Biodegradable polymeric nanomaterials (NMs), such as poly(lactic-co-glycolid acid) (PLGA) NMs, are under intensive development for a number of environmental and human health applications, including agrochemical and drug delivery. These NM formulations are typically quite complex, including surfactants and other stabilizers in addition to the polymer matrix and active ingredients. While the release of the active ingredients has been well studied, major gaps still remain in understanding the fate of the complete nanoformulation (particularly, surface coatings and other excipients), upon application. Previously, we have developed asymmetric flow field - flow fractionation (AF4) with UV-vis, fluorescence, and light scattering detection for analysis of drug loading in NMs and particle size distributions. Here, we extend this method with online total organic carbon (TOC) analysis to quantify the overall polymer concentrations. The method was applied to monitor transformations of PLGA NMs (≈ 250 nm diameter) synthesized with poly(vinyl alcohol) (PVA) surfactant and loaded with Coumarin 6 as a fluorescent probe. The AF4 method was able to generate slow release profiles of Coumarin 6 from the NMs more reliably than other methods, which suffered from low recovery of the hydrophobic coumarin compound. Furthermore, changes in polymer excipient concentration in the nanoparticulate population were monitored via the total organic carbon measurements. Complementary analysis by quadrupole time of flight (QTOF) mass spectrometry was performed on acetonitrile extracts of the NMs to verify the release profiles and identify loss of PVA surfactant from the PLGA NMs over time. Overall, this study demonstrates the development and application of new AF4 methods that can be broadly useful to evaluate the fate of polymeric nanoformulations in environmental and biomedical applications.

Achieving a complete picture of the fate of polymeric nanoformulations through complementary particle fractionation and mass spectrometry analysis

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.