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Polyamidoamine dendritic fullerene derivatives for biological and material applications
Montellano Lopez, Alejandro
2012-03-26
Abstract
Fullerene C60 science can been broadly divided into the study of three areas: (i) its reactivitythat permits the obtention of modified fullerene derivatives, which can typically found (ii) biological and (iii) material applications.
The main goal of this thesis is the synthesis and characterization of a library of monoadducts, bisadducts and hexakisadducts of fullerene C60 containing different generations of PAMAM dendron. On this purpose we have firstly studied the functionalization of fullerene C60 by means of 1,3-dipolar cycloaddition. On this purpose, we moved from the classic conditions by employing MW irradiation as the heating source, combined with ionic liquids as the solvent phase in order to obtain remarkable differences in the reactivity and the polyaddition selectivity.
In a second stage we have been dealing with the separate synthesis of four different generations of PAMAM dendron and different fulleropyrrolidine moieties including: monoadduct and five bisadducts isomers to finally attach them via amidation. We have complete this library with the employment of the Bingel-Hirsch reaction to attach twelve units of a PAMAM first generation dendron to the carbon cage to obtain a Th symmetric hexakisadduct. As a result, a variety of fullerene derivatives with an enhanced water solubility was obtained, opening the door to their utilization for biological applications. Thus, we can distinguished between those containing terminal, positive-charged amines that can be used to efficiently complex oligonucleotides and those that contains one or more terminal-free carboxylic acid that can be used as anchor points for further functionalization.
Concerning to those potentially used for transfection, the broad range of examples described in this thesis will permit to examine the role of the dendron moiety, the fullerene, and the distribution of the positive charges around the fullerene sphere, as key points into the complexation and transfection processes. Furthermore, complexation studies of some of these derivatives has been performed, all of them exhibiting a high affinity towards DNA complexation, demonstrating the great potential of these derivatives for transfection.
In the last part of this thesis, we have focused on the synthesis of two porphyrin-dendrofullerene dyads with or without an amide linker. Since the water solubility usually goes hand in hand with a good number of charges we have incorporated an asymmetric tryspyridilporphyrin conferring three more positive charges to the final structure, that provides an additional solubility to the final molecule. This system is of the most interest since electron transfer processes could be studied in polar media. In addition, electrostatic interactions could be further exploited with negative charged systems to build up high complex systems.
Subjects
Insegnamento
Publisher
Università degli studi di Trieste
Languages
en
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