Synthesis of onion-peel nanodendritic structures with sequential functional phosphorus diversity

First-in-Class Phosphorus Dendritic Framework, a Wide Surface Functional Group Palette Bringing Noteworthy Anti-Cancer and Anti-Tuberculosis Activities: What Lessons to Learn?

Based on phenotypic screening, the major advantages of phosphorus dendrimers and dendrons as drugs allowed the discovery of new therapeutic applications, for instance, as anti-cancer and anti-tuberculosis agents. These biological activities depend on the nature of the chemical groups (neutral or cationic) on their surface as well as their generation. As lessons to learn, in the oncology domain, the increase in the generation of metallo-dendrimers is in the same direction as the anti-proliferative activities, in contrast to the development of polycationic dendrimers, where the most potent anti-tuberculosis phosphorus dendrimer was observed to have the lowest generation (G0). The examples presented in this original analysis of phosphorus dendrimers and dendrons provide support for the lessons learned and for the development of new nanoparticles in nanomedicine.

Hybrid phosphorus–viologen dendrimers as new soft nanoparticles: design and properties

Design of new families of dendritic soft nanoparticles constituted of phosphorus, viologen and carbosilane fragments and their properties as nanomaterials and applications in biology.

Dendrimers toward Translational Nanotherapeutics: Concise Key Step Analysis

The goal of nanomedicine is to address specific clinical problems optimally, to fight human diseases, and to find clinical relevance to change clinical practice. Nanomedicine is poised to revolutionize medicine via the development of more precise diagnostic and therapeutic tools. The field of nanomedicine encompasses numerous features and therapeutic disciplines. A plethora of nanomolecular structures have been engineered and developed for therapeutic applications based on their multitasking abilities and the wide functionalization of their core scaffolds and surface groups. Within nanoparticles used for nanomedicine, dendrimers as well polymers have demonstrated strong potential as nanocarriers, therapeutic agents, and imaging contrast agents. In this review, we present and discuss the different criteria and parameters to be addressed to prepare and develop druggable nanoparticles in general and dendrimers in particular. We also describe the major requirements, included in the preclinical and clinical roadmap, for NPs/dendrimers for the preclinical stage to commercialization. Ultimately, we raise the clinical translation of new nanomedicine issues.

Main-Chain Phosphorus-Containing Polymers for Therapeutic Applications

Polymers in which phosphorus is an integral part of the main chain, including polyphosphazenes and polyphosphoesters, have been widely investigated in recent years for their potential in a number of therapeutic applications. Phosphorus, as the central feature of these polymers, endears the chemical functionalization, and in some cases (bio)degradability, to facilitate their use in such therapeutic formulations. Recent advances in the synthetic polymer chemistry have allowed for controlled synthesis methods in order to prepare the complex macromolecular structures required, alongside the control and reproducibility desired for such medical applications. While the main polymer families described herein, polyphosphazenes and polyphosphoesters and their analogues, as well as phosphorus-based dendrimers, have hitherto predominantly been investigated in isolation from one another, this review aims to highlight and bring together some of this research. In doing so, the focus is placed on the essential, and often mutual, design features and structure-property relationships that allow the preparation of such functional materials. The first part of the review details the relevant features of phosphorus-containing polymers in respect to their use in therapeutic applications, while the second part highlights some recent and innovative applications, offering insights into the most state-of-the-art research on phosphorus-based polymers in a therapeutic context.

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

A small water-soluble phosphorus-containing dendrimer was engineered for the complexation of gold(I) and for its reduction under mild conditions. Gold nanoparticles were obtained as colloidal suspensions simply and only when the powdered form of this dendrimer was dissolved in water, as shown by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) analyses. The dendrimers acted simultaneously as mild reducers and as nanoreactors, favoring the self-assembly of gold atoms and promoting the growth and stabilization of isolated gold nanoparticles. Thus, an unprecedented method for the synthesis of colloidal suspensions of water-soluble gold nanoparticles was proposed in this work.

Dendrimer Based Nanoarchitectures in Diabetes Management: An Overview

Diabetes has turned out to be one of the biggest worldwide health and economic burdens, with its expanded predominance and high complexity proportion. The quantity of diabetic patients is expanding enormously around the world. Several reports have demonstrated the sharp increment in the sufferers. Stable and acceptable blood glucose control is fundamental to diminish diabetes-related complications. Consequently, ceaseless endeavors have been made in antidiabetic drugs, treatment strategies, and nanotechnology based products to accomplish better diabetes control. The nanocarriers pertaining hypoglycaemics provide improved diabetes management with minimum risk of associated side effects. Dendrimers have caught an incredible attention in the field of drug delivery and personalized medicines. Dendrimers are three-dimensional well-defined homogenous nanosized structures consisting tree-like branches. The present review highlights the different aspects of dendrimers including fabrication, surface engineering, toxicological profile as well as delivery of antidiabetic drugs for the effective cure of diabetes.

Exploration of biomedical dendrimer space based on in-vitro physicochemical parameters: key factor analysis (Part 1)

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.

Interfacial complexation driven three-dimensional assembly of cationic phosphorus dendrimers and graphene oxide sheets

High content nitrogen, sulfur and phosphorus heteroatoms assembled in tree-like dendrimers (DG _n ) are confined within the galleries of two-dimensional graphene oxide (GO). The presence of the ternary diethyl-N-ethyl-ammonium groups on the dendrimer peripheries ensures the exfoliation of graphene sheets thereby affording interfacially bridged, three-dimensional heteroatom-enriched graphene-based hybrid nanostructures (DG _n -GO). Dendrimer generation (from 1 to 4) that reflects the bulkiness of these conceived nano-trees impacts increasingly the degree of dispersion-exfoliation and sheet desordering. The long-term stability of these aqueous suspensions associated with their handling flexibility allows uniform accommodation of the resulting hybrid materials as flame-retardants in bioplastics.

Design, complexing and catalytic properties of phosphorus thiazoles and benzothiazoles: a concise overview

Playing with the versatile reactivity of thiazole and phosphorus derivatives leads to active ligands and complexes in catalysis.

Urea-assisted cooperative assembly of phosphorus dendrimer–zinc oxide hybrid nanostructures

The interplay of phosphorus dendrimer–urea during sol–gel mineralization of soluble zinc precursors provides porous lamellar nanostructures.

Dendrimers: A versatile nanocarrier for drug delivery and targeting

Dendrimers are novel polymeric nanoarchitectures characterized by hyper-branched 3D-structure having multiple functional groups on the surface that increases their functionality and make them versatile and biocompatible. Their unique properties like nanoscale uniform size, high degree of branching, polyvalency, water solubility, available internal cavities and convenient synthesis approaches make them promising agent for biological and drug delivery applications. Dendrimers have received an enormous attention from researchers among various nanomaterials. Dendrimers can be used as a carrier for diverse therapeutic agents. They can be used for reducing drug toxicities and enhancement of their efficacies. The present review provide a comprehensive outline of synthesis of dendrimers, interaction of dendrimer with guest molecules, properties, characterization and their potential applications in pharmaceutical and biomedical field.

“Onion peel” glycodendrimer syntheses using mixed triazine and cyclotriphosphazene scaffolds

An expeditious synthetic protocol for the construction of glycodendrimers is illustrated using the newly discovered “onion peel” strategy. The onion peel approach and orthogonal coupling strategies were accomplished with rationally design sequential modifications of cyanuric acid. Carefully chosen building blocks and their effective attachment by chemoselective atom economical click reactions, namely Cu (I) azide–alkyne cycloaddition reaction (CuAAC) and photocatalyzed thiol-ene reaction (TEC), allowed rapid build-up of glycodendrimers in contrast to traditional dendrimers syntheses that are based on the repetitive use of identical building blocks to form each layer. The newly formed glycodendrimers were evaluated for their capacity to cross-link carbohydrate-lectin interactions using dynamic light scattering (DLS). Rapid increase in particle size was observed as a function of time when compared to their monomer counterparts resulting from the multivalent lectin cross-linking ability of the new glycodendrimers.

Polyphosphazene Based Star-Branched and Dendritic Molecular Brushes

A new synthetic procedure is described for the preparation of poly(organo)phosphazenes with star-branched and star dendritic molecular brush type structures, thus describing the first time it has been possible to prepare controlled, highly branched architectures for this type of polymer. Furthermore, as a result of the extremely high-arm density generated by the phosphazene repeat unit, the second-generation structures represent quite unique architectures for any type of polymer. Using two relativity straight forward iterative syntheses it is possible to prepare globular highly branched polymers with up to 30 000 functional end groups, while keeping relatively narrow polydispersities (1.2-1.6). Phosphine mediated polymerization of chlorophosphoranimine is first used to prepare three-arm star polymers. Subsequent substitution with diphenylphosphine moieties gives poly(organo)phosphazenes to function as multifunctional macroinitiators for the growth of a second generation of polyphosphazene arms. Macrosubstitution with Jeffamine oligomers gives a series of large, water soluble branched macromolecules with high-arm density and hydrodynamic diameters between 10 and 70 nm.

Bifunctional Phosphorus Dendrimers and Their Properties

Dendrimers are hyperbranched and monodisperse macromolecules, generally considered as a special class of polymers, but synthesized step-by-step. Most dendrimers have a uniform structure, with a single type of terminal function. However, it is often desirable to have at least two different functional groups. This review will discuss the case of bifunctional phosphorus-containing dendrimers, and the consequences for their properties. Besides the terminal functions, dendritic structures may have also a function at the core, or linked off-center to the core, or at the core of dendrons (dendritic wedges). Association of two dendrons having different terminal functions leads to Janus dendrimers (two faces). The internal structure can also possess functional groups on one layer, or linked to one layer, or on several layers. Finally, there are several ways to have two types of terminal functions, besides the case of Janus dendrimers: either each terminal function bears two functions sequentially, or two different functions are linked to each terminal branching point. Examples of each type of structure will be given in this review, as well as practical uses of such sophisticated structures in the fields of fluorescence, catalysis, nanomaterials and biology.

Thiazoyl phosphines. Design, reactivity, and complexation

Thiazoylphosphines have been prepared through regioselective structural modifications as well as some of their Ru and Au complexes.

The specific functionalization of cyclotriphosphazene for the synthesis of smart dendrimers

Hexachlorocyclotriphosphazene is an old compound which affords very new properties in the field of dendrimers. Indeed, it can be used as a branching point for the rapid synthesis of highly dense dendrimers, but also for the synthesis of dendrimers having precisely one function different from all the others. These types of dendrimers are useful in the field of materials, affording highly reusable catalysts, chemical sensors, or supports for cell cultures. However, the most developed uses concern fluorescence. These dendrimers have been used for in vivo imaging, and for trying to elucidate biological mechanisms, in particular for anti-inflammatory dendrimers. This review will display important examples in the field.

Recent advances in click chemistry applied to dendrimer synthesis

Dendrimers are monodisperse polymers grown in a fractal manner from a central point. They are poised to become the cornerstone of nanoscale devices in several fields, ranging from biomedicine to light-harvesting. Technical difficulties in obtaining these molecules has slowed their transfer from academia to industry. In 2001, the arrival of the "click chemistry" concept gave the field a major boost. The flagship reaction, a modified Hüisgen cycloaddition, allowed researchers greater freedom in designing and building dendrimers. In the last five years, advances in click chemistry saw a wider use of other click reactions and a notable increase in the complexity of the reported structures. This review covers key developments in the click chemistry field applied to dendrimer synthesis from 2010 to 2015. Even though this is an expert review, basic notions and references have been included to help newcomers to the field.

Multifaceted glycodendrimers with programmable bioactivity through convergent, divergent, and accelerated approaches using polyfunctional cyclotriphosphazenes

The cyclotriphosphazene-based platform facilitates versatile synthesis of glycodendrimers active as inhibitors of two biomedically relevant lectins.