Anisotropic three-dimensional titanium nanospike architectures drive matrix mineralization of human cementoblast-like cells through biophysical cues.

Abstract

Objective: Regenerating cementum remains a major unmet challenge in periodontal and peri-implant therapy, underscoring the need to understand how cementoblasts respond to engineered surface cues. This study examined the manner in which titanium nanosurfaces integrating anisotropic nanopatterns with three-dimensional (3D) nanospike architectures regulate mechanotransduction and matrix mineralization in human cementoblast-like cells (hCEM).

Methods: Titanium surfaces with isotropic, anisotropic, and 3D anisotropic nanospike architectures were fabricated and characterized through quantitative analyses of nanoscale geometry and topographical organization. Surface chemistry and crystallinity were characterized using Fourier transform infrared spectroscopy, grazing-incidence X-ray diffraction, and X-ray photoelectron spectroscopy. hCEM cultures on each surface were evaluated for extracellular calcium (Ca) and phosphate (P) levels, Ca/P ratios, extracellular matrix crystallinity, cytomorphology, and phosphate metabolism-associated gene expression. Mechanotransduction activity was assessed through focal adhesion-Hippo pathway signaling. Relationships between nanoscale architecture, cell stimulation, morphology, and mineralization were examined using correlation and path analyses.

Results: Despite comparable wettability and oxide chemistry to that of other nanosurfaces, 3D anisotropic nanospike surfaces produced the highest mineralization and exhibited the highest Ca/P ratios, clear hydroxyapatite signatures, pronounced extracellular nodules, and coordinated activation of phosphate metabolism gene profiles. These surfaces induced prominent nanoscale vertex-cell interactions and distinct cytomorphological responses. Mineralization did not show association with vertical roughness, hydroxyl content, or crystallographic features but positively correlated (r = 0.94) with composite nanoscale architectural metrics capturing spatial heterogeneity and vertex density.

Significance: The finding that anisotropic 3D nanospike architectures are associated with enhanced matrix mineralization in human cementoblast-like cells under osteogenic conditions provides mechanistic insight into how nanoscale architecture modulates mineralization responses and may inform the design of cementum-targeted bioactive titanium surfaces.