PROTEOMIC APPROACHES TO CHARACTERIZE A NOVEL BIOMATERIAL FOR IN-SITU DELIVERY OF BIOLOGIC DRUG FOR CANCER IMMUNOTHERAPY

Abstract

Breast cancer, particularly triple-negative breast cancer (TNBC), remains a significant challenge due to its aggressive nature and poor prognosis. TNBC is characterized by the absence of estrogen (ER), progesterone receptor (PR), and Human epidermal growth receptor-2 (HER2), rendering it resistant to conventional hormone therapies. Recent advances in immunotherapy have shown promise, primarily by targeting programmed cell death-ligand 1 (PD-L1) to enhance anti-tumor responses. However, despite promising outcomes with anti-PD-L1 monoclonal antibodies, therapy resistance remains prevalent, particularly in TNBC. Combination therapies incorporating immune cell-recruiting chemokines, such as CXCL9, have been proposed to address this resistance. CXCL9 promotes immune cell recruitment and activity, potentially improving therapeutic efficacy. This study explores using Nylon 6,6 as a delivery platform for a combination of anti-PD-L1 antibodies and CXCL9 in TNBC therapy. Nylon 6,6, a biocompatible and versatile polymer, provides advantages in drug delivery due to its high drug-loading capacity and controlled release properties. Functionalization with Cibacron Blue F3G-A further enhances the precision of drug delivery, reducing off-target effects. In addition to evaluating drug release kinetics, we utilized mass spectrometry to quantify the released drugs and analyze released extracellular vesicles (EV) to investigate the molecular changes induced by the treatment. These techniques allowed for a deeper understanding of how the drug combination modulates tumor-derived EVs and their role in immune responses. The biological activity of the released agents was assessed through molecular and cellular assays, and the in-situ release approach was tested in a murine model of breast cancer. This strategy aims to improve therapeutic efficacy and overcome resistance challenges in TNBC treatment by combining drug release with detailed molecular analysis.