Endplate role in the degenerative disc disease: A brief review

Table 1 The most common factors taken into account when talking about intervertebral disc degeneration

Factors in the degeneration of the intervertebral disc	Function in the pathological process
Genetic factors	Mutation in genes THBS2, CLIP, ASPN, PARK2, CHTS, COL1A1, COL9A3, COL11A2, COL11 lead to alterations of matrix morphology
Mechanical stress	Smoking, obesity, heavy physical labour, inappropriate flexed posture and physical inactivity
Nutritional disorders	Vessels disease in the vertebral endplate cause a fall in nutritional supply, resulting in a fall in oxygen availability and an increase in lactate concentration, affecting the cell function and synthesis of the extracellular matrix

Table 2 Summary of the main events in endplate degeneration process

Main inflammatory mediators in the endplate degenerative process	Features of endplate degeneration	Main molecular changes
Interleukin-1β	Alterations in bone composition and morphology	Degradation of aggrecan and collagen II
Tumour necrosis factor (TNF)-α	Decreasing of endplate thickens	Rise in matrix metalloproteinase actvity
Macrophage inhibition factor	Loss of blood vessels	Increased cell death
Interleukin-6	Loss of cartilage
	Increased endplate porosity

Table 3 Most common biomaterials used in the tissue engineering of the intervertebral disc scaffold

Biomaterial	Function	Advantages
Collagen	Materials for tissue matrices	Ubiquitous; Easy obtainable; Low immunogenicity; Good cell adherence and growth
Atelocollagen	Materials for tissue matrices	Good bioimmunological properties; Good mechanical stability; Good cell ingrowth
Fibroin	Materials for tissue matrices	High compressive strength; Strong and non-degradable; Good cell adherence and growth; Good biomechanical function
Chitosan	Materials for tissue matrices	Biodegradable Biocompatible; Antimicrobial effect
Alginate	Materials for tissue matrices	Biodegradable; Excellent biocompatibility
Polylactide	Materials for tissue matrices	Low immunogenicity
Polycaprolactone	Materials for tissue matrices	Low immunogenicity; Useful for modelling