Abstract 6893: Synthesis and characterization of IL-4R ligand mimic (AP1)-functionalized elastin-like polypeptide-based nanopolymers as selective delivery vehicles for paclitaxel in ovarian cancer

Abstract Introduction- Elastin-like polypeptides (ELPs) have emerged as promising nanocarriers for drug administration, owing to their advantageous properties, including biocompatibility and distinctive biophysical behavior. These polymers can be tailored to incorporate functional motifs that allow for accurate drug loading and targeted delivery. In cancer therapy, ELP-based nanocarriers have shown potential by increasing drug solubility, stability, and allowing for tumor-specific targeting. This study aims to develop and evaluate AP1-functionalized ELP-based nanopolymers as vehicles for the “selective” delivery of paclitaxel (PTX) in ovarian cancer (OC). Materials and methods- Maleimide-reactive cysteine residues were introduced into the ELP/AP1-ELP sequence. Paclitaxel, activated by N-ε-maleimidocaproic acid (EMCA), was coupled to ELP/AP1-ELP by a Michael addition reaction. Chemical conjugation was assessed using MALDI-TOF mass spectrometry, transmission electron microscopy (TEM), and dynamic light scattering (DLS). SKOV-3 and OVCAR-3 cell lines were analyzed for IL-4R expression followed by assessment of differential binding of Alexa-488 labelled ELP/AP1-ELP using flow cytometry (FACS). IC50 values of ELP/AP1-ELP-PTX were measured using the CCK-8 assay. Additionally, cell cycle progression and apoptosis were examined by FACS. Furthermore, an agarose-based 3D spheroid model of OC cells was used to establish the selective targeting efficacy of PTX-loaded AP1-ELP. Results- Sanger sequencing confirmed the successful incorporation of maleimide-reactive cysteine residues into ELP polymers. MALDI-TOF, TEM, and DLS analyses demonstrated stable conjugation of the drug to the polymer. IL-4R expression in SKOV-3 and OVCAR-3 via FACS showed positivity for the receptor. Binding assays with Alexa-488-labelled ELP/AP1-ELP showed enhanced binding to IL-4R-expressing cells for the AP1-functionalized polymers compared to the non-functionalized ELP. Cytotoxicity assays revealed that AP1-ELP-PTX exhibited relatively lower IC50 values, indicating stronger anti-cancer activity compared to ELP-PTX. FACS-based analysis of the cell cycle and apoptosis further confirmed the higher cytotoxicity of AP1-ELP-PTX. Moreover, 3D spheroid cultures of OC cell lines established the significance of AP1-based targeting, displaying superior cytotoxicity in comparison to ELP-PTX. Conclusion- In this study, we demonstrate the potential of AP1-functionalized ELP in the selective delivery of PTX in ovarian cancer. AP1-ELP exhibits superior cellular association, facilitating improved cytotoxic ability for the appended drug, PTX. Further evaluation of the AP1-ELP-PTX selective delivery ability in vivo is required for full realization of the AP1-ELP polymer as a delivery vehicle. Citation Format: Ridhima Goel, Deepak Gulwani, Thoudam Debraj Singh. Synthesis and characterization of IL-4R ligand mimic (AP1)-functionalized elastin-like polypeptide-based nanopolymers as selective delivery vehicles for paclitaxel in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6893.