2 research outputs found
Folate-Targeted Surface-Enhanced Resonance Raman Scattering Nanoprobe Ratiometry for Detection of Microscopic Ovarian Cancer
Ovarian
cancer has a unique pattern of metastatic spread, in that
it initially spreads locally within the peritoneal cavity. This is
in contrast to most other cancer types, which metastasize early on <i>via</i> the bloodstream to distant sites. This unique behavior
opens up an opportunity for local application of both therapeutic
and imaging agents. Upon initial diagnosis, 75% of patients already
present with diffuse peritoneal spread involving abdominal organs.
Complete resection of all tumor implants has been shown to be a major
factor for improved survival. Unfortunately, it is currently not possible
for surgeons to visualize microscopic implants, impeding their removal
and leading to tumor recurrences and poor outcomes in most patients.
Thus, there is a great need for new intraoperative imaging techniques
that can overcome this hurdle. We devised a method that employs folate
receptor (FR)-targeted surface-enhanced resonance Raman scattering
(SERRS) nanoparticles (NPs), as folate receptors are typically overexpressed
in ovarian cancer. We report a robust ratiometric imaging approach
using anti-FR-SERRS-NPs (αFR-NPs) and nontargeted SERRS-NPs
(nt-NPs) multiplexing. We term this method “topically applied
surface-enhanced resonance Raman ratiometric spectroscopy”
(TAS3RS (“tasers”) for short). TAS3RS successfully enabled
the detection of tumor lesions in a murine model of human ovarian
adenocarcinoma regardless of their size or localization. Tumors as
small as 370 μm were detected, as confirmed by bioluminescence
imaging and histological staining. TAS3RS holds promise for intraoperative
detection of microscopic residual tumors and could reduce recurrence
rates in ovarian cancer and other diseases with peritoneal spread
Silica Nanoparticles as Substrates for Chelator-free Labeling of Oxophilic Radioisotopes
Chelator-free nanoparticles for intrinsic
radiolabeling are highly
desirable for whole-body imaging and therapeutic applications. Several
reports have successfully demonstrated the principle of intrinsic
radiolabeling. However, the work done to date has suffered from much
of the same specificity issues as conventional molecular chelators,
insofar as there is no singular nanoparticle substrate that has proven
effective in binding a wide library of radiosotopes. Here we present
amorphous silica nanoparticles as general substrates for chelator-free
radiolabeling and demonstrate their ability to bind six medically
relevant isotopes of various oxidation states with high radiochemical
yield. We provide strong evidence that the stability of the binding
correlates with the hardness of the radioisotope, corroborating the
proposed operating principle. Intrinsically labeled silica nanoparticles
prepared by this approach demonstrate excellent in vivo stability
and efficacy in lymph node imaging