Suturable regenerated silk fibroin scaffold reinforced with 3D-printed polycaprolactone mesh: biomechanical performance and subcutaneous implantation


The menisci have crucial roles in the knee, chondroprotection being the primary. Meniscus repair or substitution is favored in the clinical management of the meniscus lesions with given indications. The outstanding challenges with the meniscal scaffolds include the required biomechanical behavior and features. Suturability is one of the prerequisites for both implantation and implant survival. Therefore, we proposed herein a novel highly interconnected suturable porous scaffolds from regenerated silk fibroin that is reinforced with 3D-printed polycaprolactone (PCL) mesh in the middle, on the transverse plane to enhance the suture-holding capacity. Results showed that the reinforcement of the silk fibroin scaffolds with the PCL mesh increased the suture retention strength up to 400%, with a decrease in the mean porosity and an increase in crystallinity from 51.9 to 55.6%. The wet compression modulus values were significantly different for silk fibroin, and silk fibroin + PCL mesh by being 0.16 ± 0.02, and 0.40 ± 0.06 MPa, respectively. Both scaffolds had excellent interconnectivity (>99%), and a high water uptake feature (>500%). The tissue’s infiltration and formation of new blood vessels were assessed by means of performing an in vivo subcutaneous implantation of the silk fibroin + PCL mesh scaffolds that were seeded with primary human meniscocytes or stem cells. Regarding suturability and in vivo biocompatibility, the findings of this study indicate that the silk fibroin + PCL mesh scaffolds are suitable for further studies to be carried out for meniscus tissue engineering applications such as the studies involving orthotopic meniscal models and fabrication of patient-specific implants.

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  1. 1.

    Cengiz IF, Pereira H, Silva-Correia J, Ripoll PL, Espregueira-Mendes J, Kaz R, et al. Meniscal lesions: from basic science to clinical management in footballers. In: van Dijk CN, Neyret P, Cohen M, Della Villa S, Pereira H, Oliveira M, editors. Injuries and health problems in football. Berlin, Germany: Springer; 2017. p. 145–63.

    Google Scholar 

  2. 2.

    Pereira H, Caridade S, Frias A, Silva-Correia J, Pereira D, Cengiz I, et al. Biomechanical and cellular segmental characterization of human meniscus: building the basis for Tissue Engineering therapies. Osteoarthr Cartil. 2014;22:1271–81.

    CAS  Article  Google Scholar 

  3. 3.

    Cengiz IF, Pereira H, de Girolamo L, Cucchiarini M, Espregueira-Mendes J, Reis RL, et al. Orthopaedic regenerative tissue engineering en route to the holy grail: disequilibrium between the demand and the supply in the operating room. J Exp Orthop. 2018;5:14.

    Article  Google Scholar 

  4. 4.

    Cengiz IF, Pereira H, Espregueira-Mendes J, Oliveira JM, Reis RL. Treatments of meniscus lesions of the knee: current concepts and future perspectives. Regener Eng Transl Med. 2017;3:32–50.

    Article  Google Scholar 

  5. 5.

    Cengiz IF, Silva-Correia J, Pereira H, Espregueira-Mendes J, Oliveira JM, Reis RL. Basics of the meniscus. In: Oliveira M, Reis RL, editors. Regenerative strategies for the treatment of knee joint disabilities. Cham, Switzerland: Springer; 2017. p. 237–47.

    Google Scholar 

  6. 6.

    Pereira H, Cengiz IF, Silva-Correia J, Cucciarini M, Gelber PE, Espregueira-Mendes J, et al. Histology-ultrastructure-biology. In: Hulet C, Pereira H, Peretti G, Denti M, editors. Surgery of the meniscus. Berlin, Germany: Springer; 2016. p. 23–33.

    Google Scholar 

  7. 7.

    Pereira H, Cengiz IF, Silva-Correia J, Oliveira JM, Reis RL, Espregueira-Mendes J. The role of arthroscopy in the treatment of degenerative meniscus tear. In: Randelli P, Dejour D, van Dijk CN, Denti M, Seil R, editors. Arthroscopy. Berlin, Germany: Springer; 2016. p. 107–17.

    Google Scholar 

  8. 8.

    Pereira H, Cengiz IF, Silva-Correia J, Ripoll PL, Varatojo R, Oliveira JM, et al. Meniscal repair: indications, techniques, and outcome. In: Randelli P, Dejour D, van Dijk CN, Denti M, Seil R, editors. Arthroscopy. Berlin, Germany: Springer; 2016. p. 125–42.

    Google Scholar 

  9. 9.

    Cengiz IF, Silva-Correia J, Pereira H, Espregueira-Mendes J, Oliveira JM, Reis RL. Advanced regenerative strategies for human knee meniscus. In: Oliveira M, Reis RL, editors. Regenerative strategies for the treatment of knee joint disabilities. Cham, Switzerland: Springer; 2017. p. 271–85.

    Google Scholar 

  10. 10.

    Pereira H, Cengiz IF, Silva-Correia J, Oliveira JM, Reis RL, Espregueira-Mendes J. Human meniscus: from biology to tissue engineering strategies. In: Doral MN, Karlsson J, editors. Sports injuries: prevention, diagnosis, treatment and rehabilitation. Berlin, Gemany: Springer; 2015. p. 1–16.

    Google Scholar 

  11. 11.

    Gruchenberg K, Ignatius A, Friemert B, von Lübken F, Skaer N, Gellynck K, et al. In vivo performance of a novel silk fibroin scaffold for partial meniscal replacement in a sheep model. Knee Surg Sports Traumatol Arthrosc. 2015;23:2218–29.

    Article  Google Scholar 

  12. 12.

    Mandal BB, Park S-H, Gil ES, Kaplan DL. Multilayered silk scaffolds for meniscus tissue engineering. Biomaterials. 2011;32:639–51.

    CAS  Article  Google Scholar 

  13. 13.

    Stein SEC, von Luebken F, Warnecke D, Gentilini C, Skaer N, Walker R, et al. The challenge of implant integration in partial meniscal replacement: an experimental study on a silk fibroin scaffold in sheep. Knee Surg Sports Traumatol Arthrosc. 2018.

    Article  Google Scholar 

  14. 14.

    Baek J, Sovani S, Choi W, Jin S, Grogan SP, D’Lima DD. Meniscal tissue engineering using aligned collagen fibrous scaffolds: comparison of different human cell sources. Tissue Eng Part A. 2018;24:81–93.

    CAS  Article  Google Scholar 

  15. 15.

    Heo J, Koh RH, Shim W, Kim HD, Yim H-G, Hwang NS. Riboflavin-induced photo-crosslinking of collagen hydrogel and its application in meniscus tissue engineering. Drug Deliv Transl Res. 2016;6:148–58.

    CAS  Article  Google Scholar 

  16. 16.

    Zitnay JL, Reese SP, Tran G, Farhang N, Bowles RD, Weiss JA. Fabrication of dense anisotropic collagen scaffolds using biaxial compression. Acta Biomater. 2018;65:76–87.

    CAS  Article  Google Scholar 

  17. 17.

    Bodin A, Concaro S, Brittberg M, Gatenholm P. Bacterial cellulose as a potential meniscus implant. Journal of Tissue Eng Regen Med. 2007;1:406–8.

    CAS  Article  Google Scholar 

  18. 18.

    Martínez H, Brackmann C, Enejder A, Gatenholm P. Mechanical stimulation of fibroblasts in micro‐channeled bacterial cellulose scaffolds enhances production of oriented collagen fibers. J Biomed Mater Res Part A. 2012;100:948–57.

    Article  Google Scholar 

  19. 19.

    Baker BM, Nathan AS, Huffman GR, Mauck RL. Tissue engineering with meniscus cells derived from surgical debris. Osteoarthr Cartil. 2009;17:336–45.

    CAS  Article  Google Scholar 

  20. 20.

    Lee CH, Rodeo SA, Fortier LA, Lu C, Erisken C, Mao JJ. Protein-releasing polymeric scaffolds induce fibrochondrocytic differentiation of endogenous cells for knee meniscus regeneration in sheep. Sci Transl Med. 2014;6:266ra171–266ra171.

    Article  Google Scholar 

  21. 21.

    Zhang Z-Z, Jiang D, Ding J-X, Wang S-J, Zhang L, Zhang J-Y, et al. Role of scaffold mean pore size in meniscus regeneration. Acta Biomater. 2016;43:314–26.

    CAS  Article  Google Scholar 

  22. 22.

    Zhang Z-Z, Wang S-J, Zhang J-Y, Jiang W-B, Huang A-B, Qi Y-S, et al. 3D-Printed Poly (ε-caprolactone) scaffold augmented with mesenchymal stem cells for total meniscal substitution: A 12-and 24-week animal study in a rabbit model. Am J Sports Med. 2017;45:1497–511.

    Article  Google Scholar 

  23. 23.

    Gunja NJ, Athanasiou KA. Additive and synergistic effects of bFGF and hypoxia on leporine meniscus cell-seeded PLLA scaffolds. J Tissue Eng Regener Med. 2010;4:115–22.

    CAS  Article  Google Scholar 

  24. 24.

    Gunja NJ, Uthamanthil RK, Athanasiou KA. Effects of TGF-β1 and hydrostatic pressure on meniscus cell-seeded scaffolds. Biomaterials. 2009;30:565–73.

    CAS  Article  Google Scholar 

  25. 25.

    Kwak HS, Nam J, Lee Jh, Kim HJ, Yoo JJ. Meniscal repair in vivo using human chondrocyte‐seeded PLGA mesh scaffold pretreated with platelet‐rich plasma. J Tissue Eng Regener Med. 2017;11:471–80.

    CAS  Article  Google Scholar 

  26. 26.

    Kremer A, Ribitsch I, Reboredo J, Dürr J, Egerbacher M, Jenner F, et al. Three-dimensional coculture of meniscal cells and mesenchymal stem cells in collagen type I hydrogel on a small intestinal matrix—a pilot study toward equine meniscus tissue engineering. Tissue Engineering Part A. 2017;23:390–402.

    CAS  Article  Google Scholar 

  27. 27.

    Sarem M, Moztarzadeh F, Mozafari M, Shastri VP. Optimization strategies on the structural modeling of gelatin/chitosan scaffolds to mimic human meniscus tissue. Mater Sci Eng: C. 2013;33:4777–85.

    CAS  Article  Google Scholar 

  28. 28.

    Ghodbane SA, Brzezinski A, Patel JM, Pfaff WH, Marzano KN, Gatt CJ, et al. Partial meniscus replacement with a collagen-hyaluronan infused 3D printed polymeric scaffold. Tissue Eng. 2018;25:379–89.

  29. 29.

    Patel JM, Ghodbane SA, Brzezinski A, Gatt CJ Jr, Dunn MG. Tissue-engineered total meniscus replacement with a fiber-reinforced scaffold in a 2-year ovine model. Am J Sports Med. 2018;46:1844–56.

    Article  Google Scholar 

  30. 30.

    Gao S, Chen M, Wang P, Li Y, Yuan Z, Guo W, et al. An electrospun fiber reinforced scaffold promotes total meniscus regeneration in rabbit meniscectomy model. Acta Biomater. 2018;73:127–40.

    CAS  Article  Google Scholar 

  31. 31.

    Yuan Z, Liu S, Hao C, Guo W, Gao S, Wang M, et al. AMECM/DCB scaffold prompts successful total meniscus reconstruction in a rabbit total meniscectomy model. Biomaterials. 2016;111:13–26.

    CAS  Article  Google Scholar 

  32. 32.

    Pillai MM, Gopinathan J, Senthil Kumar R, Sathish Kumar G, Shanthakumari S, Sahanand KS, et al. Tissue engineering of human knee meniscus using functionalized and reinforced silk‐polyvinyl alcohol composite three‐dimensional scaffolds: understanding the in vitro and in vivo behavior. J Biomed Mater Res Part A. 2018;106:1722–31.

    CAS  Article  Google Scholar 

  33. 33.

    Cengiz I, Pitikakis M, Cesario L, Parascandolo P, Vosilla L, Viano G, et al. Building the basis for patient-specific meniscal scaffolds: from human knee MRI to fabrication of 3D printed scaffolds. Bioprinting. 2016;1:1–10.

    Article  Google Scholar 

  34. 34.

    Cengiz IF, Pereira H, Pitikakis M, Espregueira-Mendes J, Oliveira JM, Reis RL. Building the basis for patient-specific meniscal scaffolds. In: Gobbi A, Espregueira-Mendes J, Lane JG, Karahan M, editors. Bio-orthopaedics. Berlin, Germany: Springer; 2017. p. 411–8.

    Google Scholar 

  35. 35.

    Koh L-D, Cheng Y, Teng C-P, Khin Y-W, Loh X-J, Tee S-Y, et al. Structures, mechanical properties and applications of silk fibroin materials. Prog Polym Sci. 2015;46:86–110.

    CAS  Article  Google Scholar 

  36. 36.

    Kundu B, Rajkhowa R, Kundu SC, Wang X. Silk fibroin biomaterials for tissue regenerations. Adv Drug Deliv Rev. 2013;65:457–70.

    CAS  Article  Google Scholar 

  37. 37.

    Rockwood DN, Preda RC, Yücel T, Wang X, Lovett ML, Kaplan DL. Materials fabrication from Bombyx mori silk fibroin. Nat Protoc. 2011;6:1612.

    CAS  Article  Google Scholar 

  38. 38.

    Cheng G, Davoudi Z, Xing X, Yu X, Cheng X, Li Z, et al. Advanced silk fibroin biomaterials for cartilage regeneration. ACS Biomater Sci Eng. 2018;4:2704–15.

    CAS  Article  Google Scholar 

  39. 39.

    Ribeiro VP, da Silva Morais A, Maia FR, Canadas RF, Costa JB, Oliveira AL, et al. Combinatory approach for developing silk fibroin scaffolds for cartilage regeneration. Acta Biomater. 2018;72:167–81.

    CAS  Article  Google Scholar 

  40. 40.

    Tellado SF, Chiera S, Bonani W, Poh PS, Migliaresi C, Motta A, et al. Heparin functionalization increases retention of TGF-β2 and GDF5 on biphasic silk fibroin scaffolds for tendon/ligament-to-bone tissue engineering. Acta Biomater. 2018;72:150–66.

    Article  Google Scholar 

  41. 41.

    Woodruff MA, Hutmacher DW. The return of a forgotten polymer—polycaprolactone in the 21st century. Prog Polym Sci. 2010;35:1217–56.

    CAS  Article  Google Scholar 

  42. 42.

    Oner T, Cengiz I, Pitikakis M, Cesario L, Parascandolo P, Vosilla L, et al. 3D segmentation of intervertebral discs: from concept to the fabrication of patient-specific scaffolds. Journal of 3D Print Med. 2017;1:91–101.

    CAS  Article  Google Scholar 

  43. 43.

    Cengiz IF, Oliveira JM, Reis RL. Micro-computed tomography characterization of tissue engineering scaffolds: effects of pixel size and rotation step. J Mater Sci: Mater Med. 2017;28:129.

    Google Scholar 

  44. 44.

    Cengiz IF, Oliveira JM, Reis RL. Micro-CT–a digital 3D microstructural voyage into scaffolds: a systematic review of the reported methods and results. Biomater Res. 2018;22:26.

    Article  Google Scholar 

  45. 45.

    Yan L-P, Oliveira JM, Oliveira AL, Caridade SG, Mano JF, Reis RL. Macro/microporous silk fibroin scaffolds with potential for articular cartilage and meniscus tissue engineering applications. Acta Biomater. 2012;8:289–301.

    CAS  Article  Google Scholar 

  46. 46.

    Horan RL, Antle K, Collette AL, Wang Y, Huang J, Moreau JE, et al. In vitro degradation of silk fibroin. Biomaterials. 2005;26:3385–93.

    CAS  Article  Google Scholar 

  47. 47.

    Li M, Ogiso M, Minoura N. Enzymatic degradation behavior of porous silk fibroin sheets. Biomaterials. 2003;24:357–65.

    CAS  Article  Google Scholar 

  48. 48.

    Lu Q, Zhang B, Li M, Zuo B, Kaplan DL, Huang Y, et al. Degradation mechanism and control of silk fibroin. Biomacromolecules. 2011;12:1080–6.

    CAS  Article  Google Scholar 

  49. 49.

    Bankhead P, Loughrey MB, Fernández JA, Dombrowski Y, McArt DG, Dunne PD, et al. QuPath: Open source software for digital pathology image analysis. Sci Rep. 2017;7:16878.

    Article  Google Scholar 

  50. 50.

    Cengiz IF, Pereira H, Pêgo JM, Sousa N, Espregueira‐Mendes J, Oliveira JM, et al. Segmental and regional quantification of 3D cellular density of human meniscus from osteoarthritic knee. J Tissue Eng Regener Med. 2017;11:1844–52.

    CAS  Article  Google Scholar 

  51. 51.

    Ellis PD. The essential guide to effect sizes: Statistical power, meta-analysis, and the interpretation of research results. Cambridge University Press; 2010.

  52. 52.

    Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum Associates; 1988.

    Google Scholar 

  53. 53.

    Fogh J, Giovanella BC, editors. Nude mouse in experimental and clinical research. Academic Press, Inc.; 1978.

  54. 54.

    Rolstad B. The athymic nude rat: an animal experimental model to reveal novel aspects of innate immune responses? Immunological Rev. 2001;184:136–44.

    CAS  Article  Google Scholar 

  55. 55.

    Morris AH, Stamer D, Kyriakides T, editors. The host response to naturally-derived extracellular matrix biomaterials. Seminars in immunology. Elsevier; 2017.

  56. 56.

    Thurber AE, Omenetto FG, Kaplan DL. In vivo bioresponses to silk proteins. Biomaterials. 2015;71:145–57.

    CAS  Article  Google Scholar 

  57. 57.

    Eymard F, Chevalier X. Inflammation of the infrapatellar fat pad. Joint Bone Spine. 2016;83:389–93.

    Article  Google Scholar 

  58. 58.

    Gallagher J, Tierney P, Murray P, O’Brien M. The infrapatellar fat pad: anatomy and clinical correlations. Knee Surg Sports Traumatol Arthrosc. 2005;13:268–72.

    CAS  Article  Google Scholar 

  59. 59.

    Macchi V, Porzionato A, Sarasin G, Petrelli L, Guidolin D, Rossato M, et al. The infrapatellar adipose body: a histotopographic study. Cells Tissues Organs. 2016;201:220–31.

    Article  Google Scholar 

  60. 60.

    Caplan AI. Adult mesenchymal stem cells for tissue engineering versus regenerative medicine. J Cell Physiol. 2007;213:341–7.

    CAS  Article  Google Scholar 

  61. 61.

    Karp JM, Teo GSL. Mesenchymal stem cell homing: the devil is in the details. Cell Stem Cell. 2009;4:206–16.

    CAS  Article  Google Scholar 

  62. 62.

    Moore E, Suresh V, Ying G, West J. M0 and M2 macrophages enhance vascularization of tissue engineering scaffolds. Regener Eng Transl Med. 2018;4:1–11.

    Article  Google Scholar 

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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). The authors thank Dr. Fatima Raquel Maia, Dr. Raphael F. Canadas, Dr. Alain da Silva Morais, Dr. Sandra Pina, Dr. Isabel B. Leonor, and Ms. Teresa Oliveira for their support. 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). The funding sources had no role in the study design, the data collection, analysis, interpretation, or the preparation and submission of this work for publication.

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Cengiz, I.F., Pereira, H., Espregueira-Mendes, J. et al. Suturable regenerated silk fibroin scaffold reinforced with 3D-printed polycaprolactone mesh: biomechanical performance and subcutaneous implantation. J Mater Sci: Mater Med 30, 63 (2019).

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