Abstract 4479: Optimization of ultrasound-responsive nanoparticles encapsulating cancer cells for enhanced immunotherapy

Due to the limited effectiveness of current cancer treatment methods, numerous innovative therapeutic strategies are being developed. Among these, immunotherapy, which leverages the patient’s immune system, has emerged as a highly investigated and promising approach for cancer therapy. Nanotechnology-based treatments enhance the efficacy of therapies, enabling innovative and advanced technological applications. Within these innovative systems, ultrasound therapy stands out as a technology particularly effective in eliciting and strengthening immune responses against cancer. Using ultrasound-active materials can enhance the mechanical ablation effect in ultrasound therapies, leading to more effective treatments. This study aims to develop biomimetic nanoparticles by synthesizing ultrasound-active gold nanocones (AuNCs), which facilitate tumor size reduction through mechanical ablation under therapeutic ultrasound. This process also releases tumor-specific molecules into the cancer microenvironment, promoting an increase in immune cells. The AuNCs were subsequently coated with B16F10 melanoma cancer cell membranes to create biomimetic nanoparticles (CCM@AuNCs). The membrane-coated nanoparticles were optimized using three distinct techniques: extruder, sonication, and microfluidizer methods. The CCM@AuNCs prepared by these methods were characterized using a Zetasizer (Malvern, Nano ZS, UK) to measure zeta potential, nanoparticle tracking analysis (NTA, Malvern, Nanosight NS300, UK) to determine size distribution, and scanning transmission electron microscopy (STEM) to examine their morphology. All methods produced nanoparticles approximately 200 nm in size with a zeta potential of -40 mV. STEM images clearly showed membrane coating around the particles. The efficiency of membrane coating on CCM@AuNCs prepared via the three methods was evaluated using the BCA Assay Kit (Thermo Scientific-23227). The extruder method demonstrated the highest coating efficiency (43.49%) and protein concentration in 100 µL (120 µg). Based on coating efficiency and characterization results, CCM@AuNCs prepared via the extruder method were selected for further studies. Anti-gp100 (Abcam, ab137078) antibodies were used to confirm membrane coating, and the fluorescence images of CCM@AuNCs were obtained. Cytotoxicity studies performed using the Resazurin assay demonstrated no cytotoxicity for CCM@AuNCs. The biomimetic nanoparticles exhibited homologous targeting, showing increased accumulation in melanoma cancer cells. Cellular uptake studies using fluorescence microscopy and flow cytometry revealed that CCM@AuNCs were internalized more efficiently by B16F10 melanoma cells than by 4T1 breast cancer cells. The study will be further extended to in vivo B16 murine models. This work is supported by the TÜBİTAK 2247-D program ( #121C221). Citation Format: Omer Aydin, Gizem Kursunluoglu, Munevver Akdeniz. Optimization of ultrasound-responsive nanoparticles encapsulating cancer cells for enhanced immunotherapy [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 4479.