Active Intracellular Delivery of a Cas9/sgRNA Complex Using Ultrasound‐Propelled Nanomotors

Direct and rapid intracellular delivery of a functional Cas9/sgRNA complex using ultrasound‐powered nanomotors is reported. The Cas9/sgRNA complex is loaded onto the nanomotor surface through a reversible disulfide linkage. A 5 min ultrasound treatment enables the Cas9/sgRNA‐loaded nanomotors to directly penetrate through the plasma membrane of GFP‐expressing B16F10 cells. The Cas9/sgRNA is released inside the cells to achieve highly effective GFP gene knockout. The acoustic Cas9/sgRNA‐loaded nanomotors display more than 80 % GFP knockout within 2 h of cell incubation compared to 30 % knockout using static nanowires. More impressively, the nanomotors enable highly efficient knockout with just 0.6 nm of the Cas9/sgRNA complex. This nanomotor‐based intracellular delivery method thus offers an attractive route to overcome physiological barriers for intracellular delivery of functional proteins and RNAs, thus indicating considerable promise for highly efficient therapeutic applications.     

Expeditious synthesis of 9-allenylpurines via cesium carbonate catalyzed isomerization of 9-alkynylpurines

An expeditious and convenient method to synthesize 9-allenylpurines via cesium carbonate catalyzed isomerization of 9-alkynylpurines has been successfully developed. The reactions proceeded rapidly under the base conditions and formed the desired products in good to excellent yields. The method was suitable with a broad substrate scope and proceeded well even on a multgram-scale. The obtained 9-allenylpurines were successfully applied to prepare various potential bioactive 9-acyclic nucleosides with high regioselectivity promoted by AgNO₃.     

Synthesis and Crystal Structure of 18-Tungstotetranickel(II) diphosphate Na_(10){(PW_9O_(34))_2Ni_4(H_2O)_2}·26H_2O

1 INTRODUCTIONThe inorganic chemistry concentrating on polyoxometallates, is in a position to connect elementary building blocks and their derivatives in different ways, enabling people to synthesize a large variety of remarkable substances, especially those in the "nanoworld". Of particular importance is the anionic-type which has {MOx}-type building-block units, where M stands for the d block elements in high oxidation states.[1] In 1973 Weakley, Evans and Showell isolated[2] K10P2W1…     

Nonideal mixing of 16-(9-anthroyloxy) palmitic acid and fatty acid in monolayer

The surface pressure-molecular area curve of the mixed monolayer of 16-(9-anthroyloxy) palmitic acid (16AP) and fatty acid (palmitic or stearic acids) showed various kink points which indicated the phase transitions of the monolayer. On the basis of the surface phase rule, the phase diagrams of the mixed monolayer were elucidated. The bifunctional molecule, 16AP, takes two orientations in a monolayer state, that is, horizontal and vertical ones. Horizontally oriented 16AP and vertically oriented fatty acid form a mixed monolayer but this exhibits deviation from the ideal mixing, which was interpreted in terms of the surface regular solution theory. On the other hand, the 16AP molecule in the vertical state was found to be immiscible with the fatty acid molecule in a monolayer de spite both molecules being vertical to the surface and parallel to each other. This was caused by the participation of the 9-anthroyloxy moiety of 16AP in the interaction of 16AP and fatty acid in the hydrophobic region of the monolayer.     

HPLC of 9-fluorenylmethylchloroformate-polyamine derivatives with fluorescence detection

Summary There are a number of reagents available for fluorescent labelling of primary amines. These include dansyl chloride, o-phthalaldehyde, fluorescamine, and a new reagent, 9-fluorenylmethylchloroformate (FMOC), reported recently. This paper describes a reversed-phase HPLC procedure for the separation and fluorescence detection of polyamines following pre-column derivatization with FMOC. The polyamines studied by this method include putrescine, cadaverine, spermidine, and spermine. Experiments were carried out to determine maximum fluorescence excitation and emission wavelengths, optimum reaction pH, linear ranges, and minimum detection limits for each of the polyamines. The HPLC method includes a gradient program which provides complete separation from serum hydrolysate components and specificity for the four polyamines with detection limits ranging from 2 to 9 pg. This procedure was applied to hydrolyzed serum samples.     

Cp*Me5P6C5: Ein neues Carbaphosphan mit einem Strukturelement aus dem Hittorfschen Phosphor

Cp*Me₅P₆C₅: A New Carbaphosphane with a Structure Unit of Hittorf-Phosphorus The thermolysis of 1,2,3-tris(pentamethylcyclopentadienyl)cyclotriphosphane [(Cp*P)₃, 1 ] or 2,3,4,6-Tetrakis(pentamethylcyclopentadienyl)bicyclo[3.1.0]hexaphosphane [Cp*₄P₆, 2 ] leads in addition to the known 3,4-bis(pentamethylcyclopentadienyl)tricyclo[3.1.0.0^{2, 6}]hexaphosphane [Cp*₂P₆, 3 ] to the pentacyclic carbaphosphanes 3,4,5,6,11-pentamethyl-endo-9-pentamethylcyclopentadienyl- 3,4,5,6,11-pentacarba-pentacyclo [6.1.1^1,8.1^3,6.0^2,70^10,11]-4-en-undecaphosphane and 3,4,5,6,11-pentamethyl-exo-9-pentamethylcyclopentadienyl-3,4,5,6,11-pentacarba-pentacyclo [6.1.1^1,8.1^3,6.0^2,70^10,11]-4-en-undecaphosphane [Cp*Me₅P₆C₅, 4a, 4b ]. Furthermore, other polyphosphanes are formed, like 1,2,3,4-tetrakis(pentamethylcyclopentadienyl)cyclotetraphosphane [(Cp*P)₄, 5 ] and 2,4-bis(pentamethylcyclopentadienyl)-tetraphosphabicyclo[1.1.0]butane [(Cp*P)₂P₂, 6 ]. The structure of 4a and 4b is determined by NMR-spectroscopy. The molecule contains a P₅C₃-cunean-unit, to which a C₂Me₂-brigde and a PCp*-brigde is bonded.     

One-pot Synthesis of 1,8-Dioxo-decahydroacridine Derivatives in Aqueous Media

A new and efficient method for the synthesis of 1,8‐dioxo‐9‐aryl‐decahydroacridine derivatives was developed via a one‐pot three component reaction of dimedone, aromatic aldehydes and ammonium acetate in the presence of ammonium chloride, or Zn(OAc)₂·2H₂O or L‐proline separately in water in the short period of time and high yields.     

Soluble and Green‐light‐emitting Oligo(9‐fluorenylideneacetic acid): Electrosynthesis and Characterization

A novel semiconducting oligo(9‐fluorenylideneacetic acid) (OFYA) with good redox activity and stability was successfully electrosynthesized by direct anodic oxidation of 9‐fluorenylideneacetic acid (FYA) in CH₂Cl₂ containing boron trifluoride diethyl etherate (BFEE) as the supporting electrolyte. The as‐formed OFYA film was readily soluble in dimethyl sulfoxide and tetrahydrofuran, and partly soluble in water, alcohol, acetonitrile and acetone. FT‐IR and ¹H NMR spectra, together with computational results proved that FYA was probably polymerized through the coupling at C(2) and C(7) positions. Further, OFYA was a typical green light‐emitter with maximal emission at 555 nm and its fluorescence quantum yield was distinctly improved in comparison with that of the monomer. The oligomer was also studied by UV‐vis spectroscopy, MALDL‐TOF mass spectrometry, and thermal analysis, respectively.     

Programmable Live-Cell CRISPR Imaging with Toehold-Switch-Mediated Strand Displacement

The widespread application of CRISPR-Cas9 has transformed genome engineering. Nevertheless, the precision to control the targeting activity of Cas9 requires further improvement. We report a toehold-switch-based approach to engineer the conformation of single guide RNA (sgRNA) for programmable activation of Cas9. This activation circuit is responsive to multiple inputs and can regulate the conformation of the sgRNA through toehold-switch-mediated strand displacement. We demonstrate the orthogonal suppression and activation of Cas9 with orthogonal DNA inputs. Combination of toehold switches leads to a variety of intracellular Cas9 activation programs with simultaneous and orthogonal responses, through which multiple genome loci are displayed in different colors in a controllable manner. This approach provides a new route for programing CRISPR in living cells for genome imaging and engineering.