Self‐Assembled “Breathing” Grana‐Like Cisternae Stacks

Abstract

Membranes in cells display elaborate, dynamic morphologies intimately tied to defined cellular functions. Cisternae stacks are a common membrane morphology in cells widely found in organelles. However, compared with the well-studied spherical cell membrane mimics, cisternae stacks as organelle membrane mimics are greatly neglected because of the difficulty of fabricating this unique structure. Herein, the grana-like cisternae stacks are assembled via the reorganization of stacked microsized bicelles to mimic grana functions. The cisternae stacks are connected by fusion regions between adjacent cisternae. The number of cisternae can be controlled from ≈4 to 15 by the variation of ethanol volume percentage. Under the stimulation of solvent or negatively charged nanoparticles, the cisternae stacks can reversibly compress and expand, similar to the "breathing" property of natural grana. During the "breathing" process, nanoparticles are reversibly captured and released. Frequency resonance energy transfer is realized on the cisternae stacks trapped with two kinds of quantum dots. The cisternae stacks provide advanced membrane model for cell biotechnology, and clues for the shaping of organelles composed of cisternae. The ability of the cisternae stacks to capture materials enables them to possibly be applied in biomimetics and the design of advanced functional materials.

Self-Assembled Rough Endoplasmic Reticulum-Like Proto-Organelles

“…Micro-sized stacked bicelles were formed from negatively charged 1,2-dipalmitoyl- sn -glycero-3-phosphocholine (DPPC)/1,2-dimyristoyl- sn -glycero-3-phospho-L -serine (sodium salt) (DMPS) ( w / w , 7/3) mixtures by slowly cooling the phospholipid dissolved in 50% ethanol-water solution from 50°C to 25°C at a rate of 0.5°C/min ( Figures 1 A–1C). Similar to the results from zwitterionic DPPC ( Li and Han, 2018 ), stacked bicelles from DPPC/DMPS ( w / w , 7/3) were formed in a well-defined round shape with an average diameter of ∼15 μm, as depicted by the fluorescence image ( Figure 1 B). The small-angle X-ray scattering (SAXS) profiles of the stacked bicelles displayed only one set of lamellar diffraction peaks, at q 1 = 1.375 nm −1 , q 2 = 2.750 nm −1 , and q 3 = 4.125 nm −1 ( Figure 1 C), which confirmed the periodic lamellar structure of the stacked bicelles with periodic spacing d of 4.56 nm, as given by d = 2π/ q 1 .…”

“…To further mimic the complexity of natural membrane systems, more complex membrane structures including multilamellar ( Matosevic and Paegel, 2013 ) and multicompartmented vesicles ( Zong et al., 2017 , Deng et al., 2017 ), stacked bicelles or nanodisks ( Matsui et al., 2015 , Yang et al., 2014 , Wang et al., 2018 ), and tube networks/stacks ( Karlsson et al., 2001 , Powers et al., 2017 , Zhang et al., 2017 ) were recently developed. These artificial membrane systems supplied platforms for the study of protein structures and functions ( Dürr et al., 2012 , Zhang et al., 2016 , Burré et al., 2010 ), the investigation of cellular processes ( Fenz et al., 2017 , Kamiya et al., 2016 , Küchler et al., 2016 ), and biomimetics ( Li and Han, 2018 , Altamura et al., 2017 , Adamala et al., 2016 , Heath et al., 2017 , Park et al., 2018 ), and provided important clues for membrane shaping ( Powers et al., 2017 , Shi and Baumgart, 2015 ). However, cisternae stacks, especially the helicoidal structures found in RER, were rarely artificially fabricated from phospholipids.…”

Programmed magnetic manipulation of vesicles into spatially coded prototissue architectures arrays

“…Before using it for GUVs assembly, the device was firstly treated in below procedure to avoid GUVs rupture during GUVs entrapment experiments. A total of 200 μL of DPPC ethanol-water solution with ethanol volume percentage of 40% and DPPC concentration of 0.10 mg mL −1 (similar composition used for bicelles formation [38][39][40] by us) were added in the cell. The device was then heated at 50°C for 5 min, and washed using 133 mM MnCl 2 solution for at least three times, resulting in the formation of supported DPPC membranes on the cover slip and SS mesh.…”

Versatile Phospholipid Assemblies for Functional Synthetic Cells and Artificial Tissues

“…[ 14 ] Recently, micro‐sized (7–11 µm in diameter) phospholipid bicelles were first obtained from phospholipids with high phase transition temperature (DMPC, DPPC, DSPC) by slowly cooling the phospholipid dissolved in ethanol–water solution at a rate of 0.4 °C min −1 (Table 1). [ 8 ] Stacked micro‐sized bicelles expanded into loosely packed structures with parallel cisternae when dispersed in water. [ 8 ] These cisternae stacks are similar to the structure of grana in chloroplast.…”

“…Cell membrane sets the barrier to distinguish the interior of the cell with outside environment to enable it to be an autonomous system, while organelle membranes not only form functional compartments inside cells, but also provide platforms for cell metabolism. The phospholipid assemblies include vesicles, [ 5–7 ] cisternae stacks, [ 8,9 ] tubes, [ 10–12 ] bicelles, [ 8,9,13–15 ] and cones. [ 16 ] They play important roles in cell functions.…”