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In this study, we investigated the role of tetrahedral framework nucleic acids (tFNAs) in irradiation‐induced salivary gland damage in vitro and in vivo. Irradiation‐damaged submandibular gland cells (SMGCs) were treated with different concentrations of tFNAs. Cell activity was measured by CCK‐8 assay. Cell death was detected by Calcein‐AM/PI double staining. Cell apoptosis was assessed by flow cytometry. The expression of apoptosis proteins and inflammatory cytokines were detected by western blot. Body weight, drinking volume, saliva flow rate and lag time was measured 8 weeks after irradiation. Micromorphological changes of submandibular gland were assessed by haematoxylin–eosin and masson staining. Cell proliferation, apoptosis and microvessel density of submandibular gland were evaluated by immunohistochemical staining. tFNAs could promote cell proliferation, inhibit cell apoptosis of irradiation‐damaged SMGCs and reduce irradiation induced cell death. Mechanism studies revealed that tFNAs inhibited cell apoptosis through regulating the Bcl‐2/Bax/Caspase‐3 signalling pathway and inhibited the release of TNF‐α, IL‐1β and IL‐6 to reduce cell damage caused by inflammation. Animal experiments showed that tFNAs could alleviate irradiation‐induced weight loss, increased water intake, decreased saliva production and prolonged salivation lag time and could ameliorate salivary gland damage. tFNAs have a positive effect on alleviating irradiation‐induced salivary gland damage and might be a promising agent for the treatment of this disease. [ABSTRACT FROM AUTHOR]

Objectives: Delivery systems that provide time and space control have a good application prospect in tissue regeneration applications, as they can effectively improve the process of wound healing and tissue repair. In our experiments, we constructed a novel micro‐RNA delivery system by linking framework nucleic acid nanomaterials to micro‐RNAs to promote osteogenic differentiation of mesenchymal stem cells. Materials and Methods: To verify the successful preparation of tFNAs–miR‐26a, the size of tFNAs–miR‐26a were observed by non‐denaturing polyacrylamide gel electrophoresis and dynamic light scattering techniques. The expression of osteogenic differentiation‐related genes and proteins was investigated by confocal microscope, PCR and western blot to detect the impact of tFNAs–miR‐26a on ADSCs. And finally, Wnt/β‐catenin signaling pathway related proteins and genes were detected by confocal microscope, PCR and western blot to study the relevant mechanism. Results: By adding this novel complex, the osteogenic differentiation ability of mesenchymal stem cells was significantly improved, and the expression of alkaline phosphatase (ALP) on the surface of the cell membrane and the formation of calcium nodules in mesenchymal stem cells were significantly increased on days 7 and 14 of induction of osteogenic differentiation, respectively. Gene and protein expression levels of ALP (an early marker associated with osteogenic differentiation), RUNX2 (a metaphase marker), and OPN (a late marker) were significantly increased. We also studied the relevant mechanism of action and found that the novel nucleic acid complex promoted osteogenic differentiation of mesenchymal stem cells by activating the canonical Wnt signaling pathway. Conclusions: This study may provide a new research direction for the application of novel nucleic acid nanomaterials in bone tissue regeneration. [ABSTRACT FROM AUTHOR]

Objectives: To provide a new research direction for nerve regeneration and strategy for Alzheimer's disease treatment, tetrahedral DNA nanostructures (TDNs)—novel tetrahedral framework nucleic acid molecule nanoparticles (tFNA) that can inhibit the apoptosis of nerve cells are employed in the experiment. Materials and methods: To verify the successful preparation of TDNs, the morphology of TDNs was observed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The expression of apoptosis‐related genes and proteins was investigated by confocal microscope, flow cytometry, PCR and Western blot to detect the impact of TDNs on the Alzheimer's model. And finally, Morris water maze experiment was used to test behavioural changes and Nissl stain was detected to observe the morphology and quantity of neurons in the hippocampus. Immunofluorescence stain was used to observe the Aβ stain, and TUNEL dyeing was utilized to observe neuronal apoptosis. Results: In vitro and in vivo experiments confirm that TDNs, in a specific concentration range, have no toxic or side effects on nerve cells, can effectively inhibit apoptosis in an Alzheimer's disease cell model and effectively improve memory and learning ability in a rat model of Alzheimer's disease. Conclusions: These findings suggest that TDNs may be a promising drug for the treatment of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Objectives: Pegaptanib might be a promising anti‐tumour drug targeting VEGF to inhibit tumour vascular endothelial cell proliferation. However, the poor biostability limited its application. In this study, we took tetrahedron DNA nanostructures (TDNs) as drug nanocarrier for pegaptanib to explore the potent anti‐angiogenesis and anti‐tumour activity of this drug delivery system. Materials and methods: The successful synthesis of TDNs and pegaptanib‐TDNs was determined by 8% polyacrylamide gel electrophoresis (PAGE), capillary electrophoresis and dynamic light scattering (DLS). The cytotoxicity of pegaptanib alone and pegaptanib‐TDNs on HUVECs and Cal27 was evaluated by the cell count kit‐8 (CCK‐8) assay. The effect of pegaptanib and pegaptanib‐TDNs on proliferation, migration and tube formation of HUVECs induced by VEGF was examined by CCK‐8 assay, wound healing assay and tubule formation experiment. The cell binding capacity and serum stability were detected by flow cytometry and PAGE, respectively. Results: Pegaptanib‐TDNs had stronger killing ability than pegaptanib alone, and the inhibiting effect was in a concentration‐dependent manner. What's more, pegaptanib‐loaded TDNs could effectively enhance the ability of pegaptanib to inhibit proliferation, migration and tube formation of HUVECs induced by VEGF. These might attribute to the stronger binding affinity to the cell membrane and greater serum stability of pegaptanib‐TDNs. Conclusions: These results suggested that pegaptanib‐TDNs might be a novel strategy to improve anti‐angiogenesis and anti‐tumour ability of pegaptanib. [ABSTRACT FROM AUTHOR]

The cover image is based on the Original Article Tetrahedral DNA nanostructures facilitate neural stem cell migration via activating RHOA/ROCK2 signalling pathway by Wenjuan Ma et al., https://doi.org/10.1111/cpr.12503. [ABSTRACT FROM AUTHOR]

Objectives: The main purpose of current study was to explore the effects of tetrahedral DNA nanostructures (TDNs) on neuroectodermal (NE‐4C) stem cells migration and unveil the potential mechanisms. Materials and methods: The successfully self‐assembled TDNs were also determined by dynamic light scattering (DLS). A bidirectional wound‐healing assay and transwell chamber assay were employed to test the migrating behaviour of NE‐4C stem cells cultured under different conditions. Results: Through an in vitro study, we found that stem cells could internalize TDNs quickly, and the cells' parallel and vertical migration was promoted effectively. Besides, the effects of TDNs were found being exerted by upregulating the gene and protein expression levels of RhoA, Rock2 and Vinculin, indicating that the RHOA/ROCK2 pathway was activated by the TDNs during the cell migration. Conclusions: In conclusion, TDNs could enter NSCs without the aid of other transfection reagents in large amounts, whereas only small amounts of ssDNA could enter the cells. TDNs taken up by NSCs activated the RHOA/ROCK2 signalling pathway, which had effects on the relevant genes and proteins expression, eventually promoting the migration of NE‐4C stem cells. These findings suggested that TDNs have great potential in application for the repair and regeneration of neural tissue. [ABSTRACT FROM AUTHOR]

Nucleic acid strands can be synthesized into various nucleic acid-based nanomaterials (NANs) through strict base pairing. The self-assembled NANs are programmable, intelligent, biocompatible, non-immunogenic, and non-cytotoxic. With the rapid development of nanotechnology, the application of NANs in the biomedical fields, such as drug delivery and biological sensing, has attracted wide attention. However, the stability of NANs is often affected by the cation concentrations, enzymatic degradation, and organic solvents. This susceptibility to degradation is one of the most important factors that have restricted the application of NANs. NANs can be denatured or degraded under conditions of low cation concentrations, enzymatic presence, and organic solvents. To deal with this issue, a lot of methods have been attempted to improve the stability of NANs, including artificial nucleic acids, modification with specific groups, encapsulation with protective structures, etc. In this review, we summarized the relevant methods to have a deeper understanding of the stability of NANs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)