Time-resolved SAXS Studies During the Synthesis of New Degradable Nanoparticles

We wish to conduct a series of time-resolved SAXS studies during the synthesis of new hydrolytically degradable diblock copolymer nanoparticles. We have recently shown that such nanoparticles can be prepared by ‘reverse sequence’ polymerisation-induced self-assembly (PISA) in aqueous media with negligible hydrolysis occurring during their synthesis. In essence, a degradable hydrophobic precursor is solubilised using a water-miscible monomer (N,N’-dimethylacrylamide, DMAC) as a co-solvent. As the DMAC polymerise, the hydrophobic block solvency worsens and, at some monomer conversion, nucleation occurs to form latently degradable nanoparticles. Given the highly asymmetric copolymer composition at this point, we predict that (i) the initial nuclei should be vesicles (rather than the spheres observed for conventional PISA syntheses) and (ii) there should be an unprecedented evolution in particle morphology from vesicles to worms to spheres as the DMAC polymerise to full conversion.