Topographical modification of titanium using diatom biosilica to promote human mesenchymal stem cell proliferation and osteogenic differentiation

Silica-based biomaterials have gained significant attention in the fields of orthopedics and dentistry due to their favorable properties that promote bone regeneration and integration. Techniques such as surface coatings or functionalization can be applied to silica-based biomaterials to further enhance the biological interactions with various composites and hybrid systems, enhancing the properties of polymers, ceramics, and metals used in implants. Diatoms microalgae are fascinating organisms that provide an innovative approach to source silica-based materials sustainably. Diatom-derived biosilica has been proved to be valuable for applications in various fields such as catalysis, drug delivery, environmental remediation. This study explores the potential of Navicula (N.) pelliculosa, a benthic diatom, to self-assemble on smooth titanium (Ti) surfaces. This self-adhesion phenomenon and subsequent topographical modification of the titanium surface are exploited to enhance the growth and osteogenic differentiation of hMSCs. By culturing hMSCs on titanium surfaces that have been nanotextured with the hierarchical silica texture of N. pelliculosa, increase in calcium deposition is observed within the extracellular matrix, along with elevated collagen production and upregulation of RUNX2, SP7, and COL1A1. These results indicate that the diatom's structure may serve as an effective bioactive interface to facilitate stem cell behavior and promote bone tissue engineering.