Polymers from PolySciTech used in study on nanoparticle control by solvent-based nanoprecipitation

 

Nanoparticles are generated by carefully controlling the precipitation of a polymer in a non-solvent condition. The choice of solvents and control of their interactions has a strong impact on nanoparticle size and properties however this has not received as much systematic study as it deserves. Recently, researchers from ETH Zurich utilized mPEG-PDLLa (AK056), mPEG-PLGA (AK037), mPEG-PCL (AK128) from PolySciTech Division of Akina, Inc. (www.polyscitech.com). Read more: Bovone, Giovanni, Lucien Cousin, Fabian Steiner, and Mark W. Tibbitt. "Solvent Controls Nanoparticle Size during Nanoprecipitation by Limiting Block Copolymer Assembly." Macromolecules (2022). https://pubs.acs.org/doi/abs/10.1021/acs.macromol.2c00907

“Abstract: Control of the properties of nanoparticles (NPs), including size, is critical for their application in biomedicine and engineering. Polymeric NPs are commonly produced by nanoprecipitation, where a solvent containing a block copolymer is mixed rapidly with a nonsolvent, such as water. Empirical evidence suggests that the choice of solvent influences NP size; yet, the specific mechanism remains unclear. Here, we show that solvent controls NP size by limiting block copolymer assembly. In the initial stages of mixing, polymers assemble into dynamic aggregates that grow via polymer exchange. At later stages of mixing, further growth is prevented beyond a solvent-specific water fraction. Thus, the solvent sets NP size by controlling the extent of dynamic growth up to growth arrest. An a priori model based on spinodal decomposition corroborates our proposed mechanism, explaining how size scales with the solvent-dependent critical water fraction of growth arrest and enabling more efficient NP engineering.”