Vessel-like channels supported by poly-l-lysine tubes

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Cellular Biology

Background:

• Three-dimensional (3D) cellular constructs require nutrient supply, often facilitated by vessel-like channels.
• Alginate gel fibers offer flexibility for channel fabrication but can shrink, closing channels with cell types like fibroblasts.
• Hydrogel shrinkage poses a significant challenge for maintaining open channels in 3D cell cultures.

Purpose of the Study:

• To develop a method for fabricating stable, open vessel-like channels in 3D cellular constructs.
• To overcome the hydrogel shrinkage issue caused by specific cell types, such as fibroblasts.
• To enable long-term culture of cells within 3D constructs using robust channel networks.

Main Methods:

• Embedding sacrificial alginate gel fibers within a collagen gel matrix.
• Coating alginate fibers with poly-l-lysine to form semi-permeable poly-l-lysine-alginate membrane tubes (PLL-tubes).
• Removing the inner alginate gel to create channels, supported by the PLL-tubes within the collagen gel.

Main Results:

• Successfully fabricated vessel-like channels, including branched structures, due to the flexibility of alginate gel fibers.
• Channels supported by PLL-tubes remained open and stable, preventing collagen gel shrinkage in the presence of fibroblasts.
• Demonstrated the feasibility of creating robust 3D cellular constructs for culturing cell types that typically induce hydrogel shrinkage.

Conclusions:

• Poly-l-lysine-alginate membrane tubes effectively support vessel-like channels in 3D cellular constructs.
• This technique prevents hydrogel shrinkage, ensuring channel patency for cell culturing.
• The method is suitable for fabricating advanced 3D cellular constructs for diverse cell types and tissue engineering applications.