Thermo-responsive nano-in-micro particles for MRI-guided chemotherapy

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cancer Therapeutics

Background:

• Developing effective theranostic systems for cancer treatment is crucial.
• Stimuli-responsive drug delivery systems offer targeted therapeutic approaches.
• Combining imaging and therapy (theranostics) enhances treatment efficacy and monitoring.

Purpose of the Study:

• To create nano-in-micro thermo-responsive microspheres for anti-cancer hyperthermia.
• To integrate layered double hydroxide (LDH) nanoparticles loaded with chemotherapy drugs (methotrexate or 5-fluorouracil) and superparamagnetic iron oxide nanoparticles (SPIONs).
• To evaluate the potential of these microspheres as MRI-guided theranostic systems.

Main Methods:

• Synthesis of drug-loaded LDH nanoparticles.
• Co-encapsulation of drug-loaded LDH and SPIONs into poly(acrylamide-co-acrylonitrile) microparticles via spray drying.
• Characterization using electron microscopy and elemental mapping.
• In vitro drug release studies at different temperatures (37 °C and 43 °C).
• Assessment of relaxivity (r2) profiles over a temperature range (35–46 °C).
• In vitro cell experiments with Caco-2 and A549 cells.

Main Results:

• Homogeneous distribution of LDH and SPIONs within concave microparticles was confirmed.
• Microspheres exhibited prolonged drug release with distinct temperature-dependent release profiles.
• Temperature-dependent changes in relaxivity (r2) were observed, enabling potential MRI-guided therapy.
• Synergistic effects of hyperthermia-aided chemotherapy were demonstrated in cancer cell lines.

Conclusions:

• The developed thermo-responsive microspheres show potential as smart, stimuli-responsive theranostics.
• These systems facilitate hyperthermia-aided chemotherapy with MRI guidance capabilities.
• The study highlights a promising approach for advanced anti-cancer treatment strategies.