Bioactive Gelatin-Alginate Scaffold to Promote Bone Regeneration

Background Surface properties of biocompatible scaffolds can be easily modified using bioactive molecules to control stem cell differentiation into the osteogenic lineage. An innovative solution is the use of a polydopamine coating as linking strategy to bind signal molecules capable of directing stem cell differentiation towards the bone lineage. This simple approach can offer a solution for the fabrication of osteoinductive materials with improved efficacy in the field of bone tissue engineering. Aim of the study. Design a bioactive scaffold coated with polydopamine as spongy material to adsorb dexamethasone and induce osteogenic differentiation of human adipose mesenchymal stem cell (hASCs). Results and discussion. In this study, a gelatin-alginate interpenetrated network (IPN) was fabricated using different amounts of N-hydroxysuccinimide (NHS), and ethyl carbodiimide (EDC) as crosslinkers to produce tunable scaffolds for hASCs differentiation into the bone lineage. High and low crosslinked hydrogels were obtained and characterized by their ability to swell, degrade and resist different mechanical stimuli. In addition, the surface of the scaffolds was coated with polydopamine as a bonding layer for bioactive molecules to promote differentiation of hASCs. Preliminary results showed a higher absorption of dexamethasone could be achieved using a polydopamine coating respect to the uncoated hydrogels. Finally, the potential in vitroas osteogenic scaffolds was investigated inducing a significantly higher differentiation of hASCs regard to the control groups. Conclusion: These preliminary results showed the possibility to coat the surface of biocompatible hydrogels with polydopamine and control osteogenic differentiation of hASCs. This scaffold could be potentially used as an osteoinductive coating to enhance bone regeneration.