Capillary-like Formations of Endothelial Cells in Defined Patterns Generated by Laser Bioprinting

Area of Science:

• Bioprinting
• Tissue Engineering
• Vascularization

Background:

• Thick tissue engineering requires functional vascular networks, including small capillaries (~10 µm).
• Current methods struggle to create predefined patterns for small capillaries, which typically form randomly via sprouting.
• Simultaneous printing of vasculature, including capillaries, is crucial for fabricating thick tissues.

Purpose of the Study:

• To investigate the direct printing of small capillaries in predefined patterns using laser-based bioprinting.
• To assess the formation of closed tubular structures with lumina from laser-printed endothelial cells.
• To determine the conditions necessary for the persistence of printed capillary structures.

Main Methods:

• Utilized a laser-based bioprinting technique for high-resolution and high-cell-density printing.
• Printed endothelial cells along predefined patterns on a surface and within bioprinted tissue constructs.
• Investigated the formation and persistence of tubular structures in printed capillaries.

Main Results:

• Demonstrated that small capillaries (~10 µm) can be directly printed in predefined patterns using laser bioprinting.
• Achieved the formation of closed tubular structures with lumina from printed endothelial cells.
• Confirmed that printed capillary structure persistence requires external stimulation from other cell types within the tissue.

Conclusions:

• Laser-based bioprinting enables the direct fabrication of patterned microvasculature, including capillaries.
• Co-culture with supporting cells is essential for maintaining the structural integrity of printed capillaries in engineered tissues.
• This technique advances the potential for creating complex, vascularized tissue constructs for regenerative medicine.