Exosomes are nanoscale lipid-bilayer vesicles that mediate intercellular communication by delivering bioactive molecules such as nucleic acids and proteins. Among them, exosomes derived from salivary gland epithelial stem cells (sgESC-Exos) exhibit antifibrotic effects in salivary gland models through the delivery of antifibrotic microRNAs, such as miR-1290 and miR-3162. However, their clinical translation is hindered by low production yield and particle heterogeneity. To address these challenges, exosome-mimetic nanoparticles (ENPs) are developed that mimic the lipid composition and therapeutic cargoes of sgESC-Exos using a microfluidic chip integrated with a reverse-Tesla structured micromixer. The microfluidic platform facilitates efficient mixing and self-assembly of lipid and aqueous phases, resulting in uniform ENPs with effective encapsulation of nucleic acids. The resulting ENPs exhibit physicochemical properties similar to exosomes, including comparable size distribution and structural features. Moreover, they demonstrate efficient encapsulation of exosomal miRNAs and more uniform physicochemical properties than sgESC-Exos, contributed to enhanced therapeutic efficacy, with ≈21-fold higher cellular uptake and two-fold faster wound closure rate. These findings highlight the potential of microfluidics-based bottom-up synthesis as a robust platform for exosome-inspired nanomedicine, addressing key limitations of exosomes and paving the way for clinical translation.