An efficient method to synthesize hyaluronan oligosaccharide lipid conjugates is described. This strategy is based on the introduction of a double bond in the glucuronic acid of the hyaluronic acid (HA), by the biodegradation of HA with hyaluronate lyase, followed by the generation of a free aldehyde group at the nonreducing end of hyaluronic acid via ozonolysis and the subsequent reduction of the generated ozonide. The resulting aldehyde-functionalized HA is then coupled to dipalmitoyl phosphatidylethanolamine (DPPE) using reductive amination chemistry. This methodology can be extended to link molecules such as biotin, polymers, or proteins to HA for numerous applications in drug delivery and in the creation of biocompatible materials for tissue repair and engineering.

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A general strategy (solution, solid-phase, and polycondensation) for the synthesis of antigenic phosphoglycans (PG) of the protozoan parasite Leishmania is presented. Phosphoglycans constitute the variable structural and functional domain of major cell-surface lipophosphoglycan (LPG) and secreted proteophosphoglycan (PPG), the molecules involved in infectivity and survival of the Leishmania parasite inside human macrophages. We have shown that the chemically labile, anomerically phosphodiester-linked phosphoglycan repeats can be assembled in an iterative and efficient manner from a single key intermediate, without involving any glycosylation steps. Furthermore, the phosphoglycan chain can be extended toward either the nonreducing (6'-OH) or the reducing (1-OH) end. We also describe a new and efficient solid-phase methodology to construct phosphoglycans based on design and application of a novel cis-allylphosphoryl solid-phase linker that enabled the selective cleavage of the first anomeric-phosphodiester linkage without affecting any of the other internal anomeric-phosphodiester groups of the growing PG chain on the solid support. The strategy to construct larger phosphoglycans in a one-pot synthesis by polycondensation of a single key intermediate is also described, enabling CD spectrometric measurements to show the helical nature of phosphoglycans. Our versatile synthetic approach provides easy access to Leishmania phosphoglycans and the opportunity to address key immunological, biochemical, and biophysical questions pertaining to the phosphoglycan family (LPG and PPG) unique to the parasite.

Lipid nanoparticles (LNPs) have been used to successfully deliver small interfering RNAs (siRNAs) to target cells in both preclinical and clinical studies and currently are the leading systems for in vivo delivery. Here, we propose the use of an ordinary differential equation (ODE)-based model as a tool for optimizing LNP-mediated delivery of siRNAs. As a first step, we have used a combination of experimental and computational approaches to develop and validate a mathematical model that captures the critical features for efficient siRNA-LNP delivery in vitro. This model accurately predicts mRNA knockdown resulting from novel combinations of siRNAs and LNPs in vitro. As demonstrated, this model can be effectively used as a screening tool to select the most efficacious LNPs, which can then further be evaluated in vivo. The model serves as a starting point for the future development of next generation models capable of capturing the additional complexity of in vivo delivery.

The review constitutes a comprehensive report on upcoming drug targets, with emphasis on glycosylphosphatidylinositol (GPI)-anchored glycoconjugates along with related biochemistry of enolase, glycosome and purine salvage pathways, as we strive to bring ourselves a step closer to being able to combat this deadly disease.