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Supramolecular self-assembly is a powerful tool for the development of polymolecular assemblies that can form the basis of useful nanomaterials. Given the increasing popularity of RNA therapy, the extension of this concept of self-assembly to RNA is limited. Herein, a simple method for the creation of nanosized particles through the supramolecular self-assembly of RNA with a three-dimensional macrocycle from the calixarene family was reported for the first time. This self-assembly into nanoparticles was realized using cooperative supramolecular interactions under mild conditions. The obtained nanoparticles are able to bind various hydrophobic (quercetin, oleic acid) and hydrophilic (doxorubicin) drugs, as a result of which their cytotoxic properties are enhanced. This work demonstrates that intermolecular interactions between flexible RNA and rigid calixarene is a promising route to bottom-up assembly of novel supramolecular soft matter, expanding the design possibilities of nanoscale drug carriers.

Therapy of colorectal cancer with protein drugs, including targeted therapy using monoclonal antibodies, requires the preservation of the drug’s structure and activity in the gastrointestinal tract or bloodstream. Here, we confirmed experimentally the fundamental possibility of creating composite protein–polysaccharide hydrogels based on non-degrading rhamnogalacturonan I (RG) and fibrin as a delivery vehicle for antitumor RNase binase. The method is based on enzymatic polymerization of fibrin in the presence of RG with the inclusion of liposomes, containing an encapsulated enzyme drug, into the gel network. The proposed method for fabricating a gel matrix does not require the use of cytotoxic chemical cross-linking agents and divalent cations, and contains completely biocompatible and biodegradable components. The process proceeds under physiological conditions, excluding the effect of high temperatures, organic solvents and ultrasound on protein components. Immobilization of therapeutic enzyme binase in the carrier matrix by encapsulating it in liposomes made from uncharged lipid made it possible to achieve its prolonged release with preservation of activity for a long time. The release time of binase from the composite carrier can be regulated by variation of the fibrin and RG concentration.

Abstract  The gelatinous type of secondary cell wall is present in tension wood and in phloem fibers of many plants. It is characterized by the absence of xylan and lignin, a high cellulose content and axially orientated microfibrils in the huge S2 layer. In flax phloem fiber, the major non-cellulosic component of such cell walls is tissue-specific galactan, which is tightly bound to cellulose. Ultrastructural analysis of flax fiber revealed that initiation of gelatinous secondary cell wall formation was accompanied by the accumulation of specific Golgi vesicles, which had a characteristic bicolor (dark-light) appearance and were easily distinguishable from vesicles made in different tissues and during the other stages of fiber development. Many of the bicolor vesicles appeared to fuse with each other, forming large vacuoles. The largest observed was 4 μm in diameter. Bicolor vesicles and vacuoles fused with the plasma membrane and spread their content in a characteristic “syringe-like” manner, covering a significant area of periplasm and forming “dark” stripes on the inner wall surface. Both Golgi derivatives and cell wall layers were labeled by LM5 antibody, indicating the presence of tissue- and stage-specific (1→4)-β-galactan. We suggest that this specific type of galactan secretion, which allows coverage of a large area of periplasm, is designed to increase the chance of the galactan meeting the cellulose microfibrils while they are still in the process of construction. The membrane fusion machinery of flax fiber must possess special components, which may be crucial for the formation of the gelatinous type cell wall. [ABSTRACT FROM AUTHOR]