Novel Silicon Titanium Diboride Micropatterned Substrates for Cellular Patterning

Area of Science:

• Biomaterials Science
• Cell Biology
• Surface Engineering

Background:

• Photolithography is crucial for patterned cell culture, but conventional methods require complex surface modifications for specific ligand or protein incorporation.
• Soft lithography allows bioactive molecule integration but often involves intricate surface treatments.

Purpose of the Study:

• To demonstrate patterned cell culture of human umbilical vein cells (HUVECs) and mesenchymal stem cells (MSCs) on microfabricated titanium diboride (TiB2) on silicon (Si) substrates.
• To investigate cell-type-dependent growth specificity and aggregate formation on TiB2/Si biomaterials using photolithography.

Main Methods:

• Electron-beam evaporation was used to deposit TiB2 films on Si substrates.
• Photolithography was employed to micropattern the TiB2/Si substrates.
• Differential growth factor adsorption with heparin was utilized to achieve patterned cell growth.
• Cell viability and gene expression were analyzed using biomarker expression and RNA-sequence transcriptome analysis.

Main Results:

• TiB2 films exhibited enhanced stiffness, hardness, hydrophilicity, and surface charge compared to Si.
• Viability of HUVECs and MSCs was confirmed on the TiB2/Si substrates.
• Micropattern-selective cell growth, including contact guidance, alignment, and durotaxis, was observed.
• MSC clustering was successfully achieved, facilitating 3D aggregate formation.

Conclusions:

• Microfabricated Si and TiB2 biomaterials are suitable for patterned cell culture in vitro.
• The developed photolithography technique enables patterned cell growth independent of additional surface modifications.
• This approach holds potential for creating controlled cellular microenvironments for various applications.