Bioplotting Alginate/Hyaluronic Acid Hydrogel Scaffolds with Structural Integrity and Preserved Schwann Cell Viability
Bioplotting is an emerging freeform scaffold fabrication technique useful for creating artificial tissue scaffolds containing living cells. Simultaneous maintenance of scaffold structural integrity and cell viability is a challenging task. In this article, we present strategies developed to bioplot alginate-based three-dimensional tissue scaffolds containing hyaluronic acid and living Schwann cells for potential use in peripheral nerve tissue engineering. The fabrication platform, upon which the scaffold is created, was coated with the polycation polyethylenimine to immobilize the first layer of the scaffold on the platform. Each layer was then dispensed into a bath containing calcium chloride to cross-link the alginate, polyvinyl alcohol, and low concentrations of polyethylenimine to improve the structural integrity of the resulting scaffolds while retaining biocompatibility. The present study illustrated that with these strategies, porous alginate/hyaluronic acid scaffolds can be fabricated with good structural integrity and long-term cell viability. Plotting method and speed were also important factors determining the printability of single-layered scaffolds. The methods developed and the results obtained from this study form the basis for a general bioplotting method by which more sophisticated alginate/hyaluronic acid scaffolds can be fabricated with the inclusion of living cells into desired structures.