Alginate/hydroxyapatite composite scaffolds for bone ingrowth: a biocompatibility and molecular study.

Bone and dentin are nano-structured composites containing mineralized collagenous tissues. Composite scaffolds consisting in biodegradable natural polymers are one of the key components of bone tissue-engineering strategies. It has been reported that hydroxyapatite (HAp) can support alginate (Alg) as inorganic and osteoconductive reinforcement of Alg/HAp-based composite scaffolds. The first aim of our study was to evaluate the biocompatibility and the regenerative potential of these novel constructs in a dental pulp mesenchymal stem cells (DPSCs) - 3D in vitro system in the presence of differentiation medium (DM). There is evidence that osteointegration failure and inflammation are frequent complications of implantology. Interleukin-6 (IL-6) acts in several in vivo cell processes such as immune regulation and tissue regeneration, and plays a pivotal role during mesenchymal stem cell commitment to the osteogenic lineage. Moreover the maintenance of a redox homeostasis seems to be crucial during stem cell differentiation. In this light, we afterwards analyzed the molecular pathways underlying the intracellular balance between redox homeostasis and extracellular matrix mineralization.