Ayush Verma - Academia.edu (original) (raw)
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Papers by Ayush Verma
Chemical Communications, 2008
All chemicals were purchased from Sigma-Aldrich unless otherwise noted (all solvents were reagent... more All chemicals were purchased from Sigma-Aldrich unless otherwise noted (all solvents were reagent grade), and were used as received. 1 H-NMR spectra were acquired by using Varian Mercury-300. Unit mass determination was done by using a Bruker Omniflex MALDI-TOF spectrometer. IR spectra of the nanoparticles were obtained using Nicolet Nexus FTIR spectrometer.. Synthesis of sodium 11-mercaptoundecanesulfonate Scheme 1: Synthetic route for the synthesis sodium 11-mercaptoundecanesulfonate Synthesis of Sodium undec-10-enesulfonate 1 : 11-Bromoundecene (1.23 g, 5 mmol), sodium sulfite Na 2 SO 3 (1.26 g, 10 mmol), benzyltriethyl-ammonium bromide (13.6 mg), MeOH (8mL), and H 2 O (18mL) were refluxed for 15 h. The mixture was extracted with ether (2x20 mL). The white
Nanoscale objects are typically internalized by cells into membrane-bounded endosomes and fail to... more Nanoscale objects are typically internalized by cells into membrane-bounded endosomes and fail to access the cytosolic cell machinery. Whereas some biomacromolecules may penetrate or fuse with cell membranes without overt membrane disruption, no synthetic material of comparable size has shown this property yet. Cationic nano-objects pass through cell membranes by generating transient holes, a process associated with cytotoxicity. Studies aimed at generating cell-penetrating nanomaterials have focused on the effect of size, shape and composition. Here, we compare membrane penetration by two nanoparticle 'isomers' with similar composition (same hydrophobic content), one coated with subnanometre striations of alternating anionic and hydrophobic groups, and the other coated with the same moieties but in a random distribution. We show that the former particles penetrate the plasma membrane without bilayer disruption, whereas the latter are mostly trapped in endosomes. Our results offer a paradigm for analysing the fundamental problem of cell-membrane-penetrating bio-and macro-molecules. * Calculated from 1 H NMR analysis after decomposition of the core, data are all ±5%. † Determined from TEM images and expressed as average diameter ± one standard deviation. ‡ Weight loss as determined by thermogravimetric analysis after complete desorption of the organic ligands, which is directly related to the ligand-shell packing density, data are all ±5%. § Zeta potential measurements are in serum-free medium.
Chem Commun, 2007
Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantia... more Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantial pre-organization of the particle monolayer.
Polymer Bulletin, 1990
Summary This paper reports the synthesis and characterization of new, functionalized poly(alkyl v... more Summary This paper reports the synthesis and characterization of new, functionalized poly(alkyl vinyl ether) oligomers, and block copolymers containing poly(alkyl vinyl ether) and poly(methyl methacrylate). Using the HI/ZnI2 initiating system in nonpolar solvents (hexane, toluene) at -15 °C, both monofunctional and difunctional poly(alkyl vinyl ether) oligomers of predicted molecular weights precisely terminated with ester end groups have been prepared. Novel
Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantia... more Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantial pre-organization of the particle monolayer.
Chemical Communications, 2008
All chemicals were purchased from Sigma-Aldrich unless otherwise noted (all solvents were reagent... more All chemicals were purchased from Sigma-Aldrich unless otherwise noted (all solvents were reagent grade), and were used as received. 1 H-NMR spectra were acquired by using Varian Mercury-300. Unit mass determination was done by using a Bruker Omniflex MALDI-TOF spectrometer. IR spectra of the nanoparticles were obtained using Nicolet Nexus FTIR spectrometer.. Synthesis of sodium 11-mercaptoundecanesulfonate Scheme 1: Synthetic route for the synthesis sodium 11-mercaptoundecanesulfonate Synthesis of Sodium undec-10-enesulfonate 1 : 11-Bromoundecene (1.23 g, 5 mmol), sodium sulfite Na 2 SO 3 (1.26 g, 10 mmol), benzyltriethyl-ammonium bromide (13.6 mg), MeOH (8mL), and H 2 O (18mL) were refluxed for 15 h. The mixture was extracted with ether (2x20 mL). The white
Nanoscale objects are typically internalized by cells into membrane-bounded endosomes and fail to... more Nanoscale objects are typically internalized by cells into membrane-bounded endosomes and fail to access the cytosolic cell machinery. Whereas some biomacromolecules may penetrate or fuse with cell membranes without overt membrane disruption, no synthetic material of comparable size has shown this property yet. Cationic nano-objects pass through cell membranes by generating transient holes, a process associated with cytotoxicity. Studies aimed at generating cell-penetrating nanomaterials have focused on the effect of size, shape and composition. Here, we compare membrane penetration by two nanoparticle 'isomers' with similar composition (same hydrophobic content), one coated with subnanometre striations of alternating anionic and hydrophobic groups, and the other coated with the same moieties but in a random distribution. We show that the former particles penetrate the plasma membrane without bilayer disruption, whereas the latter are mostly trapped in endosomes. Our results offer a paradigm for analysing the fundamental problem of cell-membrane-penetrating bio-and macro-molecules. * Calculated from 1 H NMR analysis after decomposition of the core, data are all ±5%. † Determined from TEM images and expressed as average diameter ± one standard deviation. ‡ Weight loss as determined by thermogravimetric analysis after complete desorption of the organic ligands, which is directly related to the ligand-shell packing density, data are all ±5%. § Zeta potential measurements are in serum-free medium.
Chem Commun, 2007
Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantia... more Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantial pre-organization of the particle monolayer.
Polymer Bulletin, 1990
Summary This paper reports the synthesis and characterization of new, functionalized poly(alkyl v... more Summary This paper reports the synthesis and characterization of new, functionalized poly(alkyl vinyl ether) oligomers, and block copolymers containing poly(alkyl vinyl ether) and poly(methyl methacrylate). Using the HI/ZnI2 initiating system in nonpolar solvents (hexane, toluene) at -15 °C, both monofunctional and difunctional poly(alkyl vinyl ether) oligomers of predicted molecular weights precisely terminated with ester end groups have been prepared. Novel
Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantia... more Nanoparticles featuring highly flexible sidechains template to peptides, demonstrating substantial pre-organization of the particle monolayer.