Recent Trends in the Structural Characterization and Degradation of Biodegradable Polymers By Modern Mass Spectrometry

In the last decades, the solid-waste management related to the extensively growing production of plastic materials, together with their durability, have stimulated increasing interest in biodegradable polymers. At present, a variety of biodegradable polymers has been developed and has already been introduced onto the market. However, a noteworthy economical effort is still focussed in tailoring structural properties in order to further broaden the range of applications without impairing biodegradation. Improving the performance of biodegradable materials requires a good characterization of both physico-chemical and mechanical parameters. Polymer analysis can involve many different features including detailed characterization of chemical structures and compositions as well as average molecular mass determination. It is of outstanding importance in troubleshooting of a polymer manufacturing process and for quality control, especially in biomedical applications. This book chapter describes recent trends in the structural characterization of biodegradable materials by modern mass spectrometry (MS). Furthermore, it provides an overview of the analytical tools used to evaluate their degradation. Several successful applications of MALDI TOF MS (matrix assisted laser desorption ionization time of flight mass spectrometry), ESI MS (electrospray ionization mass spectrometry) and SIMS (secondary ion mass spectrometry) for the determination of the structural architecture of biodegradable macromolecules, including their topology, composition, chemical structure of the end groups, and surface analysis have been reported. However, MS methodologies have been recently applied to evaluate the biodegradation of polymeric materials. ESI MS is the most useful technique for characterizing water-soluble polymers possessing different end group structures, with the advantage of being easily interfaced with solution - based separation techniques such as high - performance liquid chromatography (HPLC). Additionally, SIMS represents a powerful and fast technique in the surface analysis and in studies of degradation kinetics of biodegradable polymers, mainly of those employed in drug delivery systems.