This work proposes the concept of single‐cell microRNA (miR) therapy and proof‐of‐concept by engineering a nanopipette for high‐precision miR‐21‐targeted therapy in a single HeLa cell with sensitive ...photoelectrochemical (PEC) feedback. Targeting the representative oncogenic miR‐21, the as‐functionalized nanopipette permits direct intracellular drug administration with precisely controllable dosages, and the corresponding therapeutic effects can be sensitively transduced by a PEC sensing interface that selectively responds to the indicator level of cytosolic caspase‐3. The experimental results reveal that injection of ca. 4.4 × 10−20 mol miR‐21 inhibitor, i.e., 26488 copies, can cause the obvious therapeutic action in the targeted cell. This work features a solution to obtain the accurate knowledge of how a certain miR‐drug with specific dosages treats the cells and thus provides an insight into futuristic high‐precision clinical miR therapy using personalized medicine, provided that the prerequisite single‐cell experiments are courses of personalized customization.
The concept of high‐precision single‐cell microRNA therapy is proposed and devised by a functional nanopipette, which allows precise miR‐21 inhibitor delivery to induce cell apoptosis and responds selectively to caspase‐3 of a sensitive photoelectrochemical feedback. It can reveal what the precise drug amount can cause the effective therapeutic action.
Tens of billion metric tons of anthropogenic CO2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO2 to desirable, ...economical chemicals and materials. Poly（propylene carbonate）（PPC） is an emerging CO2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive（RHMPA） based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics（PC, PMMA, ABS） and metals（aluminium, steel）, which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process（up to 270 °C）. The study is expected to expand the applications of PPC and provide a new type of CO2-based renewable and eco-friendly materials.
Paclitaxel (PTX) has previously been used to treat tumours of various tissue origins, such as lung, breast, ovarian, prostate cancers and leukemia. PTX‐induced apoptosis is associated with p38 ...mitogen‐activated protein kinase (p38 MAPK), extracellular signal‐regulated kinase (ERK), nuclear factor‐kappa B (NF‐κB) and c‐Jun N‐terminal kinase or stress‐activated protein kinase (JNK/ SAPK) pathways. Transforming growth factor‐beta‐activated kinase 1 (TAK1) and TAK1‐binding protein 1 (TAB1) play an important role in cell apoptosis through the p38, ERK, NF‐κB and JNK signal transduction pathways. To investigate the role of TAK1 in PTX‐induced cell apoptosis, we treated HEK293 and 8305C cells with 0–20 µM PTX for 6, 12 or 24 h. To investigate whether TAK1 can cooperate with PTX for cancer treatment, we transfected cells with TAK1, TAB1 or control plasmid and treated them with PTX (3–10 µM) for 9–24 h. Apoptosis rates were analysed by flow cytometry (Annexin V/PI). Endogenous TAK1 and TAB1, caspase‐7 cleavage, poly ADP‐ribose polymerase (PARP) cleavage, Bcl‐xL level, phospho‐p44/42, phospho‐JNK and phospho‐p38 were detected by western blot. We show that in HEK293 and 8305C cells, PTX enhanced the endogenous TAK1/TAB1 level and induced cell apoptosis in a dose‐ and time‐dependent manner. Upon TAK1 overexpression in HEK293 cells treated with PTX, apoptosis rate, JNK phosphorylation and PARP cleavage increased contrary to heat‐shocked or untreated cells. CRISPR editing of the tak1 gene upon PTX treatment resulted in lower phospho‐JNK and PARP cleavage levels than in cells transfected with the control or the TAK1‐ or TAB1 + TAK1‐containing plasmids. TAK1‐K63A could not induce JNK phosphorylation or PARP cleavage. We conclude that PTX induces HEK293 and 8305C cell apoptosis through the TAK1–JNK activation pathway, potentially highlighting TAK1’s role in chemosensitivity.
Paclitaxel induces HEK293 and 8305C cell apoptosis through the Transforming growth factor‐beta‐activated kinase 1 (TAK1)–c‐Jun N‐terminal kinase (JNK) activation pathway. Paclitaxel increases endogenous TAK1 and TAK1‐binding protein 1(TAB1) levels in HEK293 and 8305C cells in a dose‐ and time‐dependent manner. TAK1 and TAB1 complex induced JNK activation through phosphorylation, which leads to inhibition of Bcl‐xL.
As two mainstream ionic detection techniques, ionic current rectification (ICR) suffers from large fluctuations in trace level detection, while resistive-pulse sensing (RPS) encounters easy clogs in ...high-concentration detection. By rationally matching the nanopore size with the DNA tetrahedron (TDN), this work bridges the two techniques to achieve reliable detection with wide linearity. As a representative analyte, miRNA-10b could specifically combine with and release TDN from the interior wall, which thus induced the simultaneous generation of distinct ICR and RPS signals. The ICR signals could be attributed to the balance between the effective orifice and surface charge density of the inner wall, while the RPS signals were induced by the complex of miRNA-10b and TDN passing through the nanopore. Such an operation contributed to a wide detection range of 1 fM–1 nM with a good linearity. The feasibility of this method is also validated in single-cell and real plasma detection.
Single-cell analysis of the DNA repair protein is important but remains unachieved. Exploration of nanopipettte technologies in single-cell electroanalysis has recently seen rapid growth, while the ...θ-nanopipette represents an emerging technological frontier with its potential largely veiled. Here a θ-nanopipette is first applied for single-cell resistive-pulse sensing (RPS) of the important DNA repair protein O6-alkylguanine DNA alkyltransferase (hAGT). The removal of alkyl mutations by hAGT could restore the damaged aptamer linking with a structural DNA carrier, allowing the selective binding of the aptamer to thrombin with precisely matched size to produce distinct RPS signals when passing through the orifice. Kinetic analysis of hAGT repair was studied. Meanwhile, the device shows the simultaneous on-demand infusion of inhibitors to inactivate the hAGT activity, indicative of its potential in drug screening for enhanced chemotherapy. This work provides a new paradigm for θ-nanopipette-based single-cell RPS of a DNA repair protein accompanied by drug evaluation.
The use of functional DNA nanostructures as carriers to ship proteins through solid-state nanopores has recently seen substantial growth in single-protein-molecule detection (SPMD), driven by the ...potential of this methodology and implementations that it may enable. Ultrasmall nanopores have exhibited obvious advantages in spatiotemporal biological detection due to the appropriate nanoconfined spaces and unique properties. Herein, a 6.8 nm DNA tetrahedron (TDN) with a target-specific DNA aptamer (TDN-apt) was engineered to carry the representative target of acetylcholinesterase (AChE) through an ultrasmall nanopipet with a 30 nm orifice, underpinning the advanced SPMD of AChE with good performance in terms of high selectivity, low detection limit (0.1 fM), and especially superior signal-to-noise ratio (SNR). The kinetic interaction between TDN-apt and AChE was studied and the practical applicability of the as-developed SPMD toward real samples was validated using serum samples from patients with Alzheimer’s disease. This work not only presented a feasible SPMD solution toward low-abundance proteins in complex samples and but also was envisioned to inspire more interest in the design and implementation of synergized DNA nanostructure–ultrasmall nanopore systems for future SPMD development.
Using the tricyano precursor (Bu4N)(Tp)Cr(CN)3 (Bu4N+ = tetrabutylammonium cation; Tp = tris(pyrazolyl)hydroborate), a pentanuclear heterometallic cluster ...(Tp)2Cr2(CN)6Cu3(Me3tacn)3(Tp)Cr(CN)3(ClO4)3·5H2O (1, Me3tacn = N,N′,N′-trimethyl-1,4,7-triazacyclononane), three tetranuclear heterometallic clusters (Tp)2Cr2(CN)6Cu2(LOEt)2·2.5CH3CN (2, LOEt = (Cp)Co(P(O)(OEt)2)3, Cp = cyclopentadiene), (Tp)2Cr2(CN)6Mn2(LOEt)2·4H2O (3), and (Tp)2Cr2(CN)6Mn2(phen)4(ClO4)2 (4, phen = phenanthroline), and a one-dimensional (1D) chain polymer (Tp)2Cr2(CN)6Mn(bpy) n (5, bpy = 2,2′-bipyridine) have been synthesized and structurally characterized. Complex 1 shows a trigonal bipyramidal geometry in which (Tp)Cr(CN)3− units occupy the apical positions and are linked through cyanide to Cu(Me3tacn)2+ units situated in the equatorial plane. Complexes 2–4 show similar square structures, where CrIII and MII (M = CuII or MnII) ions are alternatively located on the rectangle corners. Complex 5 consists of a 4,2-ribbon-like bimetallic chain. Ferromagnetic interactions between CrIII and CuII ions bridged by cyanides are observed in complexes 1 and 2. Antiferromagnetic interactions are presented between CrIII and MnII ions bridged by cyanides in complexes 3–5. Complex 5 shows metamagnetic behavior with a critical field of about 22.5 kOe at 1.8 K.
To investigate characteristics of silent alpha thalassemia genes in child-bearing adults in Guangdong, in order to provide data for the prevention and control of hemoglobin H disease.
A total of 8 ...752 cases were collected from January 2016 to December 2020. Gap-PCR was used to detect the deletional of α-thalassemia mutations (-α
, -α
), while PCR reverse dot blot hybridization assay (RDB) was used to detect the non-deletional α-thalassemia mutations (Hb CS, Hb QS and Hb Westmead).
Among 8 752 subjects, 717 cases of silent α-thalassemia were detected, the detection rate was 8.19%, including 555 cases of deletional α-thalassemia (77.41%) and 162 cases of non-deletional α-thalassemia 22.59%. The mean corpuscular volume (MCV) of deletional silent α-thalassemia was (82.09±4.10) fl, and mean corpuscular hemoglobin (MCH) was (27.03±1.37) pg, which both were over the diagnostic cut-off value for thalassemia. The MCV of non-deletional silent α-thalassemia was (81.07±4.93) fl, and MCH was (26.77±2.20) pg. According to
3‘,3‘-Difluoro-2‘-hydroxymethyl-4‘,5‘-unsaturated carbocyclic nucleosides 1−3 have been stereoselectively synthesized from ester 10, which can be conveniently prepared from ...2,3-isopropylidene-d-glyceraldehyde 7 in five steps. The whole synthesis highlighted the stereoselective Reformatskii−Claisen rearrangement, ring-closing metathesis (RCM), and palladium-catalyzed allylic alkylation, in which the regioselectivity was reversed from that of nonfluorinated substrates.
Trifluoromethylated analogs of macrosphelide A
1 and
2 were designed and synthesized. The key segment
6 was efficiently constructed via a series of high stereoselective transformations from ...trifluoromethylated diol
8. Methoxymethylation of compound
9 with 1.0
equiv of sodium hydride gave optically pure compound
23a in 73% yield. From
23a a novel route was developed to prepare key segment
7. The condensation and macrolactonization were smoothly proceeded under our modified Keck's protocol.
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