Nature-inspired topographies on hydroxyapatite surfaces regulate stem cells behaviour

Yogambha Ramaswamy; Iman Roohani; Young Jung No; Genevieve Madafiglio; Frank Chang; Furong Zhang; Zufu Lu; Hala Zreiqat

doi:10.1016/j.bioactmat.2020.10.001

Nature-inspired topographies on hydroxyapatite surfaces regulate stem cells behaviour

Bioact Mater. 2020 Oct 16;6(4):1107-1117. doi: 10.1016/j.bioactmat.2020.10.001. eCollection 2021 Apr.

Authors

Yogambha Ramaswamy^{1

2}, Iman Roohani³, Young Jung No^{1

2}, Genevieve Madafiglio¹, Frank Chang¹, Furong Zhang¹, Zufu Lu^{1

2}, Hala Zreiqat^{1

2}

Affiliations

¹ Biomaterials and Tissue Engineering Research Unit, School of Biomedical Engineering, University of Sydney, Sydney, NSW, 2006, Australia.
² Australian Research Centre for Innovative BioEngineering, University of Sydney, Sydney, NSW, 2006, Australia.
³ School of Chemistry, Australian Centre for Nanomedicine, University of New South Wales, Sydney NSW, Australia.

Abstract

Surface topography is one of the key factors in regulating interactions between materials and cells. While topographies presented to cells in vivo are non-symmetrical and in complex shapes, current fabrication techniques are limited to replicate these complex geometries. In this study, we developed a microcasting technique and successfully produced imprinted hydroxyapatite (HAp) surfaces with nature-inspired (honeycomb, pillars, and isolated islands) topographies. The in vitro biological performance of the developed non-symmetrical topographies was evaluated using adipose-derived stem cells (ADSCs). We demonstrated that ADSCs cultured on all HAp surfaces, except honeycomb patterns, presented well-defined stress fibers and expressed focal adhesion protein (paxillin) molecules. Isolated islands topographies significantly promoted osteogenic differentiation of ADSCs with increased alkaline phosphatase activity and upregulation of key osteogenic markers, compared to the other topographies and the control unmodified (flat) HAp surface. In contrast, honeycomb topographies hampered the ability of the ADSCs to proliferate and differentiate to the osteogenic lineage. This work presents a facile technique to imprint nature-derived topographies on the surface of bioceramics which opens up opportunities for the development of bioresponsive interfaces in tissue engineering and regenerative medicine.

Keywords: Bioceramics; Biomaterials; Micropattern; Scaffolds; Stem cell; Topography.