No abstract

Natural pore-forming proteins act as viral helical coats and transmembrane channels, exhibit antibacterial activity and are used in synthetic systems, such as for reversible encapsulation or stochastic sensing. These diverse functions are intimately linked to protein structure. The close link between protein structure and protein function makes the design of synthetic mimics a formidable challenge, given that structure formation needs to be carefully controlled on all hierarchy levels, in solution and in the bulk. In fact, with few exceptions, synthetic pore structures capable of assembling into periodically ordered assemblies that are stable in solution and in the solid state have not yet been realized. In the case of dendrimers, covalent and non-covalent coating and assembly of a range of different structures has only yielded closed columns. Here we describe a library of amphiphilic dendritic dipeptides that self-assemble in solution and in bulk through a complex recognition process into helical pores. We find that the molecular recognition and self-assembly process is sufficiently robust to tolerate a range of modifications to the amphiphile structure, while preliminary proton transport measurements establish that the pores are functional. We expect that this class of self-assembling dendrimers will allow the design of a variety of biologically inspired systems with functional properties arising from their porous structure.

The efficacy of vaccine adjuvants such as Toll-like receptor agonists (TLRa) can be improved through formulation and delivery approaches. Here, we attached small molecule TLR-7/8a to polymer scaffolds (polymer-TLR-7/8a) and evaluated how varying physicochemical properties of the TLR-7/8a and polymer carrier influenced the location, magnitude and duration of innate immune activation in vivo. Particle formation by polymer-TLR-7/8a was critical for restricting adjuvant distribution and prolonging activity in draining lymph nodes. The improved pharmacokinetic profile by particulate polymer-TLR-7/8a was also associated with reduced morbidity and enhanced vaccine immunogenicity for inducing antibodies and T cell immunity. We extended these findings to the development of a modular platform in which protein antigens are site-specifically linked to temperature-responsive polymer-TLR-7/8a adjuvants that self-assemble into immunogenic particles at physiologic temperatures in vivo. Our findings provide a chemical and structural basis for optimizing adjuvant design to elicit broad-based antibody and T cell responses with protein antigens.

The effect of solvent on the two-dimensional (2D) supramolecular ordering of monodendron 1 at the liquid-solid interface has been systematically investigated by means of scanning tunneling microscopy (STM). Solvents range from those with hydrophilic solvating properties, such as alkylated alcohols and acids, to hydrophobic solvents such as alkylated aromatics and alkanes. Dramatic differences in the 2D ordering are observed depending on the nature of the solvent. Of particular interest is the fact that in hydrophobic solvating solvents, such as aliphatic and aromatic hydrocarbons, solvent molecules are coadsorbed in the 2D molecular network while this is not the case for alkylated alcohols or acids. Furthermore, in the case of the coadsorbing solvents, a striking influence of the alkyl chain length has been observed on the 2D pattern formed. The solvent and alkyl chain length dependences are discussed in terms of molecule-molecule interactions (homo and hetero) and molecule-substrate interactions.