Braga, March 11-15, 2019
1
Magnetogels based on magnetic/plasmonic nanoparticles and self-assembled
peptide hydrogels as drug nanocarriers
Sérgio R. S. Veloso,
a
Beatriz D. Cardoso,
a
A. Rita O. Rodrigues,
a
J. A. Martins,
b
Paula M. T.
Ferreira,
b
P. J. G. Coutinho,
a
Elisabete M. S. Castanheira
a
a Centre of Physics (CFUM), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
b Centre of Chemistry (CQ-UM), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
Supramolecular hydrogels are stimulus-responsive self-assembled intertwined fibrillar structures achieved through
the cooperative effect of different non-covalent intermolecular interactions [1]. Particularly, peptide-based hydrogels
are among the most important class of biomaterials owing to the wide range of applications, which include among
others drug delivery, tissue engineering, in vivo imaging and template materials.
The hydrogels can be combined with magnetic nanoparticles (magnetogels). The presence of magnetic
nanoparticles in the hydrogel matrix allows efficient transport and accumulation of drugs in the therapeutic sites or
localization by using an external magnetic field gradient, allowing guided transport of anticancer drugs, most of them
toxic and with systemic side effects.
The addition of a gold shell to the nanoparticles improves biocompatibility and allows photothermia therapy owing to
the collective oscillation of conduction band electrons in resonance with visible frequencies of light [2], which can be
used as a photo-triggered release of the encapsulated drug. The combined hydrogel specificity, high-loading
capacity, synergistic magnetically-guided drug delivery and hyperthermia make the magnetogels highly promising
nanosystems for improving therapeutic efficiency in cancer therapy [3,4].
In this work, manganese ferrite nanoparticles synthesized as previously described [5], coated with a gold shell or
decorated with gold nanoparticles, were combined with a new self-assembled peptide-based hydrogel containing
naproxen. The magnetogels obtained were characterized and investigated as drug delivery systems by interaction
with biomembrane models. The new magnetogels were tested as nanocarriers for curcumin (an anticancer and
neuroprotective potential drug). Fluorescence-based techniques (fluorescence emission, FRET and fluorescence
anisotropy) were used to assess incorporation of curcumin in the magnetogels, its transport towards models of
biological membranes and the effect of photothermia on curcumin release and transport. For that purpose, small
unilamellar vesicles (SUVs) of phosphatidylcholine/cholesterol 7:3 were used as membrane models. Delivery of
drugs towards SUVs was monitored through FRET assays from the fluorescent drug (acting as the energy donor)
and the dye Nile Red (energy acceptor) included in the SUVs. The results obtained are promising for the use of
these magnetogels in multimodal cancer therapy, by combination of chemotherapy, magnetic guided drug delivery,
magnetic hyperthermia and photothermia.
References:
1) S. R. S. Veloso et al., Pharmaceutics, 2018, 10, 145.
2) A. R. O. Rodrigues et al., Pharmaceutics, 2019, 11, 10.
3) A. Akbarzadeh et al., Nanoscale Res. Lett., 2012, 7, 144.
4) A. Hervault, N. T. K. Thanh, Nanoscale, 2014, 6, 11553.
5) A. R. O. Rodrigues et al., RSC Advances, 2016, 6, 17302.
Acknowledgements: This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the
framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013 and UID/FIS/04650/2019) and of CQUM
(UID/QUI/00686/2019) and through research Projects PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020) and
PTDC/QUI-QOR/29015/2017 (POCI-01-0145-FEDER-029015), also funded by FEDER, Portugal2020 and COMPETE2020. B. D.
Cardoso acknowledges FCT for a PhD grant (SFRH/BD/141936/2018). S.R.S. Veloso acknowledges FCT for a research grant
under UID/FIS/04650/2013 funding.