Biology subjects

Gionet-Gonzales, M.

Publications and source records attributed to Gionet-Gonzales, M..

3 recordsLinked to original sources

bioRxiv2026

Glycoconjugates tune the viscoelastic signature of mammary tumor progression

Breast cancer progression involves extensive remodeling of the tumor extracellular matrix (ECM), resulting in changes in mechanical properties. Tumors are viscoelastic, exhibiting both an initial elastic response to loading and a time-dependent viscous response. While it is well established that tumor elasticity or stiffness is elevated, changes in tissue viscoelasticity during breast cancer progression remain poorly characterized. Here, using a mouse model that recapitulates stages of human breast cancer progression (mouse mammary tumor virus-polyoma middle T antigen, MMTV-PyMT), we show that tumors from both early and late disease time points were significantly more viscoelastic than normal mammary glands. Spatial microindentation revealed that while local stiffness and viscoelasticity are strongly coupled in soft regions of normal tissue, this relationship weakens in late carcinoma. Compared to normal glands, carcinoma tissues also exhibited marked upregulation of glycosaminoglycans (GAGs) and glycoproteins. Selective enzymatic degradation of sulfated GAGs, mucins, or O/N-linked glycans reduced viscoelasticity without altering stiffness, establishing glycoconjugates as major contributors to tumor viscoelasticity. In vitro, increasing matrix viscoelasticity drove non-transformed mammary epithelial cells (MCF10A) toward a malignant phenotype through focal adhesion kinase mechanosignaling. Our work establishes increased viscoelasticity as a defining mechanical feature of breast cancer progression, driven in part by the accumulation of glycoconjugates. These findings provide a fuller picture of tumor mechanical evolution and a benchmark for recapitulating matrix viscoelasticity in engineered models of breast cancer.

cancer biology↗

bioRxiv2024

Stress relaxation rates of myocardium from failing and non-failing hearts

The heart is a dynamic pump whose function is influenced by its mechanical properties. The viscoelastic properties of the heart, i.e. its ability to exhibit both elastic and viscous characteristics upon deformation, influence cardiac function. Viscoelastic properties change during heart failure (HF), but, direct measurements of failing and non-failing myocardial tissue stress relaxation under constant displacement are lacking. Further, how consequences of tissue remodeling, such as fibrosis and fat accumulation, alter the stress relaxation remains unknown. To address this gap, we conducted stress relaxation tests on porcine myocardial tissue to establish baseline properties of cardiac tissue. We found porcine myocardial tissue to be fast relaxing, characterized by stress relaxation tests on both a rheometer and microindenter. We then measured human left ventricle (LV) epicardium and endocardium human tissue from non-failing, ischemic HF, and non-ischemic HF patients by microindentation. We found that the ischemic HF had slower stress relaxation than non-failing endocardium; and that slower stress relaxing tissues were correlated with increased collagen deposition and increased -smooth muscle actin (-SMA) stress fibers, a marker of fibrosis and cardiac fibroblast activation, respectively. In the epicardium, we found that ischemic HF had faster stress relaxation than non-ischemic HF and non-failing; and that faster stress relaxation correlated with Oil Red O staining, a marker for adipose tissue. These data show that changes in stress relaxation vary across the different layers of the heart during ischemic vs. non-ischemic HF. These findings reveal how the viscoelasticity of the heart changes, which will lead to better modeling of cardiac mechanics for in vitro and in silico HF models.

bioengineering↗

bioRxiv2020

Hydrogel mechanical properties are more important than osteoinductive growth factors for bone formation with MSC spheroids

Mesenchymal stromal cells (MSCs) can promote tissue repair in regenerative medicine, and their therapeutic potential is further enhanced via spheroid formation. We demonstrated that intraspheroidal presentation of Bone Morphogenetic Protein-2 (BMP-2) on hydroxyapatite (HA) nanoparticles resulted in more spatially uniform MSC osteodifferentiation, providing a method to internally influence spheroid phenotype. Stress relaxation of hydrogels has emerged as a potent stimulus to enhance monodispersed MSC spreading and osteogenic differentiation, but the effect of hydrogel viscoelasticity on MSC spheroids has not been reported. Herein, we describe a materials-based approach to augment the osteogenic potential of entrapped MSC spheroids by leveraging the mechanical properties of alginate hydrogels. Compared to spheroids entrapped in covalently crosslinked, elastic alginate, calcium deposition of MSC spheroids was consistently increased in ionically crosslinked, viscoelastic alginate. We observed significant increases in calcium deposition by MSC spheroids loaded with BMP-2-HA in viscoelastic gels compared to soluble BMP-2, which was higher than all elastic alginate gels. Upon implantation in critically sized calvarial bone defects, we observed enhanced bone formation in all animals treated with viscoelastic hydrogels. Increases in bone formation were evident in viscoelastic gels, regardless of the mode of presentation of BMP-2 (i.e., soluble delivery or HA nanoparticles). These studies demonstrate that the dynamic mechanical properties of viscoelastic alginate are an effective strategy to enhance the therapeutic potential of MSC spheroids for bone formation and repair.

bioengineering↗