Ultrasmall Nanoparticle Delivery of Doxorubicin Improves Therapeutic Index for High-Grade Glioma

Area of Science:

• Nanomedicine
• Oncology
• Drug Delivery

Background:

• Limited durable therapeutic options exist for primary central nervous system malignancies.
• Systemically administered chemotherapeutic agents often show marginal efficacy in clinical trials for solid tumors.
• High-grade gliomas remain a significant challenge in neuro-oncology.

Purpose of the Study:

• To develop and evaluate ultrasmall (<8 nm) multimodal core-shell silica nanoparticles, Cornell prime dots (C' dots), for treating high-grade gliomas.
• To assess the efficacy of C' dots conjugated with doxorubicin (DOX) via pH-sensitive linkers.

Main Methods:

• Synthesis of ultrasmall (<8 nm) multimodal core-shell silica nanoparticles (C' dots).
• Surface conjugation of doxorubicin (DOX) to C' dots using pH-sensitive linkers.
• Optimization of drug-per-particle ratios and pharmacokinetic profiling.
• In vivo efficacy studies in genetically engineered mouse models and patient-derived xenograft models of high-grade glioma.

Main Results:

• Established optimal drug-per-particle ratios for nanoparticle-drug conjugates.
• Achieved favorable pharmacokinetic profiles for the C' dot-doxorubicin conjugates.
• Demonstrated significantly improved biological, therapeutic, and toxicological properties compared to native doxorubicin in vivo.
• Showcased enhanced efficacy in both platelet-derived growth factor-driven and EGFR-expressing patient-derived xenograft models.

Conclusions:

• Ultrasmall C' dot-doxorubicin conjugates exhibit significant translational potential for treating high-grade gliomas.
• These nanoparticle-drug conjugates offer improved therapeutic outcomes compared to conventional doxorubicin.
• Efficacy was demonstrated even without the incorporation of a specific cancer-targeting moiety.