Silk-based multilayered angle-ply annulus fibrosus construct to recapitulate form and function of the intervertebral disc

Recapitulation of the form and function of complex tissue organization using appropriate biomaterials impacts success in tissue engineering endeavors. The annulus fibrosus (AF) represents a complex, multilamellar, hierarchical structure consisting of collagen, proteoglycans, and elastic fibers. To mimic the intricacy of AF anatomy, a silk protein-based multilayered, disc-like angle-ply construct was fabricated, consisting of concentric layers of lamellar sheets. Scanning electron microscopy and fluorescence image analysis revealed cross-aligned and lamellar characteristics of the construct, mimicking the native hierarchical architecture of the AF. Induction of secondary structure in the silk constructs was confirmed by infrared spectroscopy and X-ray diffraction. The constructs showed a compressive modulus of 499.18 ± 86.45 kPa. Constructs seeded with porcine AF cells and human mesenchymal stem cells (hMSCs) showed ∼2.2-fold and ∼1.7-fold increases in proliferation on day 14, respectively, compared with initial seeding. Biochemical analysis, histology, and immunohistochemistry results showed the deposition of AF-specific extracellular matrix (sulfated glycosaminoglycan and collagen type I), indicating a favorable environment for both cell types, which was further validated by the expression of AF tissue-specific genes. The constructs seeded with porcine AF cells showed ∼11-, ∼5.1-, and ∼6.7-fold increases in col Iα 1, sox 9, and aggrecan genes, respectively. The differentiation of hMSCs to AF-like tissue was evident from the enhanced expression of the AF-specific genes. Overall, the constructs supported cell proliferation, differentiation, and ECM deposition resulting in AF-like tissue features based on ECM deposition and morphology, indicating potential for future studies related to intervertebral disc replacement therapy.

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Towards intervertebral disc engineering: Bio-mimetics of form and function of the annulus fibrosus lamellae

Journal of the Mechanical Behavior of Biomedical Materials ◽

10.1016/j.jmbbm.2019.03.023 ◽

2019 ◽

Vol 94 ◽

pp. 298-307 ◽

Cited By ~ 3

Author(s):

Mirit Sharabi ◽

Shir Wertheimer ◽

Kelly R. Wade ◽

Fabio Galbusera ◽

Dafna Benayahu ◽

...

Keyword(s):

Intervertebral Disc ◽

Annulus Fibrosus ◽

Form And Function ◽

And Function

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Form and function of the intervertebral disc in health and disease: a morphological and stain comparison study

Journal of Anatomy ◽

10.1111/joa.12258 ◽

2014 ◽

Vol 227 (6) ◽

pp. 707-716 ◽

Cited By ~ 21

Author(s):

B. A. Walter ◽

O. M. Torre ◽

D. Laudier ◽

T. P. Naidich ◽

A. C. Hecht ◽

...

Keyword(s):

Intervertebral Disc ◽

Comparison Study ◽

Form And Function ◽

Health And Disease ◽

And Function

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Elastic fibers in orthopedics: Form and function in tendons and ligaments, clinical implications, and future directions

Journal of Orthopaedic Research® ◽

10.1002/jor.24695 ◽

2020 ◽

Vol 38 (11) ◽

pp. 2305-2317 ◽

Cited By ~ 1

Author(s):

Jeffrey Ryan Hill ◽

Jeremy D. Eekhoff ◽

Robert H. Brophy ◽

Spencer P. Lake

Keyword(s):

Elastic Fibers ◽

Clinical Implications ◽

Future Directions ◽

Form And Function ◽

And Function

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Orchestrated biomechanical, structural, and biochemical stimuli for engineering anisotropic meniscus

Science Translational Medicine ◽

10.1126/scitranslmed.aao0750 ◽

2019 ◽

Vol 11 (487) ◽

pp. eaao0750 ◽

Cited By ~ 12

Author(s):

Zheng-Zheng Zhang ◽

You-Rong Chen ◽

Shao-Jie Wang ◽

Feng Zhao ◽

Xiao-Gang Wang ◽

...

Keyword(s):

Rabbit Model ◽

Proper Function ◽

Type I ◽

Specific Expression ◽

Tissue Organization ◽

Meniscus Tissue ◽

Biomimetic Scaffold ◽

And Function

Reconstruction of the anisotropic structure and proper function of the knee meniscus remains an important challenge to overcome, because the complexity of the zonal tissue organization in the meniscus has important roles in load bearing and shock absorption. Current tissue engineering solutions for meniscus reconstruction have failed to achieve and maintain the proper function in vivo because they have generated homogeneous tissues, leading to long-term joint degeneration. To address this challenge, we applied biomechanical and biochemical stimuli to mesenchymal stem cells seeded into a biomimetic scaffold to induce spatial regulation of fibrochondrocyte differentiation, resulting in physiological anisotropy in the engineered meniscus. Using a customized dynamic tension-compression loading system in conjunction with two growth factors, we induced zonal, layer-specific expression of type I and type II collagens with similar structure and function to those present in the native meniscus tissue. Engineered meniscus demonstrated long-term chondroprotection of the knee joint in a rabbit model. This study simultaneously applied biomechanical, biochemical, and structural cues to achieve anisotropic reconstruction of the meniscus, demonstrating the utility of anisotropic engineered meniscus for long-term knee chondroprotection in vivo.

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Chondrogenic differentiation of human mesenchymal stem cells in collagen type I hydrogels

Journal of Biomedical Materials Research Part A ◽

10.1002/jbm.a.31254 ◽

2007 ◽

Vol 83A (3) ◽

pp. 626-635 ◽

Cited By ~ 115

Author(s):

Ulrich Nöth ◽

Lars Rackwitz ◽

Andrea Heymer ◽

Meike Weber ◽

Bernd Baumann ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Chondrogenic Differentiation ◽

Collagen Type ◽

Human Mesenchymal Stem Cells ◽

Collagen Type I ◽

Type I

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Wound-healing effects of human dermal components with gelatin dressing

Journal of Biomaterials Applications ◽

10.1177/0885328217741758 ◽

2017 ◽

Vol 32 (6) ◽

pp. 716-724 ◽

Cited By ~ 17

Author(s):

Hyun-Jun Jang ◽

Yu-mi Kim ◽

Bo-Young Yoo ◽

Young-Kwon Seo

Keyword(s):

Wound Healing ◽

Normal Skin ◽

Treated Group ◽

Collagen Type I ◽

Skin Wound ◽

Blue Staining ◽

Elastic Fibers ◽

Type I ◽

Initial Area

There have been numerous investigations regarding various types of dressings and artificial dermis of solid form, yet limited research and development on paste types, such as hydrogels with dermal powder, have ensued. In this study, we compared the in vivo wound healing effects of gelatin paste containing dermal powder to a collagen type I/chondroitin 6-sulfate (coll/chondroitin) sponge and gelatin alone, after 48 days post grafting, in a skin wound rat model. In the dermis powder/gelatin paste-treated group, wound area contraction was minimized 50%, while in the gelatin and coll/chondroitin sponge groups, the initial area contracted 83–85% and 79–85%, respectively. Histological analysis revealed the wounds treated with dermal powder/gelatin were associated with many fibroblasts, which infiltrated the wound bed, as well as thick collagen bundles that were arranged in dendritic arrays, resembling normal skin. Furthermore, in contrast to the gelatin- and coll/chondroitin sponge-treated groups, the powder/gelatin paste-treated wounds exhibited an abundance of elastic fibers (Victoria blue staining) and extensive formation of blood vessels around the dermis (CD31 staining). Therefore, the dermis powder/gelatin paste not only renders convenience to users but also has prominent wound-healing effects on full-thickness wounds.

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Collagen type I 1 Sp1 polymorphism, osteoporosis, and intervertebral disc degeneration in older men and women

Annals of the Rheumatic Diseases ◽

10.1136/ard.2002.002287 ◽

2004 ◽

Vol 63 (1) ◽

pp. 71-77 ◽

Cited By ~ 67

Author(s):

S M F Pluijm

Keyword(s):

Intervertebral Disc ◽

Disc Degeneration ◽

Intervertebral Disc Degeneration ◽

Collagen Type ◽

Older Men ◽

Collagen Type I ◽

Type I ◽

Men And Women ◽

Older Men And Women

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Mesenchymal Stem Cell Seeded Nanofibrous Laminates Mimic the Multi-Scale Form and Function of the Annulus Fibrosus

ASME 2009 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2009-206812 ◽

2009 ◽

Author(s):

Nandan K. Nerurkar ◽

Sounok Sen ◽

Emily E. Wible ◽

Jeffrey B. Stambough ◽

Dawn M. Elliott ◽

...

Keyword(s):

Annulus Fibrosus ◽

Form And Function ◽

Multi Scale ◽

Aligned Arrays ◽

Tensile Response ◽

Nanofibrous Scaffolds ◽

Multiple Length Scales ◽

Spine Function ◽

And Function ◽

High Degree

The annulus fibrosus (AF) of the intervertebral disc is a multi-lamellar fibrocartilage that, together with the nucleus pulposus, confers mechanical support and flexibility to the spine. Function of the AF is predicated on a high degree of structural organization over multiple length scales: aligned collagen fibers reside within each lamella, and the direction of alignment alternates between adjacent lamellae from +30° to −30° with respect to the transverse axis of the spine. Electrospinning permits fabrication of scaffolds consisting of aligned arrays of nanofibers, and has proven effective for directing the alignment of both cells and extracellular matrix (ECM) deposition [1–3]. We recently employed electrospinning to engineer the primary functional unit of the AF, a single lamella [4]. However, it remains a challenge to engineer a multi-lamellar tissue that replicates the cross-ply fiber architecture of the native AF. Moreover, relatively few studies have considered functional properties of engineered AF, and, when measured, tensile properties of these constructs have been inferior to native AF [4]. In this study, mesenchymal stem cells (MSCs) were seeded onto aligned nanofibrous scaffolds organized into bi-lamellar constructs with opposing or parallel fiber orientations, and their functional maturation was evaluated with time. Additionally, we determined a novel role for inter-lamellar ECM in reinforcing the tensile response of bilayers, and confirmed this mechanism by testing acellular bilayers with controllable interface properties.

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