Greater endothelial cell responses on submicron and nanometer rough titanium surfaces

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Engineering

Background:

• Titanium is widely used in biomedical implants, but its surface properties can be modified to improve biocompatibility.
• Vascular cell behavior on implant surfaces is critical for device success, particularly for vascular stents.

Purpose of the Study:

• To investigate the impact of submicron and nanometer rough titanium surfaces on vascular cell functions.
• To compare the effects of different surface topographies on rat aortic endothelial cells (RAEC) and rat aortic smooth muscle cells (RASMC).

Main Methods:

• An in vitro competitive coculture system was employed using e-beam evaporated titanium surfaces with varying roughness (submicron and nanometer).
• RAEC and RASMC were cultured on these surfaces for up to 5 days, with protein synthesis assessed for 14 days.
• Surface characterization included hydrophilicity measurements.

Main Results:

• Submicron rough titanium surfaces enhanced RAEC proliferation and collagen/elastin synthesis compared to control flat surfaces.
• Nanometer rough surfaces also improved RAEC proliferation but to a lesser extent than submicron.
• RASMC proliferation was inhibited on both submicron and nanometer rough surfaces.
• RAEC morphology was significantly altered by surface features, correlating with functional changes.

Conclusions:

• Submicron to nanometer rough titanium surfaces can selectively enhance beneficial vascular cell functions (RAEC) while inhibiting detrimental ones (RASMC).
• These findings suggest that tailored surface topography is a promising strategy for improving titanium-based vascular stent performance.