Programming temporal stiffness cues within extracellular matrix hydrogels for modelling cancer niches

Gretel Major; Minjun Ahn; Won-Woo Cho; Miguel Santos; Jessika Wise; Elisabeth Phillips; Steven G Wise; Jinah Jang; Jelena Rnjak-Kovacina; Tim Woodfield; Khoon S Lim

doi:10.1016/j.mtbio.2024.101004

Programming temporal stiffness cues within extracellular matrix hydrogels for modelling cancer niches

Mater Today Bio. 2024 Feb 16:25:101004. doi: 10.1016/j.mtbio.2024.101004. eCollection 2024 Apr.

Authors

Gretel Major¹, Minjun Ahn², Won-Woo Cho², Miguel Santos³, Jessika Wise⁴, Elisabeth Phillips⁴, Steven G Wise³, Jinah Jang², Jelena Rnjak-Kovacina^{5

6}, Tim Woodfield¹, Khoon S Lim^{1

7}

Affiliations

¹ Department of Orthopaedic Surgery and Musculoskeletal Medicine, Centre for Bioengineering & Nanomedicine, University of Otago, Christchurch, New Zealand.
² Pohang University of Science and Technology (POSTECH), Pohang, South Korea.
³ Applied Materials Group, School of Medical Sciences, University of Sydney, Sydney, Australia.
⁴ Mackenzie Cancer Research Group, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.
⁵ Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia.
⁶ Tyree Institute of Health Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.
⁷ Light-Activated Materials Group, School of Medical Sciences, University of Sydney, Australia.

Abstract

Extracellular matrix (ECM) stiffening is a common occurrence during the progression of many diseases, such as breast cancer. To accurately mimic the pathophysiological context of disease within 3D in vitro models, there is high demand for smart biomaterials which replicate the dynamic and temporal mechanical cues of diseased states. This study describes a preclinical disease model, using breast cancer as an example, which replicates the dynamic plasticity of the tumour microenvironment by incorporating temporal (3-week progression) biomechanical cues within a tissue-specific hydrogel microenvironment. The composite hydrogel formulation, integrating adipose-derived decellularised ECM (AdECM) and silk fibroin, was initially crosslinked using a visible light-mediated system, and then progressively stiffened through spontaneous secondary structure interactions inherent between the polymer chains (∼10-15 kPa increase, with a final stiffness of 25 kPa). When encapsulated and cultured in vitro, MCF-7 breast cancer cells initially formed numerous, large spheroids (>1000 μm² in area), however, with progressive temporal stiffening, cells demonstrated growth arrest and underwent phenotypic changes resulting in intratumoral heterogeneity. Unlike widely-investigated static mechanical models, this stiffening hydrogel allowed for progressive phenotypic changes to be observed, and fostered the development of mature organoid-like spheroids, which mimicked both the organisation and acinar-structures of mature breast epithelium. The spheroids contained a central population of cells which expressed aggressive cellular programs, evidenced by increased fibronectin expression and reduction of E-cadherin. The phenotypic heterogeneity observed using this model is more reflective of physiological tumours, demonstrating the importance of establishing temporal cues within preclinical models in future work. Overall, the developed model demonstrated a novel strategy to uncouple ECM biomechanical properties from the cellular complexities of the disease microenvironment and offers the potential for wide applicability in other 3D in vitro disease models through addition of tissue-specific dECM materials.