Wistar rats were spinalized using NYU impactor®. Animals were randomly distributed into 4 groups: Control (Naive) or Surgical control, Sham (laminectomy with no SCI); SCI (laminectomy followed by SCI, treated with vehicle); SHED (SCI treated with intraspinal transplantation of 3×10 SHED, 1h after SCI). Functional evaluations and morphological analysis were performed to confirm the spinal injury and the benefit of SHED transplantation on behavior, tissue protection and motor neuron survival. Flow cytometry of neurons, astrocytes, macrophages/microglia and T cells of spinal cord tissue were run at six, twenty-four, forty-eight and seventy-two hours after lesion. Six hours after SCI, ELISA and Western Blot were run to assess pro- and anti-apoptotic factors. The SHED group showed a significant functional improvement in comparison to the SCI animals, as from the first week until the end of the experiment. This behavioral protection was associated with less tissue impairment and greater motor neuron preservation. SHED reduced neuronal loss over time, as well as the overexpression of pro-apoptotic factor TNF-α, while maintained basal levels of the anti-apoptotic BCL-XL six hours after lesion. Data here presented show that SHED transplantation one hour after SCI interferes with the balance between pro- and anti-apoptotic factors and reduces early neuronal apoptosis, what contributes to tissue and motor neuron preservation and hind limbs functional recovery.

The transplantation of stem cells from human exfoliated deciduous teeth (SHED) has been studied as a possible treatment strategy for spinal cord injuries (SCIs) due to its potential for promoting tissue protection and functional recovery. The aim of the present study was to investigate the effects of the early transplantation of SHED on glial scar formation and astrocytic reaction after an experimental model of SCI. Wistar rats were spinalized using the NYU Impactor. Animals were randomly distributed into three groups: control (naive) (animal with no manipulation); SCI (receiving laminectomy followed by SCI and treated with vehicle), and SHED (SCI rat treated with intraspinal SHED transplantation, 1 h after SCI). In vitro investigation demonstrated that SHED were able to express mesenchymal stem cells, vimentin and S100B markers, related with neural progenitor and glial cells, respectively. The acute SHED transplantation promoted functional recovery, measured as from the first week after spinal cord contusion by Basso, Beattie, and Bresnahan scale. Twenty-four and 48 h after lesion, flow cytometry revealed a spinal cord vimentin cells increment in the SHED group. The increase of vimentin cells was confirmed by immunofluorescence. Moreover, the bioavailability of astrocytic proteins such as S100B and Kir4.1 shown to be increased in the spinal cord of SHED group, whereas there was a glial scar reduction, as indicated by ELISA and Western blot techniques. The presented results support that SHED act as a neuroprotector agent after transplantation, probably through paracrine signaling to reduce glial scar formation, inducing tissue plasticity and functional recovery.

Materials, such as biopolymers, can be applied to produce scaffolds as mechanical support for cell growth in regenerative medicine. Two examples are polycaprolactone (PCL) and poly (lactic-coglycolic acid) (PLGA), both used in this study to evaluate the behavior of umbilical cord-derived mesenchymal stem cells. The scaffolds were produced by the 3D printing technique using PCL as a polymer covered with PLGA fibers obtained by electrospinning. The cells were seeded in three concentrations: 8.5×10 3 ; 25.5×10 3 and 51.0×10 3 on the two surfaces of the scaffolds. With scanning electron microscopy (SEM), it was observed that the electrospun fibers were integrated into the 3D printed matrices. Confocal laser scanning microscopy and SEM confirmed the presence of attached cells and the lactate dehydrogenase release test showed the scaffolds were not cytotoxic. The cells were able to differentiate into osteogenic and chondrogenic lineages on the scaffolds. Mechanical test showed that the cells seeded on the 3D printed PCL matrices coated with PLGA electrospun nanofibers (3D+ES+SC) did not show significant difference in tensile modulus than the pure PCL matrix (3D) or PCL matrices coated with PLGA electrospun nanofibers (3D+ES). The combination of the two polymers facilitated the production of a support with greater mechanical stability due to the presence of the 3D printed PCL matrices fabricated by melted filaments and greater cell adhesion due to the PLGA fibers. The scaffolds are suitable for use in cell therapy and also for tissue regeneration purposes.

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Otorrhea was the most frequently found complication. TT placement with adenoidectomy was associated with fewer otorrhea episodes. TT extruded later in those ears that had more episodes of otorrhea. Younger age at the time of the initial tube placement is associated with higher incidence of additional tube placement. One in six patients will probably require a second set of ventilation tubes.