Enhanced Synergistic Efficacy Against Breast Cancer Cells Promoted by Co-Encapsulation of Piplartine and Paclitaxel in Acetalated Dextran Nanoparticles.

Malignant breast tumors constitute the most frequent cancer diagnosis among women. Notwithstanding the progress in treatments, this condition persists as a major public health issue. Paclitaxel (PTX) is a first-line classical chemotherapeutic drug used as a single active pharmaceutical ingredient (API) or in combination therapy for breast cancer (BC) treatment.

Unveiling Hierarchical Self-Assembly of Triazolylferrocenyl Dendrimers: Producing Non-Traditional Intrinsically Green Fluorescent Vesosomes for Nanotheranostics.

Dendrimers and supramolecular chemistry continue to fascinate researchers due to the endless unrevealed potential of their combination. This study investigates the self-assembly process of a series of hydrophobic triazolylferrocenyl dendrimers in aqueous medium. Deep investigation through NMR spectroscopy, absorption UV-vis spectroscopy along with theoretical simulations demonstrates that the ferrocenyl moieties interact intramolecularly and intermolecularly driving the self-assembly process.

Ferrocene-Based Drugs, Delivery Nanomaterials and Fenton Mechanism: State of the Art, Recent Developments and Prospects.

Ferrocene has been the most used organometallic moiety introduced in organic and bioinorganic drugs to cure cancers and various other diseases. Following several pioneering studies, two real breakthroughs occurred in 1996 and 1997. In 1996, Jaouen et al.

Well-Defined Bifunctional Dendrimer Bearing 54 Nitric Oxide-Releasing Moieties and 54 Ursodeoxycholic Acid Groups Presenting High Anti-Inflammatory Activity.

Nitric oxide (NO) and ursodeoxycholic acid (UDCA) are endogenous molecules involved in physiological processes associated with inflammation. Since inflammatory processes are present in the mechanisms of many diseases, these molecules are important for the development of new drugs. Herein, we describe the synthesis of a well-defined bifunctional dendrimer with 108 termini bearing 54 NO-releasing groups and 54 UDCA units (Dendri-(NO/UDCA)).

Synthesis of Carbon Nanodots from Sugarcane Syrup, and Their Incorporation into a Hydrogel-Based Composite to Fabricate Innovative Fluorescent Microstructured Polymer Optical Fibers.

Carbon nanodots (CNDs) are interesting materials due to their intrinsic fluorescence, electron-transfer properties, and low toxicity. Here, we report a sustainable, cheap, and scalable methodology to obtain CNDs from sugarcane syrup using a domestic microwave oven. The CNDs were characterized by infrared spectroscopy, dynamic light scattering, atomic force microscopy, absorption, and emission spectroscopies.

Synthesis and Characterization of Dendronized Gold Nanoparticles Bearing Charged Peripheral Groups with Antimicrobial Potential.

Dendronized gold nanoparticles (AuNPs) were synthesized bearing charged peripheral groups. Two novel AB-type dendrons were synthesized with a thiol group at the focal point followed by their attachment to AuNPs. Dendrons were designed to have nine charged peripheral groups (carboxyl or amine), glycol solubilizing, units and one thiol moiety at the focal point.

Near-Infrared Fluorescent Micelles from Poly(norbornene) Brush Triblock Copolymers for Nanotheranostics.

This contribution describes the design and synthesis of multifunctional micelles based on amphiphilic brush block copolymers (BBCPs) for imaging and selective drug delivery of natural anticancer compounds. Well-defined BBCPs were synthesized via one-pot multi-step sequential grafting-through ring-opening metathesis polymerization (ROMP) of norbornene-based macroinitiators. The norbornenes employed contain a poly(ethylene glycol) methyl ether chain, an alkyl bromide chain, and/or a near-infrared (NIR) fluorescent cyanine dye.

Hybrids of 4-hydroxy derivatives of goniothalamin and piplartine bearing a diester or a 1,2,3-triazole linker as antiproliferative agents.

A library of nine hybrids of 4-hydroxygoniothalamin (2), 4-hydroxypiplartine (4), monastrol (5) and oxo-monastrol (6) was prepared via a modular synthetic route with a diester or a 1,2,3-triazole as linkers. The compounds were assayed against a panel of human cancer cell lines, including MCF-7 (breast adenocarcinoma), HeLa (cervical adenocarcinoma), Caco-2 (colorectal adenocarcinoma) and PC3 (prostate adenocarcinoma), as well as against normal breast (MCF10A) and prostate (PNT2) cells. In general, hybrids with an ester linker containing 4-hydroxypiplartine (4) were more potent than the corresponding hybrids with 4-hydroxygoniothalamin (2).

Self-Assembly of a Triazolylferrocenyl Dendrimer in Water Yields Nontraditional Intrinsic Green Fluorescent Vesosomes for Nanotheranostic Applications.

The promising field of nanomedicine stimulates a continuous search for multifunctional nanotheranostic systems for imaging and drug delivery. Herein, we demonstrate that application of supramolecular chemistry's concepts in dendritic assemblies can enable the formation of advanced dendrimer-based nanotheranostic devices. A dendrimer bearing 81 triazolylferrocenyl terminal groups adopts a more compact shell-like structure in polar solvents with the ferrocenyl peripheral groups backfolding toward the hydrophobic dendrimer interior, while exposing the more polar triazole moieties as the dendritic shell.

Methodology for functionalization of water oxidation catalyst IrO nanoparticles with hydrophobic and multi-functionalized chromophores.

We present a straightforward "click chemistry" methodology for the functionalization of water-oxidation catalyst iridium oxide nanoparticles (IrOx-NPs) with a multi-functionalized porphyrin-based photosynthetic model as sensitizer for the preparation of bioinspired photo-catalysts. This efficient method overcomes the usual aggregation issue found when decorating water oxidation nanocolloidal catalysts with hydrophobic sensitizers.

Enhancing the Anticancer Activity and Selectivity of Goniothalamin Using pH-Sensitive Acetalated Dextran (Ac-Dex) Nanoparticles: A Promising Platform for Delivery of Natural Compounds.

Goniothalamin (GTN), a natural compound isolated from species, has previously demonstrated cytotoxic activity against several cancer cell lines. However, similarly to many natural and synthetic anticancer compounds, GTN presents toxicity toward some healthy cells and low aqueous solubility, decreasing its bioavailability and precluding its application as an antineoplastic drug. In our efforts to improve the pharmacokinetic behavior and selectivity of GTN against cancer cells, we developed a polymeric nanosystem, in which -GTN was encapsulated in pH-responsive acetalated dextran (Ac-Dex) nanoparticles (NPs) with high loadings of the bioactive compound.

Fluorescent Imidazo[1,2-a]pyrimidine Compounds as Biocompatible Organic Photosensitizers that Generate Singlet Oxygen: A Potential Tool for Phototheranostics.

Photodynamic therapy has been used to treat a variety of diseases, however, there is continuing search for new biocompatible photosensitizers. Herein, we demonstrate for the first time that imidazo[1,2-a]pyrimidine compounds are able to generate singlet oxygen species and can act as photosensitizers in the intracellular environment. Our results show that this class of compounds absorb and emit in the 400-500 nm region, present low cytotoxicity in the dark, are efficiently uptaken by cells, are fluorescent in intracellular medium, and generate singlet oxygen upon irradiation, killing cancer cells within 2 h at low concentration (2.

General Protocol to Obtain D-Glucosamine from Biomass Residues: Shrimp Shells, Cicada Sloughs and Cockroaches.

A general protocol is developed to obtain D-glucosamine from three widely available biomass residues: shrimp shells, cicada sloughs, and cockroaches. The protocol includes three steps: (1) demineralization, (2) deproteinization, and (3) chitin hydrolysis. This simple, general protocol opens the door to obtain an invaluable nitrogen-containing compound from three biomass residues, and it can potentially be applied to other chitin sources.

Synthesis of Nitrogen-Containing Goniothalamin Analogues with Higher Cytotoxic Activity and Selectivity against Cancer Cells.

Two series of racemic goniothalamin analogues displaying nitrogen-containing groups were designed and synthesized. A total of 19 novel analogues were evaluated against a panel of four different cancer cell lines, along with the normal prostate cell line PNT2 to determine their selectivity. Among them, goniothalamin chloroacrylamide 13 e displayed the lowest IC values for both MCF-7 (0.

Biodegradable and pH-Responsive Acetalated Dextran (Ac-Dex) Nanoparticles for NIR Imaging and Controlled Delivery of a Platinum-Based Prodrug into Cancer Cells.

Nanoparticles (NPs) based on the biodegradable acetalated dextran polymer (Ac-Dex) were used for near-infrared (NIR) imaging and controlled delivery of a Pt prodrug into cancer cells. The Ac-Dex NPs loaded with the hydrophobic Pt prodrug 3 (Pt/Ac-Dex NPs) and with the novel hydrophobic NIR-fluorescent dye 9 (NIR-dye 9/Ac-Dex NPs), as well as Ac-Dex NPs coloaded with both compounds (coloaded Ac-Dex NPs), were assembled using a single oil-in-water nanoemulsion method. Dynamic light scattering measurements and scanning electron microscopy images showed that the resulting Ac-Dex NPs are spherical with an average diameter of 100 nm, which is suitable for accumulation in tumors via the enhanced permeation and retention effect.

The structure-property relationship in LAPONITE® materials: from Wigner glasses to strong self-healing hydrogels formed by non-covalent interactions.

Rheology, small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) analysis, zeta potential measurement, scanning electron microscopy (SEM), and micro-FTIR and absorbance spectroscopy were used to enlighten the controversial literature about LAPONITE® materials. Our data suggest that pristine LAPONITE® in water does not form hydrogels induced by the so-called "house of cards" assembly, but rather forms Wigner glasses governed by repulsive forces. Ionic interactions between anisotropic LAPONITE® nanodiscs, sodium polyacrylate and inorganic salts afforded hydrogels that were transparent, self-standing, moldable, strong, and biocompatible with shear-thinning and self-healing behavior.

"Click" Methodology for the Functionalization of Water Oxidation Catalyst Iridium Oxide Nanoparticles with Hydrophobic Dyes for Artificial Photosynthetic Constructs.

The unusually high tolerance toward chemical functional groups of the copper(I)-catalyzed Huisgen-Sharpless-Meldal 1,3-dipolar cycloaddition of azides and alkynes protocol (the CuAAC or "click" reaction) associated with its mild conditions and high yields has been explored in the present methodology to successfully prepare water oxidation catalyst iridium oxide nanoparticles decorated with organic dyes. The "click reaction" has proven to be an excellent synthetic tool to overcome the incompatible solubility of the hydrophilic iridium oxide nanoparticles and the hydrophobic dyes. A complex artificial photosynthetic model designed to mimic the photoinduced redox processes occurring in photosystem II is used as a hydrophobic dye to highlight the efficiency and selectiveness of the method.

Soft Nanohydrogels Based on Laponite Nanodiscs: A Versatile Drug Delivery Platform for Theranostics and Drug Cocktails.

A new nanohydrogel drug delivery platform based on Laponite nanodiscs, polyacrylate, and sodium phosphate salts is described. The hybrid nanohydrogel is tailored to obtain soft and flexible nanohydrogels with G' around 3 kPa, which has been proposed as the ideal stiffness for drug delivery applications. In vitro studies demonstrate that the new nanohydrogels are biocompatible, biodegradable, nonswellable, pH-responsive, and noncytotoxic and are able to deliver antineoplastic drugs into cancer cells.

Olefin Cyclopropanation by Radical Carbene Transfer Reactions Promoted by Cobalt(II)/Porphyrinates: Active-Metal-Template Synthesis of [2]Rotaxanes.

A Co /porphyrinate-based macrocycle in the presence of a 3,5-diphenylpyridine axial ligand functions as an endotopic ligand to direct the assembly of [2]rotaxanes from diazo and styrene half-threads, by radical-carbene-transfer reactions, in excellent 95 % yield. The method reported herein applies the active-metal-template strategy to include radical-type activation of ligands by the metal-template ion during the organometallic process which ultimately yields the mechanical bond. A careful quantitative analysis of the product distribution afforded from the rotaxane self-assembly reaction shows that the Co /porphyrinate subunit is still active after formation of the mechanical bond and, upon coordination of an additional diazo half-thread derivative, promotes a novel intercomponent C-H insertion reaction to yield a new rotaxane-like species.

, a Family of Super Dendrimers with Specific Properties and Applications.

s (from dentro, δεντρο: tree in Greek), and (μεροσ, in greek: part) are introduced as a family of dendrimers constructed according to successive divergent 1 → 3 branching. The smaller have 27 terminal branches. With alcohol termini they were originally named arborols by Newkome, who pioneered 1 → 3 constructions of dendrimers and dendrons.

Terms of endearment: Bacteria meet graphene nanosurfaces.

Microbial multidrug resistance poses serious risks in returning the human species into the pre-antibiotic era if it remains unsolved. While conventional research approaches to combat infectious diseases have been inadequate, nanomaterials are a promising alternative for the development of sound antimicrobial countermeasures. Graphene, a two-dimensional ultra-thin nanomaterial, possesses excellent electronic and biocompatibility properties, which position it in the biotechnology forefront for diverse applications in biosensing, therapeutics, diagnostics, drug delivery and device development.

Visible-light generation of the naked 12-electron fragment C5H5Fe+: alkyne-to-vinylidene isomerization and synthesis of polynuclear iron vinylidene and alkynyl complexes including hexairon stars.

Visible-light photolysis of [FeCp(η(6)-C(6)H(5)CH(3))][PF(6)] using a simple 100-W bulb or a compact fluorescent light bulb in the presence of terminal alkynes and dppe yielded the vinylidene complexes [FeCp(═C═CHR)(dppe)][PF(6)] that were deprotonated by t-BuOK to yield the alkynyl complexes [FeCp(-C≡CR)(dppe)]. The reaction has been extended to the synthesis of bis-, tris, tetra-, and hexanuclear iron complexes including three alkynes of the ferrocenyl family.

Combining aminocyanine dyes with polyamide dendrons: a promising strategy for imaging in the near-infrared region.

Cyanine dyes are known for their fluorescence in the near-IR (NIR) region, which is desirable for biological applications. We report the synthesis of a series of aminocyanine dyes containing terminal functional groups such as acid, azide, and cyclooctyne groups for further functionalization through, for example, click chemistry. These aminocyanine dyes can be attached to polyfunctional dendrons by copper-catalyzed azide alkyne cycloaddition (CuAAC), strain-promoted azide alkyne cycloaddition (SPAAC), peptide coupling, or direct S(NR)1 reactions.

Construction of a well-defined multifunctional dendrimer for theranostics.

A dendrimer-based building block for theranostics was designed. The multifunctional dendrimer is polyamide-based and contains nine azide termini, nine amine termini, and fifty-four terminal acid groups. Orthogonal functionalization of the multifunctional dendrimer with a near-infrared (NIR) cyanine dye afforded the final dendrimer that shows fluorescence in the NIR region and no toxicity toward T98G human cells.

Olefin metathesis in nano-sized systems.

The interplay between olefin metathesis and dendrimers and other nano systems is addressed in this mini review mostly based on the authors' own contributions over the last decade. Two subjects are presented and discussed: (i) The catalysis of olefin metathesis by dendritic nano-catalysts via either covalent attachment (ROMP) or, more usefully, dendrimer encapsulation - ring closing metathesis (RCM), cross metathesis (CM), enyne metathesis reactions (EYM) - for reactions in water without a co-solvent and (ii) construction and functionalization of dendrimers by CM reactions.