• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.6
• /
• pp.619-628
• /
• 2011

Human soft tissues, including muscles, ligaments, skin, and blood vessels, are an interesting subject because damage to them can be observed in everyday life. Besides the lack of available experimental data and the large deformation upon loading, the anisotropic and compressible nature of annulus fibrosus makes it more difficult to find a simple material model. A fiber-reinforced hyperelastic material model is used to determine the stress-strain curves upon uniaxial loading. The energy potential function for annulus fibrosus is composed of three different parts: matrix, fibers, and matrix-fiber interaction, which accounts for the angles between two families of fibers. In this paper, two different types of energy potential function for the matrix are considered, and are inserted into the fiber-reinforced model. The calculated results are compared with the Neo-Hookean model and experimental data, and reasonable agreement is observed overall.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.45-46
• /
• 2009

• Journal of the Korean Orthopaedic Association
• /
• v.56 no.4
• /
• pp.283-293
• /
• 2021

Degenerative disc disease has traditionally been thought of as low back pain caused by changes in the nucleus pulposus and annulus fibrous, in recent studies, however, changes in the upper and lower endplates cause degeneration of the disc, resulting in mechanical pressure, inflammatory reactions and low back pain. Recently, the bone marrow of the vertebral body-endplate-nucleus pulposus and annulus fibrous were considered as a single unit, and the relationship was explained. Once the endplate is damaged, it eventually aggravates the degeneration of the bone marrow, nucleus pulposus, and annulus fibrosus. In this process, the compression force of the annulus fibrosus increases, and an inflammatory reaction occurs due to inflammatory mediators. Hence, the sinuvertebral nerves and the basivertebral nerves are stimulated to cause back pain. If these changes become chronic, degenerative changes such as Modic changes occur in the bone marrow in the vertebrae. Finally, in the case of degenerative intervertebral disc disease, the bone marrow of the vertebral body-endplate-nucleus pulposus and annulus fibrous need to be considered as a single unit. Therefore, when treating patients with chronic low back pain, it is necessary to consider the changes in the nucleus pulposus and annulus fibrosus and a lesion of the endplate.

• Journal of Korean Neurosurgical Society
• /
• v.48 no.1
• /
• pp.1-7
• /
• 2010

Objective : Notochordal cells in the intervertebral disc interact with nucleus pulposus (NP) cells and support the maintenance of disc homeostasis by regulation of matrix production. However, the influence of notochordal cells has not been evaluated in the annulus fibrosus (AF), which is the primary pain generator in the disc. We hypothesized that the notochordal cell has the capacity to modulate inflammatory mediators secreted by AF cells secondary to stimulation. Methods : Notochordal and AF cells were isolated from adult New Zealand white rabbits. AF pellets were cultured with notochordal cell clusters or in notochordal cell-conditioned media (NCCM) for 24 or 48 hours with proinflammatory cytokines at varying concentrations. Gene expression in AF pellets were assayed for nitric oxide synthase (iNOS), cyclo-oxygenase (COX)-2, and interleukin (IL)-6 by real time reverse transcriptase polymerase chain reaction (RT-PCR). Results : AF pellet in NCCM significantly decreased the iNOS and COX-2 messenger ribonucleic acid (mRNA) levels compared to AF pellets alone and AF pellets with notochordal cells (p < 0.05). AF pellet resulted in dose-dependent iNOS and COX-2 expression in response to IL-$1{\beta}$, stimulation, demonstrating that 1 ng/ml for 24 hours yielded a maximal response. AF pellet in NCCM significantly decreased the expression of iNOS and COX-2 in response to 1ng/ml IL-$1{\beta}$, stimulation at 24 hours (p < 0.05). There was no difference in IL-6 expression compared to AF pellets alone or AF pellets with notochordal cell clusters. Conclusion : We conclude that soluble factors from notochordal cells mitigate the gene expression of inflammatory mediators in stimulated AF, as expected after annular injury, suggesting that notochordal cells could serve as a novel therapeutic approach in symptomatic disc development.

• Polymer(Korea)
• /
• v.34 no.3
• /
• pp.282-288
• /
• 2010

The porcine small intestinal submucosa (SIS) has been widely used as a biomaterial without immuno rejection responses and hyalunonic acid (HA) can be used as biocompatible materials to regenerate tissue. We developed the SIS sponge and HA loaded SIS sponges (SIS/HA) for the possibility of the application of the tissue engineering using annulus fibrosus (AF). SEM observation shows that SIS and SIS/HA sponges have interconnected and open pores. We demonstrated the presence of HA in SIS/HA sponge from C-O functional group observed by the FTIR analysis. In conclusion, we suggest that SIS/HA sponge may be useful to tissue engineering using AF cell. This may be due to the enhanced biocompatibility and higher water retention capacity of HA.

• Polymer(Korea)
• /
• v.32 no.1
• /
• pp.26-30
• /
• 2008

This study was designed to investigate the effect of hybridization of synthetic/natural materials for annulus fibrosus (AF) tissue regeneration in vitro and in vivo. The synthetic/natural hybrid scaffolds were prepared using PLGA (poly (lactic-co-glycolic) acid), SIS (small intestinal submucosa) and DBP (demineralized bone particles). PLGA, PLGA/SIS(20%), PLGA/DBP(20%) and PLGA/SIS (10%)/DBP (10%) scaffold were manufactured by solvent casting/salt leaching method. Compressive strength was measured. Rabbit AF cells were isolated, cultured and seeded into experimental groups. Hydroxyproline production and DNA quantity of AP cells on each scaffold was measured at 2, 4 and 6 weeks after in vitro culture. Cell-scaffold composites were implanted subcutaneously into athymic mice. After 1,4 and 6 weeks postoperatively, specimens were taken and H&E, Safranin-O and type I collagen staining were carried out concerning formation of cartilagenous tissue. In vitro PLGA/SIS scaffold was evaluated for total collagen content (bydroryproline/DNA content) and PLGA scaffold was evaluated for compressive strength.

• Journal of Biomedical Engineering Research
• /
• v.39 no.1
• /
• pp.22-29
• /
• 2018

Intervertebral disc(IVD) mainly consists of Annulus fibrosus(AF) and Nucleus pulposus(NP), playing a role of distributing a mechanical load on vertebral body. IVD tissue engineering has been developed the methods to achieve anatomic morphology and restoration of biological function. The goal of present study is to identify the possibilities for creating a substitute of IVD the morphology and biological functions are the same as undamaged complete IVD. To fabricate the AF and NP combine biphasic IVD tissue, AF tissue scaffolds have been printed by 3D bio-printing system with natural biomaterials and NP tissues have been prepared by scaffold-free culture system. We evaluated whether the combined structure of 3D printed AF scaffold and scaffold-free NP tissue construct could support the architecture and cell functions as IVD tissue. 3D printed AF scaffolds were printed with 60 degree angle stripe patterned lamella structure(the inner-diameter is 5mm, outer-diameter is 10 mm and height is 3 mm). In the cytotoxicity test, the 3D printed AF scaffold showed good cell compatibility. The results of histological and immunohistochemical staining also showed the newly synthesized collagens and glycosaminoglycans, which are specific makers of AF tissue. And scaffold-free NP tissue actively synthesized glycosaminoglycans and type 2 collagen, which are the major components of NP tissue. When we combined two engineered tissues to realize the IVD, combined biphasic tissues showed a good integration between the two tissues. In conclusion, this study describes the fabrication of Engineered biphasic IVD tissue by using enable techniques of tissue engineering. This fabricated biphasic tissue would be used as a model system for the study of the native IVD tissue. In the future, it may have the potential to replace the damaged IVD in the future.

• Journal of Korean Neurosurgical Society
• /
• v.65 no.2
• /
• pp.186-195
• /
• 2022

Objective : To explore the histological feature of the cervical disc degeneration in patients with degenerative ossification (DO) and its potential mechanisms. Methods : A total of 96 surgical segments, from cervical disc degenerative disease patients with surgical treatment, were divided into ossification group (group O, n=46) and non-ossification group (group NO, n=50) based on preoperative radiological exams. Samples of disc tissues and osteophytes were harvested during the decompression operation. The hematoxylin-eosin staining, Masson trichrome staining and Safranin O-fast green staining were used to compare the histological differences between the two groups. And the distribution and content of transforming growth factor (TGF)-β1, p-Smad2 and p-Smad3 between the two groups were compared by a semi-quantitative immunohistochemistry (IHC) method. Results : For all the disc tissues, the content of disc cells and collagen fibers decreased gradually from the outer annulus fibrosus (OAF) to the central nucleus pulposus (NP). Compared with group NO, the number of disc cells in group O increased significantly. But for proteoglycan in the inner annulus fibrosus (IAF) and NP, the content in group O decreased significantly. IHC analysis showed that TGF-β1, p-Smad2, and p-Smad3 were detected in all tissues. For group O, the content of TGF-β1 in the OAF and NP was significantly higher than that in group NO. For p-Smad2 in IAF and p-Smad3 in OAF, the content in group O were significantly higher than group NO. Conclusion : Histologically, cervical disc degeneration in patients with DO is more severe than that without DO. Local higher content of TGF-β1, p-Smad2, and p-Smad3 are involved in the disc degeneration with DO. Further studies with multi-approach analyses are needed to better understand the role of TGF-β/Smads signaling pathway in the disc degeneration with DO.

• Archives of Orthopedic and Sports Physical Therapy
• /
• v.14 no.2
• /
• pp.73-80
• /
• 2018

Purpose: This study was evaluated the effects of nucleoplasty and chemonucleolysis, as interventional treatments for herniated intervertebral disc disease, on spinal tissues. Methods: Nucleoplasty using plasma beam and chemonucleolysis with collagenase were conducted on the spinal motion segments that were dissected from of human cadaver spine under fluoroscopic guidance. After the procedure, the intervertebral discs were transected, and the changes in gross findings were examined. Subsequently, the influence of the procedure on the nucleus pulposus, annuls fibrosus, and endplate was analyzed through a pathologic examination. Results: Nucleoplasty was confirmed to eliminate the local range of tissues in nucleus pulposus according to the procedure tract and to not affect other tissues. In chemonucleolysis, we found that collagenase diffused from the surgical site within the nucleus pulposus and was not present in the annulus fibrosus and endplate. Conclusions: The clinically-used interventional treatments that were investigated here were not found to do not cause additional damage to areas other than those targeted.

• Journal of Korean Neurosurgical Society
• /
• v.47 no.3
• /
• pp.224-227
• /
• 2010

Small bowel injury resulting from unforeseen penetration of the anterior annulus fibrosus and longitudinal ligament is a rare complication of lumbar microdiscectomy. The patient complained of abdominal tenderness and distention immediately after microdiscectomy for L4-5 and L5-S1 disc herniation. Using abdominal computed tomography, we found several foci of air overlying the anterior aspect of the vertebral body at the L5-S1 level. Segmental resection of the small bowel including small tears and primary anastomosis of the jejunum were performed. Here, we present a case of intestinal perforation after lumbar microdiscectomy and discuss technical methods to prevent this complication with a review of literature.