Biological and polymeric self-assembled hybrid systems: Structure and properties of thylakoid/polyelectrolyte complexes

Abstract

A novel hybrid system composed of biological components and synthetic polymer, thylakoid/polycation complex, has been formed and studied. Effects of complex formation on the structure, electrostatics and functioning of thylakoid membranes have been examined. Thylakoids from bean leaves were used to form complexes with polycation polyallylamine hydrochloride (PAAH) in two systems: (i) thylakoid/polycation complexes formed in an aqueous bulk phase, and (ii) immobilized thylakoid/polycation planar complexes. Immobilized on a solid substrate surface, thylakoid/polycation complexes were prepared using layer-by-layer stepwise alternate adsorption technique, i.e., via the sequential alternate adsorption of thylakoids and polycation molecules. The morphology of built up structures was investigated by scanning electron microscopy. Light-induced electron transport in chloroplasts was studied by the electron paramagnetic resonance (EPR) method. Spin probe technique was employed to study the structural and electrostatic characteristics of thylakoid membranes. We have found that efficiency of light-induced electron transport in thylakoid membranes and membrane structure were not changed noticeably by PAAH binding to thylakoids in a wide range of PAAH concentrations. The data obtained indicate the physiologically-soft character of polycation interactions with thylakoid membranes and demonstrate effectiveness of interfacial self-assembly approach to fabrication of complex planar functional nanostructures from biological components and synthetic polymers.

Desiccation‐induced alterations in surface topography of thylakoids from resurrection plant Haberlea rhodopensis studied by atomic force microscopy, electrokinetic and optical measurements

“…B) showed а typical oval shape and intact morphology with distinct grana (the flat disks with a diameter of the range 700–800 nm) and lamella. Their lateral dimensions [6.5 × 7.3 (±0.5) μm; cross‐sectional area, Acs = 37.9 ± 1.5 μm 2 ] and height (0.6 ± 0.02 μm) agreed well with previously published microscopy data (Albertsson and Andreasson , Dementiev et al , Kirchhoff , Daum and Kühlbrandt , Sznee et al , Herbstová et al ). With the resolution attained (one pixel of approximately 20 nm), individual protein complexes could not be resolved.…”

Folate-targeted supramolecular vesicular aggregates based on polyaspartyl-hydrazide copolymers for the selective delivery of antitumoral drugs

“…As shown in Table 1, the mean size values of FTSVAs were significantly (p < 0.005) bigger than those observed for uncoated SUVs and SVAs (113.0 nm, 104.3 nm and 105.2 nm, respectively), while no significant difference was observed between uncoated SUVs and SVAs. This finding was probably due to the charged polymeric folate moieties and their localization along the surface of the lipid bilayer structures of the SVAs (facing both the external and the internal aqueous environments), thus eliciting the increase in vesicle mean size [31,32]. The presence of gemcitabine determined no significant variation of the mean size of uncoated SUVs, while a significant (p < 0.005) mean size variation was observed in the case of both SVAs and FT-SVAs, although characterized by a different trend.…”

Impact of magnetite nanoparticle incorporation on optical and electrical properties of nanocomposite LbL assemblies

“…1 Among the other nanotechnology techniques LbL deposition is a low-cost way that allows constructing multilayer structures onto virtually any surface with a great number of different materials. 2,3 LbL assembly is based on the sequential adsorption of charged molecules onto oppositely charged surfaces, 4,5 and has been shown to produce various composite structures from metal ions, nanoparticles, carbon nanotubes and other nanomaterials. [6][7][8][9][10] A distinctive feature of these nanostructures is the possibility to control their properties by adjusting the concentration, distribution, shape and size of the nanomaterials incorporated in the host matrix.…”