Increased suturability of regenerated silk fibroin scaffold with PCL mesh for meniscus tissue engineering applications

Chondroprotection is the primary function of the meniscus in the knee joint. The clinical management of meniscus lesions favours the repair of the tissue, or substitution with certain indications [1,2]. Silk fibroin is a naturally-derived biomaterial that has been studied in meniscus tissue engineering applications. Suturability is an indispensable feature of scaffolds designed for the treatment of meniscus lesions. Regenerated silk fibroin scaffolds alone are not the ideal candidates since they cannot hold suture. This work presents the production and characterization a novel silk fibroin scaffold that has a thin 3D-printed polycaprolactone mesh layer on the transverse plane that provides increased suture retention strength up to 400%, and high water uptake capacity (> 500%). In vivo biocompatibility of the scaffolds seeded with human meniscocytes or human infrapatellar fat pad-derived stem cells was studied using a mouse subcutaneous implantation model. The architecture of the explants was assessed by micro-CT. Histological analysis showed that the scaffolds support new tissue infiltration and blood vessel formation. The results of this work are promising, and further studies should assess the orthotopic performance of the scaffolds using a large animal model. Acknowledgments: This article is a result of the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This study was also supported by the FP7 Marie Curie Initial Training Network "MultiScaleHuman: Multi-scale Biological Modalities for Physiological Human Articulation" (Contract number MRTN-CT-2011-289897). I. F. Cengiz thanks the Portuguese Foundation for Science and Technology (FCT) for the Ph.D. scholarship (SFRH/BD/99555/2014). J. M. Oliveira also thanks the FCT for the funds provided under the program Investigador FCT 2015 (IF/01285/2015). References 1.Cengiz, I.F., et al. "Treatments of Meniscus Lesions of the Knee: Current Concepts and Future Perspectives." Regenerative Engineering and Translational Medicine 3.1 (2017): 32-50. 2.Cengiz I.F., et al. “Orthopaedic regenerative tissue engineering en route to the holy grail: disequilibrium between the demand and the supply in the operating room” Journal of experimental orthopaedics, 5(1), (2018) 14.