Synthesis, Characterization, and 3D Printing of an Isosorbide-Based, Light-Curable, Degradable Polymer for Potential Application in Maxillofacial Reconstruction

Although emergence of bone tissue engineering techniques has revolutionized the field of maxillofacial reconstruction, the successful translation of such products, especially concerning larger sized defects, still remains a significant challenge. Light-curable methacrylate-based polymers have ideal properties for bone repair. These materials are also suitable for 3D printing which can be applicable for restoration of both function and aesthetics. The main objective of this research was to synthesize a mechanically stable and biologically functional polymer for reconstruction of complex craniofacial defects. The experimental work initially involved synthesis of (((3R,3aR,6S,6aR)-hexahydrofuro[3,2-b]furan-3,6-diyl)bis-(oxy))bis (ethane-2,1- diyl)bis ((4-methyl-3 -oxopent-4-en-1-yl)-carbamate), CSMA-1, and ((((((((((((3R,3aR,65,6aR)-hexahydrofuro[3,2-b]furan-3,6-diyl)bis(oxy))bis(ethane-2,1 diyl))bis-(oxy))bis(carbonyl))bis(azanediyl))bis(methylene))bis(3,3,5-trimethylcyclohexane-5,1 -diyl))bis(azanediyl) )bis(carbonyl))bis-(oxy))bis(ethane-2,1-diyl)bis(2-methylacrylate), CSMA-2; nuclear magnetic resonance analysis confirmed formation of the monomers, and composite samples were fabricated respectively by exposing 11 mm diameter discs to blue light. Modulus of elasticity was determined using a biaxial flexural test and the values were found to be between 1 and 3 GPa in CSMA-1, CSMA-2, and their composites. In vitro cell culture, using human bone marrow-derived mesenchymal stem cells, confirmed nontoxicity of the samples and finally 3D printing allowed direct photo-polymerization and setting of the bio ink into a 3D construct.