In previous neural tissue engineering studies, we successfully constructed NT-3 cross-linked acellular spinal cord scaffolds (NT-3 cross-linked scaffolds), which can sustain the release of NT-3 and promote the differentiation of rat bone marrow mesenchymal stem cells (BMSCs) into neuron-like cells. However, the molecular mechanism by which NT-3 cross-linked scaffolds promote BMSC differentiation into neurons is unknown, coupled with the low drug loading of scaffolds and the sudden release of NT-3 on the first day. We used WB and PCR in combination with NT-3/TrkC, MAPK/ERK, and PI3K/Akt pathway inhibitors to determine the mechanism of action in vitro. We hypothesized that NT-3 mediates the NT-3/TrkC pathway as a major target molecule that promotes the differentiation of BMSCs into neurons. We prepared an improved NT-3 scaffold and improve the sustained release of NT-3 through the combination of heparin methacryloyl and EDC/NHS. The adhesion, proliferation, differentiation, and NT-3/TrkC signaling pathway of BMSCs on different scaffolds were analyzed. We concluded that NT-3-improved scaffolds can be loaded with more NT-3 and more effectively promote the differentiation of BMSCs into neurons through the NT-3/TrkC pathway. The proposed method has biocompatibility and provides a new idea for spinal cord repair.
This study aimed to evaluate the value of perfusion-weighted magnetic resonance imaging (MR-PWI) in assessing cerebral alveolar echinococcosis (CAE) biological activity.Totally, 15 cases of CAE patients who underwent surgery were enrolled. The MR-PWI perfusion parameters were measured and compared.The MR-PWI perfusion parameters cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time were different among different areas. Their values were in the descending order of lesion marginal area > contralateral normal brain area > lesion center area. However, time-to-peak value was in the ascending order of lesion marginal area < contralateral normal brain area < lesion center area. Spearman correlation analysis showed that CBF and CBV at the edge of the lesion were significantly positively correlated with microvessel density. Moreover, CBF and CBV at the edge of the lesion were also significantly positively correlated with maximum standardized uptake value.Perfusion-weighted magnetic resonance imaging can be used to dynamically reflect the neovascularization of CAE lesions and may have a good application prospect in evaluating the biological activity of CAE.
Spinal cord injury (SCI), usually resulting in severe sensory and motor deficits, is a major public health concern. Adipose‑derived stem cells (ADSCs), one type of adult stem cell, are free from ethical restriction, easily isolated and enriched. Therefore, ADSCs may provide a feasible cell source for cell‑based therapies in treatment of SCI. The present study successfully isolated rat ADSCs (rADSCs) from Sprague‑Dawley male rats and co‑cultured them with acellular spinal cord scaffolds (ASCs). Then, a rat spinal cord hemisection model was built and rats were randomly divided into 3 groups: SCI only, ASC only, and ASC + ADSCs. Furthermore, behavioral tests were conducted to evaluate functional recovery. Hematoxylin & Eosin staining and immunofluorence were carried out to assess histopathological remodeling. In addition, biotinylated dextran amines anterograde tracing was employed to visualize axon regeneration. The data demonstrated that harvested cells, which were positive for cell surface antigen cluster of differentiation (CD) 29, CD44 and CD90 and negative for CD4, detected by flow cytometry analysis, held the potential to differentiate into osteocytes and adipocytes. Rats that received transplantation of ASCs seeded with rADSCs benefited greatly in functional recovery through facilitation of histopathological rehabilitation, axon regeneration and reduction of reactive gliosis. rADSCs co‑cultured with ASCs may survive and integrate into the host spinal cord on day 14 post‑SCI.
In recent years, acellular spinal cord scaffolds have been extensively studied in tissue engineering. Notably, acellular spinal cord scaffolds may be used to treat spinal cord injury; however, the method of preparation can result in low efficiency and may affect the biological properties of cells. This study aimed to use EDC crosslinking, combined with chemical extraction for tissue decellularization, in order to improve the efficiency of acellular scaffolds. To make the improved stent available for the clinical treatment of spinal cord injury, it is necessary to study its immunogenicity. Therefore, this study also focused on the adherence of rat bone marrow mesenchymal stem cells to scaffolds, and their differentiation into neuron‑like cells in the presence of suitable trophic factors. The results revealed that EDC crosslinking combined with chemical extraction methods may significantly improve the efficiency of acellular scaffolds, and may also confer better biological characteristics, including improved immunogenicity. Notably, it was able to promote adhesion of rat bone marrow mesenchymal stem cells and their differentiation into neuron‑like cells. These results suggested that the improved preparation method may be promising for the construction of multifunctional acellular scaffolds for the treatment of spinal cord injury.
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