Extracting information on the surface monomer unit distribution of PLGA by ToF‐SIMS

Abstract

The surface chemistry of a range of random poly l-lactide-co-glycolide (PLGA) materials has been investigated using XPS, static secondary ion mass spectrometry (SSIMS) and gentle secondary ion mass spectrometry (G-SIMS). The estimated mole fraction of lactide units provided by SSIMS was in good agreement with bulk composition and appeared not to have been affected by contamination. Conversely, XPS assessment of lactide compositions was unreliable due to hydrocarbon contamination contributions. In this study, we propose a novel model to demonstrate that by using SSIMS it is possible to infer the degree of trans-esterification for PLGA co-polymers synthesised from a mixture of lactide and glycolide homo-dimers. This was determined by introducing two independent parameters, the ratio of trans-esterified bonds to the total number of ester bonds, P T , and the lactide composition. The model has indicated that, for this set of polymers, P T was approximately 0.25. Furthermore, we have demonstrated that G-SIMS successfully identified the structurally important key fragments leading to direct identification. Analysis by G-SIMS showed that the glycolic acid units from all PLGA compositions are emitted in a lower energy-fragmentation process than lactic acid units.

Design, synthesis, characterization, and cytotoxicity of PCL/PLGA scaffolds through plasma treatment in the presence of pyrrole for possible use in urethral tissue engineering

“…Figure 6(a) shows three peaks that correspond to the two polymers in the blend. [29][30][31][32] The first peak, located at 284.4 eV, was assigned to the C-C group, the second peak at 286.4 eV was attributed to the C-O group, and the third peak at 288.7 eV was attributed to C ¼ O bond. However, in Figure 6(b) an additional peak was observed.…”

Mass Spectrometry of Synthetic Polymers

“…Ogaki et al used static (S-) SIMS and gentle (G-) SIMS to extract information on the surface monomer unit distribution of polylactide- co -glycolide materials. They demonstrated that G-SIMS successfully identified the structurally important key fragments leading to direct identification , .…”