Immunomodulatory Potential of a Novel Bilayer Hybrid Biomaterial for Oral Regeneration

A big challenge in oral surgery includes the bioengineering of biomaterials that simultaneously promote soft and hard tissue regeneration while stimulating a pro-regenerative immune phenotype to support tissue remodeling. A strontium-rich hybrid system was developed, composed of Sr-doped HAp microspheres, delivered in an alginate vehicle. Herein a bilayer system based on the latter was developed, aiming to promote both gingival and bone tissue regeneration. This system was further enriched with decellularized human fetal membranes (dh-FMs). The objective of this work was to evaluate the immunomodulatory potential of a bilayer strontium-hybrid system doped with dh-FMs.
A triton-X-based decellularization was performed. The physicochemical integrity and absence of nuclei was analyzed by histology, electronic microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy analysis. Macrophage inflammatory response was evaluated by flow cytometry and ELISA assays. Statistically analysis was performed using Kruskal-wallis test.
The effectiveness of the decellularization process was confirmed by the absence of nuclei and maintenance of its chemical structural integrity. The preliminary results indicated a low macrophage activation and a decrease of TNF-alpha, IL-4, and IL-6 secretion upon dFMs integration. Regarding the innovative biomaterial design, the understanding of biological approaches to mitigate the foreign body response and drive the tissue inflammation into a pro-regenerative phenotype is essential. Therefore the incorporation of dh-FMs into a biomaterial showed to be an interesting strategy for tissue regeneration. The preliminary results concerning immunomodulatory properties indicated low macrophage activation. We concluded that the dh-FMs incorporation into a biomaterial showed to be a promising multifunctional tissue approach. Further tests should be performed to explore the immunomodulation capacity of the biomaterial.