Magnetic Alignment of Type I Collagen as a Method for Altering Tensile Mechanical Properties

2012 ◽  
Author(s):  
Tyler Novak ◽  
Jamie Canter ◽  
Dafang Chen ◽  
Joel Hungate ◽  
Sherry Voytik-Harbin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Structural Integrity ◽  
Biological Response ◽  
Type I ◽  
Noninvasive Methods ◽  
Tissue Constructs ◽  
Musculoskeletal Tissues ◽  
Common Technique ◽  
Scaffold Materials

To date, ligament and tendon replacements largely utilize autograft/allograft transplantation, although the use of tissue engineered materials remain a promising solution [10]. The development of an engineered solution may depend on the choice of scaffold materials with optimal fiber alignment. Type I collagen is an abundant extracellular matrix component in musculoskeletal tissues. The controlled alignment of type I collagen for tissue engineering and regenerative medicine applications enables the fabrication of unique scaffolds that emulate the ultrastructure of their native counterparts. Moreover, the alignment of type I collagen has become a common technique to manipulate mechanical properties of tissue constructs and the biological response of embedded cells [1,2]. It is additionally important to develop noninvasive methods to align collagen structures while maintaining inherent structural integrity and biological activity.

Characterization of Carbon Nanotube-Conjugated Collagen Composite Matrix Mechanics

2007 ◽  
Author(s):  
John R. Twomey ◽  
Vivek Sundaram ◽  
Krishna Madhavan ◽  
Wei Tan
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
High Stress ◽  
Type I ◽  
Composite Matrix ◽  
Matrix Mechanics ◽  
Tissue Constructs ◽  
Engineered Tissue ◽  
Walled Carbon Nanotubes

In the case of vascular grafts, enhanced mechanical properties of engineered tissue constructs are required in order to function properly in mechanically-active physiologic conditions. It is proposed that a composite matrix constructed of type I collagen, fibronectin, and covalently-functionalized single-walled carbon nanotubes (SWNTs) will provide the desired mechanical properties required for the development of implantable tissues capable of withstanding high-stress environments.

Intrinsic mechanical properties of the extracellular matrix affect the behavior of pre-osteoblastic MC3T3-E1 cells

2006 ◽  
Vol 290 (6) ◽  
pp. C1640-C1650 ◽  
Author(s):  
Chirag B. Khatiwala ◽  
Shelly R. Peyton ◽  
Andrew J. Putnam
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Focal Adhesions ◽  
Microscopic Analysis ◽  
Maximal Activity ◽  
Type I ◽  
Cell Functions ◽  
Collagen Density ◽  
Cells Cultured ◽  
In Cells

Mechanical cues present in the ECM have been hypothesized to provide instructive signals that dictate cell behavior. We probed this hypothesis in osteoblastic cells by culturing MC3T3-E1 cells on the surface of type I collagen-modified hydrogels with tunable mechanical properties and assessed their proliferation, migration, and differentiation. On gels functionalized with a low type I collagen density, MC3T3-E1 cells cultured on polystyrene proliferated twice as fast as those cultured on the softest substrate. Quantitative time-lapse video microscopic analysis revealed random motility speeds were significantly retarded on the softest substrate (0.25 ± 0.01 μm/min), in contrast to maximum speeds on polystyrene substrates (0.42 ± 0.04 μm/min). On gels functionalized with a high type I collagen density, migration speed exhibited a biphasic dependence on ECM compliance, with maximum speeds (0.34 ± 0.02 μm/min) observed on gels of intermediate stiffness, whereas minimum speeds (0.24 ± 0.03 μm/min) occurred on both the softest and most rigid (i.e., polystyrene) substrates. Immature focal contacts and a poorly organized actin cytoskeleton were observed in cells cultured on the softest substrates, whereas those on more rigid substrates assembled mature focal adhesions and robust actin stress fibers. In parallel, focal adhesion kinase (FAK) activity (assessed by detecting pY397-FAK) was influenced by compliance, with maximal activity occurring in cells cultured on polystyrene. Finally, mineral deposition by the MC3T3-E1 cells was also affected by ECM compliance, leading to the conclusion that altering ECM mechanical properties may influence a variety of MC3T3-E1 cell functions, and perhaps ultimately, their differentiated phenotype.

Assembly of type I collagen: fusion of fibril subunits and the influence of fibril diameter on mechanical properties

2000 ◽  
Vol 19 (5) ◽  
pp. 409-420 ◽  
Author(s):  
David L. Christiansen ◽  
Eric K. Huang ◽  
Frederick H. Silver
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Type I ◽  
Fibril Diameter

scholarly journals Mechanical Properties of Native and Cross-linked Type I Collagen Fibrils

2008 ◽  
Vol 94 (6) ◽  
pp. 2204-2211 ◽  
Author(s):  
Lanti Yang ◽  
Kees O. van der Werf ◽  
Carel F.C. Fitié ◽  
Martin L. Bennink ◽  
Pieter J. Dijkstra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Collagen Fibrils ◽  
Type I

scholarly journals Regenerative Rehabilitation in Injuries of Tendons

2021 ◽  
Vol 3 (2) ◽  
pp. 192-206
Author(s):  
Sergey G. Sсherbak ◽  
Stanislav V. Makarenko ◽  
Olga V. Shneider ◽  
Tatyana A. Kamilova ◽  
Alexander S. Golota
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Healing Process ◽  
Tendon Healing ◽  
Tendon Injuries ◽  
Type I ◽  
Differentiation Markers ◽  
Postoperative Rehabilitation ◽  
Potent Inducer

The mechanical properties of tendons are thought to be affected by different loading levels. Changes in the mechanical properties of tendons, such as stiffness, have been reported to influence the risk of tendon injuries chiefly in athletes and the elderly, thereby affecting motor function execution. Unloading resulted in reduced tendons stiffness, and resistance exercise exercise counteracts this. Transforming growth factor-1 is a potent inducer of type I collagen and mechanosensitive genes encoding tenogenic differentiation markers expression which play critical roles in tendon tissue formation, tendon healing and their adaptation during exercise. In recent years, our understanding of the molecular biology of tendons growth and repair has expanded. It is probable that the next advance in the treatment of tendon injuries will result from the application of this basic science knowledge and the clinical solution will encompass not only the the best postoperative rehabilitation protocols, but also the optimal biological modulation of the healing process.

Application of Tissue Engineering Techniques for Rotator Cuff Regeneration Using a Chitosan-Based Hyaluronan Hybrid Fiber Scaffold

2005 ◽  
Vol 33 (8) ◽  
pp. 1193-1201 ◽  
Author(s):  
Tadanao Funakoshi ◽  
Tokifumi Majima ◽  
Norimasa Iwasaki ◽  
Naoki Suenaga ◽  
Naohiro Sawaguchi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Rotator Cuff ◽  
Mechanical Strength ◽  
Type I Collagen ◽  
Tangent Modulus ◽  
Rotator Cuff Tears ◽  
Type I ◽  
Scaffold Materials ◽  
Novel Scaffold

Background The current surgical procedures for irreparable rotator cuff tears have considerable limitations. Tissue engineering techniques using novel scaffold materials offer potential alternatives for managing these conditions. Hypothesis A chitosan-based hyaluronan hybrid scaffold could enhance type I collagen products with seeded fibroblasts and thereby increase the mechanical strength of regenerated tendon in vivo. Study Design Controlled laboratory study. Methods The scaffolds were created from chitosan-based hyaluronan hybrid polymer fibers. Forty-eight rabbit infraspinatus tendons and their humeral insertions were removed to create defects. Each defect was covered with a fibroblast-seeded scaffold (n = 16) or a non-fibroblast-seeded scaffold (n = 16). In the other 16 shoulders, the rotator cuff defect was left free as the control. At 4 and 12 weeks after surgery, the engineered tendons were assessed by histological, immunohistochemical (n = 2), and biomechanical (n = 6) analyses. Results Type I collagen was only seen in the fibroblast-seeded scaffold and increased in the regenerated tissue. The tensile strength and tangent modulus in the fibroblast-seeded scaffold were significantly improved from 4 to 12 weeks postoperatively. The fibroblast-seeded scaffold had a significantly greater tangent modulus than did the non-fibroblast-seeded scaffold and the control at 12 weeks. Conclusion This scaffold material enhanced the production of type I collagen and led to improved mechanical strength in the regenerated tissues of the rotator cuff in vivo. Clinical Relevance Rotator cuff regeneration is feasible using this tissue engineering technique.

Modifying the Properties of Collagen Scaffolds with Microfluidics

2005 ◽  
Vol 897 ◽  
Author(s):  
David I Shreiber ◽  
Harini G Sundararaghavan ◽  
Minjung Song ◽  
Vikram Munikoti ◽  
Kathryn E Uhrich
Keyword(s):  
Mechanical Properties ◽  
Cell Adhesion ◽  
Cellular Response ◽  
Type I Collagen ◽  
Crosslinking Agent ◽  
Force Balance ◽  
Adherent Cell ◽  
Type I ◽  
Spinal Cord Regeneration ◽  
Collagen Scaffolds

AbstractIt is now well accepted that the mechanical properties and cell adhesion profile of 2D and 3D extracellular matrix molecules combine to dictate cellular fate processes, such as differentiation, migration, proliferation, and apoptosis, through a process generally known as 'mechanotransduction', or the conversion of mechanical signals into a cellular response. The stiffness and adhesion density combine to affect the force balance that exists between an adherent cell and the surrounding substrate. We have established BioMEMS, microfluidic technology to alter the mechanical properties and cell adhesion profile of collagen scaffolds. Using soft lithography, we fabricate elastomeric networks that serve as conduits for the controlled mixing of type I collagen solutions. Our technology enables us to generate reproducible, controlled homogeneous and inhomogeneous microenvironments for 3D cell culture, assays of cell behavior in 3D, and the development of bioartificial tissue equivalents for regenerative and reparative therapies. The adhesivity of collagen is modulated by covalently grafting peptides (such as RGD) or proteins (such as albumin) to soluble collagen molecules with 1- ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC), a hetero-bifunctional coupling agent. EDC activates the carboxylic group of collagen and forms an amine bond with the grafting molecule. The grafted collagen self-assembles into a fibrillar gel at physiological temperature and pH with no measurable changes in rheological properties compared to controls. A solution of peptide-grafted collagen is then mixed in microfluidic networks with unaltered collagen to form controlled gradients or other patterns of the two solutions, which immobilize upon self-assembly. Separately or in the same network, the mechanical properties of the collagen gel can be altered regionally by the microfluidic delivery a solution of a cell-tolerated crosslinking agent. We use genipin, which has the unique property of generating crosslinks that autofluoresce. The intensity of the fluorescence correlates with the degree of crosslinking (and thus the mechanical properties) enabling us to monitor and measure changes in mechanical properties dynamically and non-invasively. Lastly, though it requires constant delivery or recirculation, the same networks can be used to impose gradients of soluble factors, such as growth factors and cytokines. Thus, we have developed a platform to examine the response of cells to simultaneous chemotactic, haptotactic, and durotactic gradients in a 3D environment. We are employing this technology to examine the response of neural cells to gradients of biomaterial properties to optimize cues for spinal cord regeneration.

Mechanics and Cytocompatibility of Genipin Crosslinked Type I Collagen Nanofibrous Scaffolds

2008 ◽  
Author(s):  
Albert O. Gee ◽  
Brendon M. Baker ◽  
Robert L. Mauck
Keyword(s):  
Type I Collagen ◽  
Cell Attachment ◽  
Type I ◽  
Primary Role ◽  
Fiber Reinforced ◽  
Collagen Scaffolds ◽  
Major Drawback ◽  
Aligned Arrays ◽  
Musculoskeletal Tissues ◽  
Nanofibrous Scaffolds

Collagen is a principal constituent of the extracellular matrix (ECM) and as such, defines the microenvironmental milieu in which cells reside. In fiber-reinforced musculoskeletal tissues, collagen fibers are highly organized and generate the direction-dependent mechanical properties critical to the function of these structures. Given its primary role, collagen is particularly attractive for tissue engineering (TE) applications where scaffolds are coupled with cells to repair or regenerate damaged tissues. One method for producing collagen-based scaffolds is through electrospinning. This technique yields nano- to micron-scale fibers similar in diameter to those of the native ECM. Towards engineering orthopaedic tissues, methods have been devised to electrospin fibers into aligned arrays that can recapitulate the anisotropy of fiber-reinforced tissues [1]. While a number of polymers have been electrospun, collagen-based scaffolds are especially promising as they provide a biomimetic interface for cell attachment [2]. Numerous investigators have electrospun collagen [3], one major drawback is their inherent instability in aqueous environments. To address this, various crosslinking agents including glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, and N-hydroxysuccinimide chemistries have been used, but these chemicals often prove cytotoxic or excessively laborious in application [4]. Even with crosslinking, dry as-formed nanofibrous collagen scaffolds with moduli greater than 50MPa diminish by 100-fold with rehydration [5].

Combined Effect of Glycosaminoglycan and Mechanical Stimulation on the In Vitro Biomechanics of Tissue Engineered Tendon Constructs

2007 ◽  
Author(s):  
Kirsten R. C. Kinneberg ◽  
Victor S. Nirmalanandhan ◽  
Heather M. Powell ◽  
Steven T. Boyce ◽  
David L. Butler
Keyword(s):  
Tissue Engineering ◽  
Type I Collagen ◽  
Rabbit Model ◽  
The United States ◽  
Maximum Force ◽  
Attractive Alternative ◽  
Type I ◽  
Post Surgery ◽  
Scaffold Materials

Tissue engineering offers an attractive alternative to direct repair or reconstruction of injuries to tendons, ligaments and capsular structures that represent almost 45% of the 32 million musculoskeletal injuries that occur each year in the United States [1]. Mesenchymal stem cell (MSC)-seeded collagen constructs are currently being used by our group to repair tendon injuries in the rabbit model [2, 3]. Although these cell-assisted repairs exhibit 50% greater maximum force and stiffness at 12 weeks compared to values for natural repair, tissues often lack the maximum force sufficient to resist the peak in vivo forces acting on the repair site [3]. Our laboratory has previously demonstrated that in vitro construct stiffness and repair stiffness at 12 weeks post surgery are positively correlated [4]. Therefore, in an effort to further improve the repair outcome using tissue engineering, we continue our investigation of scaffold materials to create stiffer MSC-collagen constructs. Our group has recently evaluated two scaffold materials, type I collagen sponges fabricated within the Engineered Skin Lab (ESL, Shriners Hospitals for Children) by a freezing and lyophilization process with and without glycosaminoglycan (chondroitin-6-sulfate; GAG) [5] and found the ESL sponges to significantly improve biomechanical properties of the constructs compared to sponges we currently use in the lab (P1076, Kensey Nash Corporation, Exton, PA). This study also demonstrated that GAG significantly upregulates collagen type I, decorin, and fibronectin gene expression (unpublished results).

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