AccScience Publishing / IJB / Online First / DOI: 10.36922/ijb.5125
RESEARCH ARTICLE

Parametric computational modeling of melt electrowritten scaffolds: Predicting the cellular micromechanical environment for gradient tissue engineering in rotator cuff repair

Sam E. Winston1 Lynn M. Pezzanite2 Steven Dow2 Kirk C. McGilvray1*
Show Less
1 Mechanical Engineering, Orthopaedic Bioengineering Research Laboratory, Colorado State University, Fort Collins, Colorado, United States of America
2 Department of Clinical Sciences, Translational Medicine Institute, Colorado State University, Fort Collins, Colorado, United States of America
Submitted: 12 October 2024 | Accepted: 18 November 2024 | Published: 19 November 2024
© 2024 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract

Surgical interventions of the rotator cuff (RC) tendons are failing at unacceptably high rates. This is primarily due to clinical strategies failing to regenerate the biomechanical junction between bone and tendon (enthesis). Tissue engineering approaches for RC repair involve attempts at increasing the acute strength of the repair and directing the healing cascade to regenerate the enthesis. Advances in bioprinting, specifically melt electrowriting (MEW), allow precise fabrication of microarchitectures. Our group has utilized the functionality MEW offers to create a novel, single-material, gradient scaffold that approaches the mechanical gradients present in the RC. To characterize this novel geometry, high-throughput, parametric finite element analysis (FEA) models were generated: (1) to determine how tunable print parameters such as the radius of curvature of fibers, the fiber diameter, and the fiber spacing alter the gradient present in the scaffold’s architecture; and (2) to predict, at the cellular level, what strain the scaffold generates regionally to ``instruct’’ the local cell milieu to produce healthy tissues (e.g., bone and tendon). FEA models predicted that mechanical gradients in the scaffold approached gradient levels seen in the RC (≈2 orders of magnitude), in which global strain gradients were driven by the radius of curvature of fibers. Additionally, our novel architecture significantly affected regional mechanics, which could be optimized for tenocyte and osteoblastic bioactivity. The data presented demonstrate a novel, tunable architecture capable of approaching biologically relevant gradients observed in the RC with potential to address the clinical problems associated with tendon–bone repairs in other regions of the body using only a single material.  

Graphical abstract
Keywords
Melt electrowriting
Gradient tissue engineering scaffolds
Cellular microenvironment
Finite element analysis
Rotator cuff repair
Funding
This work was funded internally by the Orthopaedic Bioengineering Research Lab as well as the Walter Scott College of Engineering High Impact Research Award.
Conflict of interest
The authors declare they have no competing interests.
References
  1. Colvin AC, Egorova N, Harrison AK, Moskowitz A, Flatow EL. National trends in rotator cuff repair. J Bone Joint Surg Am. 2012;94(3):227-233. doi: 10.2106/JBJS.J.00739
  2. Galatz LM, Ball CM, Teefey SA, Middleton WD, Yamaguchi K. The outcome and repair integrity of completely arthroscopically repaired large and massive rotator cuff tears. JBJS. 2004;86(2); 219-224. doi: 10.2106/00004623-200402000-00002
  3. Zhang X, Wang D, Wang Z, et al. Clinical perspectives for repairing rotator cuff injuries with multi-tissue regenerative approaches. J Orthop Translat. 2022;36:91-108. doi: 10.1016/j.jot.2022.06.004
  4. Zumstein MA, Lädermann A, Raniga S, Schär MO. The biology of rotator cuff healing. Orthop Traumatol Surg Res. 2017;103(1S):S1-S10. doi: 10.1016/j.otsr.2016.11.003
  5. Iannotti JP, Codsi MJ, Kwon YW, Derwin K, Ciccone J, Brems JJ. Porcine small intestine submucosa augmentation of surgical repair of chronic two-tendon rotator cuff tears: a randomized, controlled trial. JBJS. 2006;88(6):1238-1244. doi: 10.2106/jbjs.E.00524
  6. Malcarney HL, Bonar F, Murrell GAC. Early inflammatory reaction after rotator cuff repair with a porcine small intestine submucosal implant:a report of 4 cases. Am J Sports Med. 2005;33(6):907-911. doi: 10.1177/0363546504271500
  7. Mobarak MH, Islam MA, Hossain N, et al. Recent advances of additive manufacturing in implant fabrication – a review. Appl Surf Sci Adv. 2023;18:100462. doi: 10.1016/j.apsadv.2023.100462
  8. Yang Y, Wang G, Liang H, et al. Additive manufacturing of bone scaffolds. IJB. 2018;5(1):148. doi: 10.18063/ijb.v5i1.148
  9. Wu Y, Liu J, Kang L, et al. An overview of 3D printed metal implants in orthopedic applications: present and future perspectives. Heliyon. 2023;9(7):e17718. doi: 10.1016/j.heliyon.2023.e17718
  10. Kotrych D, Angelini A, Bohatyrewicz A, Ruggieri P. 3D printing for patient-specific implants in musculoskeletal oncology. EFORT Open Rev. 2023;8(5):331-339. doi: 10.1530/EOR-23-0066
  11. Chen A, Su J, Li Y, et al. 3D/4D printed bio-piezoelectric smart scaffolds for next-generation bone tissue engineering. Int J Extrem Manuf. 2023;5(3):032007. doi: 10.1088/2631-7990/acd88f
  12. Federici AS, Tornifoglio B, Lally C, Garcia O, Kelly DJ, Hoey DA. Melt electrowritten scaffold architectures to mimic tissue mechanics and guide neo-tissue orientation. J Mech Behav Biomed Mater. 2024;150:106292. doi: 10.1016/j.jmbbm.2023.106292
  13. Kaspar D, Seidl W, Neidlinger-Wilke C, Claes L. In vitro effects of dynamic strain on the proliferative and metabolic activity of human osteoblasts. J Musculoskelet Neuronal Interact. 2000;1(2):161-164
  14. Zhu J, Zhang X, Wang C, Peng X, Zhang X. Different magnitudes of tensile strain induce human osteoblasts differentiation associated with the activation of ERK1/2 phosphorylation. Int J Mol Sci. 2008;9(12):2322-2332. doi: 10.3390/ijms9122322
  15. Yan Y-x, Gong Y-w, Guo Y, et al. Mechanical strain regulates osteoblast proliferation through integrin-mediated ERK activation. PLOS ONE. 2012;7(4):e35709. doi: 10.1371/journal.pone.0035709
  16. Guo Y, Zhang C-q, Zeng Q-c, et al. Mechanical strain promotes osteoblast ECM formation and improves its osteoinductive potential. BioMed Eng OnLine. 2012;11(1):80. doi: 10.1186/1475-925X-11-80
  17. Burger EH, Klein-Nulend J. Mechanotransduction in bone—role of the lacunocanalicular network. FASEB J. 1999;13(9001):S101-S112. doi: 10.1096/fasebj.13.9001.s101
  18. Claes LE, Heigele CA. Magnitudes of local stress and strain along bony surfaces predict the course and type of fracture healing. J Biomechan. 1999;32(3):255-266. doi: 10.1016/S0021-9290(98)00153-5
  19. Schoenenberger AD, Tempfer H, Lehner C, et al. Macromechanics and polycaprolactone fiber organization drive macrophage polarization and regulate inflammatory activation of tendon in vitro and in vivo. Biomaterials. 2020;249:120034. doi: 10.1016/j.biomaterials.2020.120034
  20. Wu S, Peng H, Li X, Streubel PN, Liu Y, Duan B. Effect of scaffold morphology and cell co-culture on tenogenic differentiation of HADMSC on centrifugal melt electrospun poly (L‑lactic acid) fibrous meshes. Biofabrication. 2017;9(4):044106-044106. doi: 10.1088/1758-5090/aa8fb8
  21. El Khatib MA-O, Mauro AA-O, Di Mattia MA-O, et al. Electrospun PLGA fiber diameter and alignment of tendon biomimetic fleece potentiate tenogenic differentiation and immunomodulatory function of amniotic epithelial stem cells. Cells. 2020;9(5):1207. doi: 10.3390/cells9051207
  22. Yang G, Im H-J, Wang JHC. Repetitive mechanical stretching modulates IL-1β induced COX-2, MMP-1 expression, and PGE2 production in human patellar tendon fibroblasts. Gene. 2005;363:166-172. doi: 10.1016/j.gene.2005.08.006
  23. Wang T, Lin Z, Day RE, et al. Programmable mechanical stimulation influences tendon homeostasis in a bioreactor system. Biotechnol Bioeng. 2013;110(5):1495-1507. doi: 10.1002/bit.24809
  24. Yang G, Crawford RC, Wang JHC. Proliferation and collagen production of human patellar tendon fibroblasts in response to cyclic uniaxial stretching in serum-free conditions. J Biomech. 2004;37(10):1543-1550. doi: 10.1016/j.jbiomech.2004.01.005
  25. Chen Y, Hao M, Bousso I, Thomopoulos S, Xia Y. Reliable fabrication of mineral-graded scaffolds by spin-coating and laser machining for use in tendon-to-bone insertion repair. Adv Healthc Mater. 2024;13:e2402531. doi: 10.1002/adhm.202402531
  26. Spalazzi JP, Dagher E, Doty SB, Guo XE, Rodeo SA, Lu HH. In vivo evaluation of a multiphased scaffold designed for orthopaedic interface tissue engineering and soft tissue-to-bone integration. J Biomed Mater Res A. 2008;86(1):1-12. doi: 10.1002/jbm.a.32073
  27. Chen C, Shi Q, Li M, et al. Engineering an enthesis-like graft for rotator cuff repair: an approach to fabricate highly biomimetic scaffold capable of zone-specifically releasing stem cell differentiation inducers. Bioact Mater. 2022;16:451-471. doi: 10.1016/j.bioactmat.2021.12.021
  28. Xie J, Li X, Lipner J, et al. “Aligned-to-random” nanofiber scaffolds for mimicking the structure of the tendon-to-bone insertion site. Nanoscale. 2010;2(6):923-926. doi: 10.1039/c0nr00192a
  29. Tindell RK, Busselle LP, Holloway JL. Magnetic fields enable precise spatial control over electrospun fiber alignment for fabricating complex gradient materials. J Biomed Mater Res A. 2023;111(6):778-789. doi: 10.1002/jbm.a.37492
  30. Xiong J, Wang H, Lan X, et al. Fabrication of bioinspired grid-crimp micropatterns by melt electrospinning writing for bone–ligament interface study. Biofabrication. 2022;14(2):025008. doi: 10.1088/1758-5090/ac4ac8
  31. Jun I, Han H-S, Edwards JR, Jeon H. Electrospun fibrous scaffolds for tissue engineering: viewpoints on architecture and fabrication. Int J Mol Sci. 2018;19(3):745. doi: 10.3390/ijms19030745
  32. Abbasi N, Abdal-hay A, Hamlet S, Graham E, Ivanovski S. Effects of gradient and offset architectures on the mechanical and biological properties of 3-d melt electrowritten (MEW) scaffolds. ACS Biomater Sci Eng. 2019;5(7):3448-3461. doi: 10.1021/acsbiomaterials.8b01456
  33. Golafshan N, Castilho M, Daghrery A, et al. Composite graded melt electrowritten scaffolds for regeneration of the periodontal ligament-to-bone interface. ACS Appl Mater Interfaces. 2023;15(10):12735-12749. doi: 10.1021/acsami.2c21256
  34. Saiz PG, Reizabal A, Vilas-Vilela JL, Dalton PD, Lanceros- Mendez S. Materials and strategies to enhance melt electrowriting potential. Adv Mater. 2024;36(24):2312084. doi: 10.1002/adma.202312084
  35. Page MI, Linde PE, Puttlitz CM. High throughput computational evaluation of how scaffold architecture, material selection, and loading modality influence the cellular micromechanical environment in tissue engineering strategies. JOR SPINE. 2021;4(3):e1152. doi: 10.1002/jsp2.1152
  36. Page M, Puttlitz C. Biaxial mechanics of 3D fiber deposited ply-laminate scaffolds for soft tissue engineering part II: finite element analyses. J Mech Behav Biomed Mater. 2019;100:103395. doi: 10.1016/j.jmbbm.2019.103395
  37. Samavedi S, Olsen Horton C, Guelcher SA, Goldstein AS, Whittington AR. Fabrication of a model continuously graded co-electrospun mesh for regeneration of the ligament–bone interface. Acta Biomater. 2011;7(12):4131-4138. doi: 10.1016/j.actbio.2011.07.008
  38. Dwivedi R, Kumar S, Pandey R, Mahajan A, Nandana D, Katti DS, Mehrotra D. Polycaprolactone as biomaterial for bone scaffolds: Review of literature. J Oral Biol Craniofac Res. 2020;10(1):381-388. doi: 10.1016/j.jobcr.2019.10.003
  39. Polak-Krasna K, Mazgajczyk E, Heikkila P, Georgiadis A. Parametric finite element model and mechanical characterisation of electrospun materials for biomedical applications. Materials (Basel). 2021;14(2):278. doi: 10.3390/ma14020278
  40. Eshraghi S, Das S. Mechanical and microstructural properties of polycaprolactone scaffolds with one-dimensional, two-dimensional, and three-dimensional orthogonally oriented porous architectures produced by selective laser sintering. Acta Biomater. 2010;6(7):2467-2476. doi: 10.1016/j.actbio.2010.02.002
  41. Wolynski JG, Ilić MM, Labus KM, Notaroš BM, Puttlitz CM, McGilvray KC. Direct electromagnetic coupling to determine diagnostic bone fracture stiffness. Ann Transl Med. 2022;10(9):510. doi: 10.21037/atm-21-5315
  42. Tourlomousis F, Ding H, Kalyon DM, Chang RC. Melt electrospinning writing process guided by a “Printability Number”. J Manuf Sci Eng. 2017;139(8):081004. doi: 10.1115/1.4036348
  43. Eichholz KF, Hoey DA. Mediating human stem cell behaviour via defined fibrous architectures by melt electrospinning writing. Acta Biomater. 2018;75:140-151. doi: 10.1016/j.actbio.2018.05.048
  44. Jenkins TL, Little D. Synthetic scaffolds for musculoskeletal tissue engineering: cellular responses to fiber parameters. NPJ Regen Med. 2019;4:15. doi: 10.1038/s41536-019-0076-5
  45. Erisken C, Zhang X, Moffat KL, Levine WN, Lu HH. Scaffold fiber diameter regulates human tendon fibroblast growth and differentiation. Tissue Eng Part A. 2013;19(3-4):519-528. doi: 10.1089/ten.tea.2012.0072
  46. Kim J, Bakirci E, O’Neill KL, Hrynevich A, Dalton PD. Fiber bridging during melt electrowriting of poly(ε-Caprolactone) and the influence of fiber diameter and wall height. Macromol Mater Eng. 2021;306(3):2000685. doi: 10.1002/mame.202000685
  47. Morgan EF, Unnikrisnan GU, Hussein AI. Bone mechanical properties in healthy and diseased states. Annu Rev Biomed Eng. 2018;20:119-143. doi: 10.1146/annurev-bioeng-062117-121139
  48. Fratzl P. Collagen: Structure and Mechanics; New York, NY: Springer; 2008:1-506.
  49. Itoi E, Berglund LJ, Grabowski JJ, et al. Tensile properties of the supraspinatus tendon. J Orthop Res. 1995;13(4): 578-584. doi: 10.1002/jor.1100130413
  50. Kolel A, Ergaz B, Goren S, Tchaicheeyan O, Lesman A. Strain gradient programming in 3D fibrous hydrogels to direct graded cell alignment. Small Methods. 2023;7(1):2201070. doi: 10.1002/smtd.202201070
  51. Vader D, Kabla A, Weitz D, Mahadevan L. Strain-induced alignment in collagen gels. PLoS One. 2009;4(6):e5902. doi: 10.1371/journal.pone.0005902
  52. Cordin M, Bechtold T, Pham T. Effect of fibre orientation on the mechanical properties of polypropylene–lyocell composites. Cellulose. 2018;25(12):7197-7210. doi: 10.1007/s10570-018-2079-6
  53. Engler AJ, Sen S, Sweeney HL, Discher DE. Matrix elasticity directs stem cell lineage specification. Cell. 2006;126(4):677-689. doi: 10.1016/j.cell.2006.06.044
  54. Singh D, Rana A, Jhajhria SK, Garg B, Pandey PM, Kalyanasundaram D. Experimental assessment of biomechanical properties in human male elbow bone subjected to bending and compression loads. J Appl Biomater Funct Mater. 2019;17(2):2280800018793816. doi: 10.1177/2280800018793816
  55. Chae S, Yong U, Park W, et al. 3D cell-printing of gradient multi-tissue interfaces for rotator cuff regeneration. Bioact Mater. 2023;19:611-625. doi: 10.1016/j.bioactmat.2022.05.004
  56. Credille KT, Wang ZRC, Horner NS, et al. Biphasic interpositional allograft for rotator cuff repair augmentation is safe in an ovine model. Arthroscopy. 2023;39(9):1983-1997. doi: 10.1016/j.arthro.2023.03.018
  57. Korpershoek JV, Ruijter M, Terhaard BF, et al. Potential of melt electrowritten scaffolds seeded with meniscus cells and mesenchymal stromal cells. Int J Mol Sci. 2021;22(20):11200. doi: 10.3390/ijms222011200
  58. Xu T, Gu J, Meng J, Du L, Kumar A, Xu H. Melt electrowriting reinforced composite membrane for controlled drug release. J Mech Behav Biomed Mater. 2022;132:105277. doi: 10.1016/j.jmbbm.2022.105277
  59. Nieuwoudt M, Woods I, Eichholz KF, et al. Functionalization of electrospun polycaprolactone scaffolds with matrix-binding osteocyte-derived extracellular vesicles promotes osteoblastic differentiation and mineralization. Ann Biomed Eng. 2021;49(12):3621-3635. doi: 10.1007/s10439-021-02872-2
  60. Hrynevich A, Elçi BŞ, Haigh JN, et al. Dimension-based design of melt electrowritten scaffolds. Small. 2018;14(22): 1800232. doi: 10.1002/smll.201800232
  61. Loewner S, Heene S, Baroth T, et al. Recent advances in melt electro writing for tissue engineering for 3D printing of microporous scaffolds for tissue engineering. Front Bioeng Biotechnol. 2022;10:896719. doi: 10.3389/fbioe.2022.896719
  62. Mifsud T, Chatzistergos P, Maganaris C, et al. Supersonic shear wave elastography of human tendons is associated with in vivo tendon stiffness over small strains. J Biomech. 2023;152:111558. doi: 10.1016/j.jbiomech.2023.111558
  63. Reizabal A, Kangur T, Saiz PG, et al. MEWron: an open-source melt electrowriting platform. Additive Manuf. 2023;71:103604. doi: 10.1016/j.addma.2023.103604
  64. Apostolakos J, Durant TJ, Dwyer CR, et al. The enthesis: a review of the tendon-to-bone insertion. Muscles Ligaments Tendons J. 2014;4(3):333-342.
  65. Abdal-hay A, Kocak-Oztug NA, Sheikh FA, et al. Fabrication of 3D bioactive melt electrowriting composite scaffold with high osteogenic potential. Colloids Surf B: Biointerfaces. 2025;245:114270. doi: 10.1016/j.colsurfb.2024.114270
  66. Ielo I, Calabrese G, De Luca G, Conoci S. Recent advances in hydroxyapatite-based biocomposites for bone tissue regeneration in orthopedics. Int J Mol Sci. 2022;23(17): 9721. doi: 10.3390/ijms23179721
  67. Sgroi TA, Cilenti M. Rotator cuff repair: post-operative rehabilitation concepts. Curr Rev Musculoskelet Med. 2018;11(1):86-91. doi: 10.1007/s12178-018-9462-7
  68. Bas O, D’Angella D, Baldwin JG, et al. An integrated design, material, and fabrication platform for engineering biomechanically and biologically functional soft tissues. ACS Appl Mater Interfaces. 2017;9(35):29430-29437. doi: 10.1021/acsami.7b08617
  69. Richardson WJ, Kegerreis B, Thomopoulos S, Holmes JW. Potential strain-dependent mechanisms defining matrix alignment in healing tendons. Biomech Model Mechanobiol. 2018;17(6):1569-1580. doi: 10.1007/s10237-018-1044-5
  70. Chen K, Hu X, Blemker SS, Holmes JW. Multiscale computational model of Achilles tendon wound healing: Untangling the effects of repair and loading. PLoS Comput Biol. 2018;14(12):e1006652. doi: 10.1371/journal.pcbi.1006652
  71. Wittkowske C, Reilly GC, Lacroix D, Perrault CM. In vitro bone cell models: impact of fluid shear stress on bone formation. Front Bioeng Biotechnol. 2016;4:87. doi: 10.3389/fbioe.2016.00087

 

 

Share
Back to top
International Journal of Bioprinting, Electronic ISSN: 2424-8002 Print ISSN: 2424-7723, Published by AccScience Publishing