Thursday, February 7, 2013

Positively Charged Dendron Micelles Display Negligible Cellular Interactions

Ryan M. Pearson,Niladri Patra,§ Hao-jui Hsu,Sayam Uddin,Petr Kraĺ,§,and Seungpyo Hong*,,

ACS Macro Lett. 2013, 2, 77−81

Study of surface-modified PEGylated dendron-based copolymers with -NH2, -COOH, -Ac and -OMe end-group functionalities.  It was demonstrated that the micelles did not exhibit charge-dependent cellular interactions as expected which could be a result of high molecular weight to surface ratio and/or the orientation of the end groups (H-bonding).  In addition, the dendron micelles were found to be nontoxic up to concentrations of 100 uM making them potential drug delivery systems.

NMP of drug loaded isoprene nanoparticles

Nanoparticles with In Vivo Anticancer Activity from Polymer Prodrug
Amphiphiles Prepared by Living Radical Polymerization
Simon Harrisson, Julien Nicolas, Andrei Maksimenko, Duc Trung Bui, Julie Mougin, and
Patrick Couvreur

This paper details the synthesis and use of gemcitabine loaded polyisoprene nanoparticles of 130-160 nm as a way of delivering anticancer drugs without the 'burst effect.' They discuss attachment of a non-polar polymer backbone to a polar drug like gemicitabine as a type of pro-drug delivery, allowing the highly cytotoxic gemitabine to be released more slowly. They found that higher molecular weight polymers (and therefore more hydrophobic nanoparticles) showed the greatest anticancer activity.

Using Self-Organization To Control Morphology in Molecular Photovoltaics

Using Self-Organization To Control Morphology in Molecular Photovoltaics
Seok Ju Kang,†,# Seokhoon Ahn,†,# Jong Bok Kim,‡ Christine Schenck,† Anna M. Hiszpanski,‡ Seokjoon Oh,† Theanne Schiros,§ Yueh-Lin Loo,‡ and Colin Nuckolls*,† 

Solution-processable doubly-contorted hexabenzocoronene and C70 derivative are used to assemble a p-n junction. ~8% HBC gives them the best solar cell power-conversion efficiency.


Catalytic Hydrotrifluoromethylation of Unactivated Alkenes

Catalytic Hydrotrifluoromethylation of Unactivated Alkenes
Satoshi Mizuta, Stefan Verhoog, Keary M Engle, Tanatorn Khotavivattana, Miriam O'Duill, Katherine Wheelhouse, Gerasimos A Rassias, Maurice Medebielle, and Veronique Emilie Gouverneur 

In this paper, terminal mono- and di-substituted alkenes, as well as terminal alkynes are converted to omega-CF3 reduced species (alkanes or alkenes, respectively).

Molecular nano-cars: Even more fun than it sounds

The most recent issue of ACS Nano featured several articles about single-molecule nanocars, complete with wheels, chassis, and motors. Admittedly this idea started as a joke, but appears to be taking off as a novel way to look at surfaces. The synthesis article listed above claims that the ultimate goal for these molecules is payload transport along a surface. 

Nitronyl Nitroxide Radical-Containing Poly(norbornene)s

From Macromolecules:

Synthesis of Pendant Nitronyl Nitroxide Radical-Containing Poly(norbornene)s as Ambipolar Electrode-Active Materials 

The authors ROMP'ed nitronyl nitroxide (NN) radical substituted norbornenes and obtained narrow dispersities of around 1.2.  The NN polymers exhibited p- and n- type redox processes. 

Abstract Image

π-Conjugated Nickel Bis(dithiolene) Complex Nanosheet


Hiroshi Nishihara

A π-conjugated nanosheet comprising planar nickel bis(dithiolene) complexes was synthesized by the reaction on water surface using a liquid−liquid interfacial reaction using benzenehexathiol in the organic phase and nickel(II) acetate in the aqueous phase. It produced a semiconducting bulk material with a thickness of several micrometers.   Atomic force microscopy and scanning tunneling microscopy confirmed that the π-conjugated nanosheet was single-layered. Modulation of the oxidation state of the nanosheet was possible using chemical redox reactions.