Aptamer-Functionalized Liposome Delivery System Based on Multifunctional Microreactor Design

Breast cancer remains the leading cause of cancer-related mortality in women, with conventional chemotherapy often limited by systemic toxicity due to poor drug targeting. Here, we present an integrated microfluidic chip (MMLP) that enables one-step integrated postprocessing, including solvent removal and ligand conjugation. The MMLP chip combines Y-shaped, crescent-shaped, U-shaped, and Tesla-type microchannels, augmented with pillar arrays to enhance mixing efficiency at low flow rates. A dedicated third channel allows simultaneous solvent removal and aptamer conjugation. Through computational fluid dynamics (CFD) simulations, we optimized the flow-rate ratio (lipid phase/aqueous phase/postprocessing phase = 1:5:2) and achieved AS1411 aptamer modification via thiol-maleimide chemistry. The resulting AS1411 aptamer-functionalized liposomes loaded with doxorubicin (D@Lip-Apt) exhibited uniform size (155 ± 3.2 nm, PDI = 0.17) and high drug encapsulation efficiency (76.64 ± 0.52%). In vitro and in vivo studies confirmed the nanoparticles' superior stability and tumor-targeting specificity. This modular microreactor offers exceptional flexibility in tailoring liposome properties for breast cancer therapy and demonstrates scalability for industrial production through dimensional or parallel amplification.