• TWO-PHASE DEGRADATION
A two-phase process: Degradation of biodegradable polymers
Degradation of polymers in the body is a two-phase process: simple chemical hydrolysis of the chemically unstable backbone and active metabolism.

During the first phase, water penetrates to the bulk of the biodegradable device, preferentially attacking the chemical bonds in the amorphous phase and converting the long polymer chains into shorter water-soluble fragments. The reduction in molecular weight is soon followed by a reduction in physical properties, as water begins to fragment the biodegradable device.

In the second phase, enzymatic attack and metabolization of the fragments occurs when macrophages and polymorphonuclear leukocytes fragment the polymer further to monomeric acids, which enter the citric acid cycle and are excreted as water and carbon dioxide.

• The Unique Art of Making Biodegradable Polymers

The most widely used and investigated biodegradable polymers are different variations and combinations of Polylactic-Acid (PLA) and Polyglycolic-Acid (PGA).

PLA is a slow-degrading non-water-soluble polymer, whereas PGA is water soluble and degrades fast. Using the properties of different variations of PLA and PGA, it is possible to combine the two monomers to extend the range of properties. The properties can be further tailored by incorporation of soft and rubbery units.

Other important variables affecting the properties of biodegradable implants are the morphological structure, the manufacturing process, and the sterilization method. A manufacturer's know-how in polymer and manufacturing technology is best measured by the final performance and usability of the implant.

The most widely used and investigated biodegradable polymers are different variations and combinations of Polylactic-Acid (PLA) and Polyglycolic-Acid (PGA).

• INION Optima
INION Optima™: Optimal materials for optimal implant performance
Selective material composition has guided Inion's product development:
As a result of the company's extensive research programme and world-class polymer and manufacturing know-how, we have been able to define an optimal combination of polymer parameters and their processing techniques for each specific application, thereby optimizing the final characteristics of the product.

For the screw application, the polymers used give optimal shear and torque strength for the fixation of plates. For plates, a different polymer combination is used for each application to give optimal flexural and tensile strength. For mesh plates, again a different polymer is used.

By using this unique approach - developing the most suitable materials for each application - INION Optima™ guarantees optimal implant performance.