Has anyone seen my polymer?

C. C. Yip, R. A. Goldberg, T. L. Cook and J. D. McCann. (2004)

A needle loaded with sutures (seen as black threads) being used to perform eye surgery [1]

Virtually everyone has used biodegradable polymers – in fact, as you are reading this, your recent grocery shopping might be nestling in one. However, not everyone would have had the opportunity to use them on/within their bodies. If you have ever had some stitches, then you might have had practical contact with a member of the family of biodegradable polymers, although the term ‘biodegradable polymer’ is viewed as too general by some researchers, who have then gone on to make a distinction between biodegradable polymers and bioresorbable polymers. Biodegradable polymers have been defined as polymers that degrade in the living body, but whose degradation by-products remain in the tissue long-term. Conversely, bioresorbable polymers have been defined as polymers that degrade into non-toxic products after implantation, products which are then expelled from the body or metabolised therein [2] – essentially, these materials have the capacity to disappear from the body after some period during which they have been implanted in the body. In spite of the differences, however, the terms biodegradable polymers and bioresorbable polymers are used interchangeably [2], the former probably more commonly used than the latter.

History

When poly(glycolic acid) – PGA, the first of the biodegradable polymers to be synthesised - was developed in 1954, its hydrolytic instability was considered a major limitation [3]. It is however ironic that what was then considered a limitation is now considered the most important property of these materials, and since the 1960s this has been exploited to produce medical devices in the form of sutures and fracture fixation pins, to mention a few. The first commercial product fabricated from a biodegradable...