Using temperature-sensitive smart polymers to regulate DNA-mediated nanoassembly and encoded nanocarrier drug release

Area of Science:

• Materials Science
• Nanotechnology
• Biotechnology

Background:

• DNA-mediated assembly and drug delivery systems require precise control over molecular interactions.
• Thermoresponsive polymers offer tunable properties based on temperature changes.
• Gold nanoparticles (Au NPs) are versatile platforms for biomedical applications.

Purpose of the Study:

• To develop a temperature-responsive polymer coating for gold nanoparticles (Au NPs) to regulate DNA interactions.
• To demonstrate the application of this system in DNA-mediated assembly and DNA-encoded drug delivery.
• To investigate the effect of the polymer on drug release kinetics and cytotoxicity.

Main Methods:

• Synthesis of a thermoresponsive poly(N-isopropylacrylamide-co-acrylamide) (pNIPAAm-co-pAAm) polymer with thiol modification.
• Grafting the polymer onto Au NPs functionalized with single-stranded oligonucleotides (ssDNA).
• Investigating the effect of temperature on polymer conformation and DNA hybridization.
• Evaluating drug (doxorubicin) release from DNA-functionalized Au NPs with and without the polymer coating.

Main Results:

• The polymer coating effectively controlled DNA hybridization between complementary ssDNA-functionalized Au NPs based on temperature.
• At temperatures below the transition temperature (TC), the polymer blocked hybridization; above TC, it allowed hybridization.
• Drug release from dsDNA-functionalized Au NPs was reduced at T < TC and enhanced at T > TC.
• The temperature-triggered drug release improved the cytotoxicity of the nanocarrier system.

Conclusions:

• Thermoresponsive polymer-grafted Au NPs provide a dynamic interface for controlling DNA interactions.
• This system demonstrates potential for developing smart nanocarriers for on-demand drug delivery.
• Temperature-responsive regulation of drug release can enhance therapeutic efficacy.