Silk Fibroin Nanoparticles Coated with Secretome-Derived Extracellular Vesicles via GMP-Ready Microfluidics: A Biomimetic Carrier-in-Carrier Platform with Preferential Tumor Cell Internalization

The integration of synthetic nanocarriers with biologically derived membranes represents a promising strategy to engineer biomimetic systems for precision medicine. Here, we report a hybrid carrier-incarrier nanoplatform in which silk fibroin nanoparticles (SFNs) are encapsulated within extracellular vesicles (EVs), enabling the combination of tunable material properties with intrinsic biological functionality. A key advancement of this work is the development of a microfluidic, GMP-compatible assembly process that allows controlled and scalable production of EV-coated nanoparticles, addressing a major translational bottleneck in the field. The resulting hybrid nanostructures were characterized by nanoparticle tracking analysis and Förster resonance energy transfer, confirming the formation of a stable core-shell architecture at the nanoscale. Using a model lipophilic compound, we demonstrate that EV encapsulation enhances colloidal stability, protects the payload from degradation, and enables sustained release profiles. Importantly, the biological identity of the EV membrane was found to modulate cellular interactions: EVs derived from mesenchymal stromal cells promoted preferential uptake in healthy cells, whereas tumor-derived EVs enhanced homologous targeting in cancer cells. These findings establish EV-coated SFNs as a versatile biomimetic platform with programmable targeting properties and scalable manufacturability. This approach provides a foundation for the development of next-generation nanotherapeutics that integrate material design with biological specificity for precision oncology.