Silk-Based 3D-Printed Scaffolds to Treat Meniscus Defects

Meniscus is one of the most injured tissues in orthopedics that require surgical care. Saving the meniscus is the initial intention, and repairing it with sutures is not always feasible. If the suturing of the meniscus is not possible, substitution of the meniscus with scaffolds is prefered considering the indications and contra-indications [1, 2]. Silk fibroin is a commonly used biomaterial in tissue engineering. It is known that the regenerated silk fibroin scaffolds support cell culture, they are not suturable, therefore not suitable for meniscus applications. In the present study, we manufactured and characterized scaffolds made of regenerated silk fibroin, which is reinforced, with 3D-printed mesh from polycaprolactone in the middle. The results of this study indicated that the developed reinforced scaffolds had the suture retention strength up to four times as that of the scaffolds without reinforcement, while up to five times regarding the water uptake capacity. To characterize the biocompatibility of the scaffolds in vivo that were either seeded with meniscus cells or human Hoffa’s fat pad-derived stem cells, a subcutaneous implantation model in mice was performed. The micro-structure of the explants was analyzed by micro-CT. The histological study of the explants showed that good tissue infiltration, and it was observed those new blood vessels were formed within the scaffold. The results are encouraging to study further the in vivo performance in a large animal model. Acknowledgments: The authors thank the financial support under the Norte2020 project (NORTE-08-5369-FSE000044) and the Portuguese Foundation for Science and Technology (FCT) program (PD/BD/143081/2018). IFC thanks the TERM RES-Hub, Tissue Engineering and Regenerative Medicine Infrastructure project, funded by FCT. The FCT distinction attributed to JMO under the Investigator FCT program (number IF/01285/2015) is also greatly acknowledged. References 1. Pereira, H. et al. EFORT Open Reviews 4.6 (2019): 279-295. 2. Cengiz I.F. et al. J. of Experimental Orthopaedics, 5(1), (2018) 14. Keywords: Implant, Meniscal implant, Scaffold, Meniscus, Animal model