Health & Medical Environment & Energy Society & Lifestyle Technology & Space Rural & Agriculture Business & Politics More Tiny surface shapes steer cancer cells, paving the way for better lab tests and safer implants

Griffith University researchers have shown the shape and surface chemistry of microscopic “re‑entrant” structures - tiny overhanging caps arranged like mushroom tops - can tune how cancer cells stick, spread and multiply.

Using an aggressive, triple-negative breast cancer cell line (MDA‑MB‑231), the team demonstrated simple design rules could guide cell behaviour in the lab.

The study has been published in Advanced Materials Interfaces and has also been selected to feature on the back cover of the upcoming issue of the journal.

What are re-entrant microstructures?

Re-entrant microstructures have overhanging edges that create confined spaces and curved surfaces. The team fabricated arrays with circular, triangular and linear (microline) caps in two materials: hydrophilic silicon dioxide (SiO₂) and hydrophobic silicon carbide (SiC) and investigated how geometry and wettability affected the cancer cell responses.

Using a lab model, the team showed they could guide how MDA-MB-231 cancer cells – an invasive breast cancer cell – stuck, spread, and multiplied by tweaking the curves and chemistry of these tiny structures.

“Cells don’t just respond to chemicals: they ‘feel’ their surroundings,” said Dr Navid Kashaninejad from Griffith’s Queensland Quantum and Advanced Technologies Research Institute (QUATRI) and School of Engineering and Built Environment.

“By changing curvature, spacing and surface chemistry, we can nudge how aggressive cancer cells attach and grow.

“That gives us more realistic tumour-like lab models for drug screening and design cues for implants and coatings that are less welcoming to cancer.”

How was it tested?

Researchers cultured MDA-MB-231 cells on each surface and tracked growth over three days using a PrestoBlue metabolic assay, alongside fluorescence microscopy and SEM to visualise spreading and cytoskeletal organisation.

Dr Kashaninejad said the method mimicked the environment of real tumours more accurately in the lab, which meant it could greatly improve how new cancer drugs were tested.

“It also opens the door to better ways of identifying treatments that stop cancer cells from spreading,” he said.

"In the future, this approach could even be used to design medical implants or surface coatings that make it harder for cancer to grow on them.

“Our method shows cancer cell behaviour can be precisely tuned by the curvature and chemistry of re-entrant microstructures.”

This study extended on previous work on simple micropillar arrays by demonstrating mechanosensitive behaviours that emerged when curvature and confinement were introduced through re-entrant structures.

The re-entrant designs were also structurally stable, supporting their use in long-term biointerface applications.

This work was part of Dr Kashaninejad's Discovery Early Career Researcher Award (DECRA) funded in 2022 by the Australian Research Council: Engineering micropatterned surfaces for cell mechanics and mechanobiology.

The study 'Exploring Cellular Response to Re-Entrant Surface Topographies' has been published in Advanced Materials Interfaces.

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