3 research outputs found
Hydrophobic IR-780 Dye Encapsulated in cRGD-Conjugated Solid Lipid Nanoparticles for NIR Imaging-Guided Photothermal Therapy
This
is high demand to enhance the accumulation of near-infrared theranostic
agents in the tumor region, which is favorable to the effective phototherapy.
Compared with indocyanine green (a clinically applied dye), IR-780
iodide possesses higher and more stable fluorescence intensity and
can be utilized as an imaging-guided PTT agent with laser irradiation.
However, lipophilicity and short circulation time limit its applications
in cancer imaging and therapy. Moreover, solid lipid nanoparticles
(SLNs) conjugated with cÂ(RGDyK) was designed as efficient carriers
to improve the targeted delivery of IR-780 to the tumors. The multifunctional
cRGD-IR-780 SLNs exhibited a desirable monodispersity, preferable
stability and significant targeting to cell lines overexpressing α<sub><i>v</i></sub>β<sub>3</sub> integrin. Additionally,
the in vitro assays such as cell viability and in vivo PTT treatment
denoted that U87MG cells or U87MG transplantation tumors could be
eradicated by applying cRGD-IR-780 SLNs under laser irradiation. Therefore,
the resultant cRGD-IR-780 SLNs may serve as a promising NIR imaging-guided
targeting PTT agent for cancer therapy
Aptamer-Modified Temperature-Sensitive Liposomal Contrast Agent for Magnetic Resonance Imaging
A novel aptamer modified thermosensitive
liposome was designed
as an efficient magnetic resonance imaging probe. In this paper, Gd-DTPA
was encapsulated into an optimized thermosensitive liposome (TSL)
formulation, followed by conjugation with AS1411 for specific targeting
against tumor cells that overexpress nucleolin receptors. The resulting
liposomes were extensively characterized <i>in vitro</i> as a contrast agent. As-prepared TSLs-AS1411 had a diameter about
136.1 nm. No obvious cytotoxicity was observed from MTT assay, which
illustrated that the liposomes exhibited excellent biocompatibility.
Compared to the control incubation at 37 °C, the liposomes modified
with AS1411 exhibited much higher T<sub>1</sub> relaxivity in MCF-7
cells incubated at 42 °C. These data indicate that the Gd-encapsulated
TSLs-AS1411 may be a promising tool in early cancer diagnosis
Poly(glycerol) Used for Constructing Mixed Polymeric Micelles as <i>T</i><sub>1</sub> MRI Contrast Agent for Tumor-Targeted Imaging
There
was much interest in the development of nanoscale delivery
vehicles based on polymeric micelles to realize the diagnostic and
therapeutic applications in biomedicine. Here, with the purpose of
constructing a micellar magnetic resonance imaging (MRI) contrast
agent (CA) with well biocompatibility and targeting specificity, two
types of amphiphilic diblock polymers, mPEG–PGÂ(DOTAÂ(Gd))-<i>b</i>-PCL and FA-PEG-<i>b</i>-PCL, were synthesized
to form mixed micelles by coassembly. The nanostructure of the resulting
micellar system consisted of polyÂ(caprolactone) (PCL) as core and
polyÂ(glycerol) (PG) and polyÂ(ethylene glycol) (PEG) as shell, simultaneously
modified with DOTAÂ(Gd) chelates and folic acid (FA), which afforded
functions of MRI contrast enhancement and tumor targeting. The mixed
micelles in aqueous solution presented a hydrodynamic diameter of
about 85 nm. Additionally, this mixed micelles exhibited higher <i>r</i><sub>1</sub> relaxivity (14.01 mM<sup>–1</sup> S<sup>1–</sup>) compared with commercial Magnevist (3.95 mM<sup>–1</sup> S<sup>1–</sup>) and showed negligible cytotoxicity
estimated by WST assay. In vitro and in vivo MRI experiments revealed
excellent targeting specificity to tumor cells and tissue. Furthermore,
considerably enhanced signal intensity and prominent positive contrast
effect were achieved at tumor region after tumor-bearing mice were
intravenously injected with the mixed micelles. These preliminary
results indicated the potential of the mixed micelle as <i>T</i><sub>1</sub> MRI CA for tumor-targeted imaging