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The versatile reactivity of hexachlorocyclotriphosphazene (N3P3Cl6) has been developed for the synthesis of specifically engineered dendrimers. Dendrimers are hyperbranched macromolecules built by concentric layers constituted of associated monomeric units. Many of the properties of dendrimers depend on the type of their surface (terminal) functions, which are generally all identical. For some specific purposes, it is desirable to have one function that is different at the level of the core. Hexachlorocyclotriphosphazene offers the possibility to differentiate the reactivity of one (or more) Cl from the others, for producing specifically engineered dendritic tools. These specific reactions on N3P3Cl6 have produced highly dense dendrimers, Janus dendrimers (two faces), tools for functionalizing materials, with uses as catalysts, as chemical sensors, for trapping CO2, for the culture of cells, or for imaging biological events. These properties will be emphasized in this review. [ABSTRACT FROM AUTHOR]

A new concept is presented, namely the synthesis of dendrimers intrinsically composed in alternation of building blocks pertaining to two known families of dendrimers: phosphorhydrazone dendrimers and triazine-piperazine dendrimers. These mixed dendrimers with layered controlled architecture inherit their easy 31P NMR characterization and their thermal stability from the phosphorhydrazone family, and their decreased solubility from the triazine-piperazine family. However, they have also their own and original characteristics. Both parent families are white powders, whereas the mixed dendrimers are yellow, orange, or red powders, depending on the generation. DFT calculations were carried out on model dendrons to understand these special color features. Remarkably, these dendrimers incorporating redox-active organic entities allow for the first time the monitoring of the growth of an organic dendrimer by electrochemistry while highlighting an even-odd generation behavior. [ABSTRACT FROM AUTHOR]

Dendrimers are hyperbranched macromolecules constituted of repetitive branched units. They are synthesized step-by-step, a method which ensures a perfectly defined structure. This mini-review reports examples of rare “multiplurifunctionalized” dendrimers that have several types of functional groups precisely located on each terminal branching point. They are obtained thanks to the specificity of the reactivity of each Cl of P(X)Cl2(X = generally S, but also O) terminal groups on the surface of poly(phosphorhydrazone) dendrimers. [ABSTRACT FROM PUBLISHER]

The synthesis of three new families of dendrimeric compounds possessing two different types of functions is reported. These functions are triethoxysilyl group(s), potentially suitable for grafting onto materials, in particular silica, and primary amines (in their protected form), potentially suitable for trapping CO2. All these dendrimeric compounds are based on phosphorus dendrimers, and possess either one Si(OEt)3 group at the core of dendrons or of 'off-centre' dendrimers, or several Si(OEt)3 groups precisely placed on half of the terminal groups. These compounds are characterized by 31P NMR spectroscopy, which affords precious information on the structure, confirmed, in one case, by the X-ray diffraction structure of a first-generation dendrimer. [ABSTRACT FROM AUTHOR]

It is well documented that dendrimers were described as one of the most tunable nanomaterials both for therapeutic applications and diagnostics. This concise review surveys the different types of both non-targeted and targeted drug-encapsulated dendrimers and dendrimer–drug conjugates in oncology. In addition, progress in biocompatible dendritic architectures is discussed as it relates to the development of anti-cancer agents through in vitro and in vivo studies. In particular, we present relevant examples of these nanodevices to treat aggressive cancers such as colon and brain tumors. This review concludes with a brief survey of perspectives for clinical translation. [ABSTRACT FROM AUTHOR]

Dendrimers are multifunctional, hyperbranched and perfectly defined macromolecules, synthesized layer after layer in an iterative manner. Besides the nature of the terminal groups responsible for most of the properties, the nature of the internal structure, and more precisely of the branching points, is also of crucial importance. For more than 15 years, we have demonstrated that the presence of phosphorus atom(s) at each branching point of the dendrimeric structure is particularly important and highly valuable for three main reasons: (i) the versatility of phosphorus chemistry that allows diversified organochemistry for the synthesis of dendrimers; (ii) the use of 31P-NMR, which is a highly valuable tool for the characterization of dendrimers; (iii) some properties (in the fields of catalysis, materials, and especially biology), that are directly connected to the nature of the internal structure and of the branching points. This review will give an overview of the methods of synthesis of phosphorus-containing dendrimers, as well on the ways to graft phosphorus derivatives as terminal groups, with emphasis on the various roles played by the chemistry of phosphorus [ABSTRACT FROM AUTHOR]

A new family of phosphorus dendrimers containing at the same time triolefinic 15-membered azamacrocycles as core and on the surface have been prepared. The new macromolecules contain up to thirteen macrocycles with potential metal coordinating ability. [ABSTRACT FROM AUTHOR]

The concomitant use of polycationic dendrimers and cationic surfactants for the elaboration of periodic mesoporous silica of type MCM-41 is described. The hexagonal structure is preserved up to about 26% in weight of dendrimer included in the silica. The cationic surfactant can be selectively removed to liberate the pores, while preserving the non-covalently incorporated dendrimers. These dendrimers included in the mesoporous silica are fully accessible through the mesoporous volume to small molecules such as HCl and tetrahydrofuran. [ABSTRACT FROM AUTHOR]

Abstract: This review concerns metallic groups linked to the internal structure (core or branches) of phosphorus-containing dendrimers that are dendrimers possessing one phosphorus at each branching point. The synthetic aspect will be described first, ranked depending on the precise location of the metal: either at the core, or throughout the structure, or at one or several specific layers (layer-block type dendrimers), or in selected branches (segment-block type dendrimers). The second part concerns the properties of these metallo-phosphorus dendrimers, with emphasis on the information afforded by the metallic centers about the internal structure, and on the influence of the “burying” of a function inside a dendrimer on the properties of this function. The last part concerns the applications of some of these metallodendrimers in catalysis. [Copyright &y& Elsevier]

Abstract: In most cases, the water solubility of phosphorus-containing dendrimers is mainly due to the presence of hydrophilic end groups, which bear either positive or negative charges. In the first part of this paper, several methods of synthesis and functionalization of phosphorus dendrimers are described leading to the grafting either of ammonium groups or carboxylate groups, which ensure the water-solubility. The structural conflict between the hydrophobic interior and the hydrophilic exterior of these dendrimers leads to special properties, which are emphasized in a second part. For instance, some of them behave like nanometric sponges toward lipophilic substances; whereas, others form supramolecular arrangements leading to vesicles or hydrogels. Some of these dendrimers also possess interesting biological properties and can be used as in vitro DNA transfecting agents or in vivo anti-prion agents. [Copyright &y& Elsevier]

Several series of phosphorus-containing dendrimers have been designed to study the variation of their properties, depending on the type, the location (surface, branches, core, and cavities), and the number of functions implied. [ABSTRACT FROM AUTHOR]

Review: < 200 refs. [ABSTRACT FROM AUTHOR]

The synthesis of two new derivatives of Rhodamine B functionalized by phenols is reported. For one rhodamine derivative, the equilibrium between the open form and the ring-closed (spirolactam) form is completely shifted toward the latter, whereas the constitution of the other rhodamine derivative precludes ring closure. The spirolactam derivative was grafted as terminal group to a first generation phosphorus-containing dendrimer. Attempts to open the spirolactam form by adding HCl failed and resulted only in protonation of the NEt2 substituent of rhodamine. [ABSTRACT FROM AUTHOR]

Abstract: Dendrimers pertain both to the molecular chemistry world for their step by step controlled syntheses, and to the polymer world because of their repetitive structure made of monomers; thus they benefit from analytical techniques from both worlds. This review is a survey of the main analytical techniques used for the characterization of the chemical composition, the morphology, the shape, and the homogeneity of dendrimers. It includes NMR, IR, Raman, UV–Visible, fluorescence, circular dichroism, X-ray diffraction, mass spectrometry, SAXS, SANS, Laser Light Scattering, microscopy, SEC, EPR, electrochemistry, electrophoresis, intrinsic viscosity, DSC, and dielectric spectroscopy. [Copyright &y& Elsevier]

Phosphoryl azides are known as azide-transfer agents in organic chemistry; such behavior denotes the pseudo-halogen character of the azide group when linked to a tetracoordinated phosphorus atom, but it was considered up to now only for the functionalization of organic substrates by N3. We show in this paper that the azide can also be considered as a good leaving group, which facilitates the functionalization of the phosphorus atom which bore it. This reaction is first demonstrated on a small thiophosphoryl azide, then applied to the functionalization of more complex macromolecules, i.e. macrocycles incorporating in their structure thiophosphoryl azido groups. [Copyright &y& Elsevier]

[Display omitted] • Phosphorus dendrimers have been functionalized by a large variety of ligands suitable for the complexation of copper. • Copper complexes of phosphorus dendrimers are efficient catalysts in a range of reactions. • Copper complexes of phosphorus dendrimers can be efficiently recovered and reused. Phosphorus dendrimers are highly branched macromolecules, built with one phosphorus atom at each branching point. These dendrimers can be functionalized at will on the terminal functions. Grafting as terminal functions ligands suitable for the complexation of copper has been carried out several times, in particular with the aim of using the corresponding complexes as catalysts in a range of reactions, from O- and N -arylations and -vinylations, to the asymmetric benzoylation of linear or cyclic diols. A sequel of this work concerns the study of anticancer activity of analogous dendritic copper complexes. [ABSTRACT FROM AUTHOR]

• Exploration of biomedical dendrimer space based on in-vitro physicochemical parameters. • Description of structural dendrimer characteristics in nanomedicine. • In-vitro cytotoxicity and hemolytic activities of dendrimers. • Key parameters to secure the development of dendrimers until clinical trial and to enhance clinical translation. Dendrimers are highly branched, star-shaped macromolecules with nanometer-scale dimensions that can be readily modified with a range of functional groups, thus modifying their physicochemical and biological properties. In nanomedicine, dendrimers can be used as vectors for the targeted delivery strategy of a variety of biologically active agents or can be used as drug per se. In the future, it will be necessary to designate and develop 'safe' dendrimers, which is currently a crucial concern. Here, we analyze the key in vitro physicochemical parameters to be considered for preclinical evaluation of biomedical dendrimers. [ABSTRACT FROM AUTHOR]

In the field of nanotechnology, dendrimers represent a new class of highly branched macromolecules that is receiving a stimulating and rising interest. The structural organization of these synthetic macromolecules provides promising opportunities for using them as nano-carriers of drugs or gene material to be delivered to the target cells. For applications of dendrimers as drug carriers, analysis of their specific interactions with biological structures at molecular level is very important. This paper describes the molecular interactions between cationic phosphorus dendrimers of third and fourth generation (CPD G3 and CPD G4) and 3 plasma regulatory proteins, namely aspartate transaminase, alkaline phosphatase and l -lactic dehydrogenase. Dendrimer–protein interactions were studied using spectrofluorimetric, circular dichroism and dynamic light scattering techniques. Their morphology in the presence or absence of dendrimers was examined by transmission electron microscopy. The results suggest that both dendrimers form positively charged complexes with HIV-derived peptides. The circular dichroism spectra show that these dendrimers can significantly change the secondary structure of proteins, indicating formation of protein/dendrimer complexes. [ABSTRACT FROM AUTHOR]

Dendrimers are hyperbranched macromolecules having a perfectly defined and multifunctionalized structure, constituted of branches emanating radially from a central core. The structure of dendrimers is particularly modular, and can incorporate in different parts coordination complexes. In this review, we will present the interplay between dendrimers and coordination chemistry in three main fields: catalysis, materials, and biology. Most of the examples will be taken from the work done with phosphorus-containing dendrimers, but the pioneering work carried out with other dendrimers will be also presented. One of the major improvements that metallodendrimers have afforded concerning catalysis is their easy recovery and reuse, bridging the gap between homogeneous and heterogeneous catalysis. Another major improvement concerns the “dendritic effect” which can afford impressive outcomes concerning the increase of yield and of enantioselectivity, together with a decrease of the leaching of metals, and consequently of waste. Dendrimers can be used also for the synthesis and stabilization of metallic nanoparticles, for the modification of metallic surfaces at the nanometric scale, and for the synthesis of mesoscopically ordered hybrid materials. Finally metallodendrimers have high potency against cancerous cell lines, and they appear to operate via a different mechanism of action compared with native metallodrugs, opening new avenues for the search of improved anti-cancer agents. [ABSTRACT FROM AUTHOR]

Dendrimer are hyperbranched macromolecules, which can be used as support of catalytic entities. This review focusses on polyphosphorhydrazone (PPH) dendrimers, bearing as terminal groups, transition metal complexes of 3d elements (Cu, Sc) and 4d elements (Pd, Ru, Rh). These complexes have been used as catalysts for various organic reactions, in particular C–C couplings. Most of these dendritic complexes can be recovered and re-used several times (up to 12 successive runs with the same efficiency). In several cases, a dendritic (or dendrimer) effect is observed, i.e., an increased efficiency and/or enantioselectivity when comparing a monomeric catalyst with increasing generations of the dendrimers, using in all cases the same number of catalytic entities. [ABSTRACT FROM AUTHOR]

Abstract: This review emphasizes the role of phosphorus for the elaboration of dendrimers and of various highly sophisticated dendritic structures, and the invaluable role played by 31P NMR for their characterization and to ascertain their purity. A few properties, highlighting the importance of phosphorus are reported at the end of this review. [Copyright &y& Elsevier]

Abstract: Inhibition of fibril assembly is a potential therapeutic strategy in prion diseases. The effect of cationic phosphorous dendrimers on the aggregation process of the prion peptide PrP 185–208 was studied using a spectrofluorometric assay with thioflavin T (ThT) and Fourier transformed infrared spectroscopy in order to monitor the kinetics of the process and the changes in the peptide secondary structure. The results show that phosphorous dendrimers are able to clearly interfere with PrP 185–208 aggregation process by both slowing down the formation of aggregates (by causing a decrease of the nucleation rate) and by lowering the final amount of amyloid fibrils, a common hallmark of conformational diseases. The dendrimers effect on the aggregation process would imply their interaction with peptide monomers and oligomers during the nucleation phase. [Copyright &y& Elsevier]

Abstract: A series of densely functionalized dendrimers is synthesized using two branched monomers of type AB2 and CD2, in which the A function (NH2) reacts with D (CHO) and the B function (Cl) reacts with C (OH). The reaction has been carried out up to the fourth generation possessing 96 end groups and has been obtained in only four steps. [Copyright &y& Elsevier]

Abstract: Several series of phosphorus dendrimers decorated by potential fluorescent end groups (naphthalene, anthracene, and pyrene) have been synthesized. Unexpectedly, we found that it is absolutely necessary to link the fluorophore to the dendrimer through an alkyl link, and not directly through heteroelements such as oxygen or nitrogen, in order to preserve the fluorescence. One series of dendrimers from generation 1 (6 pyrene end groups) to generation 4 (48 pyrene end groups) has been tested for the elaboration of organic light-emitting diodes (OLEDs). The threshold voltage for the emission of light is high (over 20V), however, electroluminescence is observed in all cases. [Copyright &y& Elsevier]

Abstract: In order to shorten the long and tedious synthesis of dendrimers, several improvements have been proposed. This paper is a review of the improved methods recently published concerning the synthesis of phosphorus-containing dendrimers. It describes first the synthesis of hyperbranched polymers and their comparison with real dendrimers obtained from the same monomer. Then, the influence of the modification of the core of dendrimers is shown. In a third part, the use of dendrons is illustrated by several examples; they allow for instance to built a generation 8 directly from a generation 3 dendrimer. The last part describes the use of branched monomers of types AB2 and CD2, in which A reacts only with D and B reacts only with C. These reactions do not need any protecting groups, and the only by-products are H2O and N2. Using these monomers, the 4th generation is obtained in only four steps, instead of 8 for classical methods. This method has been improved by using more branched monomers AB5 and CD5, built from the cyclotriphosphazene. In this case, a dendrimer having 750 end groups is obtained in only three steps. The A (NH2), B (PPh2), C (N3) and D (CHO) functions are identical in all cases, and they allow a real “Lego” chemistry, as shown by the synthesis of CA2 and DB2 monomers, also used for the accelerated synthesis of dendrimers. [Copyright &y& Elsevier]

The selective reaction of amines and hydrazides with only one Cl on each P(S)Cl2 or P(O)Cl2 end group of phosphorus dendrimers, followed by the grafting of hydroxybenzaldehyde on the remaining P–Cl functions, and the subsequent growing of the dendrimer from the aldehyde is described. Allyl and pyrene derivatives have been grafted in this way inside the dendrimers during their growing. This constitutes a new way for the internal functionalization of dendrimers. [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]

• The common forms of SDNs are concisely reviewed. • SDNs can be prepared using dendrimers as reactive modules via various methods. • The synthesized SDNs have varied sizes, dimensions, and dispersities. • SDNs enable improved cancer nanomedicine applications. • Perspectives related to SDNs applied in cancer nanomedicine have been discussed. Poly(amidoamine) (PAMAM) dendrimers, as a family of synthetic macromolecules with highly branched interiors, abundant surface functional groups, and well-controlled architecture, have received immense scientific and technological interests for a range of biomedical applications, in particular cancer nanomedicine. However, due to the drawbacks of single-generation dendrimers with a quite small size (e.g., generation 5 (G5) PAMAM dendrimer has a size of 5.4 nm) such as limited drug loading capacity, restricted tumor passive targeting based on enhanced permeability and retention effect, and lack of versatility to render them with stimuli-responsiveness, superstructured dendrimeric nanoconstructs (SDNs) have been designed to break through these obstacles in their applications in cancer nanomedicine. Here, we review the recent advances related to the creation of SDNs such as dendrimer dumbbells, core–shell tecto dendrimers, dendrimer nanoclusters (NCs), dendrimer nanogels and dendrimer-templated hybrid NCs, and how these SDNs have been designed as nanoplatforms for different biomedical applications related to cancer nanomedicine including MR imaging, drug/gene delivery, combination therapy and theranostics. This review concisely describes the latest key developments in the field and also discusses the possible challenges and perspectives for translation applications. [ABSTRACT FROM AUTHOR]

This article reports that phosphorus dendrimers solubilized in water behave like solid colloidal particles, which swell and "bloom" progressively like dried sponges, to afford micelle-like compounds when tetrahydrofuran (THF) is added. This state modification at the nanoscopic scale has dramatic consequences on the dendrimer environment at the nanoscopic level, but also at the macroscopic level. The phosphorus dendrimers used in this study are built from an octaaldehyde metal-free phthalocyanine core, usable for sensing the internal behavior of dendrimers; the octasubstitution avoids complications due to regioisomers, previously shown for tetra-substituted phthalocyanines. The synthesis was carried out using a divergent strategy, up to the fifth generation, which is soluble in organic solvents such as THF.