The effect of stiffness on cell behavior and drug resistance in patient-derived breast cancer organoids.

Triple-negative breast cancer (TNBC) accounts for 10-15 % of breast cancer cases and is characterized by its high aggressiveness, influenced by extracellular matrix (ECM) proteins such as collagen IV and laminin. Creating a cancer microenvironment that mimics these conditions could enhance the clinical relevance of breast cancer models for patient-specific treatments. In this study, a Segmented Organoids with Agile Reassembly (SOAR) printing was established by compartmentalizing TNBC spheroids with ECM proteins (Matrigel®) to simulate varying levels of aggressiveness. Increasing ECM concentration elevated spheroid's stiffness to approximately 2 kPa, resulting in desmoplasia-like structures and enhanced cancer aggressiveness, as indicated by nuclear pleomorphism, increased Ki-67 expression, and β-catenin translocation. The SOAR-printed TNBC spheroids demonstrated a correlation between increased drug resistance and higher ECM concentrations. Elevated IC₅₀ values and reduced efficacy of doxorubicin, paclitaxel, and cyclophosphamide were observed. This SOAR printing platform effectively captured patient-specific drug responses related to variations in cancer aggressiveness in patient-derived cancer organoids. The SOAR printing facilitates the rapid formation of patient-specific cancer organoids, making it a promising approach for personalized medicine. This versatile strategy offers a robust in vitro cancer model manufacturing platform, with toxicology and drug screening applications. STATEMENT OF SIGNIFICANCE: Segmented Organoids with Agile Reassembly (SOAR) printing is an innovative biomanufacturing technique that enables rapid and precise construction of 3D organoids. By segmenting and reassembling cancer cells with tailored extracellular matrix (ECM) environments, SOAR can recreate varying levels of tumor aggressiveness more accurately than conventional organoid methods. In this study, we demonstrate that SOAR printing can reliably generate patient-specific cancer organoids directly from biopsy-derived cells. These organoids enable efficient testing of chemotherapy responses, supporting more personalized and effective treatment selection. The scalability and adaptability of SOAR also broaden its impact beyond oncology, offering a versatile platform for high-throughput drug screening, toxicology assessments, and applications in regenerative medicine.