Chitosan-collagen biomembrane embedded with calcium-aluminate enhances dentinogenic potential of pulp cells

Abstract

The development of biomaterials capable of driving dental pulp stem cell differentiation into odontoblast-like cells able to secrete reparative dentin is the goal of current conservative dentistry. In the present investigation, a biomembrane (BM) composed of a chitosan/collagen matrix embedded with calcium-aluminate microparticles was tested. The BM was produced by mixing collagen gel with a chitosan solution (2:1), and then adding bioactive calcium-aluminate cement as the mineral phase. An inert material (polystyrene) was used as the negative control. Human dental pulp cells were seeded onto the surface of certain materials, and the cytocompatibility was evaluated by cell proliferation and cell morphology, assessed after 1, 7, 14 and 28 days in culture. The odontoblastic differentiation was evaluated by measuring alkaline phosphatase (ALP) activity, total protein production, gene expression of DMP-1/DSPP and mineralized nodule deposition. The pulp cells were able to attach onto the BM surface and spread, displaying a faster proliferative rate at initial periods than that of the control cells. The BM also acted on the cells to induce more intense ALP activity, protein production at 14 days, and higher gene expression of DSPP and DMP-1 at 28 days, leading to the deposition of about five times more mineralized matrix than the cells in the control group. Therefore, the experimental biomembrane induced the differentiation of pulp cells into odontoblast-like cells featuring a highly secretory phenotype. This innovative bioactive material can drive other protocols for dental pulp exposure treatment by inducing the regeneration of dentin tissue mediated by resident cells.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

“…Thus, a scaffold and a biomembrane composed by collagen and chitosan, containing calcium aluminate cement as mineral phase, is believed to form a biomaterial able to provide adequate support for bone repair (11). This in vivo study evaluated the biocompatibility and osteoinductive capacity of these new experimental biomaterials as a biomembrane and a scaffold.…”

“…Calcium aluminate causes intense Ca ion release in the implanted medium, stimulating the differentiation and migration of bone cells (12). In addition, as the scaffold had a three-dimensional structure, greater porosity and quantity of calcium aluminate in its mineral phase, in comparison with the biomembrane, osteoprogenitor cells were able to interlace with the biomaterial, triggering intense fibroangioblastic proliferation, accelerating the process of bone repair and neoformation (11,12).…”

“…On the other hand, the scaffold group presented similar results to the group submitted to bone graft, in the final period of analysis. This fact could be explained mainly by the differences observed in the biomaterials' architecture and porosity (11,20). According to the required bone repair to be made, these differences in composition may interfere in a positive or negative manner in the velocity of the tissue new bone formation process (11,20).…”

“…This fact could be explained mainly by the differences observed in the biomaterials' architecture and porosity (11,20). According to the required bone repair to be made, these differences in composition may interfere in a positive or negative manner in the velocity of the tissue new bone formation process (11,20). However, despite these findings, the bioactivity observed in both biomaterials over the course of the experimental time intervals could be considered similar.…”

“…The interaction of these biomaterials with minerals has been widely reported (3,7,8,11). Chitosan in association with hydroxyapatite was shown to maximize the in vivo osteogenic capacity, allowing internal growth of the compound with accelerated resorption of the matrix (9).…”