The combination of poly-L-lactide (PLLA) and magnesium (Mg) alloys hold great potential for application in cardiovascular stent-based implants and orthopaedic bone grafts. A composite made from these materials has specific advantages combining Mg with high strength, biodegradability, and biocompatibility with PLLA, which is a synthetic, biocompatible, biodegradable polymer and well established in medical implant applications. Therefore, biomaterials made of PLLA/Mg composites might avoid permanent foreign body reaction, recurrent intervention, or revision surgery. However, the chemical reactions occurring during degradation depend on a variety of factors, including microstructure, composition of the materials systems, the composition and flow of the surrounding media, as well as the tissue type and influence the way the composite degrades. Additionally, degradation products can interfere with or stimulate cellular reactions, which in turn will dynamically change the chemical and biological environment of the composite. To enhance comprehension of these relationships, preliminary experiments were conducted to produce and characterise such composites and their degradation under near-physiological conditions.

For this purpose, injection moulded samples of PLLA were coated with ultrathin, nanoscale magnesium by physical vapour deposition and nanostructured PLLA nonwovens were loaded with Mg particles. Both materials were characterised with respect to their structure and degradation properties.

Coating thickness was determined using X-ray reflectivity and a focused ion beam scanning electron microscope. The PLLA/Mg nonwovens were determined by X-ray microcomputed tomography.

This pilot study demonstrates a successful combination of PLLA with Mg, suggesting that a successful structuring is possible while maintaining the stability and degradability of both entities at acceptable levels.