Effect of surface grain boundary density on preosteoblast proliferation on titanium

Area of Science:

• Biomaterials Science
• Materials Science
• Cell Biology

Background:

• Ultrafine grain (UG) commercial purity (CP) titanium exhibits significantly higher cytocompatibility than coarse grain (CG) CP titanium, with reported variations from 30% to 20-fold.
• The precise factors influencing this variability in CP titanium's cytocompatibility remain incompletely understood.

Purpose of the Study:

• To investigate and isolate the specific factors contributing to the wide variability in CP titanium's cytocompatibility.
• To establish a correlation between cell proliferation and quantifiable surface characteristics of titanium.

Main Methods:

• Fabrication of UG and CG titanium discs with precisely controlled surface texture and roughness.
• Seeding of MC3T3-E1 pre-osteoblastic cells onto titanium discs and culturing for 72 hours.
• Quantification of cell proliferation and analysis of surface properties, including grain boundary characteristics.

Main Results:

• Cell proliferation on polished UG-titanium was 3.04-fold higher than on unpolished CG-titanium.
• A novel biophysical parameter, average grain boundary length per surface-attached cell, was identified as a key factor influencing cell proliferation.
• Surface characteristics like texture and roughness play a significant role in modulating titanium's cytocompatibility.

Conclusions:

• The cytocompatibility of CP titanium is significantly influenced by its microstructure, particularly grain size and surface characteristics.
• Average grain boundary length per cell is a critical determinant of pre-osteoblastic cell proliferation on titanium surfaces.
• Understanding these parameters can optimize the design of titanium biomaterials for enhanced osseointegration and clinical performance.