Microfluidic fabrication of lipid nanoparticles for co-delivery of siRNA and hydroxychloroquine: An engineered theranostic platform for enhanced breast cancer treatment

Utilizing advanced microfluidic engineering, this study develops a precision co-delivery system for hydroxychloroquine (HCQ) and siRNA targeting CDK4/6, crucial in breast cancer therapy. The engineered lipid nanoparticles (LNPs) enhance siRNA’s cellular uptake and endosomal escape, mediated by HCQ’s autophagy inhibition, optimizing therapeutic delivery. Results of in vitro and in vivo experiments demonstrated that this system robustly arrests the cell cycle and curtails tumor proliferation, showcasing a promising engineered nanoplatform for dual drug delivery in oncological applications. • CDK4/6 inhibitors’ efficacy in breast cancer is often hindered by toxicity and drug resistance. • A novel lipid nanoparticle (LNP) co-delivery system was developed using precise microfluidic technology. • Synergistic inhibition of tumor growth was achieved through RNAi-mediated CDK4/6 silencing and HCQ-induced autophagy blockade. • The engineered LNP platform for co-delivery of small molecules and nucleic acids broadens therapeutic applications in cancer treatment. The efficacy of CDK4/6 inhibitors as anti-tumor agents, especially in breast cancer, has been constrained by direct treatment-associated toxicities and the development of drug resistance. To overcome these limitations, we developed a novel lipid nanoparticle (LNP) platform utilizing microfluidic technology, a pioneering approach for the co-loading of small interfering RNA (siRNA) and hydroxychloroquine (HCQ). This innovative strategy leverages the synergistic effects of siRNA-mediated CDK4/6 silencing, which induces cell cycle inhibition, and HCQ-facilitated suppression of autophagy, enhancing anti-tumor therapy. Additionally, HCQ plays a pivotal role in improving the delivery efficiency of nucleic acid drugs by facilitating endosomal escape. In vitro studies demonstrated that co-delivery of si CDK4/6 and HCQ effectively blocked autophagy, arrested the cell cycle, induced cellular senescence, and significantly reduced tumor cell proliferation. Subsequent in vivo experiments confirmed the superior anti-tumor efficacy of this co-administration strategy compared to single-agent treatments, without observable adverse effects. This microfluidics-based LNP platform offers an engineerable strategy for the simultaneous delivery of small molecule drugs and nucleic acids, thereby providing immense potential for broader applications in cancer therapy.