Hybrid alginate-polyester bimodal network hydrogel for tissue engineering--Influence of structured water on long-term cellular growth.

The development of biodegradable scaffolds (which promote cell-binding, proliferation, long-term cell viability and required biomechanical stability) for cardiac tissue engineering is a challenge. In this study, biosynthetic amphiphilic hybrid hydrogels were prepared using a graft comacromer of natural polysaccharide alginate and synthetic polyester polypropylene fumarate (PPF). Monomodal network hydrogel (HPAS-NO) and bimodal network hydrogel (HPAS-AA) were prepared. Between the two hydrogels, HPAS-AA hydrogel excels over the HPAS-NO hydrogel. HPAS-AA hydrogel is mechanically more stable in the culture medium and undergoes gradual degradation in vitro in PBS (phosphate buffered saline). HPAS-AA contains nano-porous structure and acquires structured water (non-freezing-bound water) (53.457%) along with free water (11.773%). It absorbs more plasma proteins and prevents platelet adsorption and hemolysis when contacted with blood. HPAS-AA hydrogel is cytocompatible and promote 3D cell growth (≈ 70%) of L929 fibroblast even after 18 days and H9C2 cardiomyoblasts. The enhanced and long-term cellular growth of HPAS-AA hydrogel is attributed to the cell responsive features of structured water. HPAS-AA hydrogel can be a better candidate for cardiac tissue engineering applications.