Engineering the Size of Bicontinuous Nanospheres via Multi-Inlet Vortex Mixing

Bicontinuous nanospheres (BCNs) are self-assembled nanostructures with interconnected aqueous channels that enable the coloading of hydrophilic and hydrophobic cargo; however, their size has been difficult to control. Here, we present a scalable approach to tune the size distribution of poly(ethylene glycol)-<i>b</i>-poly(propylene sulfide) BCNs using a multi-inlet vortex mixer. Higher mixing times and polymer concentrations produced larger BCNs, while shorter mixing times and lower concentrations yielded spherical micelles. Small-angle X-ray scattering and cryogenic transmission electron microscopy confirmed the BCN bicontinuous morphology, which persisted at smaller sizes. The porous BCN structure resulted in increased surface roughness compared to polymersomes (PSs). <i>In vitro</i>, BCNs and PSs of comparable sizes recruited distinct protein coronas early, but their profiles showed convergence by 24 h. <i>In vivo</i>, organ biodistribution was determined primarily by the nanocarrier size rather than the morphology. These findings establish a robust approach to BCN fabrication while revealing dynamic biological interactions that inform nanocarrier design.