Microfluidic fabrication of cell adhesive chitosan microtubes

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Microfluidics

Background:

• Chitosan is a biocompatible scaffolding material for tissue engineering.
• Microand nanoscale environments significantly influence cellular behavior.
• Fabricating microscale chitosan structures is crucial for advanced tissue engineering applications.

Purpose of the Study:

• To develop a microfluidic method for generating cell-adhesive chitosan microtubes with controlled dimensions.
• To investigate the effect of gelatin incorporation on cell adhesion and proliferation within the microtubes.
• To optimize fabrication conditions, including pH, for enhanced cell viability and integration.

Main Methods:

• Utilized a microfluidic coaxial flow-focusing system to extrude chitosan pre-polymer solution.
• Controlled microtube size by adjusting flow rates of chitosan and phosphate-buffered saline (PBS).
• Ionic crosslinking with sodium tripolyphosphate (TPP) and incorporation of gelatin to enhance cell adhesion.

Main Results:

• Fabricated chitosan microtubes with inner diameters of 70-150 μm and outer diameters of 120-185 μm.
• Achieved 92% cell viability at physiological pH values (5.8 for chitosan, 7.4 for TPP).
• Incorporation of gelatin significantly enhanced fibroblast adhesion, spreading, and proliferation within the microtubes.

Conclusions:

• Microfluidic fabrication provides precise control over chitosan microtube size and properties.
• Chitosan-gelatin microtubes fabricated at physiological pH support high cell viability and promote cell growth.
• This method presents a versatile platform for creating microengineered tissue constructs compatible with various cell types.