The Effects of 3D-Bioprinting Materials on HEPM Cell Cytokine Release

Objectives: 3D-bioprinting is an additive manufacturing process that incorporates viable cells into a three-dimensional matrix. The objectives of this study are to characterize a novel matrix of collagen and hydroxyapatite and to assess the effects of the 3D-bioprinting process on cytotoxicity, proliferation rate, and cytokine expression of HEPM (Homo sapiens palatal mesenchyme) cells.
Methods: For this we prepared a three-dimensional matrix of collagen and hydroxyapatite without and with cells. We used SEM and histology to characterize the structure and arrangement of the collagen fibers. We then incubated the matrix with known standards of cytokines to measure absorption. Finally, we assessed the cytotoxicity of this matrix for HEPM cells and assessed its effect on the production of chemokines and cytokines. A one-way fixed effect ANOVA was fit to concentrations of cytokines and pairwise group comparisons were conducted using Tukey’s Honest Significant Differences test (p<0.05).
Results: The matrix was found to contain strands of collagen and some hydroxyapatite crystals that did not absorb cytokines except for CCL3 (p< 0.05). The matrix was found to be non-cytotoxic using an AlamarBlue assay. In the presence of the hydrogel the HEPM cells had similar expression profiles of the cytokines measured (P > 0.05 for GM-CSF, IL-6, IL-8, and RANTES).
Conclusions: 3D-bioprinting has the potential to be used in dentistry as a novel osteogenic bone grafting material. Here we show that a novel matrix of collagen and hydroxyapatite is non-cytotoxic to HEPM cells and does not induce a proinflammatory response.