Microfluidics-driven templating preparation of polymer vesicles with tailorable dimensions and rapid cellular internalization

Polymer vesicles hold immense potential in biomedicine and nanotechnology, yet conventional rehydration methods face critical limitations in controlling the vesicle architecture due to stochastic block copolymer (BCP) self-assembly. Here, we present a first-reported microsphere-templated strategy that synergizes microfluidic precision with BCP assembly to overcome these constraints. By engineering emulsion templates <i>via</i> flow rate, BCP concentration and collection distance optimization, we established a method based on the radius-square law governing the evolution of uniform vesicles (size range diameter: 70-170 nm, PDI: 0.16), enabling on-demand size tuning, a capability unattainable with traditional approaches. Multi-scale characterization (DLS, OM, SEM and TEM) elucidates the non-equilibrium templating-to-vesicle transition, revealing critical dynamics of BCP film reorganization. The resultant nano-scale vesicles exhibit rapid cellular uptake (>95% in 3 h) by HUVECs and 4T1 cells with exceptional biocompatibility (>85% viability, 36 h), outperforming many cytotoxic counterparts. This work not only provides a scalable platform for precision vesicle fabrication but also establishes foundational principles for templated self-assembly, bridging microfluidics and soft matter science. Our methodology opens avenues for tailored vesicles in drug delivery, nanoreactors and synthetic biology, addressing the persistent demand for functionally adaptive polymeric nanostructures.