3-D Printed Biomimetic Scaffolds for Repair of Large Skull Defect

Objectives: Scaffolds with biomimetic anatomic and internal geometry is essential for bone tissue engineering. This study was designed to demonstrate the scaffolds with controlled biomimetic geometry made with 3-D printing for repair of large skull defect.
Methods: Scaffolds were fabricated through 3-D printing using ceramic particles with nanoporous surfaces. Anatomic features of defected skull of dog model were collected from CT scans and translated through 3-D printing into the shape of scaffolds. Detailed pores and connecting channels of controlled diameters were also designed and programmed for scaffold 3-D printing. Channels with diameters of 150 μm - 300 μm were designed to facilitate cell seeding and cell distribution. Channels with diameters of 400 μm - 500 μm were designed to facilitate blood vessel ingrowth. Internal pores of 50 μm - 100 μm were designed for bone regeneration. Nano-sized surface topography was designed for enhanced degradation of the scaffold. The 3-D printed scaffolds were evaluated using scanning electronic microscopy.
Results: The scaffolds were printed with the anatomic shape of large skull defect. SEM of fabricated scaffolds revealed the controlled inter-connecting channels for cell distribution and new blood vessel ingrowth. The internal pores were connected to each other by the inter-connecting channels. The nano-sized pores showed on the surfaces of inter-connecting channels and internal pores, which would play an important role in increasing the surface areas of materials and facilitating material degradation.
Conclusions: The scaffolds could be 3-D printed for large skull defect with anatomic shape and heterogeneous profile of controlled biomimetic inter-connecting channels, internal pores, and nanoporous surface topography suitable for bone tissue engineering.