Multimodal Shape Transformation of Dual-Responsive DNA Block Copolymers

Area of Science:

• Polymer Chemistry
• Nanotechnology
• Biomaterials Science

Background:

• DNA and thermoresponsive polymers can be combined to create advanced materials.
• Dual-responsive systems offer unique stimuli-triggered behaviors.
• Controlling nanoparticle assembly and shape is crucial for nanomaterial applications.

Purpose of the Study:

• To synthesize and characterize dual-responsive DNA diblock and triblock copolymers.
• To investigate the self-assembly and multimodal shape transformation of these copolymers.
• To explore the use of these copolymers in creating functional nanoparticles with temperature-dependent behaviors.

Main Methods:

• Synthesis of DNA-poly(N-isopropylacrylamide) (DNA-b-PNIPAM) diblock copolymers.
• Synthesis of DNA-poly(N-isopropylacrylamide)-poly(methyl acrylate) (DNA-b-PNIPAM-b-PMA) triblock copolymers.
• Characterization of copolymer self-assembly, thermoresponsive transitions, and shape changes using techniques like Dynamic Light Scattering and Transmission Electron Microscopy.

Main Results:

• DNA-b-PNIPAM copolymers exhibited reversible temperature-triggered transitions between molecular states and polymer micelles with DNA coronas.
• Hybridization with DNA-modified nanoparticles resulted in temperature-dependent aggregation and disaggregation.
• DNA-b-PNIPAM-b-PMA triblock copolymers formed spherical micelles that transformed into cylinders above the lower critical solution temperature (LCST) and reverted to spheres upon cooling.
• Shape transformation was also achieved above LCST by introducing complementary DNA strands.

Conclusions:

• Dual-responsive DNA copolymers demonstrate controllable self-assembly and multimodal nanoscale shape transformation.
• The combination of thermal triggers and DNA binding provides a versatile platform for dynamic nanomaterial design.
• These findings open possibilities for advanced drug delivery, sensing, and responsive materials.