Porous Alginate Scaffolds Designed by Calcium Carbonate Leaching Technique

One of the main challenges in modern tissue engineering is to design biocompatible scaffolds with finely tuned porous architecture and capacity to load bioactive molecules that guide the growth and differentiation of the cells during tissue reconstruction. This work proposes a strategy to design porous alginate scaffolds (PAS) with well-tuned architecture by leaching of sacrificial vaterite CaCO3 microspheres packed in alginate. Pore size and interconnectivity depend on CaCO3 sphere dimensions and packing as well as alginate concentration. Varying of these parameters, almost hundred percent pore interconnectivity (or, by contrast, a zero pore interconnectivity) can be achieved. Junctions between interconnected pores are about 50-70% of the pore dimensions that provides molecular transport through the PASs potentially ensuring diffusion of nutrition, oxygen and metabolic products when cell seeding. An opportunity to fabricate a multifunctional scaffold is demonstrated by encapsulation of desired macromolecules into the individual pores of a scaffold (is illustrated by dextran loading). Mechanical properties of PASs are found typical for soft and hydrated structures (Young's modulus of 19 +/- 15 kPa) which is appropriate for cell seeding. The three cell lines (HeLa, HEK293, and L929) are cultured on different alginate scaffolds to examine cell viability and adhesiveness.

Automated summary

One of the main challenges in modern tissue engineering is designing biocompatible scaffolds with finely tuned porous architecture and the ability to load bioactive molecules that guide cell growth and differentiation. This study proposes a strategy to design porous alginate scaffolds by leaching sacrificial vaterite CaCO3 microspheres packed in alginate, resulting in well-tuned architecture. The pore size and interconnectivity of the scaffold depend on the dimensions and packing of the CaCO3 spheres, as well as the concentration of alginate. By varying these parameters, it is possible to achieve almost complete pore interconnectivity or no interconnectivity at all. The mechanical properties of the scaffolds are suitable for cell seeding, with the potential for encapsulation of macromolecules in individual pores to create a multifunctional scaffold. Culturing different cell lines on these scaffolds showed promising results in terms of cell viability and adhesiveness.