Modular two-photon polymerized microfluidics for on-chip synthesis and functionalization of nanogels for ovarian cancer drug delivery

The effective functionalization of polymeric nanoparticles with specific biomotifs has emerged in nanomedicine as a crucial aspect for achieving selective targeting and improving therapeutic efficacy. Hence, precise control over both nanoparticle synthesis and surface functionalization remain key challenges. Here, a modular microfluidic platform fabricated via two-photon polymerization (2PP) 3D printing was developed and validated for the continuous production and in-chip decoration of polymeric nanogels (NGs). The system integrates three functional modules: i) a micromixer for blending the polymer precursors (hyaluronic acid and polyethylene glycol), ii) a droplet generator for controlled NG formation, and iii) a dedicated in-flow functionalization unit enabling surface conjugation with a tumor-targeting biomotif. This modular architecture allows independent tuning of material inputs and process conditions, enabling direct transition from raw materials to fully functionalized nanosystems, while the use of 2PP offers greater design flexibility and fabrication precision without the constraints of conventional soft-lithography workflows. This approach enabled controlled and reproducible NG synthesis, yielding nanosystem with diameters approaching 100 nm and narrow size distributions (PDI between 0.011–0.135), under the investigated conditions. Importantly, in-chip functionalization achieved up to a 20% increase in grafting efficiency of the decorating molecule compared to semi-batch method. The resulting functionalized NGs were validated in ovarian cancer cell models, demonstrating enhanced therapeutic activity. Overall, this work establishes a versatile and reproducible platform for the integrated synthesis and functionalization of nanogels, demonstrating the novelty of on-chip decoration via chemical coupling and highlighting the potential of modular 2PP-fabricated microfluidics for advanced and customizable drug delivery applications.