The treatment of bone injuries must be timely and effective to improve the chances of full recovery. In this respect, a mix of hyaluronic acid and an amino acidic pool has been marketed to promote soft tissue healing, fastening recovery times. Several studies have reported the in vitro and in vivo influence of hyaluronic acid and amino acids on fibroblasts and keratinocytes, highlighting the enhancement of cell proliferation, motility and cytokines synthesis. Even though the effectiveness of this combination of molecules on bone repair has been described in vivo, to the best of our knowledge, its in vitro effects on osteoblasts still need to be investigated. Therefore, this work describes for the first time osteoblast metabolism, proliferation and in vitro differentiation in the presence of hyaluronic acid and amino acids, aiming at understanding the mechanisms underlying their effectiveness in injured tissue repair. The reported results demonstrate the enhancement of osteoblasts' metabolic activity and the fastening of cell cycle progression. Furthermore, gene expression studies show a significant increase in differentiation markers, i.e., osteoprotegerin and osteonectin. Finally, alkaline phosphatase activity is also boosted by the combination of hyaluronic acid and aminoacids, confirming the ability of in vitro cultured cells to properly differentiate through the osteogenic lineage.
Keywords: Normal Human Osteoblast (NHOst) cells; alkaline phosphatase; amino acids; osteoblast differentiation; sodium hyaluronate.