Spinal cord regeneration using dental stem cell-based therapies.

Spinal cord injury (SCI) is traumatic central nervous system damage resulting in a motor and sensory dysfunction that usually causes a severe and permanent paralysis. Today, the treatment of SCI principally includes surgical treatment, pharmacological treatments and rehabilitation therapies, which target secondary events determining only some clinical improvements in patients. SCI is still a worldwide problem in the clinic and remains a big challenge for neuroscientists and neurologists throughout the world. Therefore, new therapies able to restore the function of the injured spinal cord are urgently needed for SCI patients. An interesting approach to overcome the growth inhibiting properties present in the injured spinal cord is to transplant cells with reparative and protective properties such as mesenchymal stem cells. In this context, human dental-derived stem cells represent a promising new cell source for cell-based therapies. It has been shown that dental-derived stem cells isolated from dental pulp, named dental pulp stem cells or stem cells from human exfoliated deciduous teeth induce functional improvement after SCI in animal models. This review summarises the current state of the literature regarding the use of dental-derived stem cells for spinal cord repair and regeneration and highlights the neuroprotective effects of these cells when administered after spinal cord injury.

Effects of graphene modification on the bioactivation of polyethylene-terephthalate-based artificial ligaments.

The objective of this study was to investigate whether surface coating with graphene could enhance the surface bioactivation of PET-based artificial ligaments to accelerate graft-to-bone healing after anterior cruciate ligament reconstruction. In an in vitro study, the proliferation of MC3T3-E1 cells and their differentiation on the scaffolds were quantified via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and real-time polymerase chain reaction assays. The significantly higher optical-density values and transcription levels of osteoblast-specific genes indicated that graphene modification could promote the proliferation of MC3T3-E1 cells and accelerate their specific differentiation into osteogenic lineages on scaffolds. In an in vivo test, rabbits were used to establish an extra-articular graft-to-bone healing model. At 4, 8, and 12 weeks after surgery, biomechanical tests, microcomputed tomography analysis, and histological observations were performed. The final results demonstrated that the microstructural parameters, the average mineral apposition rate of the bone, and the biomechanical properties of the graphene-coated polyethylene terephthalate (PET)-based artificial ligament (G-PET-AL) group were significantly higher than those of the PET-AL graft group (P < 0.05). The results of Van Gieson staining indicated that in the G-PET-AL group, there was more newly formed bone than there was in the group in which nongraphene-coated PET-ALs were used. In conclusion, graphene exhibits considerable potential for enhancing the surface bioactivation of materials.