Anion Transport Using Core Functionalized Hyperbranched Polymers and Evidence of a Dense Packed Limit Based on Molecular Weight.

Being able to bind, select, and transport species is central to a number of fields, including medicine, materials, and environmental science. In particular, recognizing a specific species from one phase and transporting it across, or into another phase, has obvious applications in environ-mental science, for example, removal of unwanted or toxic materials from an aqueous or organic phase. In this paper, we describe an approach that uses a functionalized dendritic polymer to bind and transport a small anionic molecule across an organic phase (and between two aqueous phases).

Synthesis of Oligomeric and Monomeric Functionalized Graphene Oxides and a Comparison of Their Abilities to Perform as Protein Ligands and Enzyme Inhibitors.

Graphene oxide (GO) is a versatile, monomolecular layered nanomaterial that possesses various oxygen-containing functionality on its large surface. These characteristics allow GO to interact with a variety of materials and to be applied towards a number of areas. The strength and selectivity of these interactions can be improved significantly through further functionalization.

Synthesis and Aggregation of a Porphyrin-Cored Hyperbranched Polyglycidol and Its Application as a Macromolecular Photosensitizer for Photodynamic Therapy.

Macromolecules are potentially useful delivery systems for cancer drugs, as their size allows them to utilize the enhanced permeability and retention effect (EPR), which facilitates selective delivery to (and retention within) tumors. In addition, macromolecular delivery systems can prolong circulation times as well as protect and solubilize toxic and hydrophobic drug moieties. Overall, these properties and abilities can result in an enhanced therapeutic effect.

Increased Oxygen Solubility in Aqueous Media Using PEG-Poly-2,2,2-trifluoroethyl Methacrylate Copolymer Micelles and Their Potential Application As Volume Expanders and As an Artificial Blood Product.

One of the most important functions of blood is to solubilize and distribute oxygen within the body. As such, it is vital that this property is replicated (safely) by any artificial blood product. In this paper, we describe the facile synthesis of a series of simple diblock polymers capable of self-assembling into micellar structures at concentrations around 3 × 10 mg/mL.

Effect of Terminal-Group Functionality on the Ability of Dendrimers to Bind Proteins.

It is known that dendrimers can bind proteins with good selectively. This selectivity comes about from an optimization based on matching the size of the dendrimer with the size of the protein's interfacial binding area. In this paper, we report how this selectivity can be moderated by the functionality on the surface of the dendrimer.

Graphene Oxide-Gallic Acid Nanodelivery System for Cancer Therapy.

Despite the technological advancement in the biomedical science, cancer remains a life-threatening disease. In this study, we designed an anticancer nanodelivery system using graphene oxide (GO) as nanocarrier for an active anticancer agent gallic acid (GA). The successful formation nanocomposite (GOGA) was characterized using XRD, FTIR, HRTEM, Raman, and UV/Vis spectroscopy.

Self-replicating systems.

Over the past 25 years, there has been a surge of development in research towards self-replication and self-replicating systems. The interest in these systems relates to one of the most fundamental questions posed in all fields of science - How did life on earth begin? Investigating how the self-replication process evolved may hold the key to understanding the emergence and evolution of living systems and, ultimately, gain a clear insight into the origin of life on earth. This introductory review aims to highlight the fundamental prerequisites of self-replication along with the important research that has been conducted over the past few decades.

Controlling microenvironments and modifying anion binding selectivities using core functionalised hyperbranched polymers.

An isophthalamide anion binding site has been incorporated into hyperbranched polymers resulting in a change in the selectivity of the receptor from chloride to bromide.

Exploiting dense shell/packing principles to invoke stereoselectivity in a reaction accelerated by a chiral dendrimer.

As dendrimers approach their dense shell or dense packed limit, a certain amount of conformational organization exists. Any substrate binding within the dendrimer's external layer will experience the same organizational effects. This paper describes how these effects can be exploited towards stereocontrol with respect to binding and reactivity.

Bimolecular catalysis and turnover from a macromolecular host system.

The synthesis of a globular macromolecule and its application as a bimolecular catalyst are reported. The macromolecular structure supports (at least) two zinc-metalated porphyrin units, each capable of binding a single reactant. The proximity of the two bound reactants results in an increased local concentration, leading to a maximum 300-fold increase in the reaction rate.

Catalytic hyperbranched polymers as enzyme mimics; exploiting the principles of encapsulation and supramolecular chemistry.

Nature uses the principles of encapsulation and supramolecular chemistry to bind and orientate substrates within active catalytic sites. Over the years, synthetic chemistry has generated a number of small molecule active site mimics capable of catalysing reactions involving bound substrates. Another approach uses larger molecules that better represent an enzymes globular structure.

Pyridine encapsulated hyperbranched polymers as mimetic models of haeme containing proteins, that also provide interesting and unusual porphyrin-ligand geometries.

This communication describes the use of non-covalent chemistry to construct recyclable porphyrin cored HBPs. The non-covalent design allows the polymeric backbone to be rescued and reused after porphyrin degradation. The steric environment within the polymeric encapsulated ligand notably affected the porphyrin coordination geometry.

Dendrimers as size selective inhibitors to protein-protein binding.

This communication describes how the "quantized" size effect of dendrimers can be exploited towards a size selective binding mechanism for the inhibition of protein-protein binding.

Synthesis and characterization of immobilized PAMAM dendrons.

This communication describes the synthesis and characterization of immobilized PAMAM dendrons onto a surface modified silicon wafer substrate (functionalized using plasma polymerized PAA) using a "growing from" strategy.

Porphyrin cored hyperbranched polymers as heme protein models.

The single step synthesis of an Fe(II) porphyrin cored hyperbranched polymer, possessing similar size and topology to the natural heme containing proteins, is reported: UV spectroscopy successfully demonstrated the ability of this polymer to reversibly bind oxygen.

Water-soluble organic dppz analogues--tuning DNA binding affinities, luminescence, and photo-redox properties.

Three new water-soluble dppz derivatives are reported, one of which binds to DNA with an affinity comparable to any mononuclear metal complex and also displays a high selectivity for GC sites.

Postsynthetic modification at the focal point of a hyperbranched polymer.

Functionalization at the focal point of hyperbranched polyester was achieved using a series of amines and a postsynthetic reaction utilizing an activated p-nitrophenyl ester unit. An element of dense packing was also detected, as evident from differences in levels of incorporation between linear and bulky reagents.

Dendrimers as scaffolds for the synthesis of spherical porphyrin arrays.

This communication describes a self assembled porphyrin sphere. The globular macromolecular assembly contains 12 terminal porphyrins and has a molecular mass in excess of 15,000 g mol-1.

Formation of A2B2 supramolecular porphyrin co-polymers.

New supramolecular A2B2 co-polymers formed in solution from a rigid diporphyrin monomer (the A2 unit) and a short flexible dipyridine monomer (the B2 unit) are reported; NMR experiments show that complete binding occurs at mM concentrations; UV titrations reveal that the dipyridine unit and a monomeric control ligand have identical binding constants, confirming that linear polymers were generated (in preference to small cyclic oligomers); at 2 x 10(-2) M polymers with an average molecular weight of 17,100 g mol-1 and containing approximately 14 porphyrin units have formed.

Catalysis inside dendrimers.

Catalytic sites can be placed at the core, at interior positions or at the periphery of a dendrimer. There are many examples of the use of peripherally functionalized dendrimers in catalysis and this subject has been thoroughly reviewed in the recent literature. This review is concerned only with dendrimer based catalysis involving catalytic sites at the core of a dendrimer and within the interior voids.