Project Summary: Triple-negative breast cancer (TNBC) accounts for approximately 15% of invasive breast cancers and is associated with aggressive tumor biology, poor prognosis, resistance, visceral metastases and earlier disease recurrence. TNBC is more common in younger women than in older women and in African- American and Hispanic women. Platinum-based drugs showed higher sensitivity in TNBC compared to non- TNBC patients and recently there has been a renewed interest for platinum therapy in TNBC, especially combination of carboplatin with paclitaxel (PTX). Sacituzumab govitecan is made up of an anti–Trop-2 antibody linked to the chemotherapy drug (SN-38) and was cleared by the FDA for TNBC patients who have undergone at least two prior chemotherapies. The FDA granted an accelerated approval for the immunotherapy drug atezolizumab in combination with chemotherapy (nab-paclitaxel) for the treatment of TNBC (for tumors positive for PD-L1). Thus chemotherapy is important in the therapeutic management of TNBC even in the advent of immunotherapy and targeted therapy. However, chemotherapies are known to cause fatal peripheral neuropathy in addition to poor response, metastasis, relapse and development of multidrug resistance. The goal of this application is the development of multifunctional targeted nanoparticles capable of achieving better outcomes for TNBC patients: (a) targeted delivery of large doses of multiple drugs into cancer cells (per a single biorecognition event compared to a single immunotargeted drug (e.g. sacituzumab govitecan-hziy)) to maximize therapeutic effects while reducing systemic toxicity (off target toxicity); (b) EGFR-receptor targeted nanoparticles that promote intracellular drug delivery and release and which can bypass multidrug resistant protein (p-glycoprotein) which mediates efflux of drug molecules; (c) capable of long circulation without being sequestered into the liver. EGFR is overexpressed by TNBC and literature is replete with examples of the use of cetuximab in therapy by targeting EFGR. We hypothesize that the development of biodegradable polymeric nanotechnology platform containing carboplatin and paclitaxel in the core and using cetuximab (tagged on nanoparticle surface) as a targeting moiety will improve TNBC patients’ outcomes, unlike repeated chemotherapy cycles with high doses of cytotoxic drugs. We hypothesize that the dual-loaded multifunctional targeted nanoparticles will be active in vitro and show in vivo efficacy in mouse xenograft models of TNBC positive tumors. Aim #1: Fabrication of polymeric dye-loaded and-paclitaxel and carboplatin-loaded stealth hydrolysable crosslinked cetuximab surface-targeted polylactide (PLL) nanoparticles. Aim #2: Characterization of anti-EGFR mAb (cetuximab) surface-targeted-PLL-nanoparticles containing carboplatin and paclitaxel in the core. Aim #3: Biodistribution and efficacy studies in tumor-bearing mice. This work will bring to bear the combined power of chemoth...