Hydrophobicity-Adaptive Nanogels for Programmed Anticancer Drug Delivery

Area of Science:

• Biomedical Engineering
• Materials Science
• Oncology

Background:

• Current nano drug delivery systems face challenges in balancing circulation time, tumor cell uptake (including cancer stem cells), and tissue penetration.
• Developing sophisticated nanocarriers is crucial for overcoming these limitations in cancer chemotherapy.

Purpose of the Study:

• To design and evaluate smart poly(N-isopropylacrylamide)-based nanogels with adaptive hydrophobicity for enhanced cancer chemotherapy.
• To address the contradictory requirements of prolonged circulation, deep tumor penetration, and efficient uptake by both bulk tumor cells and cancer stem cells (CSCs).

Main Methods:

• Synthesis of poly(N-isopropylacrylamide)-based nanogels exhibiting tunable hydrophobicity.
• Evaluation of nanogel behavior in response to tumor microenvironment acidity (pH).
• In vivo studies assessing nanogel circulation time, tumor accumulation, penetration, cellular uptake, and drug release kinetics (doxorubicin).
• Assessment of lysosomal escape via pH-regulated charge reversal and redox-responsive drug release.

Main Results:

• Nanogels demonstrated hydrophilic behavior in blood for prolonged circulation and rapidly became hydrophobic in acidic tumor extracellular environments.
• The adaptive hydrophobicity enhanced tumor accumulation, deep tissue penetration, and efficient uptake by bulk tumor cells and CSCs.
• Lysosomal escape and intracellular doxorubicin release were achieved through charge reversal and redox responsiveness.
• Significant improvement in in vivo anticancer efficacy and reduction in doxorubicin side effects were observed.
• A notable decrease in the cancer stem cell (CSC) ratio was achieved after treatment.

Conclusions:

• Smart nanogels with fast adaptive hydrophobicity offer a promising strategy for overcoming limitations in current nano drug delivery systems.
• These nanogels effectively enhance anticancer efficacy by improving drug targeting, penetration, and CSC reduction.
• The study provides valuable insights for the rational design of advanced nanocarriers for improved cancer chemotherapy.