Silica-based EGFR-degrading nano-PROTACs for efficient therapy of non-small cell lung cancer

Proteolysis targeting chimeras (PROTACs) technology is a promising strategy for degrading proteins of interest. Traditional PROTACs, however, often face challenges such as poor solubility, low stability, and off-target toxicity. To address these challenges, we integrated nanotechnology to enhance the delivery of target-protein degraders to the tumor sites, thereby improving their properties. Here, we report silica-based nano-PROTACs (SiPROTACs) that feature multiple ligands on the surface to target and degrade the transmembrane protein epidermal growth factor receptor (EGFR). SiPROTACs, with a diameter of approximately 50 nm, can efficiently bind to EGFR, recruit cereblon (CRBN) to induce EGFR ubiquitination, and facilitate their degradation by proteasomes. In HCC-827 and PC-9 cell lines, SiPROTACs initiated EGFR degradation at a notably low concentration of 50 nM, demonstrating greater efficiency compared to traditional PROTACs. In HCC-827 xenograft tumor-bearing mice, SiPROTACs accumulated at tumor site for at least 48 h and exhibited significant anti-tumor effects in vivo without causing noticeable side effects. These findings suggest a novel approach for the application of PROTACs highlighting their therapeutic potential for the treatment of non-small cell lung cancer (NSCLC).