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Yuan X, Zhu W, Yang Z, He N, Chen F, Han X, Zhou K. Recent Advances in 3D Printing of Smart Scaffolds for Bone Tissue Engineering and Regeneration. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2403641. [PMID: 38861754 DOI: 10.1002/adma.202403641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Indexed: 06/13/2024]
Abstract
The repair and functional reconstruction of bone defects resulting from severe trauma, surgical resection, degenerative disease, and congenital malformation pose significant clinical challenges. Bone tissue engineering (BTE) holds immense potential in treating these severe bone defects, without incurring prevalent complications associated with conventional autologous or allogeneic bone grafts. 3D printing technology enables control over architectural structures at multiple length scales and has been extensively employed to process biomimetic scaffolds for BTE. In contrast to inert and functional bone grafts, next-generation smart scaffolds possess a remarkable ability to mimic the dynamic nature of native extracellular matrix (ECM), thereby facilitating bone repair and regeneration. Additionally, they can generate tailored and controllable therapeutic effects, such as antibacterial or antitumor properties, in response to exogenous and/or endogenous stimuli. This review provides a comprehensive assessment of the progress of 3D-printed smart scaffolds for BTE applications. It begins with an introduction to bone physiology, followed by an overview of 3D printing technologies utilized for smart scaffolds. Notable advances in various stimuli-responsive strategies, therapeutic efficacy, and applications of 3D-printed smart scaffolds are discussed. Finally, the review highlights the existing challenges in the development and clinical implementation of smart scaffolds, as well as emerging technologies in this field.
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Affiliation(s)
- Xun Yuan
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Wei Zhu
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Zhongyuan Yang
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Ning He
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Feng Chen
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Xiaoxiao Han
- National Engineering Research Centre for High Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Kun Zhou
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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Zhuikova YV, Zhuikov VA, Khaydapova DD, Lunkov AP, Bonartseva GA, Varlamov VP. Evaluation of Chemical and Biological Properties of Biodegradable Composites Based on Poly(3-hydroxybutyrate) and Chitosan. Polymers (Basel) 2024; 16:1124. [PMID: 38675043 PMCID: PMC11053872 DOI: 10.3390/polym16081124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/11/2024] [Accepted: 04/14/2024] [Indexed: 04/28/2024] Open
Abstract
In this study, composite films and scaffolds of polyester poly(3-hydroxybutyrate) and polysaccharide chitosan obtained via a simple and reproducible blending method using acetic acid as a solvent were considered. The degradation process of the films was studied gravimetrically in a model biological medium in the presence of enzymes in vitro for 180 days. The kinetics of weight reduction depended on the amount of chitosan in the composition. The biocompatibility of the films was evaluated using the Alamar blue test and fluorescence microscopy. The materials were non-cytotoxic, and the addition of poly(3-hydroxybutyrate) to chitosan improved its matrix properties on mesenchymal stem cells. Then, the 3D composites were prepared by freeze-drying. Their structure (using SEM), rheological behavior, moisture absorption, and porosity were investigated. The addition of different amounts of chitosan allowed us to vary the chemical and biological properties of poly(3-hydroxybutyrate) materials and their degradation rate, which is extremely important in the development of biomedical poly(3-hydroxybutyrate) materials, especially implantable ones.
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Affiliation(s)
- Yulia V. Zhuikova
- Research Center of Biotechnology of the Russian Academy of Sciences, 33, Bld. 2 Leninsky Ave, Moscow 119071, Russia; (Y.V.Z.); (A.P.L.); (G.A.B.); (V.P.V.)
| | - Vsevolod A. Zhuikov
- Research Center of Biotechnology of the Russian Academy of Sciences, 33, Bld. 2 Leninsky Ave, Moscow 119071, Russia; (Y.V.Z.); (A.P.L.); (G.A.B.); (V.P.V.)
| | - Dolgor D. Khaydapova
- Faculty of Soil Science, M.V. Lomonosov Moscow State University, Moscow 119234, Russia;
| | - Alexey P. Lunkov
- Research Center of Biotechnology of the Russian Academy of Sciences, 33, Bld. 2 Leninsky Ave, Moscow 119071, Russia; (Y.V.Z.); (A.P.L.); (G.A.B.); (V.P.V.)
| | - Garina A. Bonartseva
- Research Center of Biotechnology of the Russian Academy of Sciences, 33, Bld. 2 Leninsky Ave, Moscow 119071, Russia; (Y.V.Z.); (A.P.L.); (G.A.B.); (V.P.V.)
| | - Valery P. Varlamov
- Research Center of Biotechnology of the Russian Academy of Sciences, 33, Bld. 2 Leninsky Ave, Moscow 119071, Russia; (Y.V.Z.); (A.P.L.); (G.A.B.); (V.P.V.)
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Deymier AC, Deymier PA. Open-system force-elongation relationship of collagen in chemo-mechanical equilibrium with water. J Mech Behav Biomed Mater 2024; 152:106464. [PMID: 38367533 DOI: 10.1016/j.jmbbm.2024.106464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 02/07/2024] [Accepted: 02/13/2024] [Indexed: 02/19/2024]
Abstract
A significant deformation mechanism of collagen at low loads is molecular uncoiling and rearrangement. Although the effect of hydration and cross-linking has been investigated at larger loads when collagen undergoes molecular sliding, their effects on collagen molecular reorganization remain unclear. Here we develop two thermodynamic models that use the notion of open-system elasticity to elucidate the effect of swelling due to water uptake during deformation of collagen networks under low and high cross-linking conditions. With low crosslinking, entropic contributions dominate resulting in rejection of solvent from the polymer network leading to reduced collagen stiffness with increased loads. Contrarily, high cross-linking inhibits initial coiling and structural kinking and the mechanical behavior is dominated by elastic energy. In this configuration, the solvent content depends on the sign of the applied load resulting in a non-linear open-system stress-strain relationship. The models provide insight on the parameters that impact the stress-strain relationships of hydrated collagen and can inform the way collagenous matrices are treated both in medical and laboratory settings.
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Affiliation(s)
- A C Deymier
- Department of Biomedical Engineering, UConn Health, Farmington, CT, USA.
| | - P A Deymier
- Department of Materials Science and Engineering, University of Arizona, Tucson, AZ, 85721, USA
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Šupová M. The Significance and Utilisation of Biomimetic and Bioinspired Strategies in the Field of Biomedical Material Engineering: The Case of Calcium Phosphat-Protein Template Constructs. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E327. [PMID: 31936830 PMCID: PMC7013803 DOI: 10.3390/ma13020327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/03/2020] [Accepted: 01/07/2020] [Indexed: 02/07/2023]
Abstract
This review provides a summary of recent research on biomimetic and bioinspired strategies applied in the field of biomedical material engineering and focusing particularly on calcium phosphate-protein template constructs inspired by biomineralisation. A description of and discussion on the biomineralisation process is followed by a general summary of the application of the biomimetic and bioinspired strategies in the fields of biomedical material engineering and regenerative medicine. Particular attention is devoted to the description of individual peptides and proteins that serve as templates for the biomimetic mineralisation of calcium phosphate. Moreover, the review also presents a description of smart devices including delivery systems and constructs with specific functions. The paper concludes with a summary of and discussion on potential future developments in this field.
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Affiliation(s)
- Monika Šupová
- Department of Composites and Carbon Materials, Institute of Rock Structure and Mechanics, The Czech Academy of Sciences, V Holešovičkách 41, 182 09 Prague, Czech Republic
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Tiffany AS, Gray DL, Woods TJ, Subedi K, Harley BAC. The inclusion of zinc into mineralized collagen scaffolds for craniofacial bone repair applications. Acta Biomater 2019; 93:86-96. [PMID: 31121312 PMCID: PMC6615986 DOI: 10.1016/j.actbio.2019.05.031] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/23/2019] [Accepted: 05/10/2019] [Indexed: 12/19/2022]
Abstract
Implant osteoinduction and subsequent osteogenic activity are critical events that need improvement for regenerative healing of large craniofacial bone defects. Here we describe the augmentation of the mineral content of a class of mineralized collagen scaffolds under development for craniomaxillofacial bone regeneration via the inclusion of zinc ions to promote osteogenesis in vitro. Zinc is an essential trace element in skeletal tissue and bone, with soluble zinc being shown to promote osteogenic differentiation of porcine adipose derived stem cells. We report the development of a new class of zinc functionalized scaffolds fabricated by adding zinc sulfate to a mineralized collagen-glycosaminoglycan precursor suspension that was then freeze dried to form a porous biomaterial. We report analysis of zinc functionalized scaffolds via imaging (scanning electron microscopy), mechanical testing (compression), and compositional (X-ray diffraction, inductively coupled plasma mass spectrometry) analyses. Notably, zinc-functionalized scaffolds display morphological changes to the mineral phase and altered elastic modulus without substantially altering the composition of the brushite phase or removing the micro-scale pore morphology of the scaffold. These scaffolds also display zinc release kinetics on the order of days to weeks and promote successful growth and pro-osteogenic capacity of porcine adipose derived stem cells cultured within these zinc scaffolds. Taken together, we believe that zinc functionalized scaffolds provide a unique platform to explore strategies to improve in vivo osteogenesis in craniomaxillofacial bone injuries models. STATEMENT OF SIGNIFICANCE: Craniomaxillofacial bone defects that arise from traumatic, congenital, and post-oncologic origins cannot heal on their own and often require surgical intervention. We have developed a class of mineralized collagen scaffolds that promotes osteogenesis and bone regeneration. Here we describe the inclusion of zinc sulfate into the mineralized collagen scaffold to improve osteogenesis. Zinc functionalized scaffolds demonstrate altered crystallite microstructure but consistent Brushite chemistry, improved mechanics, and promote zinc transporter expression while supporting stem cell viability, osteogenic differentiation, and mineral biosynthesis.
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Affiliation(s)
- Aleczandria S Tiffany
- Dept. Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Danielle L Gray
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Toby J Woods
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Kiran Subedi
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States
| | - Brendan A C Harley
- Dept. Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
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6
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Xu X, Zhou J, Feng C, Jiang Y, Zhang Q, Shi H. 3D printing algorithm of anisotropic biological scaffold with oxidized nanocellulose and gelatin. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2019; 30:1260-1275. [DOI: 10.1080/09205063.2019.1627651] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Xiaodong Xu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
- Yangzhou Polytechnic Institute, Yangzhou, China
| | - Jiping Zhou
- College of Mechanical Engineering, Yangzhou University, Yangzhou, China
| | - Chen Feng
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
- Yangzhou Polytechnic Institute, Yangzhou, China
| | - Yani Jiang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Qi Zhang
- College of Mechanical Engineering, Yangzhou University, Yangzhou, China
| | - Hongcan Shi
- Medical College of Yangzhou University, Yangzhou, China
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Dewey MJ, Johnson EM, Weisgerber DW, Wheeler MB, Harley BAC. Shape-fitting collagen-PLA composite promotes osteogenic differentiation of porcine adipose stem cells. J Mech Behav Biomed Mater 2019; 95:21-33. [PMID: 30953806 DOI: 10.1016/j.jmbbm.2019.03.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/17/2018] [Accepted: 03/17/2019] [Indexed: 10/27/2022]
Abstract
Craniomaxillofacial bone defects can occur as a result of congenital, post-oncologic, and high-energy impact conditions. The scale and irregularity of such defects motivate new biomaterials to promote regeneration of the damaged bone. We have recently described a mineralized collagen scaffold capable of instructing stem cell osteogenic differentiation and new bone infill in the absence of traditional osteogenic supplements. Herein, we report the integration of a millimeter-scale reinforcing poly (lactic acid) frame fabricated via 3D-printing into the mineralized collagen scaffold with micron-scale porosity to form a multi-scale mineralized collagen-PLA composite. We describe modifications to the PLA frame design to increase the compressive strength (Young's Modulus, ultimate stress and strain) of the composite. A critical challenge beyond increasing the compressive strength of the collagen scaffold is addressing challenges inherent with the irregularity of clinical defects. As a result, we examined the potential for modifying the frame architecture to render the composite with increased compressive strength in one axis or radial compressibility and shape-fitting capacity in an orthogonal axis. A library of mineralized collagen-PLA composites was mechanically characterized via compression testing and push-out test to describe mechanical performance and shape-fitting capacity. We also report in vitro comparison of the bioactivity of porcine adipose derived stem cells in the mineralized collagen-PLA composite versus the mineralized collagen scaffold via metabolic activity, gene expression, and functional matrix synthesis. The results suggest that incorporation of the PLA reinforcing frame does not negatively influence the osteoinductive nature of the mineralized collagen scaffold. Together, these findings suggest a strategy to address often competing bioactivity, mechanical strength, and shape-fitting design requirements for biomaterials for craniomaxillofacial bone regeneration.
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Affiliation(s)
- Marley J Dewey
- Dept. of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eileen M Johnson
- Dept. of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Daniel W Weisgerber
- Dept. of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Matthew B Wheeler
- Dept. of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Brendan A C Harley
- Dept. of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Dept. of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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8
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Xu X, Zhou J, Jiang Y, Zhang Q, Shi H, Liu D. 3D printing process of oxidized nanocellulose and gelatin scaffold. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2018; 29:1498-1513. [DOI: 10.1080/09205063.2018.1472450] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Xiaodong Xu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
- College of Machinery and Automobile Engineering, Yangzhou Polytechnic Institute, Yangzhou, China
| | - Jiping Zhou
- College of Mechanical Engineering, Yangzhou University, Yangzhou, China
| | - Yani Jiang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Qi Zhang
- College of Mechanical Engineering, Yangzhou University, Yangzhou, China
| | - Hongcan Shi
- Medical College of Yangzhou University, Yangzhou, China
| | - Dongfang Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
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9
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Cell structure, stiffness and permeability of freeze-dried collagen scaffolds in dry and hydrated states. Acta Biomater 2016; 33:166-175. [PMID: 26827778 DOI: 10.1016/j.actbio.2016.01.041] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/22/2015] [Accepted: 01/27/2016] [Indexed: 02/03/2023]
Abstract
Scaffolds for tissue engineering applications should be highly permeable to support mass transfer requirements while providing a 3-D template for the encapsulated biological cells. High porosity and cell interconnectivity result in highly compliant scaffolds. Overstraining occurs easily with such compliant materials and can produce misleading results. In this paper, the cell structure of freeze-dried collagen scaffolds, in both dry and hydrated states, was characterised using X-ray tomography and 2-photon confocal microscopy respectively. Measurements have been made of the scaffold's Young's modulus using conventional mechanical testing and a customised see-saw testing configuration. Specific permeability was measured under constant pressure gradient and compared with predictions. The collagen scaffolds investigated here have a coarse cell size (∼100-150 μm) and extensive connectivity between adjacent cells (∼10-30 μm) in both dry and hydrated states. The Young's modulus is very low, of the order of 10 kPa when dry and 1 kPa when hydrated. There is only a single previous study concerning the specific permeability of (hydrated) collagen scaffolds, despite its importance in nutrient diffusion, waste removal and cell migration. The experimentally measured value reported here (5 × 10(-)(10)m(2)) is in good agreement with predictions based on Computational Fluid Dynamics simulation and broadly consistent with the Carman-Kozeny empirical estimate. It is however about three orders of magnitude higher than the single previously-reported value and this discrepancy is attributed at least partly to the high pressure gradient imposed in the previous study. STATEMENT OF SIGNIFICANCE The high porosity and interconnectivity of tissue engineering scaffolds result in highly compliant structures (ie large deflections under low applied loads). Characterisation is essential if these scaffolds are to be systematically optimised. Scaffold overstraining during characterisation can lead to misleading results. In this study, the stiffness (in dry and hydrated states) and specific permeability of freeze-dried collagen scaffolds have been measured using techniques customised for low stiffness structures. The scaffold cell structure is investigated using X-ray computed tomography, which has been applied previously to visualise such materials, without extracting any structural parameters or simulating fluid flow. These are carried out in this work. 2-photon confocal microscopy is used for the first time to study the structure in hydrated state.
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Weisgerber D, Caliari S, Harley B. Mineralized collagen scaffolds induce hMSC osteogenesis and matrix remodeling. Biomater Sci 2015; 3:533-42. [PMID: 25937924 PMCID: PMC4412464 DOI: 10.1039/c4bm00397g] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biomaterials for bone tissue engineering must be able to instruct cell behavior in the presence of the complex biophysical and biomolecular environments encountered in vivo. While soluble supplementation strategies have been identified to enhance osteogenesis, they are subject to significant diffusive loss in vivo or the need for frequent re-addition in vitro. This investigation therefore explored whether biophysical and biochemical properties of a mineralized collagen-GAG scaffold were sufficient to enhance human mesenchymal stem cell (hMSC) osteogenic differentiation and matrix remodeling in the absence of supplementation. We examined hMSC metabolic health, osteogenic and matrix gene expression profiles, as well as matrix remodeling and mineral formation as a function of scaffold mineral content. We found that scaffold mineral content enhanced long term hMSC metabolic activity relative to non-mineralized scaffolds. While osteogenic supplementation or exogenous BMP-2 could enhance some markers of hMSC osteogenesis in the mineralized scaffold, we found the mineralized scaffold was itself sufficient to induce osteogenic gene expression, matrix remodeling, and mineral formation. Given significant potential for unintended consequences with the use of mixed media formulations and potential for diffusive loss in vivo, these findings will inform the design of instructive biomaterials for regenerative repair of critical-sized bone defects, as well as for applications where non-uniform responses are required, such as in biomaterials to address spatially-graded interfaces between orthopedic tissues.
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Affiliation(s)
- D.W. Weisgerber
- Dept. of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - S.R. Caliari
- Dept. of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - B.A.C. Harley
- Dept. of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA, Phone: 217-244-7112, Fax: 217-333-5052
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Devi S, Williams DR. Density dependent mechanical properties and structures of a freeze dried biopharmaceutical excipient – Sucrose. Eur J Pharm Biopharm 2014; 88:492-501. [DOI: 10.1016/j.ejpb.2014.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 06/25/2014] [Accepted: 06/26/2014] [Indexed: 10/25/2022]
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12
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Caliari SR, Harley BAC. Collagen-GAG scaffold biophysical properties bias MSC lineage choice in the presence of mixed soluble signals. Tissue Eng Part A 2014; 20:2463-72. [PMID: 24568607 DOI: 10.1089/ten.tea.2013.0400] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Biomaterial strategies for regenerating multitissue structures require unique approaches. One strategy is to design scaffolds so that their local biophysical properties can enhance site-specific effects of an otherwise heterogeneous biomolecular environment. This investigation examined the role of biomaterial physical properties (relative density, mineral content) on the human mesenchymal stem cell phenotype in the presence of mixed soluble signals to drive osteogenesis or chondrogenesis. We tested a series of three-dimensional collagen-glycosaminoglycan scaffolds with properties inspired by extracellular matrix characteristics across the osteotendinous interface (tendon, cartilage, and bone). We found that selective scaffold mineralization induced a depressed chondrogenic response compared with nonmineralized groups as demonstrated by gene expression and histological analyses. Interestingly, the greatest chondrogenic response was found in a higher density, nonmineralized scaffold variant despite increased contraction and cellular condensation in lower density nonmineralized scaffolds. In fact, the lower density scaffolds demonstrated a significantly higher expression of osteogenic transcripts as well as ample mineralization after 21 days of culture. This effect may be due to local stiffening of the scaffold microenvironment as the scaffold contracts, leading to increased cell density, accelerated differentiation, and possible endochondral ossification as evidenced by a transition from a glycosaminoglycan (GAG)-rich milieu to higher mineralization at later culture times. These findings will help shape the design rules for graded biomaterials to regenerate distinct fibrillar, fibrocartilagenous, and mineralized regions of orthopedic interfaces.
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Affiliation(s)
- Steven R Caliari
- 1 Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois
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13
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Devi S, Williams D. Morphological and Compressional Mechanical Properties of Freeze-Dried Mannitol, Sucrose, and Trehalose Cakes. J Pharm Sci 2013; 102:4246-55. [DOI: 10.1002/jps.23736] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/16/2013] [Accepted: 09/03/2013] [Indexed: 02/06/2023]
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Weisgerber DW, Kelkhoff DO, Caliari SR, Harley BAC. The impact of discrete compartments of a multi-compartment collagen-GAG scaffold on overall construct biophysical properties. J Mech Behav Biomed Mater 2013; 28:26-36. [PMID: 23973610 DOI: 10.1016/j.jmbbm.2013.07.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/10/2013] [Accepted: 07/15/2013] [Indexed: 01/08/2023]
Abstract
Orthopedic interfaces such as the tendon-bone junction (TBJ) present unique challenges for biomaterials development. Here we describe a multi-compartment collagen-GAG scaffold fabricated via lyophilization that contains discrete mineralized (CGCaP) and non-mineralized (CG) regions joined by a continuous interface. Modifying CGCaP preparation approaches, we demonstrated scaffold variants of increasing mineral content (40 vs. 80wt% CaP). We report the impact of fabrication parameters on microstructure, composition, elastic modulus, and permeability of the entire multi-compartment scaffold as well as discrete mineralized and non-mineralized compartments. Notably, individual mineralized and non-mineralized compartments differentially impacted the global properties of the multi-compartment composite. Of particular interest for the development of mechanically-loaded multi-compartment composites, the elastic modulus and permeability of the entire construct were governed primarily by the non-mineralized and mineralized compartments, respectively. Based on these results we hypothesize spatial variations in scaffold structural, compositional, and mechanical properties may be an important design parameter in orthopedic interface repair.
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Affiliation(s)
- D W Weisgerber
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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15
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Yu X, Xia Z, Wang L, Peng F, Jiang X, Huang J, Rowe D, Wei M. Controlling the structural organization of regenerated bone by tailoring tissue engineering scaffold architecture. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm30332a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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The influence of collagen-glycosaminoglycan scaffold relative density and microstructural anisotropy on tenocyte bioactivity and transcriptomic stability. J Mech Behav Biomed Mater 2011; 11:27-40. [PMID: 22658152 DOI: 10.1016/j.jmbbm.2011.12.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 12/14/2011] [Accepted: 12/15/2011] [Indexed: 01/14/2023]
Abstract
Biomaterials for orthopedic tissue engineering must balance mechanical and bioactivity concerns. This work describes the fabrication of a homologous series of anisotropic collagen-GAG (CG) scaffolds with aligned tracks of ellipsoidal pores but increasing relative densities (ρ(∗)/ρ(s)), and we report the role scaffold relative density plays in directing tenocyte bioactivity. Scaffold permeability and mechanical properties, both in tension and compression, were significantly influenced by relative density in a manner predicted by cellular solids models. Equine tenocytes showed greater levels of attachment, metabolic activity, soluble collagen synthesis, and alignment as well as less cell-mediated scaffold contraction in anisotropic CG scaffolds of increasing relative density. Notably, the lowest density scaffolds experienced significant cell-mediated contraction with associated decreases in tenocyte number as well as loss of microstructural integrity, aligned contact guidance cues, and preferential tenocyte orientation over a 14 day culture period. Gene expression analyses suggested tenocyte de-differentiation in the lowest density scaffold while indicating that the highest density scaffold supported significant increases in COMP (4-fold), tenascin-C (3-fold), and scleraxis (15-fold) expression as well as significant decreases in MMP-1 (9-fold) and MMP-13 (13-fold) expression on day 14. These results suggest that anisotropic scaffold relative density can help to modulate the maintenance of a more tendon-like microenvironment and aid long-term tenocyte transcriptomic stability. Overall, this work demonstrates that relative density is a critical scaffold parameter, not only for insuring mechanical competence, but also for directing cell transcriptomic stability and behavior.
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Effects of crystalline phase on the biological properties of collagen-hydroxyapatite composites. Acta Biomater 2010; 6:2189-99. [PMID: 20040387 DOI: 10.1016/j.actbio.2009.12.042] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2009] [Revised: 12/17/2009] [Accepted: 12/21/2009] [Indexed: 01/06/2023]
Abstract
The objective of this study was to investigate the effects of spatial structure and crystalline phase on the biological performance of collagen-hydroxyapatite (Col-HA) composite prepared by biomineralization crystallization. Two types of Col-HA composites were prepared using mineralization crystallization (MC composites) and pre-crystallization (PC composites), respectively. Structural characteristics were analyzed by scanning electron microscopy and transmission electron microscopy. Surface elemental compositions were measured by electron spectroscopy for chemical analysis (ESCA). These composites were used in in vivo repair of bone defects. The effects of the crystalline phase on the biological performance of Col-HA composites were investigated using radionuclide bone scan, histopathology and morphological observation. It was observed that in MC composites, HA was located on the surface of the collagen fibers and aggregated into crystal balls, whereas HA in PC composites was scattered among the collagen fibers. ESCA showed that phosphorus and calcium were 8.99% and 17.56% on MC composite surface, compared with 4.39% and 5.86% on the PC composite surface. In vivo bone defect repair experiments revealed that radionuclide uptake was significantly higher in the area implanted with the PC composite than in the contralateral area implanted with the MC composite. Throughout the whole repair process, the PC composite proved to be superior to the MC composite with regard to capillary-forming capacity and the amount of newly formed bone tissue. So it could be concluded that HA placement on collagen fibers affected the biological performance of Col-HA composites. Pre-crystallization made HA scattered among collagen fibers, creating a better structure for bone defect repair in comparison with MC Col-HA composites.
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Cell contraction forces in scaffolds with varying pore size and cell density. Biomaterials 2010; 31:4835-45. [PMID: 20362329 DOI: 10.1016/j.biomaterials.2010.01.149] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 01/17/2010] [Indexed: 11/22/2022]
Abstract
The contractile behavior of cells is relevant in understanding wound healing and scar formation. In tissue engineering, inhibition of the cell contractile response is critical for the regeneration of physiologically normal tissue rather than scar tissue. Previous studies have measured the contractile response of cells in a variety of conditions (e.g. on two-dimensional solid substrates, on free-floating tissue engineering scaffolds and on scaffolds under some constraint in a cell force monitor). Tissue engineering scaffolds behave mechanically like open-cell elastomeric foams: between strains of about 10 and 90%, cells progressively buckle struts in the scaffold. The contractile force required for an individual cell to buckle a strut within a scaffold has been estimated based on the strut dimensions (radius, r, and length, l) and the strut modulus, E(s). Since the buckling force varies, according to Euler's law, with r(4)/l(2), and the relative density of the scaffold varies as (r/l)(2), the cell contractile force associated with strut buckling is expected to vary with the square of the pore size for scaffolds of constant relative density. As the cell density increases, the force per cell to achieve a given strain in the scaffold is expected to decrease. Here we model the contractile response of fibroblasts by analyzing the response of a single tetrakaidecahedron to forces applied to individual struts (simulating cell contractile forces) using finite element analysis. We model tetrakaidecahedra of different strut lengths, corresponding to different scaffold pore sizes, and of varying numbers of loaded struts, corresponding to varying cell densities. We compare our numerical model with the results of free-floating contraction experiments of normal human dermal fibroblasts (NHDF) in collagen-GAG scaffolds of varying pore size and with varying cell densities.
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