Fig. 4.

Regeneration model for dental pulp canal using collagen hydrogel loaded with different growth factors: A. Schematic illustration of model, with an outer collagen hydrogel of 2.88 ​mg/ml (800 ​Pa) containing dental pulp stem cells (DPSCs) and bone morphogenic protein 2 (BMP-2), and an inner collagen hydrogel (1.37 ​mg/ml, 235 ​Pa) containing DPSC and vascular endothelial growth factor (VEGF). B. Concentrically injected collagen hydrogels in tooth transversal slice. C. Interface adaptation between the two matrices evidenced by reflectance microscopy. Reproduced with permission from Ref. [78].