Biomimetic method for combining the nucleus pulposus and annulus fibrosus for intervertebral disc tissue engineering

Tissue engineering strategies for the intervertebral disc (IVD) have traditionally focused either on the annulus fibrosus (AF) or the nucleus pulposus (NP) in isolation, or have simply compared AF cells and NP cells in identical culture conditions. Recently, others in the field have become aware of the advantage of combining the AF and NP into a more comprehensive strategy to address IVD tissue engineering, and have introduced biomimetic approaches to either AF or NP tissue engineering. Here, we introduced a new method for developing a biomimetic, cell-seeded IVD by electrospinning circumferentially-orientated polycaprolactone fibres (AF analogue), seeding them with cells (porcine chondrocytes) and then gelling a cell-agarose solution in the centre (NP analogue). Scanning electron microscopy images demonstrated a high degree of fibre alignment and, along with fluorescent actin staining, confirmed a preferred orientation of cells in the direction of the fibres. Viability assays and histology collectively demonstrated that cells were viable and well-distributed around the interface between the NP and AF regions. In addition, mechanical testing confirmed that the composite IVD scaffolds had higher moduli than the agarose hydrogels alone. As we enter the new decade and the fields of AF and NP tissue engineering begin to merge into a new interfacial and functional IVD tissue-engineering field, approaches such as the method presented here will serve as the foundation for continuously advancing technology that we ultimately endeavour to bring to the clinic for the treatment of patients severely afflicted by degenerative disc disease.     

聚乳酸乙醇酸共聚物与纳米羟基磷灰石共混制备组织工程纤维环支架的实验研究

目的探讨以聚乳酸乙醇酸共聚物(poly(lactic-co-glycolic acid),PLGA)与纳米羟基磷灰石(hydroxyapa-tite,HA)为原料,利用静电纺丝的技术制备出的三维多孔支架构建组织工程纤维环的可行性。方法将PLGA与HA溶解于丙酮中,配制20%(w/v)的溶液,磁力搅拌均匀后,进行静电纺丝,制备三维多孔支架。支架通过扫描电镜和磷酸盐缓冲液降解(phosphate buffered saline,PBS)的方式,观察支架的形貌和降解性能;利用CCK-8和伊红染色的方法观察支架的生物相容性。结果支架具有良好的纤维形貌,直径均匀,扫描电镜下可见HA结晶。支架在磷酸盐缓冲液中降解速度较快,8周时支架失重可达40%,表现出良好的降解性能。细胞毒性试验和伊红染色均表明细胞在支架上的生长情况较好,支架具有良好的生物相容性。结论 PLGA与HA共混制备的纳米纤维支架具有良好的空间结构和生物相容性,因此该支架是一种良好的组织工程纤维环支架材料。     

颈椎关节突关节矢状角不对称对颈椎间盘纤维环应力影响的三维有限元研究

目的:利用有限元技术探究颈椎关节突关节矢状角不对称对颈椎间盘纤维环和关节突关节的应力影响.方法:选择一名26岁健康女性志愿者的颈椎CT扫描数据构建颈椎有限元模型.首先,构建C3-C7的颈椎正常模型,该模型通过先前发表的研究数据进行了验证.其次,提取C5-C6的数据,并改变C5-C6关节突关节矢状角的角度以重新构建实验模...     

腰椎4、5间盘纤维环纤维层力学性能的实验研究

测试成人腰椎间盘纤维环纤维层的力学性能。用显微外科技术将纤维环逐层分离,每层纤维平均分成8个测点,每层每测点处按纤维走向切取5个试件,长度l=15~20mm,宽b=1~1.5mm,厚t=0.1~0.5mm。进行拉伸实验测得应力-应变曲线,并给出拟合曲线及方程,得出弹性模量、破坏应变、破坏应力、测点处的力学性能参数和方程。测试结果表明:各测点处,沿径向,由外向内弹性模量皆随层数的增加,不断变小;每层纤维弹性模量由前侧向后侧逐渐变小;破坏应力由外层向内层线性递减;破坏应变外部9层随层数增加略有提高,9层以后基本上为一常数(0.34±0.14)。可见,腰椎间盘纤维环纤维具有特殊的力学性能,与其功能相适应,与腰椎疾病的发生有密切的关系。     

桂枝加葛根汤对椎间盘纤维环细胞蛋白多糖表达的影响

目的:探讨颈椎病的发病机制及桂枝加葛根汤防治该病的作用机制。方法:采用自制桂枝加葛根汤大鼠含药血清,对培养的椎间盘纤维环细胞进行不同浓度的药物干预,利用荧光定量PCR检测椎间盘纤维环中主要蛋白多糖Aggrecan mRNA的表达变化情况。结果:中、高剂量组Aggrecan mRNA表达的Ct值明显高于空白组(P<0.05),低剂量组Ct值与空白组比较无明显差异,而高剂量组Ct值明显高于中剂量组(P<0.05)。结论:中、高剂量组桂枝加葛根汤大鼠含药血清能增强纤维环细胞Aggrecan mRNA的表达,高剂量组效果最为明显。桂枝加葛根汤从转录水平上影响纤维环细胞蛋白多糖的产生。     

循环牵张应力对人退变纤维环细胞增殖的影响

目的 探讨不同水平循环牵张应力对人退变椎间盘细胞增殖的影响.方法 取1例29岁手术切除的腰椎间盘突出患者的椎间盘,通过病理学方法评价其退变程度,酶消化法分离椎间盘纤维环细胞.选取P3代细胞,利用ElectroForce 3200力学试验仪搭载的BioDynamic生物反应舱系统,以3h为固定时间点对其进行不同水平的频率...     

新型组织工程椎间盘纤维环支架的制备与性能检测****

摘要 背景：以组织工程技术修复退变椎间盘,目前的研究多集中在如何修复摘除的髓核组织,然而髓核组织工程方法无法完整重建椎间盘的结构和功能,所以相应的纤维环组织工程被认为是组织工程椎间盘治疗策略的主要限制因素之一。 目的：制备天然猪脱细胞脱钙骨基质明胶,并验证其作为组织工程椎间盘纤维支架的可行性。 方法：取猪股骨近端松质骨,用环钻钻取直径10 mm、内径5 mm、厚3 mm的中空环状骨,高压水枪冲洗,进行脱脂、脱钙、脱细胞等相关处理,制成环状的支架材料。对材料进行大体、组织学、光镜、扫描电镜观察,并对支架的吸水率、孔隙率、生物力学参数等进行检测。分离培养犬骨髓间充质干细胞,采用MTT法分析支架浸提液毒性。 结果与结论：支架为乳白色,中空环状,质地柔软的多孔结构。苏木精-伊红染色示组织无细胞结构残留。光镜及扫描电镜示支架孔隙均匀,孔隙相通,平均孔径为(401.4±13.1) μm,孔隙率为(62.12±1.52)%,吸水率为(409.77±11.34)%。生物力学结果示支架的弹性模量为(47.75±6.32) kPa。MTT法显示不同浓度支架浸提液与对照 DMEM 培养液吸光度值比较,差异无显著性意义(P > 0.05),支架无细胞毒性。提示猪脱细胞脱钙骨基质明胶去细胞彻底,具有良好的孔径、孔隙率及生物力学强度,并且无毒,具备良好的生物相容性,可作为组织工程椎间盘纤维环支架材料。 关键词：纤维环;支架;脱钙骨基质明胶;生物相容性;组织工程 doi:10.3969/j.issn.1673-8225.2011.03.005     

芍药苷促椎间盘纤维环细胞增殖的作用

背景：芍药在颈椎病治疗中使用频率超过30%,其主要单体之一芍药苷具有抗炎、抗凋亡等作用,芍药苷对椎间盘纤维环细胞是否有保护作用,国内外未见报道。 目的：探讨芍药苷对椎间盘纤维环细胞的增殖和保护作用。 方法：采用酶消化法体外培养椎间盘纤维环细胞。取第3代纤维环细胞,培养过程中加入20 μg/L Fas配体诱导建立纤维环细胞凋亡模型,通过MTT法测定芍药苷干预纤维环细胞的最适宜浓度,Annexin V/FITC-PI法观察芍药苷对椎间盘纤维环细胞的保护作用。 结果与结论：芍药苷浓度20.8和2.08 μmol/L对椎间盘纤维环细胞具有明显的促增殖作用。20 μg/L Fas配体能诱导细胞凋亡,20.8 μmol/L芍药苷对Fas配体诱导椎间盘纤维环细胞有保护作用。     

Mort criminelle par arme blanche dans la région de Kairouan,Tunisie : Etude rétrospective 2008-2018

Introduction: Homicides by stabbing are the most common forensic form of criminal death in Tunisia. These homicides represent a type of violent death that requires investigation in a forensic setting. Aim: To describe the epidemiological and forensic profile of stab wounds in the region of Kairouan, Tunisia Methods: We conducted a retrospective study of stab-wounds autopsy cases collected at the Forensic Department at the Ibn El Jazzar University Hospital in Kairouan over eleven years (01/01/2008 to 31/12/2018). Results: Forty-seven cases of homicide were retained. A male predominance was observed with a sex ratio of 22 (45H/2F, 96%). The mean age of the victims was 33.3±10.84 with ages ranging from 12 to 63 years. Most victims (79%) were of rural origin, singles (62%), and daily-laborers (89%). The months that recorded the highest numbers of homicides were November and August. The most common reason for the assault was a settling-score on the street. The perpetrator was known by the victim in 90% of cases, having used a knife as a weapon in 90% of cases. The thorax was the most frequently affected area, resulting in fatal heart wounds in 28 cases. Conclusion: Autopsy remains an essential tool for drawing up a detailed injury assessment in homicides by stabbing and determining the injury mechanism of the wounds. The comparison of the autopsy findings with the data of the judicial investigation is of great help in the legal qualification of the facts and the determination of the responsibility of the aggressors.