CRISPR-Cas gene editing technologies offer the potential to modify crops precisely; however, in vitro plant transformation and regeneration techniques present a bottleneck due to the lengthy and genotype-specific tissue culture process. Ideally, in planta transformation can bypass tissue culture and directly lead to transformed plants, but efficient in planta delivery and transformation remains a challenge. This study investigates transformation methods that have the potential to directly alter germline cells, eliminating the challenge of in vitro plant regeneration. Recent studies have demonstrated that carbon nanotubes (CNTs) loaded with plasmid DNA can diffuse through plant cell walls, facilitating transient expression of foreign genetic elements in plant tissues. To test if this approach is a viable technique for in planta transformation, CNT-mediated plasmid DNA delivery into rice tissues was performed using leaf and excised-embryo infiltration with reporter genes. Quantitative and qualitative data indicate that CNTs facilitate plasmid DNA delivery in rice leaf and embryo tissues, resulting in transient GFP, YFP, and GUS expression. Experiments were also initiated with CRISPR-Cas vectors targeting the phytoene desaturase (PDS) gene for CNT delivery into mature embryos to create heritable genetic edits. Overall, the results suggest that CNT-based delivery of plasmid DNA appears promising for in planta transformation, and further optimization can enable high-throughput gene editing to accelerate functional genomics and crop improvement activities. 相似文献
Carbon nanotubes (CNTs) can be effectively dispersed and functionalized by wrapping with long single-stranded DNA (ssDNA) synthesized by asymmetric PCR. The ssDNA-CNTs attached on surface of glass carbon electrode made it possible for electrochemical analysis and sensing, which was demonstrated by reduction of H2O2 on hemoglobin/ssDNA-CNTs modified electrodes. This research showed the potential application of DNA-functionalised CNTs in construction of future electrochemical biosensors. 相似文献
Nanoparticles are efficient drug delivery vehicles for targeting specific organs as well as systemic therapy for a range of diseases, including cancer. However, their interaction with the immune system offers an intriguing challenge. Due to the unique physico-chemical properties, carbon nanotubes (CNTs) are considered as nanocarriers of considerable interest in cancer diagnosis and therapy. CNTs, as a promising nanomaterial, are capable of both detecting as well as delivering drugs or small therapeutic molecules to tumour cells. In this study, we coupled a recombinant fragment of human surfactant protein D (rfhSP-D) with carboxymethyl-cellulose (CMC) CNTs (CMC-CNT, 10–20 nm diameter) for augmenting their apoptotic and immunotherapeutic properties using two leukemic cell lines. The cell viability of AML14.3D10 or K562 cancer cell lines was reduced when cultured with CMC-mwCNT-coupled-rfhSP-D (CNT + rfhSP-D) at 24 h. Increased levels of caspase 3, 7 and cleaved caspase 9 in CNT + rfhSP-D treated AML14.3D10 and K562 cells suggested an involvement of an intrinsic pathway of apoptosis. CNT + rfhSP-D treated leukemic cells also showed higher mRNA expression of p53 and cell cycle inhibitors (p21 and p27). This suggested a likely reduction in cdc2-cyclin B1, causing G2/M cell cycle arrest and p53-dependent apoptosis in AML14.3D10 cells, while p53-independent mechanisms appeared to be in operation in K562 cells. We suggest that CNT + rfhSP-D has therapeutic potential in targeting leukemic cells, irrespective of their p53 status, and thus, it is worth setting up pre-clinical trials in animal models. 相似文献
Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs) with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current–voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis. 相似文献
In this work, synthesis and optical properties of a new composite based on poly(o-phenylenediamine) (POPD) fiber like structures, poly(vinylidene fluoride) (PVDF) spheres and double-walled carbon nanotubes (DWNTs) are reported. As increasing the PVDF weight in the mixture of the chemical polymerization reaction of o-phenylenediamine, the presence of the PVDF spheres onto the POPD fibers surface is highlighted by scanning electron microscopy (SEM). The down-shift of the Raman line from 1421 cm−1 to 1415 cm−1 proves the covalent functionalization of DWNTs with the POPD-PVDF blends. The changes in the absorbance of the IR bands peaked around 840, 881, 1240 and 1402 cm−1 indicate hindrance steric effects induced of DWNTs to the POPD fiber like structures and the PVDF spheres, as a consequence of the functionalization process of carbon nanotubes with macromolecular compounds. The presence of the PVDF spheres onto the POPD fiber like structures surface induces a POPD photoluminescence (PL) quenching process. An additional PL quenching process of the POPD-PVDF blends is reported to be induced in the presence of DWNTs. The studies of anisotropic PL highlight a change of the angle of the binding of the PVDF spheres onto the POPD fiber like structures surface from 50.2° to 38° when the carbon nanotubes concentration increases in the POPD-PVDF/DWNTs composites mass up to 2 wt.%. 相似文献
Despite extensive research, there is still no vaccine against the hepatitis C virus (HCV). The aim of this study was to investigate whether MSCs can exhibit adjuvant properties during DNA vaccination against hepatitis C. We used the pcNS3-NS5B plasmid encoding five nonstructural HCV proteins and MSCs derived from mice bone marrow. Five groups of DBA mice were immunized with the plasmid and/or MSCs in a different order. Group 1 was injected with the plasmid twice at intervals of 3 weeks; Group 2 with the plasmid, and after 24 h with MSCs; Group 3 with MSCs followed by the plasmid the next day; Group 4 with only MSCs; and Group 5 with saline. When the MSCs were injected prior to DNA immunization, the cell immune response to HCV proteins assessed by the level of IFN-γ synthesis was markedly increased compared to DNA alone. In contrast, MSCs injected after DNA suppressed the immune response. Apparently, the high level of proinflammatory cytokines detected after DNA injection promotes the conversion of MSCs introduced later into the immunosuppressive MSC2. The low level of cytokines in mice before MSC administration promotes the high immunostimulatory activity of MSC1 in response to a DNA vaccine. Thus, when administered before DNA, MSCs are capable of exhibiting promising adjuvant properties. 相似文献
An in situ lubrication dispersion method is developed to achieve electrical conductivity in PP containing a small amount of MWCNTs. Good dispersion of the MWCNTs in PP is observed even after a short mixing time because the interactions between the entangled nanotubes are reduced. By in situ lubrication dispersion, the electrical percolation threshold of the PP nanocomposite can be as low as 0.5–0.7 wt% MWCNT. Rheological data also support percolation at 0.5 wt% MWCNT. With 0.5 wt% MWCNT, the slope of G′ at low frequency approaches unity and shows non‐terminal behavior. The proposed dispersion method enhances the wetting of MWCNTs and improves MWCNT dispersion compared to both direct mixing of MWCNT powder with a polymer melt and conventional master batch dilution.
