Biodegradable Materials: Bioglass to Mend Bones


Photo: Implants made of biodegradable polymers

These are implants made of biodegradable polymers that could help to mend broken bones; © UPV/EHU

Researchers in the materials engineering department of the UPV/EHU-University of the Basque Country, have been studying new materials or implants that are of interest in medicine and in helping to mend bones, in particular.

They have in fact measured the effect that the bioglass has on the thermal degradation of polymers currently used in medicine. Bones are capable of regenerating themselves if they suffer slight damage. But if the damage is above a certain degree, bone lacks the capability of mending itself. When breaks are too big, bones need to be helped. Even today, metal nails or other components are often inserted to help these breaks to mend. So, once the bone has mended, a second operation has to be performed to extract these components. The aim of these new materials or implants is, among other things, to obviate the need for the second operation.

These materials or implants that are of interest in medicine have to meet a number of requirements before they can be used in therapeutic applications. Among other things, the materials have to be biocompatible, in other words, they must not damage the cells or the organism itself. At the same time, being biodegradable is also a very interesting property, so that the body will easily convert them into metabolic products that are not toxic. But other factors also have to be taken into consideration: mechanical robustness and the straightforward nature of the production process, for example.

With all this in mind, the UPV/EHU researchers are synthesizing and shaping tailor-made bioimplants. The main component, on the whole, tends to be a biodegradable polymer, in other words, one that will gradually disappear as the bone occupies its own place. As the polymer is too soft, bioglass was added to the polymer in this piece of work. Bioglass is a bioactive agent and helps the bone to regenerate; what is more, it gives the polymer tough mechanical properties. So the biodegradable polymer/bioglass composite system is stiffer and tougher than the polymer alone.

So "these composites that have a biodegradable polymer base are candidates with a bright future in mending broken bones or in regenerating bone defects," says Professor Sarasua. In fact, after the material has temporarily substituted the bone and encouraged it to regenerate, it gradually disappears as the bone returns to its proper place. So, "this obviates the need for the second operations required nowadays to remove nails and other parts that are inserted in order to somehow support the bones in major breaks above a critical size, with all the advantages that has from a whole range of perspectives," he added.; Source: Elhuyar Fundazioa