Anti-PD-L1 Antibody\nFragment Linked to Tumor-Targeting\nLipid Nanoparticle Can Eliminate Cancer and Its Metastasis via Photoimmunotherapy

Effective cancer therapy aims to treat primary tumors\nand metastatic\nand recurrent cancer. Immune checkpoint blockade-mediated immunotherapy\nhas shown promising effects against tumors; however, its efficacy\nin metastatic or recurrent cancer is limited. Here, based on the advantages\nof nanomedicine, lipid nanoparticles (LNPs) that can target tumors\nare synthesized for photothermal therapy (PTT) and immunotherapy to\ntreat primary and metastatic recurrent cancer. These LNPs, termed\npiLNPs, are encapsulated with indocyanine green and incorporated with\nthe antigen (Ag)-binding fragment of the anti-PD-L1 antibody for targeting\ntumors and immunotherapy. Intravenously injected piLNPs in 4T1 breast\ntumor-bearing BALB/c mice effectively target the 4T1 tumor and are\nsuitable for performing PTT using a near-infrared laser. Moreover,\nlung metastatic 4T1 tumor growth is completely prevented in mice previously\ncured of the 4T1 breast tumor by piLNP treatment and rechallenged\nwith lung 4T1 metastatic cancer. Blockage of the second challenged\nmetastatic 4T1 breast cancer by piLNP is due to the activation of\nAg-specific T cells. Cytotoxic T lymphocytes from piLNP-cured mice\nselectively attack 4T1 breast cancer cells. Therefore, piLNP can be\nused as a multifunctional breast cancer treatment composition that\ncan target tumors, treat primary tumors, and prevent metastasis and\nrecurrence.