3D bioprinted rat Schwann cell-laden structures with shape flexibility and enhanced nerve growth factor expression.

Three-dimensional (3D) bioprinting composite alginate-gelatin hydrogel has encouraged the fabrication of cell-laden functional structures with cells from various tissues. However, reports focusing on printing this hydrogel for nerve tissue research are limited. This study aims at building in vitro Schwann cell 3D microenvironment with customized shapes through 3D bioprinting technology. Rat Schwann cell RSC96s encapsulated in composite alginate-gelatin hydrogel were printed with an extrusion-based bioprinter. Cells maintained high viability of 85.35 ± 6.19% immediately after printing and the printed hydrogel supported long-term Schwann cell proliferation for 2 weeks. Furthermore, after 14 days of culturing, Schwann cells cultured in printed structures maintained viability of 92.34 ± 2.19% and showed enhanced capability of nerve growth factor (NGF) release (142.41 ± 8.99 pg/ml) compared with cells from two-dimensional culture (92.27 ± 9.30 pg/ml). Specific Schwann cell marker S100β was also expressed by cells in printed structures. These printed structures may have the potential to be used as in vitro neurotrophic factor carriers and could be integrated into complex biomimetic artificial structures with the assistance of 3D bioprinting technology.