Nanomedicine for Spontaneous Brain Tumors: A Companion Clinical Trial

Nanoparticles’ enhanced permeation
and retention (EPR) variations
due to tumor heterogeneity in naturally occurring brain tumors are
commonly neglected in preclinical nanomedicine studies. Recent pathological
studies have shown striking similarities between brain tumors in humans
and dogs, indicating that canine brain tumors may be a valuable model
to evaluate nanoparticles’ EPR in this context. We recruited
canine clinical cases with spontaneous brain tumors to investigate
nanoparticles’ EPR in different brain tumor pathologies using
surface-enhanced Raman spectroscopy (SERS). We used gold nanoparticles
due to their surface plasmon effect that enables their sensitive and
microscopic resolution detection using the SERS technique. Raman microscopy
of the resected tumors showed heterogeneous EPR of nanoparticles into
oligodendrogliomas and meningiomas of different grades, without any
detectable traces in necrotic parts of the tumors or normal brain.
Raman observations were confirmed by scanning electron microscopy
(SEM) and X-ray elemental analyses, which enabled localization of
individual nanoparticles embedded in tumor tissues. Our results demonstrate
nanoparticles’ EPR and its variations in clinically relevant,
spontaneous brain tumors. Such heterogeneities should be considered
alongside routine preoperative imaging and histopathological analyses
in order to accelerate clinical management of brain tumors using nanomedicine
approaches.