Carboxymethyl dextran-based hypoxia-responsive nanoparticles for doxorubicin delivery

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cancer Therapy

Background:

• Hypoxia is a hallmark of solid tumors, creating a unique microenvironment.
• Targeted drug delivery to hypoxic regions can improve cancer treatment efficacy.
• Developing responsive drug delivery systems is crucial for effective cancer therapy.

Purpose of the Study:

• To create hypoxia-responsive nanoparticles for targeted cancer therapy.
• To investigate the drug release characteristics of these nanoparticles under varying oxygen conditions.
• To evaluate the in vitro and in vivo performance of the drug-loaded nanoparticles.

Main Methods:

• Preparation of carboxymethyl dextran (CMD) and black hole quencher 3 (BHQ3) polymer conjugate.
• Self-assembly of the conjugate into nanoparticles (CMD-BHQ3 NPs) and loading with doxorubicin (DOX) to form DOX@CMD-BHQ3 NPs.
• In vitro drug release studies under physiological and hypoxic conditions.
• In vitro cytotoxicity assays and confocal microscopy for intracellular drug release.
• In vivo biodistribution studies in tumor-bearing mice.

Main Results:

• CMD-BHQ3 NPs demonstrated sustained doxorubicin release under physiological conditions.
• A significant increase in doxorubicin release was observed under hypoxic conditions due to azo bond cleavage.
• DOX@CMD-BHQ3 NPs exhibited enhanced cytotoxicity in hypoxic environments compared to normoxic conditions.
• Oxygen-dependent intracellular doxorubicin release was confirmed.
• Preferential accumulation of CMD-BHQ3 NPs in tumor tissues was observed in vivo.

Conclusions:

• CMD-BHQ3 nanoparticles are effective carriers for hypoxia-responsive drug delivery.
• The system enables selective doxorubicin release in the tumor microenvironment.
• This approach holds promise for targeted cancer therapy in hypoxic tumors.