Membrane bionic supramolecular nanomaterials for co-delivered of ribociclib and PEG10 siRNA for targeted therapy in breast cancer.

Resistance to cyclin-dependent kinase (CDK) 4/6 inhibitors, such as ribociclib (RB), limits breast cancer therapy. Although PEG10 siRNA (siPEG10) can counteract this resistance, achieving targeted, synchronized co-delivery to reshape the immunosuppressive tumor microenvironment (TME) remains a formidable challenge. By loading RB and siPEG10 into PEG-β-CD-modified mesoporous silica nanoparticles (PMSNs) and coating them with breast cancer cell membranes (CM), the nanocomposite RB/siPEG10@PMSNs-CM was synthesized. The nanomaterials were characterized for their size, charge, drug loading, and pH-responsive release. Therapeutic efficacy, immunotherapy-related potentials, and underlying mechanisms were evaluated using in vitro functional assays, an anoikis resistance model, and in vivo breast cancer models. Toxicity was assessed in liver and kidney tissue. The nanodrug RB/siPEG10@PMSNs-CM (<200 nm) exhibited enhanced cellular uptake and pH-dependent drug release. The zeta potential of the RB/siPEG10@PMSNs-CM was negative. The nanodrug significantly inhibited tumor cell growth, migration, invasion, and metastasis, while inducing apoptosis. Crucially, the nanodrug overcame anoikis resistance, upregulated cleaved caspase-3 and cleaved PARP, reversed epithelial-mesenchymal transition (EMT) markers (increased E-cadherin and decreased Vimentin), and inhibited p-STAT3 and p-ERK signaling. Furthermore, the nanodrug exhibited lower toxicity to liver and kidney than RB. In Conclusion, the developed biomimetic nano-delivery system RB/siPEG10@PMSNs-CM successfully co-delivers RB and siPEG10 and exhibits a favorable safety profile. This platform exhibits anti-primary tumor and anti-metastatic efficacy and effectively overcomes anoikis resistance in breast cancer, which correlated with the suppression of the MEK/ERK and STAT3 signaling pathways, offering a promising combination strategy for advanced breast cancer immunotherapy and targeted treatment.