Application of magnetic resonance spectroscopy (MRS) in photo-thermal therapy response of U87-MG human glioma cells with gold-coated iron oxide nanoparticles: an in vivo study.

OBJECTIVE

Accurate prediction of the response to nano-photothermal therapy (NPTT) requires rapid feedback from the tumor. This study utilizes proton magnetic resonance spectroscopy (1H-MRS) to non-invasively assess metabolic changes in glioma treated with NPTT using gold-coated iron oxide nanoparticles, providing insight into early therapeutic efficacy.

MATERIALS AND

METHODS

The study was conducted on nude mice bearing U87-MG human glioma xenografts, which were assigned to distinct treatment cohorts: Au@Fe₂O₃ core-shell nanoparticles alone, laser irradiation alone, and the combined nano-photothermal therapy. The efficacy was determined by assessing post-treatment alterations in tumor volume and corresponding changes in choline and lipid metabolite signals detected via 1H-MRS.

RESULTS

Analysis of metabolite ratios, normalized to the water peak, demonstrated a significant post-NPTT therapeutic response. A marked decrease was observed in both the choline/creatine ratio (from 0.48 ± 0.17 to 0.24 ± 0.07) and the choline/lipid ratio (from 0.47 ± 0.23 to 0.13 ± 0.06). Notably, these metabolic alterations were evident within 24 h of the procedure. In contrast, significant reductions in tumor volume were not detectable until day 9 post-treatment.

CONCLUSION

1H-MRS analysis of metabolite ratios serves as a sensitive, early biomarker of the biological response to NPTT. The capacity for in vivo assessment of therapeutic efficacy within 24 h post-procedure provides a significant advantage. This rapid feedback can critically inform clinical decision-making and guide the strategic planning of subsequent cancer treatments.