Abstracts Book - IMRC 2018

• SB6-P063
GEMINI SURFACTANTS FOR GENE THERAPY: THE INFLUENCE OF
THE SPACER ON THEIR SELF-ASSEMBLY AND
CYTOCOMPATIBILITY
Delvis R. Acosta Martinez 1,2 , Eustolia Rodriguez Velazquez 3 , Georgina Pina Luis 1 , Pablo
Taboada 2 , Manuel Alatorre Meda 1
1 Instituto Tecnológico de Tijuana, Centro de Graduados e Investigacion en Quimica, Mexico.
2 Universidad de Santiago de Compostela, Fisica de Particulas, Spain. 3 Universidad Autónoma
de Baja California, Facultad de Odontologia-Tijuana, Mexico.
Gemini surfactants (GS´s) are a novel class of surfactants composed of two polar
heads and two long alkyl chains linked by a spacer. As compared to singlechained
surfactants, they present distinctive features that highlight them for
applications as drug and gene carriers, such as a lower Critical Micelle
Concentration (CMC), a higher stability against dilution, and a higher loading
capacity of hydrophobic compounds inside their micelles.
Recognizing their great potential for the biomedical field, we herein analyze the
influence of the spacer length on the self-assembly and cytocompatibility of a
family of three bis-(quaternary ammonium halide) GS´s. The GS´s under study,
referred to as GS-4, GS-6, and GS-14, were selected to present fixed side alkyl
chains of 14 carbons and different head-to-head alkyl chain spacers of 4, 6, and
14 carbons, respectively.
The self-assembly process was studied by conductometry, UV-vis, and
fluorescence spectroscopy. Meanwhile, the morphology and size of the resulting
aggregates (micelles) were analyzed by STEM, AFM, and DLS. Finally, the
cytocompatibility was characterized by ELISA-based tests in the absence and
presence of DNA.
With respect to their self-assembly, GS-4 and GS-6 displayed a single CMC of
0.202 and 0.189 mM, respectively. By contrast, GS-14 displayed two CMC’s of
0.053 and 0.132 mM. Regarding morphology and size, the resulting micelles all
studied GS´s were found to present a well-defined spherical shape, displaying
increasing sizes with the spacer length of ca. 55, 75, and 145 nm for GS-4, GS-6,
and GS-14, respectively. Finally, with respect to the cytocompatibility, we found
that the lower the length of spacer the higher the cytocompatibility attained (24
h) with values of ca. 85, 85, and 75% for GS-4, GS-6, and GS-14, respectively.
Interestingly, this cytocompatibility was maintained when running the