Rapid generation of three-dimensional microchannels for vascularization using a subtractive printing technique

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Materials Science

Background:

• Tissue-engineered products require functional microvasculature for nutrient delivery and cell survival.
• Existing vascularization methods, including additive 3D printing, face significant limitations.
• Lack of perfusable microvasculature hinders the development of larger, viable tissue constructs.

Purpose of the Study:

• To validate an ultra-fast laser subtractive printing technique for generating capillary-sized channels in cell-laden hydrogels.
• To assess cell viability in proximity to laser-fabricated channels.
• To demonstrate the compatibility of the technique with various hydrogel formulations.

Main Methods:

• Utilized an ultra-fast laser system with galvanometric scanners and a Galilean telescope for precise channel fabrication.
• Employed a subtractive printing approach to create channels within blended polyethylene glycol and collagen hydrogels.
• Investigated the effect of laser energy and focal spot positioning on channel characteristics and cell viability.

Main Results:

• Achieved rapid channel generation (2500 mm/s lateral movement) in diverse hydrogel compositions.
• Demonstrated high cell viability (≥18 μm from channels) after laser treatment.
• Confirmed control over channel width and pattern through laser parameter adjustments.

Conclusions:

• The ultra-fast laser subtractive printing technique offers a flexible and rapid method for creating vascular channels in tissue-engineered constructs.
• This technology has the potential to significantly advance the field of tissue engineering by enabling better vascularization.
• The demonstrated cell viability supports the suitability of this technique for creating functional tissue scaffolds.