We have developed and used a novel method for studying the lumenal pH of specific cellular organelles: a membrane-permeable, pH-sensitive fluorescein-biotin derivative is targeted to specific organelles expressing avidin chimera proteins. Until recently, the major hurdle to studying organelle pH in live cells had been the lack of appropriate methods for targeting pH probes to specific organelle...

Coacervates have been widely studied as model compartments in protocell research. Complex coacervates composed of disordered proteins and RNA have also been shown to play an important role in cellular processes. Herein, we report on a microfluidic strategy for constructing monodisperse coacervate droplets encapsulated within uniform unilamellar liposomes. These structures represent a bottom-up ...

Cells organize their interior through membrane-bound organelles and membraneless condensates that are formed by liquid–liquid phase separation (LLPS). The complex process of coacervation is involved in LLPS challenging to study living cells. Hence, studying cell-mimicking synthetic containers can yield valuable insights. Here, we review recent progress with respect (particularly coacervation) a...

Few endocytosed ligands, including bacterial toxins and simian virus 40 (SV40) have been shown to reach the endoplasmic reticulum (ER) in mammalian cells. Using calcein and fluorescently labelled lactoferrin encapsulated in fusogenic liposomes we found that the cargo uses a microtubule-based pathway with ER delivery. Endocytic uptake of the lipid vesicles was cholesterol dependent in all cell l...

Tamoxifen has been reported to inhibit acidification of cytoplasmic organelles in mammalian cells. Here, the mechanism of this inhibition is investigated using in vitro assays on isolated organelles and liposomes. Tamoxifen inhibited ATP-dependent acidification in organelles from a variety of sources, including isolated microsomes from mammalian cells, vacuoles from Saccharomyces cerevisiae, an...

Sialoadhesin (Sn, Siglec-1, CD169) is a member of the sialic acid binding Ig-like lectin (siglec) family expressed on macrophages. Its macrophage specific expression makes it an attractive target for delivering antigens to tissue macrophages via Sn-mediated endocytosis. Here we describe a novel approach for delivering antigens to macrophages using liposomal nanoparticles displaying high affinit...