Bioresorbable Polymers: How do they Degrade?

Poly-Med’s bioresorbable polymers offer customized product solutions when an implant does not need to permanently remain in the body. The key trait for our materials is that they degrade within a physiological environment. Often times, this can be misconstrued to be a variety of degradation mechanisms including surface erosion, bulk erosion, among others.

Surface erosion takes place when mass loss for a device occurs at the water/implant interface, causing the implant to resorb from its outer surface toward its center while maintaining its bulk integrity. This is sometimes referred to as ‘device thinning’.

The majority of Poly-Med’s polymers degrade by a process known as bulk erosion. Bulk erosion occurs when the main mechanism for degradation is by the diffusion of water into the device or polymer structure, leading to hydrolysis. For bulk degradation, polymer properties are generally affected first by a decrease in molecular weight, followed by a decrease in strength, and finally, a decrease in mass.

By having a staggered rate of degradation for different polymer properties, it is extremely important to perform in vitro characterization of your product to truly understand the time scale for degradation and the appreciable loss of properties.
If you are working on a medical device application, and are interested in learning more about our bulk eroding polymers, contact us to learn how we can advance your idea.