Method: A composite of polycaprolactone (PCL) and hydroxylapatite (HA) (90:10wt%) was molten at 120°C and fabricated into 3D cylinders (10×3 mm2) via layer-by-layer fiber deposition using a 3D Bioplotter per our previous work. The scaffolds comprised repeats of interlaid microstrands (~200 μm) and interconnected microchannels of specific sizes: 0 μm (no channels), 50 μm, and 100 μm. Upon coating with collagen type I gel (2mg/mL), human DPSCs were seeded on surface of the scaffolds (100K cells/scaffold). After 4wk culture in osteogenic/odontogenic differentiation medium, odontogenic differentiation of DPSCs was evaluated qualitatively and quantitatively using immuno-/histological analysis and confocal microscopy.
Result: Microscopy showed a unique surface tomography with parallel-aligned microgrooves and vertically oriented microchannels (50~100 μm) in the 3D printed scaffolds. At 4wks, DPSCs seeded on scaffolds with 50-μm and 100-μm channels formed DSP+ mineralized matrix, in comparison with scaffolds without microchannels. Interestingly, the mineralized structures formed on scaffolds with 100-μm channels were dense and polarized, reminiscent of native dentin. Additional experiments showed that channels greater than 100 μm fails to yield the dentin-like, polarized mineralization.
Conclusion: Our findings demonstrate that scaffold’s microchannel size is one of the key valuables in promoting odontogenic differentiation of DPSCs in ways potentially useful for dentin regeneration.
Keywords: Dentin, Odontoblasts, Stem cells and Tissue engineering
See more of: AADR/Johnson & Johnson Oral Health Products Hatton Awards