Hierarchical Self-Assembly of Organic Prolate Nanospheroids from Hydrophobic Rosette Nanotubes

Langmuir ◽  
2008 ◽  
Vol 24 (9) ◽  
pp. 4447-4450 ◽  
Author(s):  
Grigory Tikhomirov ◽  
Takeshi Yamazaki ◽  
Andriy Kovalenko ◽  
Hicham Fenniri
2001 ◽  
Vol 123 (16) ◽  
pp. 3854-3855 ◽  
Author(s):  
Hicham Fenniri ◽  
Packiarajan Mathivanan ◽  
Kenrick L. Vidale ◽  
Debra M. Sherman ◽  
Klaas Hallenga ◽  
...  

2007 ◽  
Vol 1057 ◽  
Author(s):  
Gabor Borzsonyi ◽  
Andrew J. Myles ◽  
Ross Johnson ◽  
Jae-Young Cho ◽  
Takeshi Yamazaki ◽  
...  

ABSTRACTIn an effort to increase the internal and external diameter of the RNT's, tricyclic GΛC base derivatives (XGΛC) have been synthesized and characterized. Hierchichal self-assembly results in formation of RNT's with an increased diameter, as evidenced by AFM and TEM measurements. Progress on the derivitization and characterization of the XGΛC RNT's will be presented.


2011 ◽  
Vol 1312 ◽  
Author(s):  
Gabor Borzsonyi ◽  
Rachel L. Beingessner ◽  
Takeshi Yamazaki ◽  
Jae-Young Cho ◽  
Andrew J. Myles ◽  
...  

ABSTRACTThe synthesis and self-assembly of a water-soluble, tricyclic, self-complementary heterocycle that features the hydrogen bond donor-acceptor arrays of both guanine (G) and cytosine (C) juxtaposed between a pyridine ring is presented. In solution, this tricycle, which has been termed xK1, self-assembles into Rosette Nanotubes (RNTs) that have an inner diameter of 1.4 nm. Unlike the RNTs formed from the bicyclic congener K1, we demonstrate that xK1 with its extended ð system, forms a J-type RNT assembly determined through UV-Vis, CD and fluorescence spectroscopy experiments. This observation brings the possibility of developing electrically conducting RNTs for applications in the areas of photovoltaics and molecular wires.


2011 ◽  
Vol 1316 ◽  
Author(s):  
Alaaeddin Alsbaiee ◽  
Mustapha St. Jules ◽  
Rachel L. Beingessner ◽  
Hicham Fenniri

ABSTRACTRosette nanotubes (RNTs) are obtained through the self-organization of biologically inspired self-complementary guanine-cytosine modules (G∧C motif) under physiological conditions. These architectures can express bioactive molecules on their surface by functionalizing the G∧C motif prior to self-assembly. As a result, RNTs are promising drug delivery vehicles for the treatment of diseases such as cancer and inflammatory disorders. Towards these studies, we have explored the toxicity and immunological response of RNTs and are now focused on understanding their cellular uptake, biological distribution and kinetics in vivo. For these investigations, we need to construct a RNT labeled with a radionuclide that can be followed in vivo by SPECT (single photon emission computed tomography) imaging. In this proceeding, we describe a twin G∧C motif that is functionalized with mercaptoacetyl triglycine (MAG3). This is a well known ligand which is able to form a stable chelate with the radionuclides 99mTc or 186/188Re. In order to develop the chemistry for this radiolabeling strategy for the RNTs, we demonstrate the chelation of the MAG3 functionalized twin-G∧C motif with cold rhenium and investigate the self-assembly properties of the complex into RNTs under aqueous conditions.


2007 ◽  
Vol 1057 ◽  
Author(s):  
Usha Hemraz ◽  
Hicham Fenniri

ABSTRACTRosette Nanotubes (RNTs) are formed by the self-assembly of a guanine-cytosine motif (GΛC), a hybrid of the DNA bases guanine and cytosine, to give a six membered macrocycle maintained by 18 H-bonds. In theory, any moiety covalently attached to the GΛC base can be expressed on the nanotubes surface. However we anticipate that the self-assembly and stability of these functionalised RNTs will also be governed by steric effects. Herein we describe the synthesis and the self assembly of the Twin Base Lysine (TBL-K) and its monobase (MBL-K). While TBL-K self-assembles readily in water and methanol to give nanotubular structures, MBL-K does not form nanotubes. Various techniques were used to characterize the RNTs and the factors, preventing self-assembly in the case of MBL-K, were investigated.


2002 ◽  
Vol 99 (Supplement 2) ◽  
pp. 6487-6492 ◽  
Author(s):  
H. Fenniri ◽  
B.-L. Deng ◽  
A. E. Ribbe ◽  
K. Hallenga ◽  
J. Jacob ◽  
...  

2015 ◽  
Vol 1796 ◽  
pp. 1-6 ◽  
Author(s):  
Belete Legesse ◽  
Jae-Young Cho ◽  
Rachel L. Beingessner ◽  
Takeshi Yamazaki ◽  
Hicham Fenniri

ABSTRACTRosette nanotubes (RNTs) are tubular architectures generated through the hierarchical self-assembly of the guanine-cytosine (G∧C) motif 1 or 2 (Figure 1). Motif 2 differs from 1 by the substitution at the N-atom in the G-ring with a C-atom as shown in red. In this paper, we prepare a new tricyclic G∧C base 3 from a functionalized derivative of 2 and demonstrate its self-assembly into fluorescent helical RNTs in N,N-dimethylformamide (DMF). The self-assembly and fluorescent properties of RNTs 3 were established using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-visible spectroscopy.


2011 ◽  
Vol 1316 ◽  
Author(s):  
Mounir El-Bakkari ◽  
Rachel L. Beingessner ◽  
Aws Alshamsan ◽  
Jae-Young Cho ◽  
Hicham Fenniri

ABSTRACTDiscrete nanoscale tubular architectures have received significant attention during the past decade because of their potential role in electronic and photonic devices, sensors, liquid crystals, artificial channel systems and biomedical engineering [1-2]. Our research group has reported the synthesis and characterization of the bicyclic G∧C motif, a self complementary DNA base analogue, which undergoes hierarchical self-assembly to form Rosette Nanotubes (RNTs) [3]. The stability of this system depends however, on functional group density (sterics) and net charge (electrostatics) on the RNT surface [5c]. To this end, we have synthesized several G∧C modules bearing oligopeptides with different lengths and net charge and investigated their self-assembling properties.


2011 ◽  
Vol 1316 ◽  
Author(s):  
Alaaeddin Alsbaiee ◽  
Mounir El Bakkari ◽  
Hicham Fenniri

ABSTRACTBone fractures are one of the most common bone complications. In more severe cases, bone fixation is accomplished using titanium (Ti) implant materials. Unfortunately, the need for revision surgery often arises due to implant loosening and/or deterioration of the implant/bone interface. Rosette nanotubes (RNTs) are a class of self-assembled organic materials obtained through the self-assembly of a guanine-cytosine hybrid base (G∧C motif). These organic materials have been found to increase osteoblast (bone forming cells) adhesion and hydroxyapatite deposition (bone regeneration) on titanium implants as well as on engineered hydrogels. In order to increase the bioactivity of RNTs to enhance bone cell function on Ti implants, two RNT motifs functionalized with different bioactive deca-peptides (A, B) chosen from the knuckle region of bone morphogenic proteins-7 (BMP-7) were synthesized. Their self-assembly process was investigated in water using UV-Vis and SEM techniques.


Sign in / Sign up

Export Citation Format

Share Document