Step-wise linking of vesicles by combining reversible and irreversible linkers - towards total control on vesicle aggregate sizes

Ultrafast Dynamics of the Medicinal Pigment Curcumin inside the Imidazolium Surface Active Ionic Liquid Containing Giant Vesicles and White Light Generation via Triple-FRET Technique

The naturally occurring yellow polyphenolic medicinal pigment curcumin shows ultrafast dynamics in the excited states. These ultrafast dynamics are strongly influenced by the rigidity of the environments of the systems. The present investigation unveils the ultrafast excited-state intramolecular hydrogen atom transfer (ESIHT) (which is involved in the antioxidant mechanism) and the solvation dynamics of curcumin inside the imidazolium surface active ionic liquid (SAIL), 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl) micelle, and giant vesicles after introducing sorbitan monoesters (Span 20 and Span 80) in the aqueous medium. Interestingly, the short hydrocarbon chain containing Span 20 forms smaller, less rigid vesicles, and the long hydrocarbon chain containing Span 80 forms larger, more rigid giant vesicles after being assembled with [C16mim]Cl. The ESIHT and the solvation dynamics are slower in Span 80, containing rigid vesicles, than that in Span 20, comprising less rigid vesicles. Finally, we have established a three-component fluorescence resonance energy transfer (Triple-FRET) system to generate white light (WL) in the micelle and giant vesicles. Here the hydrophobic dye 1,6-diphenyl-1,3,5-hexatriene (DPH) acts as the donor, and the hydrophilic anticancer drug doxorubicin hydrochloride (DOX) serves as the acceptor along with the intermediate donor, curcumin. At a specific combination of the concentrations of these dyes in a particular self-assembled system, WL is generated due to the triple-FRET phenomena.

Synthesis of lipid membranes for artificial cells

A major goal of synthetic biology is to understand the transition between non-living matter and life. The bottom-up development of an artificial cell would provide a minimal system with which to study the border between chemistry and biology. So far, a fully synthetic cell has remained elusive, but chemists are progressing towards this goal by reconstructing cellular subsystems. Cell boundaries, likely in the form of lipid membranes, were necessary for the emergence of life. In addition to providing a protective barrier between cellular cargo and the external environment, lipid compartments maintain homeostasis with other subsystems to regulate cellular processes. In this Review, we examine different chemical approaches to making cell-mimetic compartments. Synthetic strategies to drive membrane formation and function, including bioorthogonal ligations, dissipative self-assembly and reconstitution of biochemical pathways, are discussed. Chemical strategies aim to recreate the interactions between lipid membranes, the external environment and internal biomolecules, and will clarify our understanding of life at the interface of chemistry and biology.