbable materials include PLA (polylactic acid), PLG (polylactide-co-glycolide), PLDL (polylactide/DL-lactide copolymer) and PCL (polycaprolactone), among others.
Unique polymers are created when additions are made to these materials to make them special like pharmaceuticals, fillers, and lower molecular weight materials that dissolve quicker. The recipe for a custom blend of resorbable material is determined based on the application of the molded part. Some medical applications require bioabsorbable materials with more flexibility, higher rigidity, higher or lower rates of absorption. Required material properties can be dialed in to create custom blends that are tailored to meet the needs of the specific application. There are many possibilities and the various iterations of products that are available are wide-spectrum.
MD+DI: What are some typical medtech applications of this material?
Lindsay Mann, director of marketing: These materials are popular in many of the newest micro medical applications because the materials can dissolve/absorb into the body, minimizing concerns about any adverse effects. Devices made from these materials metabolize over time so secondary invasive procedures are not needed to remove them. They are absorbed into the body, leaving only benign by-products.
Brian Matachun, director of sales: Tissue Fixation is a popular MedTech application for resorbable materials. Implantable fixation products include anchors, staples, screws, and tacks for applications like hernia repair. Fixation may be in the form of tissue to tissue, tissue to bone, or tissue to biologic meshes, and the temporary fixation a bioabsorbable product provides leaves no foreign material in the body over time. Bioabsorbable materials are also popular for products in the closure market (i.e. fascia closure, femoral artery closure, etc.) and laparoscopic procedures.
Dennis Tully: In the near future, products like drug-eluting bioabsorbable implants will become more prevalent in the market. These products consist of an active drug compounded with a bioabsorbable material that gets molded, then implanted inside the body. The bioabsorbable carrier dissolves, delivering the drug over an extended period of time.
[Images courtesy of MTD MICRO MOLDING]