1 research outputs found
Designing Theranostic Agents Based on Pluronic Stabilized Gold Nanoaggregates Loaded with Methylene Blue for Multimodal Cell Imaging and Enhanced Photodynamic Therapy
At present, multifunctional noble
metal-based nanocomposites are extensively investigated for their
potential in performing cellular imaging, diagnostics, and therapy
by integration of unique plasmonic properties with the spectroscopic
expression and therapeutic activity of appropriate drug. In this work,
we report the fabrication of 3-dimensional (3-D) close-packed nanoassemblies
of gold nanoparticles by controlling the aggregation of individual
nanoparticles in solution and subsequent stabilization of formed aggregates
by Pluronic block copolymer (F127) coating. Besides conferring high
stability, Pluronic mediates the loading of Methylene Blue (MB) molecules
which exhibit interesting spectroscopic and photochemical properties
to be employed as both optical label and photosensitizing drug. Indeed,
here we demonstrate the pertinence of the fabricated nanoassemblies
to provide optical imaging of murine colon carcinoma cells (C-26)
via both Raman and fluorescence signals collected from MB molecules,
specifically by using scanning confocal surface-enhanced resonant
raman spectroscopy (SERRS) and fluorescence lifetime imaging microscopy
(FLIM) techniques. The specific configuration of as fabricated nanoassemblies
allows a small population of MB molecules to be located in very small
areas between the aggregated nanoparticles (“hot spots”)
to provide SERRS signal while the other population remains captured
in Pluronic coating and preserves both its fluorescence signal and
singlet-oxygen generation capability. Remarkably, we demonstrate an
enhanced photodynamic therapeutic activity of MB-loaded gold nanoaggregates
against murine colon carcinoma cells (C-26), as compared to the free
photosensitizer. To our knowledge, this is the first report on plasmonic
nanoplatforms conveying photosensitizing drug into cells to operate
as optical label via both SERÂ(R)S and FLIM and to perform enhanced
photodynamic therapy