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Abstract: Dendrons constituted of an adamantane core, a focal point and three arms, were synthetized starting from a multifunctional adamantane derivative. Maleimido groups at the periphery of the scaffold were used to covalently attach the peptide called P140, a therapeutic phosphopeptide controlling disease activity in systemic lupus, both in mice and patients. Biotinylation of the trimers at the focal point was performed using click chemistry and the conjugates were studied in terms of solubility, binding affinity to its receptor, the HSPA8/HSC70 chaperone protein, effect on HSPA8 folding property and in vivo activity. The results showed that the trimerization of P140 peptide does not trigger aggregation or steric hindrances during the interaction with HSPA8 protein. Compared to the monomeric cognate peptide, the trivalent P140 peptide displayed the same capacity, in vitro, to down-regulate HSPA8 activity and, in vivo in MRL/lpr lupus-prone mice, to reduce abnormal blood hypercellularity. The control trimer synthesized with the same scaffold and a scrambled sequence of P140 showed no effect in vivo. This work reveals that adamantane-based scaffolds with a well-defined spatial conformation are promising trivalent systems for molecular recognition and for biomedical applications. [Copyright &y& Elsevier]

We describe the design, synthesis, and 'stimuli-responsive' study of ferrocene-linked Fréchet-type [poly(aryl ether)]-dendron-based organometallic gels, in which the ferrocene moiety is attached to the dendron framework through an acyl hydrazone linkage. The low-molecular-weight gelators (LMWGs) form robust gels in both polar and non-polar solvent/solvent mixtures. The organometallic gels undergo stimuli-responsive behavior through 1) thermal, 2) chemical, and 3) electrochemical methods. Among them, conditions 1 and 3 lead to seamlessly reversible with repeated cycles of identical efficiency. Results indicate that the flexible nature of the poly(aryl ether) dendron framework plays a key role in retaining the reversible electrochemical behavior of ferrocene moiety in the LMWGs. Further, the organometallic gelators have exhibited unique selectivity towards Pb2+ ions (detection limit ≈10−8 M). The metal ion-sensing results in a gel-sol phase transition associated with a color change visible to the naked eye. Most importantly, decomplexing the metal ion from the system leads to the regeneration of the initial gel morphology, indicating the restoring ability of the organometallic gel. The metal-ligand binding nature has been analyzed by using 1H NMR spectroscopy, mass spectrometry, and DFT calculations. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis of the 2- and 4-functional acrylic exo-7-oxanorbornene species 2-((2-((3a R,7a S)-1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2 H-4,7-epoxyisoindol-2-yl)ethoxy) carbonyl)-2-methylpropane-1,3-diyl diacrylate and (((2-((2-((3a R,7a S)-1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2 H-4,7-epoxyisoindol-2-yl)ethoxy) carbonyl)-2-methylpropane-1,3-diyl)bis(oxy))bis(carbonyl))bis(2-methylpropane-2,1,3-triyl) tetraacrylate, and their use as common precursors for the preparation of a small library of dendronized thioether adducts via nucleophile-mediated thiol- Michael coupling chemistry. We subsequently demonstrate that the dendronized monomers can be (co)polymerized via ring-opening metathesis polymerization employing Grubbs'-type Ru-based initiators to give novel functional dendronized (co)polymers of predictable molecular weights and acceptable dispersities ( ĐM = [ABSTRACT FROM AUTHOR]

Abstract: Syntheses of several examples of a new type of trivalent building blocks for the preparation of aliphatic polyester dendrimers are presented. Starting from the well-known mono-O-benzylidenepentaerythritol, AB3 type acid dendrons can be obtained in high yield in only two steps. Other triprotected bis-2,2-(hydroxymethyl)-3-hydroxypropanoic acid derivatives with varying protecting groups were also synthesized readily. This type of dendron was used in combination with 2,2′-bis(hydroxymethyl) propanoic acid (bis-HMPA) divalent dendrons to produce low generation mixed polyester dendrimers with increased number of branching points. [Copyright &y& Elsevier]

Abstract: In this paper we describe the fabrication of honeycomb-shaped polyurethane films from dendritic side-chain polymers presenting reactive pendent units. Two novel functional polyurethanes, poly(urethane-co-acylurea) (PU-PACY) and polyurethane-co-azetidine-2,4-dione containing polyurethane (PU-PAZ), were synthesized. The waxy dendrons featured focal urea/malonamide linkages favorable for hydrogen bonding and peripheral alkyl chains. These intermolecular forces caused two functional PUs to undergo phase separation and self-assembly. This resulted in honeycomb-like films with well-controlled surface roughness characterized in terms of the ratio of rim width (W) to the pore size (D), i.e. W/D. The PU-PAZ film had a higher contact angle (CA) and a lower value of W/D than did the PU-PACY analogue, due to the presence of relatively more hydrophobic azetidine-2, 4-dione functionalities in the former film. Subsequent chemical modification of the PU-PAZ films through reaction with a hydrophobic poly(oxyalkylene)amine enhanced the CA from 113 to 134°. Further physical modification through a peeling-off process rendered the film surface with a three-dimensional (3D) rod-co-valley-structure having feature dimensions on a submicrometer scale. The 3D rod-co-valley–like film exhibited superhydrophobicity with a CA of 151°. The films also displayed excellent solvent-resistance after crosslinking with a diamine. Through hydrophobic or hydrophilic chemical modification, we could readily manipulate the surface properties of these honeycomb-like films with controllable surface roughnesses and reactive functionalities. [Copyright &y& Elsevier]

Highlights: [•] The FT Raman spectra of the dendrons with terminal carbamate groups were studied. [•] The structural optimization and normal mode analysis were performed for dendrons. [•] Dendron molecule has a concave lens structure. [ABSTRACT FROM AUTHOR]

Objectives Phosphoserine-based functionalization has been proposed as a tool to improve integration of endosseous implants by promoting osteoblast adhesion and differentiation in vitro. The present work investigates whether phosphoserine-tethered poly(epsilon-lysine) dendrons, when applied as a film to titanium surfaces, enhance the differentiation of osteoblastic cells and the activation of Wnt/β-catenin signaling. Materials and methods These films were tested in a murine model of calvaria-derived MC3T3 osteoblastic cells, primary bone marrow cells and mesenchymal, undifferentiated C2C12 cells. Gene expression was assayed by Real Time PCR, and activation of Wnt signaling pathway was measured with a reporter assay. Results Dendrons increased expression of alkaline phosphatase and osteocalcin, two osteoblastic markers, in both murine osteoblastic MC3T3 cells and primary bone marrow cells. The expression of osteoprotegerin, a protein opposing osteoclastogenesis was also significantly higher in cells growing on dendron-coated substrates both at 3 and 6 days of culture. Similarly, the mRNA levels of Wisp-2 and of β-catenin, two Wnt target genes, were also markedly increased in this group at day 6. The activation of this signaling pathway in cells growing on the dendron-coated surfaces was confirmed by use of a TCF/β-catenin reporter system in the C2C12 cell line. Conclusions The findings of the present study show that phosphoserine-tethered poly(epsilon-lysine) dendron films act as stimuli for the activation of specific signal cascades and promote the differentiation of adhering progenitor cells into an osteoblastic phenotype. [ABSTRACT FROM AUTHOR]

Liquid crystalline blue phases (BPs) show excellent potential for application in tunable photonic devices because they possess the unique optical property that the selective 3D Bragg diffraction in a visible wavelength region can be continuously shifted using an electric field. A new approach to simultaneously extend the wavelength range of field-induced Bragg diffraction shift and the temperature range of thermodynamically stable BPs is critically needed. Here, a new BP material system is shown using a dendron molecule to extend simultaneously the two BP ranges. One is the temperature range of thermodynamically stable BPs, which is expanded from 2.1 to 4.6 °C. The other is the reversible maximum shift range of Bragg wavelength on the electric field, which is extended from 85 to 109 nm. The physical mechanism of the dendron-stabilizing effect in BPs is discussed in terms of elastic property and orientational order of liquid crystal molecules. [ABSTRACT FROM AUTHOR]

Highlights: [•] The FTIR and FT Raman spectra of the “Janus”-type dendrimers were studied. [•] The structural optimization and normal mode analysis were performed for dendron. [•] Dendron molecule has a concave lens structure. [•] FTIR spectra reveal the presence of the different types of H-bonds in the dendrimers. [ABSTRACT FROM AUTHOR]

A novel star-shaped polymer, porphyrin-poly(L-lysine) dendrons (PP-PLLD), is synthesized by the click reaction between azido-modified porphyrin and propargyl focal point poly(L-lysine) dendrons. Its chemical structure is characterized by 1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography (GPC) is analyses etc. Due to its amphiphilic property, the obtained PP-PLLD has a low critical micelle concentration in an aqueous solution, and can load doxorubicin (DOX) with a loading amount of 64 μg mg−1. By in vitro toxicity assay, PP-PLLD has no dark cytotoxicity but has significant phototoxicity. Moreover, DOX-loaded PP-PLLD shows a higher cytotoxicity under the light condition than PP-PLLD or DOX alone, suggesting PP-PLLD has a potential application in combined photodynamic therapy and chemotherapy. [ABSTRACT FROM AUTHOR]

Due to their relative easy synthesis and commercial availability, nanovectors based on dendrimers and dendrons are among the most utilized non-viral vectors for gene transfer. Concomitantly, recent advances in molecular simulations and computer architectures not only allow for accurate predictions of many structural, energetical, and eventual self-assembly features of these nanocarriers per se, but are able to yield fundamental information about the interactions of these nanovectors with their nucleic acid cargoes at a molecular level. In this work, we aim at reviewing some of our own efforts in the field of multiscale molecular modeling of these fascinating materials. This review is written by computational scientists for experimental scientists, with the specific purpose of illustrating the potentiality of these methodologies and the usefulness of multiscale molecular modeling as an innovative and complementary tool in their current research. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a straightforward method to prepare 1st and 2nd generation adamantane-based dendrons, previously called HYDRAmers, bearing at the periphery the anti-inflammatory drug, ibuprofen. The multivalency effect on the drug activity was studied, demonstrating that our multivalent ibuprofen-dendron conjugates exert an enhanced anti-inflammatory activity compared to free ibuprofen, in vitro. These results provide insights into the effect of HYDRAmer multivalency on biological interactions for therapeutic applications. [Copyright &y& Elsevier]

A series of polyelectrolyte-dendritic amphiphilic complexes with high degrees of substitution were prepared by ionic self-assembly of the polyelectrolyte poly (3-aminopropyl) methylsilane hydrochloride (PSI) with dendritic 3,4,5-tris(n-alkan-1-yloxy)-benzoic acid potassium salt [(3,4,5)nG1-COOK, n = 8, 10, 12, 14, and 16, where n was the number of carbon atoms in the alkyl tail]. These complexes PSI-(3,4,5)nG1 were characterized with wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), Fourier transform infrared (FT-IR), thermogravimetry (TG), differential scanning calorimetry (DSC), and polarized optical microscopy (POM). WAXD profiles indicated a transition from liquid crystalline (n = 8, 10) to crystalline phase (n = 12, 14, and 16) in the PSI-(3,4,5)nG1 resulted from the dendritic amphiphiles at room temperature. PSI-(3,4,5)nG1 (n = 8, 10) were found to be in the hexagonal columnar (Φh) liquid crystalline phase, with the lattice parameter a = 3.05, 3.35 nm for n = 8, 10, respectively. On the other hand, PSI-(3,4,5)nG1 (n = 12, 14, and 16) formed end-to-end bilayer lamellar crystalline structures with the long periods d = 4.56, 5.04, and 5.68 nm for n = 12, 14, 16, respectively, at room temperature. An ionic thermotropic liquid crystalline state was obtained from PSI-(3,4,5)nG1 at temperatures: (a) below the clearing point Ti (n = 8, 10), and (b) between the melting point Tm and Ti (n = 12, 14, and 16). This research provides an easy way to obtain complexes with high degrees of substitution through the self-assembly of the linear polysiloxane and dendron amphiphiles, and demonstrates that the alkyl tail lengths of the bound dendritic amphiphiles play an important role in determining the mesomorphous structure for the polyelectrolyte-dendritic amphiphile complexes. [ABSTRACT FROM PUBLISHER]

This article contains an account of the career of John Eccles that can be divided into two parts. The first extends from 1925, when he won a Rhodes scholarship to Magdalen College Oxford, to 1975, when he took voluntary retirement from the State University of New York at Buffalo. During this period, he set up six different laboratories in which he carried out research on synaptic mechanisms that provide the basis of neuroscience. The second period is the 20 years between his retirement and death in Switzerland, which he spent on the problem of the relationship between mind and brain. [ABSTRACT FROM AUTHOR]

Polyester dendrimers have been comprehensively reviewed starting from their first synthesis in the early 1990s by Hawker and Fréchet. Polyester dendrimers have attracted and continue to attract extensive interest because they are comparatively easy to make and because, whenever they have been tested, they have been found to be non-toxic. A number of different strategies for their synthesis have been examined and the methods employed for formation of the ester bond during dendrimer assembly have been summarized. The newest approaches, including the use of bifunctional orthogonally reacting dendrons and accelerated synthesis have been surveyed. [ABSTRACT FROM AUTHOR]

Abstract: The electrografting of oligoethylene glycol or (OEG)ylated carbazole linear dendrons and their protein adsorption resistance properties have been investigated by surface plasmon resonance (SPR) spectroscopy. A series of the carbazole dendron generations, G0, G1, G2 were synthesized and electrodeposited by cyclic voltammetry (CV) on Au-glass substrate which also served as a surface for evanescent waveguide excitation in SPR. In addition, the films were characterized by in-situ electrochemical SPR (EC-SPR), static water contact angle, and X-ray photoelectron spectroscopy (XPS) measurements. It was observed that electropolymerized films prepared from the higher generation linear-dendron G2, is most effective in preventing non-specific protein adsorption as observed by SPR kinetic measurements using fibrinogen as model protein. Film thickness also played a critical role in protein adsorption resistance - electrodeposition approaching monolayer thickness gave the highest protein resistance. In addition, the films were evaluated for non-specific protein binding against the smaller proteins, lysozyme and bovine serum albumin (BSA). The study provides insight to manipulating the architecture and composition of protein resistant materials deposited on metals and semi-conducting substrates and their possible use in biomedical applications. [Copyright &y& Elsevier]

Three binuclear ruthenium complexes with dendritic side chains, 1,4-[RuCl(CO)(PMe3)3CH=CH]2C6H2-2,5-(Gn)2 with Gn = G0 (1), G1 (2), and G2 (3), have been synthesized by the reactions of the corresponding diethynylaryls with the ruthenium hydride complex [RuHCl(CO)(PPh3)3] and subsequent ligand exchange with PMe3. The complexes have been characterized by elemental analysis, NMR, and UV–Vis spectrophotometry. The structure of complex 1 has been determined by X-ray crystallography. Their electrochemical properties have been investigated. Electrochemical studies in solution may imply that the two metal centers in complexes 1–3 have good electronic communications between each other. However, the electron communication is not effectively enhanced with increasing generation of the dendrons in solution. [Copyright &y& Elsevier]

Abstract: Two new water soluble dendronized polymers (PLn) from acrylate Behera amine monomer of different molecular weights were successfully synthesized. The polymers were characterized by FTIR, NMR, GPC and DLS. Both GPC and DLS results indicated that these PLn have a remarkable tendency to form aggregates in solution that lead to apparent molecular weights that are much higher than their theoretical values, as well as large diameters in solution. However, the addition of any PLn to water did not cause any increase in viscosity up to concentrations of 1000ppm. The possible interactions of PLn with the cationic surfactant CTAT were explored by solution rheometry. A synergistic viscosity enhancement was found by adding small amounts of dendronized PLn polymers to a CTAT solution composed of entangled worm-like micelles. The highest association tendency with CTAT was found for PL1 at the maximum polymer concentration before phase separation (i.e., 100ppm). The solution viscosity at low-shear rates could be increased by an order of magnitude upon addition of 100ppm of PL1 to a 20mM CTAT solution. For this mixture, the fluid obtained was highly structured and exhibited only shear thinning behavior from the smallest shear rates employed. These PL1/CTAT mixtures exhibited an improved elastic character (as determined by dynamic rheometry) that translated in a much longer value of the cross-over relaxation time and a pronounced thixotropic behavior which are indicative of a strong intermolecular interaction. In the case of the polymer with a higher theoretical molecular weight, PL2, its association with CTAT leads to an extraordinary doubling of solution viscosity with just 0.25ppm polymer addition to a 20mM CTAT solution. However, such synergistic viscosity enhancement saturated at rather low concentrations (25ppm) indicating an apparent lower solubility as compared to PL1, a fact that may be related to its higher molecular weight. [Copyright &y& Elsevier]

Three dendronized polymers from generation one to generation three have been prepared by complexing negatively charged Fréchet-type dendrons with a polyanion, poly(diallydimethylammonium chloride) (PDADMAC). The grafting degree has been confirmed mainly by elemental analysis. In dilute solutions of tetrahydrofuran, static light scattering studies indicate that the first generation complex has a coil-like conformation, even more flexible than PDADMAC. The second and third generation complexes exhibit polyelectrolyte behavior. Dynamic light scattering experiments indicate that all the three complexes have almost the same hydrodynamic radius, indicating that they might own similar coil conformation. Atomic force microscopy shows the existence of disordered globules formed by one or a couple of complex coils. All these observations can be explained by the flowerlike coil conformation, which is formed by the intra-molecular association. This is totally different from the stretched chain conformation formed by covalently connected dendronized polymers. This result also explains why some ordered supramolecular structures, found in condensed state of the similar complexes, are not as perfect as those of conventional dendronized polymers. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis and catalytic testing of several dendron–ordered mesoporous silica hybrids are reported. These materials are active in both the nitroaldol (Henry) reaction and the transesterification of glyceryl tributyrate to afford methyl esters. In both reactions it is observed that dendrons terminated with primary amines are more catalytically active than samples containing dendrons terminated with secondary amines. On a mmol nitrogen per gram of silica basis, the first generation dendrons are the most active for both chemistries, and the SBA-15 samples display a higher activity than the MCM-41 samples. The pore-size effect observed is consistent with significant diffusion resistance in the MCM-41 samples. The activity trend observed in the SBA-15 materials is consistent with decreased cooperative effects between the amines and surface silanols as the dendrons become larger. Clear trends are observed indicating that higher generation dendrons are more selective to alcohol formation in the Henry reaction. The dendron catalysts are much more active and stable than simple amines attached to silica in the transesterification of triglycerides. Preliminary results shown indicate that these materials can also catalyze more demanding chemistries, an example of which is the Aldol condensation of 5-(hydroxymethyl)furfural and acetone. The results shown indicate that dendron–OMS hybrids can serve as effective solid base catalysts for a diverse range of chemistries. [Copyright &y& Elsevier]

Facile synthesis of second-generation dendrons with an aldehyde, epoxy, or t-Boc group at the focal point and nine carboxylic acid groups at the periphery is reported. The scheme includes a coupling of the first-generation dendrons and a two-step, one-pot reaction that proceeds through a Boc deprotection and in situ conjugation at the focal point. [ABSTRACT FROM AUTHOR]

The reactions of RuCl2(PPh3)3 with either a small amino diphosphine or a first-generation phosphorus-containing dendron possessing an aminodiphosphine as the core induce the formation of complexes in which two amino diphosphines are associated through the metallic center. Determination of the structure of the smallest complex by X-ray diffraction shows that the metal is surrounded by a square-based bi-pyramid defined by the four phosphorus atoms of both diphosphines in a single plane, with the chlorine atoms at both summits. The first generation dendrons behave in the same way as the small compound, and allow us to isolate an original bis dendron, associated through the ruthenium atom. [ABSTRACT FROM AUTHOR]

Supramolecular structures, such as micelles, liposomes, polymerosomes or dendrimerosomes, are widely studied and used as drug delivery systems. The behavior of amphiphilic building blocks strongly depends on their spatial distribution and shape of polar and nonpolar component. This report is focused on the development of new versatile synthetic protocols for amphiphilic carbosilane dendrons (amp-CS-DDNs) capable of self-assembly to regular micelles and other supramolecular objects. The presented strategy enables the fine modification of amphiphilic structure in several ways and also enables the facile connection of a desired functionality. DLS experiments demonstrated correlations between structural parameters of amp-CS-DDNs and the size of formed nanoparticles. For detailed information about the organization and spatial distribution of amp-CS-DDNs assemblies, computer simulation models were studied by using molecular dynamics in explicit water. [ABSTRACT FROM AUTHOR]

Dendritic molecules bearing metal complexes in their structure (metallodendrimers and metallodendrons) are considered prospective therapeutic entities. In particular, metallodendrons raise interest as antitumor agents for the treatment of poorly curable or drug-resistant tumors. Herein, we have synthesized amphiphilic triazine-phosphorus dendrons bearing multiple copper (II) or gold (III) complexes on the periphery and a branched hydrophobic fragment at the focal point. Due to their amphiphilic nature, metallodendrons formed single micelles (mean diameter ~9 nm) or multi-micellar aggregates (mean diameter ~60 nm) in a water solution. We have tested the antitumor activity of amphiphilic metallodendrons towards glioblastoma, a malignant brain tumor with a notoriously high level of therapy resistance, as a model disease. The metallodendrons exhibit higher cytotoxic activity towards glioblastoma stem cells (BTSC233, JHH520, NCH644, and SF188 cell lines) and U87 glioblastoma cells (IC50 was 3–6 µM for copper-containing dendron and 11–15 µM for gold-containing dendron) in comparison with temozolomide (IC50 >100 µM)—the clinical standard of care for glioblastoma. Our findings show the potential of metallodendron-based nanoformulations as antitumor entities. [ABSTRACT FROM AUTHOR]

Abstract: This review presents an overview of 1→2 branched dendrimers and dendrons, created by a divergent procedure, from their synthesis to modern day applications. The first members of this branched class of fractal macromolecules were prepared through a cascade synthesis, which was later replaced by the iterative divergent synthetic approach. Most classes of this 1→2 N-, Aryl-, C-, Si-, and P-branched families are included and catalogued by their mode of connectivity. Dendritic macromolecules have had significant impact in the field of material sciences and are one of the major starting points for nanotechnology as a result of the numerous modifications that can be conducted, either on the surface or within their molecular infrastructure, thus taking advantage of their unimolecular micelle properties. These host cavities, maintained by the dendritic branches, allow for the incorporation of nanoparticles as well as metal particles, which make these attractive in catalysis and imaging studies. The solubility of these fractal constructs can be tailored depending on their surface modifications. Highly water-soluble, neutral dendrimers appended with, grown from, or acting as hosts to specific molecules give rise to a wide variety of biomedical applications such as drug delivery systems and MRI imaging agents. The inherent supramolecular or supramacromolecular chemistry has been exploited but the design and construction of uniquely tailored macrostructures have just begun. Laser dyes, as well as electron and energy donor and acceptor functionality, have also been paired with these fractal constructs in order to probe their uses in the field of molecular electronics. With their synthetic control, seemingly limitless modifications and wide variety of potential applications, as well as their now commercial availability, these 1→2 branched dendrimers have become an important nanostructured tools for diverse utilitarian applications. This review mainly covers 1→2 branched non-chiral dendrimers prepared by a divergent process but selected chiral surfaces are considered as well as metal encapsulation and a few hyperbranched routes to related imperfect dendrimers. [Copyright &y& Elsevier]

Abstract: Three novel series of amphiphiles based on poly(amidoamine) dendrons (from G1 to G3) and having different aromatic chromophores (Cz I, Cz II, and Py) at the focal point were synthesized and studied for their self-assembly behavior in aqueous solution by using electronic microscopies (i.e., SEM and TEM), UV–vis, fluorescence, IR, and 1H NMR spectroscopy. It was found that the generation of dendrons affected significantly the self-assembly of these amphiphiles in aqueous solution and the morphological structures of the resulting assemblies depended greatly on the architecture of the focal chromophores. As a result, the first generation of dendrons assembled readily into vesicles at low concentrations. These vesicular structures subsequently fused to form a stable tubular structure. Similar tubular structures could also be directly obtained through self-assembly of these amphiphilic dendrons at high concentrations. X-ray investigations showed that the resulting tubules possessed a lamellar structure. A head-to-head packing model of amphiphilic dendrons in the assemblies was proposed. [Copyright &y& Elsevier]

Abstract: The synthesis of thiophene-containing second (G2) and third generation (G3) dendronized macromonomers with methacrylate polymerizable units as well as their corresponding dendronized polymers is reported. The dendrons are prepared from branched thiophene oligomers and are decorated with straight alkyl chains for solubility reasons. The polymerization reactions were done with AIBN as initiator and the polymers were characterized by NMR spectroscopy, elemental analysis and GPC. Molar masses are in the range of 2.2–5.4×105 gmol−1 (G2) and 1.3–3.0×104 gmol−1 (G3) for different runs. These polymers are investigated by cyclic voltammetry and optical spectroscopy. [Copyright &y& Elsevier]

Abstract: Dendrons possessing one activated vinyl group at the core and several chlorine atoms at the end of the branches are used as starting materials to study the possibility to react independently the surface functions and the core function. In particular, the most powerful sequence of reactions for decorating them by organometallic complexes as end groups and amine or alcohol at the core has been determined. In the first step, phenol phosphines are grafted as end groups of the dendrons, and they can be used for the complexation of metals. However, these phosphines must be kept free when amines are used to react with the vinyl core in the next step. Depending on the type of phosphine end groups and on the type of function of the core (amine or alcohol), the complexation of ruthenium ([RuCl2(p-cymene)]2) and rhodium ([RhCl(COD)]2) derivatives by the phosphine end groups can occur without side reaction at the core. [Copyright &y& Elsevier]

Abstract: The dendron derivatives, which have methylthio groups at peripheral sites acting as multiple anchor on the surface of Au, and a Rhodamine B (RhB) molecule at the focal point as a fluorescent marker, have been successfully synthesized. These dendrons on the surface of Au are expected to show a cone shape form, and to act as a pseudo single molecule on a spacer isolating functional site at the focal point from both the surface and the neighboring dendron molecules. [Copyright &y& Elsevier]

Abstract: We have recently synthesized new amphiphilic light-emitting dendrons with oligo(phenylene vinylene) core–branches and oligo(ethylene oxide) terminal chains (designated as: OPPV-d-OPEO). Due to the amphiphilic properties arising from the large difference in solubility between the two components, unique concentration- and temperature-dependent photoluminescence emissions were observed for aqueous solutions of the amphiphilic conjugated dendrons. The synthesis and amphiphilic behaviour of the OPPV-d-OPEO in solution are reported in this paper. Effects of the amphiphilic behavior on fluorescence emissions of the dendrons are discussed. [Copyright &y& Elsevier]

Abstract: Two polycationic lipophilic-core carbohydrate-based dendrons 2a–b and five polycationic lipophilic-core peptide dendrons 3–6, containing four arginine or lysine terminal residues, were synthesized and then tested in rats as penetration enhancers for the oral delivery of low molecular weight heparin. Better results were obtained with dendrons containing terminal lysine residues than terminal arginine. A significant anti-factor Xa activity was obtained when low molecular weight heparin was coadministered with dendron 5. [Copyright &y& Elsevier]

Abstract: This paper reviews aspects of the association of dendrons and dendrimers into a variety of supramolecular structures. There is such a wide range of primary dendron and dendrimer chemistries that it is still difficult to predict behaviour in aqueous media, and there are few studies in non-aqueous media. The aggregation of the primary units into larger and more complex forms leads to a wider range of potential carrier systems for drugs, genes and vaccines. This review deals principally with the association structures which can be formed. These include liquid crystalline structures and dendron block copolymer aggregates, surface monolayer formation, dendrimer derived nanoparticles, micellar structures and dendrisome (vesicle) formation. Of particular interest are DNA-dendrimer complexes and dendrimer-polyanion interactions. The in vivo behaviour of dendrons and dendrimers is of course crucial and is addressed. Dendrimer vesicle solubilisation by surfactants and emulsion stabilisation by dendrimers completes the survey of secondary structures. The challenge is to understand better the processes involved and to concentrate further on the design of the synthesis of dendrons and dendrimers which will associate into specific complex structures to increase the scope of dendrimer science. [Copyright &y& Elsevier]

Abstract: By using convergent approach poly(aryl ether) dendritic structures carrying a donor (4-methyl-7-hydroxycoumarin) on the surface and an acceptor (3-cyano-7-hydroxycoumarin) at the focal point with G0, G1 and G2 generation number were synthesized. The photophysical properties of the series of poly(aryl ether) dendrimers have been determined, and the effect of the generation number on the absorption and emission properties of the synthesized dendritic structures was investigated. As the chromophore group number on the surface of the dendritic structure increased, molar absorptivity coefficients and emission intensities of the structures 1–6 were found to increase. [Copyright &y& Elsevier]

Abstract: A novel lipidic peptide dendron was synthesised using solid-phase techniques. To a third-generation polylysine dendron were coupled eight α-amino tetradecanoic acid (C14) molecules to the eight Nα and Nɛ of the terminal lysines and three pendant C14 chains were coupled to the C-terminal of the starting lysine. This novel dendron was found to self-assemble in water into vesicular structures or “dendrisomes”. These dendrisomes were prepared using a reverse-phase evaporation (REV) technique and visualised by transmission electron microscopy (TEM). The interaction of these second order structures with the non-ionic surfactant iso-octyl phenyl poly(10)oxyethylene ether (Triton X-100) was studied by turbidimetry, photon correlation spectroscopy (PCS) and TEM. Quantitative estimation of the solubilised peptide dendron was carried out by the bicinchoninic acid (BCA) assay. The dendrisomes are transformed into surfactant–dendron mixed micelles. The dispersion became optically clear at a concentration 8mM (13.4:1 Triton X-100:dendron molar ratio). When the concentration of the surfactant was increased up to 60–100mM (100–170:1 Triton X-100:dendron molar ratio) the aggregate diameter decreased to the micellar range, namely 12–50nm. At a 100:1 Triton X-100:dendron molar ratio, the BCA assay showed complete dendron solubilisation. This suggests that the cationic lipidic dendron and their assemblies can be solubilised by amphipathic non-ionic moieties when the surfactant–dendron interaction is more energetically favourable than dendron–dendron and surfactant–surfactant interactions. [Copyright &y& Elsevier]

Abstract: This review is introduced by an examination of the historical roles that quantized building blocks, such as atoms and monomers have played in the development of small molecule and traditional polymer synthesis, respectively. The unique features of traditional macromolecular architectures (i.e. linear, crosslinked, branched), as well as controlled nanostructures in biology were used as frames of reference to anticipate potential new properties, phenomena and synthetic constructs that should be expected to emerge at the interface of the ‘dendritic architectural state’ with the nanotechnology revolution. Intrinsic new properties associated with the ‘dendritic architectural state’, such as the ability to control monodisperse nanoscale sizes, shapes and presentation of surface functionality are reviewed. Unique ‘dendritic effects’ related to de Gennes dense packing (i.e. unimolecular encapsulation, periodic nanocontainer properties), polyvalency (nanoscaffolding), as well as shape designing both within (i.e. cystamine core dendrimers) and beyond dendrimers (i.e. core–shell tecto(dendrimers)) to mimic biological proteins are described. The precise, quantized core–shell architectural properties and monomer shell filling features of dendrimers are compared to the electron shell filling patterns of elemental atoms by utilizing the Niels Bohr Periodic Table. This comparison has provided a rationale for explaining autoreactivity patterns observed at the sub-nanoscale (atoms), lower nanoscale (dendrimers) and higher nanoscale levels involving either unsaturated electron shells, monomer shells or dendrimer shells, respectively. Clearly, dendritic polymers, especially dendrons and dendrimers are expected to fulfill important roles as fundamental, reactive modules for nanoscale polymer syntheses. [Copyright &y& Elsevier]

Abstract: Poly(amidoamine) (PAMAM) dendrimers containing disulfide cores (i.e., cystamine) and possessing carboxylic acid or hydroxyl terminal groups were reduced with dithiothreitol (DTT) to yield single site, thiol core, functionalized PAMAM dendron reagents. These thiol functionalized dendron reagents were used to surface modify (dendronize) both gold nanoparticles, as well as CdSe/CdS (core–shell) quantum dots (QDs). Dendronization involved self-assembly of the focal point thiol functional dendrons at the metal interface of both gold and CdSe/CdS QDs by ligand exchange of protective surfactants used for their synthesis. The synthesis, characterization and preliminary luminescence studies of these new dendritic hybrids are reported. [Copyright &y& Elsevier]

Abstract: New pyridylthioether-based dendrons bearing a thiol moiety at their focal point have been prepared by a convergent synthetic approach. These dendrons were readily attached to a Fe2(CO)6 core to generate two-directional dendritic molecules incorporating an iron-carbonyl cluster. [Copyright &y& Elsevier]

After pioneering works concerning the synthesis of dendrimers and dendrons possessing fluorine atoms in some part of their structure, recent advances are dedicated to the search for uses and applications of these highly branched compounds. Three major fields are concerned: catalysis, materials science and biology to a lesser extend. [Copyright &y& Elsevier]

The article describes the perhaps most important synthetic access, the so-called macromonomer route to dendronized polymers which are comb polymers with dendrons of varying generations as the teeth. After a brief description of this route in general terms, some recent examples are discussed. The polymerisation mechanisms are either step or chain growth which has considerable impact not only on achievable molar mass and mass distribution but also on the chemical nature of the polymers’ backbone. Even for macromonomers with high generation dendrons, the highest molar mass dendronized polymers presently available are prepared by chain growth procedures. To cite this article: A.D. Schlu¨ter et al., C. R. Chimie 6 (2003). [Copyright &y& Elsevier]

Various methods of synthesis of phosphorus dendrimers are presented, in particular a fast method which allows creating each generation in only one step, while multiplying by 5 the number of end-groups. These methods of synthesis can easily be modified to place selectively on the surface, inside, within the branches or at the core, functional groups chosen according to the properties or the applications which they can bring. In many cases, the size of the dendrimer (its generation) has an influence on these properties. Various applications in the fields of catalysis, materials, and biology are presented. To cite this article: Anne-Marie Caminade et al., C. R. Chimie 6 (2003). [Copyright &y& Elsevier]