Editorial [Hot Topic: “Supramolecular Transmembrane Nanocarriers for Targeted Therapeutics” (Guest Editor: Grzegorz Bazylak) ]

One of the prerequisite processes in living cells is the ability to maintain the simultaneous, hierarchical and selective transmembrane transport of ions, molecules and waste products employing highly evolved proteins, self-organized in the form of specific and sophisticated ion channels or biomolecule nanocarriers. The examples of synthetic approach to the preparation of such supramolecular transporters include natural protein scaffolds, abiotic structures, peptide-abiotic hybrids, nanotubular cyclic peptides, hydraphiles and their variants. In many cases these synthetic ion channels exhibiting a selective and specific in vitro activity as antibiotics acting by disruption of cellular ion balance of various microbials. Similarly, free and macrocycle encapsulated chloride channels blockers have been found to be useful to promote therapy induced apoptosis. These both examples show that synthetic biomembrane nanocarriers would be applied in near perspective as the promising targeted and/or triggered therapeutics. Thus, in recent years efforts of supramolecular chemist evolving continuously from the traditional target-directed to the more complete property-oriented strategies of synthesis to enable design, preparation and screening of more substantial, selective, and pharmacoactive molecules with enhanced transporters mimicking ability. The significance of these supramolecular nanocarrier approaches still increasing by the demands of modern gene delivery and cell transfection technologies. Examples of such novel solutions offered by a potential supramolecular nanocarrier system will be illustrated in this special issue of Current Drug Discovery Technologies. The introductory review paper by Tecilla et al. focuses on the currently designed supramolecular synthetic systems, both artificial channels and nanocarriers, promoting selective anion transport, thus enabling development of new therapeutics for variable anion channelopathies, a commonly diagnosed genetic disease in humans. This approach is continued in the minireview paper by Mutihac describing the potential applications of calixarenes and their derivatives in transport of diverse low-molecular biologically relevant substances through liquid membranes and for development of new drug formulations with enhanced drug-target specificity. Basing on a typical supramolecular function of immobilized chiral stationary phase (CSP) involving dynamic enantiorecognition of the analyte during the translocation process in bilayer interphase comprising of each HPLC systems Bazylak et al. discussed chiral separation of profens, as the well known non-selective NSAIDs and recently recognized potential anticancer agents, with use of past-developed polysaccharide-, cyclodextrin-, glycoantibiotics-CSPs and currently proposed bimodal, combinatorial, monolithic and polymeric modes. Similar approach is also elaborated in the last minireview paper by Bielecki and Wasiak et al. presenting some recent results on use of various supramolecular nanocarrier molecules in design of range of analytical devices applicable in drug screening procedures employing membrane mimicking processes. In the first research paper by de Villiers et al. the results of extended study on solubility, stability and availability of nifedipine encapsulated in various nanocavity sized para-sulfonato-calixarenes have been described. Similarly, Bazylak et al. have illustrated separation abilities of currently available HPLC techniques employing supramolecular host-guest stationary phases, e.g. octadecylsilica versus calixarene bonded silica with variable nanosize of their cavity and upper-rim modification, for screening of the 1,3,4-oxadiazolureas with potent analgesic activity. The highly selective separation of positional and E/Z isomers of these analytes were described in this report as well as some preliminary data indicating on especially attractive possibility of use calixarenes as the future nanocarriers for these compounds. The next four research papers by Torres- Labandeira et al., Diaz et al., Jiang et al. and Terekhova deal with detailed thermodynamic, spectral, kinetic, and computational studies on the solubilization process of the water insoluble sodium dicloxacillin, benzimidazolic antihelmintics, purine alkaloids and insecticide intermediates, respectively, with different cyclodextrins. In addition, the series of highly innovative divalent metal complexes of moensin A, a polyether-type antibiotic and anticoccidial agent, have been described and characterized in research paper by Pantcheva et al. which enabled to obtain the new kind of antimicrobials with increased membrane permeabilizing properties and enhanced activity against Gram-positive bacteria. In last research paper by Przybylo et al. the results of study by fluorescence resonance energy transfer (FRET) method on the oligonucleotide orientation and binding with the lipid bilayer, used as the carrier of genetic material and mimicking a gene delivery system, has been reported.......