scholarly journals Multi-laminate Annulus Fibrosus Repair Scaffold with an Interlamellar Matrix Enhances Impact Resistance, Prevents Herniation and Assists in Restoring Spinal Kinematics

2018 ◽  
Author(s):  
Ryan Borem ◽  
Allison Madeline ◽  
Ricardo Vela ◽  
Sanjitpal Gill ◽  
Jeremy Mercuri

AbstractFocal defects in the annulus fibrosus (AF) of the intervertebral disc (IVD) from herniation or surgical injury have detrimental impacts on IVD mechanical function. Thus, biomaterial-based repair strategies, which can restore the mechanical integrity of the AF and support long-term tissue regeneration are needed. Accordingly, a collagen-based multi-laminate scaffold with an underlying “angle-ply” architecture has been previously reported demonstrating similar mechanical properties to native AF tissue. The objectives of this work were to: 1) enhance the biomaterials impact strength, 2) define its contribution to spinal kinematics, and 3) assess its ability to prevent IVD herniation. First, AFRP’s were enriched with a glycosaminoglycan-based (GAG) interlamellar matrix (ILM), and then tested for its radially-directed impact resistance under physiological stresses. Subsequent kinematic testing was conducted using a characterized GAG-enriched AFRP as an AF focal defect closure device. In summary, AFRPs demonstrated 1) incorporation of a GAG-based ILM significantly increased radial impact strength, 2) restoration of axial FSU kinematics and 3) ability to prevent herniation of native IVD tissues. Together, these results suggest that the AFRP demonstrates the mechanical robustness and material properties to restore an IVD’s physiological mechanical function through the adequate closure of an AF focal defect.

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 700 ◽  
Author(s):  
Alyah H. Shamsah ◽  
Sarah H. Cartmell ◽  
Stephen M. Richardson ◽  
Lucy A. Bosworth

The annulus fibrosus—one of the two tissues comprising the intervertebral disc—is susceptible to injury and disease, leading to chronic pain and rupture. A synthetic, biodegradable material could provide a suitable scaffold that alleviates this pain and supports repair through tissue regeneration. The transfer of properties, particularly biomechanical, from scaffold to new tissue is essential and should occur at the same rate to prevent graft failure post-implantation. This study outlines the effect of hydrolytic degradation on the material properties of a novel blend of polycaprolactone and poly(lactic acid) electrospun nanofibers (50:50) over a six-month period following storage in phosphate buffered saline solution at 37 °C. As expected, the molecular weight distribution for this blend decreased over the 180-day period. This was in line with significant changes to fiber morphology, which appeared swollen and merged following observation using Scanning Electron Microscopy. Similarly, hydrolysis resulted in considerable remodeling of the scaffolds’ polymer chains as demonstrated by sharp increases in percentage crystallinity and tensile properties becoming stiffer, stronger and more brittle over time. These mechanical data remained within the range reported for human annulus fibrosus tissue and their long-term efficacy further supports this novel blend as a potential scaffold to support tissue regeneration.


Author(s):  
C. Houseman ◽  
M. Scro ◽  
S. Belverud ◽  
D. Chen ◽  
P. Razzano ◽  
...  

Intervertebral disc (IVD) degeneration typically involves changes in the multiple constitutive tissues of the IVD. Many tissue repair efforts have focused on the use of differentiated disc cells or stem cells for the regeneration of an IVD in vitro. Consequently, successful long term culture of human disc cells is pivotal for tissue regeneration of the IVD. The aim of this study is to establish a long-term in vitro culture system for the growth of disc cells that maintain their phenotype based on the anatomical origin (annulus fibrosus (AF), nucleus pulposus (NP), or the vertebral end-plates (EP)). This maintenance of phenotype is crucial for examination of treatment efficacy, which is typically designed to induce regeneration of a single tissue type (i.e. injection of growth factors into the NP or anti-inflammatory treatment of the EPs).


2020 ◽  
Vol 06 ◽  
Author(s):  
Sayed Md Mumtaz ◽  
Madhu Gupta ◽  
Ramesh K. Goyal

Abstract:: The placenta that maintains and regulates the growth of fetus, consists of various biological treasures nutrients such as cytomedines, vitamins, trace elements, amino acids, peptides, growth factors and other biologically active constituents. Their therapeutic usefulness can well define in the terms of biochemical mechanisms of various components present in it. Biomedical waste derived extract is also a panacea for treatment of various diseases. Placental therapy has been reported specifically to have potent action on recovery of diseases and tissue regeneration. Placental bioactive components and their multi targeting identity prompted us to compile the précised information on placental extract products. However, some findings are needed to be explored by scientific community to prove their clinical potential with clinically significant statistical conclusions. In the light of available information and the usefulness of the placental extract, it is necessary for the development of various formulations for various unmet meet for the treatment as well as access their adverse effects as well as contradictions and precisely evaluated in the short and in the long-term periods.


2021 ◽  
pp. 096739112110093
Author(s):  
RM Abhilash ◽  
GS Venkatesh ◽  
Shakti Singh Chauhan

Reinforcing thermoplastic polymers with natural fibres tends to improve tensile and flexural strength but adversely affect elongation and impact strength. This limits the application of such composites where toughness is a major criterion. In the present work, bamboo fibre reinforced polypropylene (PP) composites were prepared with bamboo fibre content varying from 30% to 50% with improved impact resistance. Homopolymer and copolymer PP were used as the matrix polymer and an elastomer was used (10% by wt.) as an additive in the formulation. Copolymer based composites exhibited superior elongation and impact strength as compared to homopolymer based composites. The adverse impact of elastomer on tensile and flexural strength was more pronounced in homopolymer based composites. The study suggested that the properties of the bamboo composites can be tailored to suit different applications by varying reinforcement and elastomer percentage.


Author(s):  
John McMorran ◽  
Diane Gregory

Abstract In light of the correlation between chronic back pain and intervertebral disc degeneration, this literature review seeks to illustrate the importance of the hydraulic response across the nucleus pulposus- annulus fibrosus interface, by synthesizing current information regarding injurious biomechanics of the spine, stemming from axial compression. Damage to vertebrae, endplates, the nucleus pulposus, and the annulus fibrosus, can all arise from axial compression, depending on the segment's posture, the manner in which it is loaded, and the physiological state of tissue. Therefore, this movement pattern was selected to illustrate the importance of the bracing effect of a pressurized nucleus pulposus on the annulus fibrosus, and how injuries interrupting support to the annulus fibrosus may contribute to intervertebral disc degeneration.


1993 ◽  
Vol 2 (3) ◽  
pp. 126-131 ◽  
Author(s):  
K. Puustj�rvi ◽  
T. Takala ◽  
W. Wang ◽  
M. Tammi ◽  
H. J. Helminen ◽  
...  

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