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Eckstein KN, Hergert JE, Uzcategui AC, Schoonraad SA, Bryant SJ, McLeod RR, Ferguson VL. Controlled Mechanical Property Gradients Within a Digital Light Processing Printed Hydrogel-Composite Osteochondral Scaffold. Ann Biomed Eng 2024; 52:2162-2177. [PMID: 38684606 DOI: 10.1007/s10439-024-03516-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 04/07/2024] [Indexed: 05/02/2024]
Abstract
Tissue engineered scaffolds are needed to support physiological loads and emulate the micrometer-scale strain gradients within tissues that guide cell mechanobiological responses. We designed and fabricated micro-truss structures to possess spatially varying geometry and controlled stiffness gradients. Using a custom projection microstereolithography (μSLA) system, using digital light projection (DLP), and photopolymerizable poly(ethylene glycol) diacrylate (PEGDA) hydrogel monomers, three designs with feature sizes < 200 μm were formed: (1) uniform structure with 1 MPa structural modulus ( E ) designed to match equilibrium modulus of healthy articular cartilage, (2) E = 1 MPa gradient structure designed to vary strain with depth, and (3) osteochondral bilayer with distinct cartilage ( E = 1 MPa) and bone ( E = 7 MPa) layers. Finite element models (FEM) guided design and predicted the local mechanical environment. Empty trusses and poly(ethylene glycol) norbornene hydrogel-infilled composite trusses were compressed during X-ray microscopy (XRM) imaging to evaluate regional stiffnesses. Our designs achieved target moduli for cartilage and bone while maintaining 68-81% porosity. Combined XRM imaging and compression of empty and hydrogel-infilled micro-truss structures revealed regional stiffnesses that were accurately predicted by FEM. In the infilling hydrogel, FEM demonstrated the stress-shielding effect of reinforcing structures while predicting strain distributions. Composite scaffolds made from stiff μSLA-printed polymers support physiological load levels and enable controlled mechanical property gradients which may improve in vivo outcomes for osteochondral defect tissue regeneration. Advanced 3D imaging and FE analysis provide insights into the local mechanical environment surrounding cells in composite scaffolds.
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Affiliation(s)
- Kevin N Eckstein
- Paul M. Rady Department of Mechanical Engineering, University of Colorado at Boulder, 427 UCB, Boulder, CO, 80309, USA
| | - John E Hergert
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO, USA
| | - Asais Camila Uzcategui
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO, USA
| | - Sarah A Schoonraad
- Department of Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - Stephanie J Bryant
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado at Boulder, Boulder, CO, USA
- Department of Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - Robert R McLeod
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO, USA
- Department of Electrical, Computer & Energy Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - Virginia L Ferguson
- Paul M. Rady Department of Mechanical Engineering, University of Colorado at Boulder, 427 UCB, Boulder, CO, 80309, USA.
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO, USA.
- BioFrontiers Institute, University of Colorado at Boulder, Boulder, CO, USA.
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Elahi SA, Castro-Viñuelas R, Tanska P, Korhonen RK, Lories R, Famaey N, Jonkers I. Contribution of collagen degradation and proteoglycan depletion to cartilage degeneration in primary and secondary osteoarthritis: an in silico study. Osteoarthritis Cartilage 2023; 31:741-752. [PMID: 36669584 DOI: 10.1016/j.joca.2023.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 10/13/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Current experimental approaches cannot elucidate the effect of maladaptive changes on the main cartilage constituents during the degeneration process in osteoarthritis (OA). In silico approaches, however, allow creating 'virtual knock-out' cases to elucidate these effects in a constituent-specific manner. We used such an approach to study the main mechanisms of cartilage degeneration in different mechanical loadings associated with the following OA etiologies: (1) physiological loading of degenerated cartilage, (2) injurious loading of healthy intact cartilage and (3) physiological loading of cartilage with a focal defect. METHODS We used the recently developed Cartilage Adaptive REorientation Degeneration (CARED) framework to simulate cartilage degeneration associated with primary and secondary OA (OA cases (1)-(3)). CARED incorporates numerical description of tissue-level cartilage degeneration mechanisms in OA, namely, collagen degradation, collagen reorientation, fixed charged density loss and tissue hydration increase following mechanical loading. We created 'virtual knock-out' scenarios by deactivating these degenerative processes one at a time in each of the three OA cases. RESULTS In the injurious loading of intact and physiological loading of degenerated cartilage, collagen degradation drives degenerative changes through fixed charge density loss and tissue hydration rise. In contrast, the two later mechanisms were more prominent in the focal defect cartilage model. CONCLUSION The virtual knock-out models reveal that injurious loading to intact cartilage and physiological loading to degenerated cartilage induce initial degenerative changes in the collagen network, whereas, in the presence of a focal cartilage defect, mechanical loading initially causes proteoglycans (PG) depletion, before changes in the collagen fibril network occur.
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Affiliation(s)
- S A Elahi
- Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven, Leuven, Belgium; Mechanical Engineering Department, Biomechanics Section, Soft Tissue Biomechanics Group, KU Leuven, Leuven, Belgium.
| | - R Castro-Viñuelas
- Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven, Leuven, Belgium; Department of Development and Regeneration, Skeletal Biology and Engineering Research Centre, Laboratory of Tissue Homeostasis and Disease, KU Leuven, Leuven, Belgium.
| | - P Tanska
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
| | - R K Korhonen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
| | - R Lories
- Department of Development and Regeneration, Skeletal Biology and Engineering Research Centre, Laboratory of Tissue Homeostasis and Disease, KU Leuven, Leuven, Belgium; Division of Rheumatology, University Hospitals Leuven, Leuven, Belgium.
| | - N Famaey
- Mechanical Engineering Department, Biomechanics Section, Soft Tissue Biomechanics Group, KU Leuven, Leuven, Belgium.
| | - I Jonkers
- Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven, Leuven, Belgium; Department of Development and Regeneration, Skeletal Biology and Engineering Research Centre, Laboratory of Tissue Homeostasis and Disease, KU Leuven, Leuven, Belgium.
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Schoonraad SA, Fischenich KM, Eckstein KN, Crespo-Cuevas V, Savard LM, Muralidharan A, Tomaschke AA, Uzcategui AC, Randolph MA, McLeod RR, Ferguson VL, Bryant SJ. Biomimetic and mechanically supportive 3D printed scaffolds for cartilage and osteochondral tissue engineering using photopolymers and digital light processing. Biofabrication 2021; 13. [PMID: 34479218 DOI: 10.1088/1758-5090/ac23ab] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 09/03/2021] [Indexed: 02/08/2023]
Abstract
Successful 3D scaffold designs for musculoskeletal tissue engineering necessitate full consideration of the form and function of the tissues of interest. When designing structures for engineering cartilage and osteochondral tissues, one must reconcile the need to develop a mechanically robust system that maintains the health of cells embedded in the scaffold. In this work, we present an approach that decouples the mechanical and biochemical needs and allows for the independent development of the structural and cellular niches in a scaffold. Using the highly tuned capabilities of digital light processing-based stereolithography, structures with complex architectures are achieved over a range of effective porosities and moduli. The 3D printed structure is infilled with mesenchymal stem cells and soft biomimetic hydrogels, which are specifically formulated with extracellular matrix analogs and tethered growth factors to provide selected biochemical cues for the guided differentiation towards chondrogenesis and osteogenesis. We demonstrate the ability to utilize these structures to (a) infill a focal chondral defect and mitigate macroscopic and cellular level changes in the cartilage surrounding the defect, and (b) support the development of a stratified multi-tissue scaffold for osteochondral tissue engineering.
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Affiliation(s)
- Sarah A Schoonraad
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Kristine M Fischenich
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Kevin N Eckstein
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Victor Crespo-Cuevas
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Lea M Savard
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Archish Muralidharan
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Andrew A Tomaschke
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Asais Camila Uzcategui
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Mark A Randolph
- Department of Orthopaedic Surgery, Laboratory for Musculoskeletal Tissue Engineering, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, United States of America
| | - Robert R McLeod
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO 80309, United States of America.,Department of Electrical, Computer and Energy Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Virginia L Ferguson
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO 80309, United States of America.,Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America.,BioFrontiers Institute, University of Colorado at Boulder, Boulder, CO 80309, United States of America
| | - Stephanie J Bryant
- Materials Science and Engineering Program, University of Colorado at Boulder, Boulder, CO 80309, United States of America.,BioFrontiers Institute, University of Colorado at Boulder, Boulder, CO 80309, United States of America.,Department of Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, CO 80309, United States of America
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Cao Y, Cheng P, Sang S, Xiang C, An Y, Wei X, Shen Z, Zhang Y, Li P. Mesenchymal stem cells loaded on 3D-printed gradient poly(ε-caprolactone)/methacrylated alginate composite scaffolds for cartilage tissue engineering. Regen Biomater 2021; 8:rbab019. [PMID: 34211731 PMCID: PMC8240606 DOI: 10.1093/rb/rbab019] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/08/2021] [Accepted: 04/12/2021] [Indexed: 01/06/2023] Open
Abstract
Cartilage has limited self-repair ability due to its avascular, alymphatic and aneural features. The combination of three-dimensional (3D) printing and tissue engineering provides an up-and-coming approach to address this issue. Here, we designed and fabricated a tri-layered (superficial layer (SL), middle layer (ML) and deep layer (DL)) stratified scaffold, inspired by the architecture of collagen fibers in native cartilage tissue. The scaffold was composed of 3D printed depth-dependent gradient poly(ε-caprolactone) (PCL) impregnated with methacrylated alginate (ALMA), and its morphological analysis and mechanical properties were tested. To prove the feasibility of the composite scaffolds for cartilage regeneration, the viability, proliferation, collagen deposition and chondrogenic differentiation of embedded rat bone marrow mesenchymal stem cells (BMSCs) in the scaffolds were assessed by Live/dead assay, CCK-8, DNA content, cell morphology, immunofluorescence and real-time reverse transcription polymerase chain reaction. BMSCs-loaded gradient PCL/ALMA scaffolds showed excellent cell survival, cell proliferation, cell morphology, collagen II deposition and hopeful chondrogenic differentiation compared with three individual-layer scaffolds. Hence, our study demonstrates the potential use of the gradient PCL/ALMA construct for enhanced cartilage tissue engineering.
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Affiliation(s)
- Yanyan Cao
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, MicroNano System Research Center, College of Information and Computer, Taiyuan University of Technology, Taiyuan 030024, China.,College of Information Science and Engineering, Hebei North University, Zhangjiakou 075000, China
| | - Peng Cheng
- Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Department of Orthopedics, The Second Hospital of Shanxi Medical University, Taiyuan 030001, China
| | - Shengbo Sang
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, MicroNano System Research Center, College of Information and Computer, Taiyuan University of Technology, Taiyuan 030024, China
| | - Chuan Xiang
- Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Department of Orthopedics, The Second Hospital of Shanxi Medical University, Taiyuan 030001, China
| | - Yang An
- Department of Plastic Surgery, Peking University Third Hospital, Beijing 100191, China
| | - Xiaochun Wei
- Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Department of Orthopedics, The Second Hospital of Shanxi Medical University, Taiyuan 030001, China
| | - Zhizhong Shen
- Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education, MicroNano System Research Center, College of Information and Computer, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yixia Zhang
- Department of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Pengcui Li
- Shanxi Key Laboratory of Bone and Soft Tissue Injury Repair, Department of Orthopedics, The Second Hospital of Shanxi Medical University, Taiyuan 030001, China
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