Effect of Photothermal Therapy Using Gold Nanoparticles Conjugated with Hyaluronic Acid in an Intracranial Murine...

Glioblastoma multiforme (GBM) is the most common and aggressive malignant brain tumor. Conventional treatments for GBM include surgery, chemotherapy, radiotherapy, or a combination of these. However, emerging therapies, such as hyperthermia treatments, are being developed. One of these new therapies is nanoparticle-mediated photothermal therapy (PTT), a non-invasive treatment that converts light into heat using photoagents such as plasmonic nanoparticles. High molecular weight hyaluronic acid (HA) has been described as a potential inhibitor of tumor progression and exhibits a high affinity for the CD44 receptor, which is present in GBM cells. The in vivo efficacy of gold nanorods (GNRs) biofunctionalized with HA-700kDa in PTT has been evaluated in a murine GBM model.

Adult male C57/BL-6 mice (N=15), 3-8-month-old, were used for PTT experiments. CT2A cells were injected into the mouse brain to establish a GBM model. Tumor-bearing mice were randomly divided into three groups: Control (untreated, n=5), GNRs (injected with GNRs, n=5) and PTT-treated (injected with GNRs and treated with laser, n=5). After GNR injection, mice were irradiated with a laser at 0.98 A (250mW) for 25 min over three consecutive days.

As observed in the analysis of tumor sizes from all MR images, animals treated with a laser following GNR injection exhibited significantly smaller tumor sizes compared to control and GNR-treated animals one week after the treatment. In addition, PTT treatment led to a notable improvement in the exploratory behavior of the treated animals and an increase in their life expectancy compared to untreated control mice.

This study demonstrates the efficacy of GNR-based-PTT, applied to an orthotopic tumor model, using GNRs biofunctionalized with HA to target GBM CT2A cells. The treatment resulted in a reduction in tumor mass and an extension of life expectancy in GNR-PTT treated mice.