Tissue Engineering Scaffolds Fabricated in Dissolvable 3D-Printed Molds for Patient-Specific Craniofacial Bone Regeneration

Abstract

The current gold standard treatment for oral clefts is autologous bone grafting. This treatment, however, presents another wound site for the patient, greater discomfort, and pediatric patients have less bone mass for bone grafting. A potential alternative treatment is the use of tissue engineered scaffolds. Hydrogels are well characterized nanoporous scaffolds and cryogels are mechanically durable, macroporous, sponge-like scaffolds. However, there has been limited research on these scaffolds for cleft craniofacial defects. 3D-printed molds can be combined with cryogel/hydrogel fabrication to create patient-specific tissue engineered scaffolds. By combining 3D-printing technology and scaffold fabrication, we were able to create scaffolds with the geometry of three cleft craniofacial defects. The scaffolds were then characterized to assess the effect of the mold on their physical properties. While the scaffolds were able to completely fill the mold, creating the desired geometry, the overall volumes were smaller than expected. The cryogels possessed porosities ranging from 79.7% to 87.2% and high interconnectivity. Additionally, the cryogels swelled from 400% to almost 1500% of their original dry weight while the hydrogel swelling did not reach 500%, demonstrating the ability to fill a defect site. Overall, despite the complex geometry, the cryogel scaffolds displayed ideal properties for bone reconstruction.

Embedded 3D Printing of Cryogel-Based Scaffolds

“…In addition to the limited number of studies on 3D printing of gelatin-based cryogels, none of them have been printed in complex shapes without the use of any synthetic polymers or molds. − Herein, we present a novel approach for 3D printing of complex-shaped GelMA cryogels, and the 3D printing approach we developed makes it possible to fabricate 3D printed biopolymer-based cryogels with complex shapes without the need to use any molds or synthetic polymer.…”

Extrusion‐Based 3D Bioprinting of Adhesive Tissue Engineering Scaffolds Using Hybrid Functionalized Hydrogel Bioinks

“…Compared to conventional scaffold fabrication methods, bioprinting enables creation of complex structural/functional designs, including both internal and external features such as vascular networks, [50] heterogenous pattering of cells and/or small molecules, [51] and patient-specific scaffold shape/geometry. [30,52] The integration of intrinsic and enhanced adhesive properties, together with complex structural/functional features in bioprinted ATES systems can provide robust implant solutions for a variety of regenerative medicine applications.…”

Three-Dimensional Printing in Cleft Care: A Systematic Review

“…However, this creates an additional wound site with postoperative pain, scarring, and risk for infection. Further, it can be difficult to obtain sufficient marrow for grafting on pediatric patients and there remains a lack of specificity to the child/ defect (Hixon et al, 2017;de la Lastra et al, 2018). The resorbable scaffolds produced in these studies were seeded with undifferentiated cell types with the goal of reducing or eliminating the morbidity associated with the current standard of care, while simultaneously providing a patient-specific repair (Berger et al, 2015;Hixon et al, 2017;Ahn et al, 2018;de la Lastra et al, 2018).…”