Effect Of Tetrahedral DNA Nanostructures Research Articles

Effects of tetrahedral DNA nanostructures on the treatment of osteoporosis.

Osteoporosis (OP) is a common disease characterized by bone loss and bone tissue microstructure degradation. Drug treatment is a common clinical treatment that aims to increase bone mass and bone density. Tetrahedral DNA nanostructures (TDNs) are three-dimensional tetrahedral frames formed by folding four single-stranded DNA molecules, which have good biological safety and can promote bone regeneration. In this study, a mouse model of OP was established by ovariectomy (OVX) and TDN was injected into the tail vein for 8 weeks. We found that ovariectomized mice could simulate some physiological changes in OP. After treatment with TDNs, some of this destruction in mice was significantly improved, including an increase in the bone volume fraction (BV/TV) and bone trabecular number (Tb. N), decrease in bone separation (Tb. SP), reduction in the damage to the mouse cartilage layer, reduction in osteoclast lacunae in bone trabecula, and reduction in the damage to the bone dense part. We also found that the expression of ALP, β-Catenin, Runx2, Osterix, and bone morphogenetic protein (BMP)2 significantly decreased in OVX mice but increased after TDN treatment. Therefore, this study suggests that TDNs may regulate the Wnt/β-Catenin and BMP signalling pathways to improve the levels of some specific markers of osteogenic differentiation, such as Runx2, ALP, and Osterix, to promote osteogenesis, thus showing a therapeutic effect on OP mice.

Effect of tetrahedral DNA nanostructures on LPS‐induced neuroinflammation in mice

Neuroinflammation plays a significant role in inducing depression-like behavior. Tetrahedral DNA nanostructures (TDNs) are molecules that exhibit anti-inflammatory properties and can effectively penetrate the blood-brain barrier. Thus, researchers have hypothesized that TDNs regulate the secretion of proinflammatory cytokines and consequently alleviate depression-like behavior. To test this hypothesis, we investigated the effect of TDNs on the depression-like behavior of C57 mice induced by lipopolysaccharide (LPS). We performed open-field, tail suspension, and sucrose preference tests on LPS- and LPS/TDN-treated mice. The results indicated that the injection of TDNs into LPS-treated mice resulted in increased velocity, center zone duration, frequency to the center zone, and sucrose preference, and decreased immobility time. Immunofluorescence results indicated that peripheral administration of LPS in the mice activated inflammation, which culminated in distinct depression-like behavior. However, TDNs effectively alleviated the inflammation and depression-like behavior through the reduction of the expression levels of proinflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α in the brain. Additionally, TDNs normalized the expression level of microglia cell activation markers, such as ionized calcium binding adaptor molecule 1, in the hippocampus of mice. These results indicated that TDNs attenuated the LPS-induced secretion of inflammatory factors and consequently alleviated depression-like behavior.

Effect of tetrahedral DNA nanostructures on proliferation and osteogenic differentiation of human periodontal ligament stem cells.

ObjectiveTo explore the effects and underlying biological mechanisms of tetrahedral DNA nanostructures (TDNs) on the proliferation and osteogenic differentiation of periodontal ligament stem cells (PDLSCs).Materials and methodsReal‐time cell analysis (RTCA) and CCK8 were used to screen the best concentration of TDN for PDLSCs. Cell proliferation and osteogenic differentiation were assessed after PDLSCs were treated with TDN. Data were analysed using one‐way ANOVA.ResultsTetrahedral DNA nanostructures could play a crucial role in accelerating the proliferation of PDLSCs and had the strongest promotive effect on PDLSCs at a concentration of 250 nmol/L. Simultaneously, the osteogenic differentiation of PDLSCs could be promoted significantly by TDNs and the finding displayed that the Wnt/β‐catenin signalling pathway might be the underlying biological mechanisms of TDNs on promoting the osteogenic differentiation of PDLSCs.ConclusionTetrahedral DNA nanostructure treatment facilitated the proliferation of PDLSCs, significantly promoted osteogenic differentiation by regulating the Wnt/β‐catenin signalling pathway. Therefore, TDNs could be a novel nanomaterial with great potential for application to PDLSC‐based bone tissue engineering.

The Clearance Effect of Tetrahedral DNA Nanostructures on Senescent Human Dermal Fibroblasts.

Senescent cells are characterized by their resistance to apoptosis, and upon their long-term survival senescent cells affect tissue function and eventually become deleterious to the organism. Thus, far, it has been gradually accepted that clearance of these senescent cells could reduce tissue dysfunction. This study aimed to investigate biological effects of tetrahedral DNA nanostructures (TDNs) on senescent cells. The results revealed a different biological effect of TDNs, and their clearance effect on senescent cells. TDNs can induce phenotypic changes in senescent cells, suppressing antiapoptotic BCL-2 family proteins and upregulating BAX, a BCL-2 family proapoptotic protein, to influence the expression levels and function of downstream proteins. Consequently, cytochrome C releasing promoted cleavage-mediated activation of pro-caspase-3 and its nuclear translocation from the cytoplasm to mediate apoptosis. The present results provide a foundation for further studies on the application of TDNs in studies on aging.

Tetrahedral DNA Nanostructure Promotes Endothelial Cell Proliferation, Migration, and Angiogenesis via Notch Signaling Pathway

The problem of tissue vascularization is one of the obstacles that currently restricts the application of tissue engineering products to the clinic. Achieving tissue vascularization and providing adequate nutrients for tissues are an urgent problem to build complex and effective tissue-engineered tissues and organs. Therefore, the aim of this study was to investigate the effect of tetrahedral DNA nanostructures (TDNs), a novel and biocompatible nanomaterial, on angiogenesis. The results showed that TDNs can enter into endothelial cells (ECs) and promote EC proliferation, migration, tube formation, and expressions of angiogenic growth factors at the concentration of 250 nmol L-1, which was accompanied by activation of the Notch signaling pathway. These results provided a theoretical basis for the further understanding and potential use of TDNs in tissue engineering vascularization.

Tetrahedral DNA Nanomaterial Regulates the Biological Behaviors of Adipose-Derived Stem Cells via DNA Methylation on Dlg3.

As a simple and classical three-dimensional shape, tetrahedral DNA nanostructures (TDNs) can provide robust properties for better stability and can serve as a versatile platform for biosensing and drug delivery. More in-depth, its safety should be assessed by sensitive detection methods. However, the effect of TDNs at the epigenetic level has not received much attention. Here, DNA methylation alteration in adipose-derived stem cells (ASCs) after exposure to TDNs was comprehensively evaluated. The results from reduced representation bisulfite sequencing, bisulfite-specific polymerase chain reaction, and further gene function analysis revealed that TDNs induced a few differentially methylated regions where negatively correlated gene expressions occur. Moreover, TDNs facilitated ASC proliferation and attenuated apoptosis via DNA hypermethylation of the Dlg3 gene promotor. This study may help pave the way for potential applications with the nanosafety of TDNs and offer deep insights into the proliferation promotion effect and antiapoptosis ability of TDNs.

Tetrahedral DNA nanostructures facilitate neural stem cell migration via activating RHOA/ROCK2 signalling pathway.

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. 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. 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. 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.

Neuroprotective Effect of Tetrahedral DNA Nanostructures in a Cell Model of Alzheimer's Disease.

Accumulating evidence supports the abnormal deposition of amyloid β-peptide (Aβ) as the main cause of Alzheimer's disease (AD). Therefore, fighting against the formation, deposition, and toxicity of Aβ is a basic strategy for the treatment of AD. In the process of in vitro nerve cell culture, screening out drugs that can antagonize a series of toxic reactions caused by β-amyloid deposition has become an effective method for the follow-up treatment of AD. Our previous studies showed that tetrahedral DNA nanostructures (TDNs) had good biocompatibility and had some positive effects on the biological behavior of cells. In this study, the main aim of our work was to explore the effects and potential mechanism of TDNs in protecting neuronal PC12 cells from the toxicity of Aβ. Our study demonstrated that TDNs can protect and rescue PC12 cell death through Aβ25-35-induced PC12 cell apoptosis. Further studies showed that TDNs significantly improved the apoptosis by affecting the abnormal cell cycle, restoring abnormal nuclear morphology and caspase activity. Western blot analysis showed that TDNs could prevent the damage caused by Aβ deposition by activating the ERK1/2 pathway and thus be a potential therapeutic agent with a neuroprotective effect in Alzheimer's disease. Our finding provides a potential application of TDNs in the prevention and treatment of AD.

Effect of tetrahedral DNA nanostructures on proliferation and osteo/odontogenic differentiation of dental pulp stem cells via activation of the notch signaling pathway

Dental pulp stem cells (DPSCs) derived from the human dental pulp tissue have multiple differentiation capabilities, such as osteo/odontogenic differentiation. Therefore, DPSCs are deemed as ideal stem cell sources for tissue regeneration. As new nanomaterials based on DNA, tetrahedral DNA nanostructures (TDNs) have tremendous potential for biomedical applications. Here, the authors aimed to explore the part played by TDNs in proliferation and osteo/odontogenic differentiation of DPSCs, and attempted to investigate if these cellular responses could be driven by activating the canonical Notch signaling pathway. Upon exposure to TDNs, proliferation and osteo/odontogenic differentiation of DPSCs were dramatically enhanced, accompanied by up regulation of Notch signaling. In general, our study suggested that TDNs can significantly promote proliferation and osteo/odontogenic differentiation of DPSCs, and this remarkable discovery can be applied in tissue engineering and regenerative medicine to develop a significant and novel method for bone and dental tissue regeneration.

Self-Assembled Tetrahedral DNA Nanostructures Promote Neural Stem Cell Proliferation and Neuronal Differentiation.

Stem cell-based therapy is considered a promising approach for the repair of nervous tissues. Neural stem cells (NSCs) cannot proliferate or differentiate efficiently; hence, different biomaterials have been explored to improve NSC proliferation and differentiation. However, these agents either had low bioavailability or poor biocompatibility. In this work, our group investigated the effects of tetrahedral DNA nanostructures (TDNs), a novel DNA biological material, on the self-renew and differentiation of neuroectodermal (NE-4C) stem cells. We observed that TDN treatment promoted self-renew of the stem cells via activating the Wnt/β -catenin pathway. In addition, our findings suggested that NE-4C stem cells' neuronal differentiation could be promoted effectively by TDNs via inhibiting the notch signaling pathway. In summary, this is the first report about the effects of TDNs on the proliferation and differentiation of NE-4C stem cells and the results demonstrate that TDNs have a great potential in nerve tissue regeneration.

Anti-inflammatory and Antioxidative Effects of Tetrahedral DNA Nanostructures via the Modulation of Macrophage Responses.

Tetrahedral DNA nanostructures (TDNs) are a new type of nanomaterials that have recently attracted attention in the field of biomedicine. However, the practical application of nanomaterials is often limited owing to the host immune response. Here, the response of RAW264.7 macrophages to TDNs was comprehensively evaluated. The results showed that TDNs had no observable cytotoxicity and could induce polarization of RAW264.7 cells to the M1 type. TDNs attenuated the expression of NO IL-1β (interleukin-1β), IL-6 (interleukin-6), and TNF-α (tumor necrosis factor-α) in LPS-induced RAW264.7 cells by inhibiting MAPK phosphorylation. In addition, TDNs inhibited LPS-induced reactive oxygen species (ROS) production and cell apoptosis by up-regulating the mRNA expression of antioxidative enzyme heme oxygenase-1 (HO-1). The findings of this study demonstrated that TDNs have great potential as a novel theranostic agent because of their anti-inflammatory and antioxidant activities, high bioavailability, and ease of targeting.

Effects of tetrahedral DNA nanostructures on autophagy in chondrocytes.

Tetrahedral DNA nanostructures (TDNs) have gathered great attention and are being widely used in biomedicine. We demonstrated that autophagy increased after exposure to TDNs (250 nM) along with the up-regulation of several autophagy-related genes and proteins. TDNs enhanced cell autophagy through the PI3K/AKT/mTOR signaling pathway.

Modulation of chondrocyte motility by tetrahedral DNA nanostructures.

Contemporarily, a highly increasing attention was paid to nanoconstructs, particularly DNA nanostructures possessing precise organization, functional manipulation, biocompatibility and biodegradability. Amongst these DNA nanomaterials, tetrahedral DNA nanostructures (TDNs) are a significantly ideal bionanomaterials with focusing on the property that can be internalized into cytoplasm in the absence of transfection. Therefore, the focus of this study was on investigating the influence of TDNs on the chondrocytes locomotion. Tetrahedral DNA nanostructures was confirmed by 6% polyacrylamide gel electrophoresis (PAGE) and dynamic light scattering (DLS). Subsequently, the effect of TDNs on chondrocyte locomotion was investigated by real-time cell analysis (RTCA) and wound healing assay. The variation of relevant genes and proteins was detected by quantitative polymerase chain reaction (qPCR), western blotting and immunofluorescence respectively. We demonstrated that tetrahedral DNA nanostructures have positive influence on chondrocytes locomotion and promoted the expression of RhoA, ROCK2 and vinculin. Additionally, upon exposure to TDNs with the concentration of 250nmolL-1 , the chondrocytes were showed the highest motility via both RTCA and wound healing assay. Meanwhile, the mRNA and protein expression of RhoA, ROCK2 and vinculin were also significantly enhanced with the same concentration. It can be concluded that the TDNs with the optimal concentration of 250nmolL-1 could extremely promoted the chondrocytes locomotion through facilitating the expression of RhoA, ROCK2 and vinculin. These results seemed to reveal that this special three-dimensional DNA tetrahedral nanostructures may be applied to cartilage repair and treatment in the future.

Effect of tetrahedral DNA nanostructures on osteogenic differentiation of mesenchymal stem cells via activation of the Wnt/β-catenin signaling pathway

Adipose-derived stem cells (ADSCs) are considered to be ideal stem cell sources for bone regeneration owing to their ability to differentiate into osteo-like cells. Therefore, they have attracted increasing attention in recent years. Tetrahedral DNA nanostructures (TDNs), a new type of DNA-based biomaterials, have shown great potential for biomedical applications. In the present work, we aimed to investigate the role played by TDNs in osteogenic differentiation and proliferation of ADSCs and tried to explore if the canonical Wnt signal pathway could be the vital biological mechanism driving these cellular responses. Upon exposure to TDNs, ADSCs proliferation and osteogenic differentiation were significantly enhanced, accompanied by the up-regulation of genes correlated with the Wnt/β-catenin pathway. In conclusion, our results indicate that TDNs are crucial regulators of the increase in osteogenic potential and ADSCs proliferation, and this noteworthy discovery could provide a promising novel approach toward ADSCs-based bone defect regeneration.