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. Specifically, we describe the synthesis of amino acid functionalized dendrimers and the effect of functionality on the dendrimer’s ability to bind and inhibit the enzymatic protein, chymotrypsin. The results show how dendrimer binding can be increased or decreased depending on the terminal functionality. These results will allow new ligands to be designed and synthesized, possessing increased and selective protein-binding abilities.

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.

A water-soluble colloidosome composed of PGMA–PS latex was used as a microcapsule to host a catalyzed oxidation reaction within its dodecane core. When compared to a control reaction a significant colloidosome effect was observed. Specifically, a 233% increase in the relative yield of all products was observed for the colloidosome reaction. Furthermore, when the product distributions were calculated it was evident that a switch in selectivity had taken place. These studies showed there is a significant reduction in the relative yield of the epoxide product compared to the remaining oxidation products. Additional control experiments confirmed that rate enhancements were not simply a result of concentration and that reactions were not occurring in the outer latex phase. As a consequence of these control experiments, we suggest that the colloidosome enhancement and shift in product distribution, comes about from differences in electronic environment at or close to the interface between the internal oil phase and the outer colloidal particles. This environment is able to stabilize any specific intermediates and or transition states leading to enhanced reactions for these products and higher relative yields.

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.

In the area of dendritic chemistry (hyperbranched polymers and dendrimers) it is often generalized that dendrimers are the molecule of choice for smart, selective, or technical applications involving encapsulation or controlled/selective environments. This is despite the fact that hyperbranched polymers (HBP)s are generally easier and cheaper to synthesize, making them more amenable to large-scale applications. Dendrimers have been successful in these applications by virtue of a dense packed or dense shell limit. This paper describes the synthesis of a series of narrowly dispersed HBPs possessing binding and catalytic cores with a high and uniform loading. Subsequent binding experiments clearly demonstrated the existence of a dense packed limit with respect to polymer molecular weight and ligand size. A series of catalytic experiments were also performed in an attempt to exploit these molecules and their dense packed limit to the area of shape/size selective catalysis—an area where dendrimers have previously been used with celebrated success. However, although we were able to show the existence of a dense packed limit, we were initially unable to demonstrate any selectivity based on substrate size or shape. Nevertheless, further studies into core branching motif and multiplicity eventually enabled us to obtain a series of HBPs capable of perturbing the shape/size selectivity of a simple oxidation reaction involving two alkenes. Specifically, we were able to demonstrate a 3.5-fold shift in chemoselectivity toward a smaller alkene of lower reactivity. These results compare favorably with those obtained using dendrimers and allow us to conclude that, with careful thought regarding core design, HBPs are indeed capable of being applied to technical/smart applications involving controlled and selective environments.

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. In contrast to other synthetic catalysts, where bidentate products inhibit further reactions, this macromolecular system allows the product to be displaced by the reactants leading to turnover and catalysis. We believe that this is due to the dynamics of the macromolecular host system, which maintains enough flexibility to adopt a favorable/reactive geometry, which allows the reactants to get close and react while possessing sufficient rigidity/poor geometry to reduce and disrupt any cooperative/inhibitive bidentate binding.

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. These molecules mimic an enzymes structure by incorporating binding/catalytic sites within the globular structure of the polymer. As such, the electronic and steric properties around the binding/catalytic site(s) can be controlled and fine-tuned. One class of polymer that is particularly adept at mimicking the globular structure of enzymes are dendritic polymers. This review will concentrate on the use of hyperbranched polymers as synthetic enzyme mimics.

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.

Building on our previous results that revealed a sized based mechanism for dendrimer/protein binding, the mechanism of complexation is further probed using CD spectroscopy; the results demonstrate that dendrimer/protein binding is not accompanied by changes in the protein's structure and that binding takes place on the interfacial area/active site entrance.

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.

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.

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.

This communication describes a self assembled porphyrin sphere. The globular macromolecular assembly contains 12 terminal porphyrins and has a molecular mass in excess of 15000 g mol−1.

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 functionalised 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. In covering the significant achievements in this area, we have concentrated on examples that highlight key features with respect to positive and/or negative catalytic activity.

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 × 10−2 M polymers with an average molecular weight of 17100 g mol−1 and containing approximately 14 porphyrin units have formed.

The cmc and IC50 values of the β-amyloid (Aβ) aggregation inhibitors, 3-p-toluoyl-2-[4′-(3-diethylaminopropoxy)-phenyl]-benzofuran 1, and 2-[4′-(3-diethylaminopropoxy)-phenyl]-benzofuran 2 have been determined. After comparison of the cmc data and biological data (IC50 values), we conclude that these active benzofurans do not act as surfactants or micelles at the concentration required to inhibit β-amyloid-peptide aggregation.

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.

Building on our previous results that revealed a sized based mechanism for dendrimer/protein binding, the mechanism of complexation is further probed using CD spectroscopy; the results demonstrate that dendrimer/protein binding is not accompanied by changes in the protein's structure and that binding takes place on the interfacial area/active site entrance.

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.

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. These molecules mimic an enzymes structure by incorporating binding/catalytic sites within the globular structure of the polymer. As such, the electronic and steric properties around the binding/catalytic site(s) can be controlled and fine-tuned. One class of polymer that is particularly adept at mimicking the globular structure of enzymes are dendritic polymers. This review will concentrate on the use of hyperbranched polymers as synthetic enzyme mimics.

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.

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.