RESUMEN
p-aminobenzoic acid (PABA), a structural moiety of many commercial drugs, is self-assembled with linker alkyl side chains to form tubular nanostructures. The tubes exhibited fluorescence either intrinsic or from fluorescent molecules embedded in the wall during self-assembly. Uptake and inter-cellular delivery of the conjugated nanotubes in human cancer cells and in mouse embryonic stem cells were demonstrated by fluorescence imaging and flow cytometry. Biocompatibility, cytotoxicity and clearance were monitored both ex vivo in mouse multipotent embryonic stem cells and in vivo in adult Drosophila. Accumulation of nanotubes had no adverse effects and abnormalities on stem cell morphology and proliferation rate. A distinct distribution of two separate nanotubes in various internal organs of Drosophila interprets that accumulation of nanomaterials might be interdependent on the side chain modifications and physiological settings of cell or tissue types. Unlike carbon nanomaterials, exposure of PABA nanotubes does not produce any hazards including locomotion defects and mortality of adult flies. Despite differential uptake and clearance from multiple live tissues, the use of self-assembled nanotubes can add new dimensions and scope to the development of dual-purpose oral carriers for the fulfilment of many biological promises.
Asunto(s)
Aminopiridinas/farmacología , Benzamidas/farmacología , Materiales Biocompatibles/farmacología , Drosophila melanogaster/efectos de los fármacos , Drosophila melanogaster/metabolismo , Células Madre Embrionarias/citología , Células Madre Embrionarias/efectos de los fármacos , Nanotubos/química , Administración Oral , Aminopiridinas/química , Animales , Benzamidas/química , Materiales Biocompatibles/química , Drosophila melanogaster/citología , Células Madre Embrionarias/metabolismo , Larva/citología , Larva/efectos de los fármacos , Larva/metabolismo , Ratones , Nanotubos/ultraestructura , Especificidad de Órganos/efectos de los fármacosRESUMEN
Residue based control of specific helical folding is explored in hybrid peptide oligomers consisting of alternating L-Ala and cis-beta-furanoid sugar amino acid (FSAA) residues as building blocks; two series of these hybrid oligomers are designed, synthesized and extensively characterized by using NMR, CD, FT-IR and MD simulation studies; results show the co-existence of left-handed 11- and 14/15-helical conformations in these short oligomers of Boc-(alpha/beta) and Boc-(beta/alpha) series.