Preparation of Designed Poly(trimethylene carbonate) Meniscus Implants by Stereolithography: Challenges in Stereolithography

Abstract

Three-armed poly(trimethylene carbonate) macromers with a relatively high molecular weight of 28.9 kg mol are prepared by ring opening polymerization and subsequent functionalization with methacrylate end groups. A resin suitable for processing by stereolithography is developed using propylene carbonate as a diluent, a photoinitiator, and a dye to control the curing characteristics. The difficulties in building designed structures with digital light processing stereolithography and the ways of optimizing the resin compositions are described in detail. Using an optimized resin composition, which contained 50 wt% macromer, 50 wt% diluent, 0.05 wt% (relative to the macromer) dye, and 5 wt% (relative to the macromer) photoinitiator, designed 3D porous structures with a gyroid pore network geometry are manufactured. By varying pore sizes and porosities between, respectively, 300 and 1000 μm and 60% and 90%, cylindrical porous poly(trimethylene carbonate) network structures with compression moduli of 85-2320 kPa are prepared. A porous poly(trimethylene carbonate) network meniscus implant is designed on the basis of computed tomography imaging data. By adjusting the characteristics of the gyroid pore architecture, an implant with a compression modulus close to 400 kPa, which fits the compression modulus of human meniscal tissue, is manufactured by stereolithography.

Drug-releasing biopolymeric structures manufactured via stereolithography

“…In some cases, the viscosity of the macromer becomes too high and diluents are required to decrease the viscosity [50]. This is especially the case with macromers with a relative high molecular weight [49]. The macromers used in this study were of sufficiently low molecular weight and could thus be used without the addition of any diluents.…”

Nano-biphasic calcium phosphate/polyvinyl alcohol composites with enhanced bioactivity for bone repair via low-temperature three-dimensional printing and loading with platelet-rich fibrin

“…5 3D printing is a broad concept that can be classified as additive manufacturing. Common additive technologies applied in medicine include selective laser sintering, 12 fused deposition modeling, 13 multi-jet modeling, 14 stereolithography, 15 powder-based printing, 16 and robocasting. 17 All of these techniques can be used to rapidly fabricate products with specific shapes, well-defined internal structures, and highly interconnected porosities.…”

Three Dimensional Printing-Based Strategies for Functional Cartilage Regeneration

“…van Bochove et al 103 prepared goat meniscal implants by SLA using poly(trimethylene carbonate) as a raw material. Their study showed that the mechanical properties of the scaffold can be made to closely mimic those of the natural meniscus by adjusting the pore size and porosity.…”

“…Their study showed that the mechanical properties of the scaffold can be made to closely mimic those of the natural meniscus by adjusting the pore size and porosity. 103 Zhang et al 104 created meniscal scaffolds with different pore sizes through FDM technology; furthermore, they demonstrated in vivo and in vitro that the average pore size of 3D-printed PCL scaffolds can significantly affect cell behavior and meniscal repair effects and that PCL scaffolds with an average pore size of 215 mm are suitable for meniscus tissue engineering. 104 Yang et al fabricated highly anisotropic artificial meniscus by electrically assisted 3D printing.…”