Nanoparticle-in-Hydrogel Delivery System for the Sequential Release of Two Drugs

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Neuro-oncology

Background:

• Glioblastoma causes lethal brain edema, often requiring high-dose systemic dexamethasone with severe side effects.
• Localized drug delivery aims to improve therapeutic efficacy and reduce systemic toxicity for glioblastoma patients.

Purpose of the Study:

• To investigate a biodegradable dextran-hydroxyethyl methacrylate (dex-HEMA) hydrogel for localized, sustained delivery of dexamethasone.
• To incorporate dexamethasone via polymeric micelles and dexamethasone phosphate via liposomes for sequential drug release.

Main Methods:

• Synthesized and characterized poly(ethylene glycol)-b-poly(N-2-benzoyloxypropyl methacrylamide) (mPEG-b-p(HPMA-Bz)) micelles loaded with dexamethasone.
• Encapsulated dexamethasone phosphate into liposomes.
• Dispersed micelles and liposomes in a dex-HEMA solution, followed by photopolymerization to form the hydrogel.
• Determined drug release kinetics and mechanisms from the hydrogel.

Main Results:

• Nanoparticles (micelles and liposomes) were successfully immobilized within the hydrogel network.
• Dexamethasone was released from micelles over two weeks.
• Dexamethasone phosphate was released from liposomes after 15 days upon hydrogel degradation, resulting in biphasic release.

Conclusions:

• The developed hydrogel system enables sequential, localized release of dexamethasone and dexamethasone phosphate.
• This platform shows potential for treating glioblastoma-associated intracranial edema with improved safety and efficacy.