The concept of biocompatibility of medical devices has been around nearly as long as humans have been using such devices — and that’s far longer than you might think. Evidence exists indicating ancient Egyptians and Etruscans were making and using false teeth as early as 1500 and 700 B.C., respectively.
Even those first denture makers must have noted that their patients’ mouths were able to tolerate certain materials better than others. Today, we have a much better understanding of biocompatibility and the next logical progression in the evolution of medical devices — bioabsorbability.
While all modern medical devices must be biocompatible (capable of being used in the human body without harming living tissue), not all are bioabsorbable — that is, able to be absorbed into the body over time. Of course, medical implants such as artificial joints need to stay intact in the human body for the long haul. In other applications, however, it’s beneficial for the patient for a device to be made of a material that will allow it to fade away over time, without requiring a surgical procedure to remove it.
Bioabsorbable polymers have been around for a while, and are used in everything from stents to sutures. But even established applications for bioabsorables are constantly improving to make devices more effective and safer. Here are four types of bioabsorbable medical devices that promise to continue revolutionizing patient care:
1. Tissue scaffolds
Key to the emerging field of tissue engineering, tissue scaffolds help damaged tissues regenerate by providing a structure that promotes and guides the growth of new tissue. Of course, once the scaffold’s job is done, it’s essential that the implant be able to dissolve in the body. Removing it surgically would defeat the purpose of the scaffold and, therefore, isn’t an option.
Tissue scaffolds have been used to repair hernias, reconstruct abdominal walls, reinforce muscle flaps and for general tissue reconstruction. Now, a group of researchers at the University of Toronto has created a tissue scaffold for use in cardiac applications, medGadget reports.
Probably one of the earliest applications for bioabsorbable materials, dissolving stitches are commonplace in modern health care. A variety of options exist, allowing health-care professionals to choose a type of suture that will remain intact long enough to allow for healing and then quickly dissolve.
3. Screws and pins
Physicians and surgeons have long used metal screws, pins and bars to facilitate the healing of complex or catastrophic bone fractures. While the metal devices typically did a fine job holding bone fragments in place until they could heal, they ultimately had to be removed — a process that was often painful for the patient — or remain in place, which could lead to infection, rejection or other long-term problems. Bioabsorbable polymer alternatives made from PLGA (lactic/glycolic acid copolymer) get metabolized in the body through hydrolysis.
4. Drug delivery systems
Bioabsorbable polymers can be used to deliver drugs in a variety of ways, including the very common use of subcutaneous implants that dissolve over time while releasing medication into the patient’s body. A new type of coronary stent that also delivers medication is one exciting new development in the field. Under FDA review, the stent incorporates a balloon dilatation catheter to help open arteries, an absorbable PLLA scaffold, and a drug-eluting coating that uses PDLLA (a bioabsorbable polymer) to deliver medication directly to affected blood vessels.
Bioabsorbable medical devices can help improve patient outcomes by promoting better healing, and by lowering risks of infections and adverse reactions. It’s one more way polymers are helping people live longer and healthier lives.