Biomechanical Contrast Between Native and Decellularized Triple-Negative Breast Tumors in Mice Publisher



Farjam MJ ; Asadi S ; Azimzadeh A ; Amanpour S ; Kajbafzadeh A ; Nazari MA
Source: 32nd National and 10th International Iranian Conference on Biomedical Engineering, ICBME 2025 Published:2025

Abstract

Triple-negative breast cancer (TNBC) is an aggressive subtype that does not have any targeted receptor-based therapies available, for which the 4T1 cell line-based murine model hosted in BALB/c ('Bagg Albino') mice offers a viable syngeneic model. In this work, we provided a comparative assessment of the structural and mechanical properties of native and decellularized tumors induced by the 4T1 cell line (hereafter referred to as 4T1 tumors). Hematoxylin and eosin (H&E) images visually confirmed successful removal of nuclear content with maintenance of the architecture of the cross-linking throughout the extracellular matrix (ECM). Scanning electron microscopy (SEM) displayed hierarchical ultrastructure, with fibrous and porous morphology preserved after decellularization. Atomic force microscopy (AFM) nanoindentation testing illustrated a significant reduction in stiffness following decellularization: the native 4T1 tumor exhibited a mean Young's modulus of 71.3 ± 19.7 kPa, whereas the decellularized ECM measured 10.5 ± 8.6 kPa. This ∼ 7-fold decrease highlights the role of cellular components in conferring tumor rigidity while confirming the preservation of ECM scaffolds. The normality test (Lilliefors) showed p=0.0181 for native tumor samples and p=0.0010 for decellularized samples, indicating that data may not be normally distributed (p<0.05). AFM indentation was performed using a quadratic pyramid probe. Tumors were generated in 8 BALB/c mice, of which 4 samples were subsequently decellularized for analysis. These findings validate the feasibility of decellularized 4T1 tumors as biomimetic scaffolds for studying tumor-stroma interactions, mechanobiology, and therapeutic modeling. © 2025 IEEE.