The development of ionizable lipid (IL) was necessary to enable effective formulation of small interfering RNA (siRNA) to inhibit P2X7 receptors (P2X7R), a key player in tumor proliferation, apoptosis, and metastasis. In this way, the generation and utility of IL for enhancing cellular uptake of lipid nanoparticles (LNP) improves the proper delivery of siRNA-LNPs for knockdown overexpression of P2X7R. In this study, we synthesized a branched ionizable lipid (SIL) that e ciently transfects LNP with P2X7 siRNA (siP2X7) for evaluation of BC migration and apoptosis in mouse 4T-1 cells. Following synthesis and structural analysis of SIL, LNP was prepared with excellent characterization (Z-average 126.8 nm, Zeta-potential − 12.33, and PDI 0.16, and encapsulation e ciency 85.35%). Afterwards, the stability of the LNP was evaluated through an analysis of each leftover composition, and toxic concentration values for SIL and siP2X7 were determined.Furthermore, siP2X7-LNP cellular uptake in the formulation was assessed via confocal microscopy.We used scratch assay microscopy and ow cytometry to assess wound healing analysis and apoptosis after determining the optimal dose (45 pm). As a result, the formulated siP2X7-LNP with innovative SIL indicates that offbeat cellular uptake inhibits migration and induces apoptosis of 4T-1 cells. Subsequently, SIL plays a critical role in LNP formulation to deliver siRNA e ciently against murine triplenegative breast cancer cells (TNBC).with signi cant e cacy.