Fig. 4

HA for bone tissue engineering. A (I) Loaded-core scaffold (LCS) with a polycaprolactone (PCL) ink as the shell phase and drug-loaded integrated doxycycline (DX) nanoparticle ink as the core phase. (II) Cone-beam computed tomography images of bone regeneration in tibial samples showing the superiority of DX/HAp/PCL-LCS freeze-dried scaffolds for in vivo bone regeneration [170]. Copyright 2021, Elsevier B.V. All rights reserved. License Number: 5619340180570. B. Cranial bone regeneration after 4 and 8 weeks of in vivo placement of NIDN hydrogel scaffolds [171]. Copyright 2021, Wiley–VCH GmbH. License Number: 5619340843709. C Implantation of rat cranial high inserts integrated into the recipient bone [60]. Copyright 2021, the Author(s). Published by IOP Publishing Ltd. Based on Creative Commons Attribution License (CC BY) D. 3D printing bioink for bone tissue engineering. (I) Printing speed vs. line width using a 25% HAp ink, 0.41 mm straight steel needle, and 105 kPa printing pressure. (II) Adhesion of 25% HAp ink surface after 3 days of incubation with MSCs in spindle-like morphology [172]. Copyright 2019, Elsevier B.V. All rights reserved. License Number: 5619341400346