Intervertebral disc degeneration is a multifactorial pathological process which is one of the leading causes of disability worldwide. The main pathological changes of intervertebral disc degeneration are the degradation of extracellular matrix, apoptosis, autophagy, senescence and inflammation. Dysregulation of microRNAs has been implicated in various pathologies, including various degenerative diseases such as disc degeneration. This article reviews the research status of microRNA in degenerative disc pathology, with emphasis on the biological mechanisms and potential therapeutic prospects of microRNA in extracellular matrix degradation, apoptosis, inflammation, and cartilage endplate degeneration.
Degenerative disc disease is a prevalent chronic disease that orthopaedic surgeons currently face as a difficulty. Tissue engineering represents the most promising possible therapeutic strategy for disc repair and regeneration. Surgery is the primary treatment for degenerative disc disease, but there are still inherent limits in practical practice. Electrospinning technique is a method for manufacturing nanoscale fibers with varied mechanical properties, porosity, and orientation, which can imitate the structural qualities and mechanical properties of natural intervertebral discs. Therefore, electrospinning materials can be utilized for disc regeneration and replacement. This article reviews recent advancements in disc tissue engineering and electrostatically spun nanomaterials typically utilized for the fabrication of disc scaffolds, as well as present and future techniques that may enhance the performance of electrostatically spun fibers.
Objective To investigate the effect of local injection of curcumin-loaded mesoporous silica nanoparticles (Cur@MSN) on the repair and treatment of degenerative intervertebral disc tissue in rats, and provide a new strategy for the treatment of intervertebral disc degeneration. Methods Mesoporous silica nanoparticles (MSN) and Cur@MSN were prepared according to the method reported in the literature. Rat nucleus pulposus cells were co-cultured with curcumin and Cur@MSN, respectively, and the growth status and activity of cells in normal environment and inflammatory environment (adding lipopolysaccharide) were observed respectively. Twelve 8-week-old SD rats were randomly divided into 4 groups, including normal group, degeneration group, curcumin group, and Cur@MSN group, with 3 rats in each group. Acupuncture degeneration model was established in coccygeal intervertebral discs (Co7-8, Co8-9) of rats, and corresponding intervention were injected. Imaging, gross pathology, and histological examination were performed after 4 weeks, respectively, to observe the tissue structure and pathological changes of intervertebral discs. Results Under scanning electron microscope, Cur@MSN was spherical in shape, with groove-like pores on its surface. Particle size analysis showed that the particle size of MSN was concentrated in 120-160 nm, and that of Cur@MSN was distributed in 130-170 nm. Zeta potential analysis showed that the average Zeta potential of MSN, curcumin, and Cur@MSN was −12.5, −22.5 and −13.5 mV, respectively. The entrapment efficiency of Cur@MSN was 20.4%, and the drug loading rate was 0.2%. Curcumin released by Cur@MSN in 12 h accounted for about 60% of the total drug dose, and curcumin released in 28 h accounted for about 70%. In cell experiment, there was no significant difference in cell proliferation absorbance among the groups in normal environment (P>0.05), but the cell proliferation absorbance in the Cur@MSN group on the 3rd and 5th day in inflammatory environment was significantly higher than that in the control group and the curcumin group (P<0.01). The percentage of disc height index and the Pfirrmann grade of the Cur@MSN group were better than those of the degeneration group and the curcumin group (P<0.01). The histological score of the Cur@MSN group was lower than that of the degeneration group and the curcumin group (P<0.01). Conclusions Cur@MSN can delay the degeneration process of rat coccygeal intervertebral disc, and has certain repair and treatment effects on its degenerated intervertebral disc. Among them, curcumin can delay the degeneration of intervertebral disc by inhibiting inflammation, and the loading of MSN is helpful for curcumin to exert its biological effects.