Dual Stimuli-Responsive Block Copolymers for Controlled Release Triggered by Upconversion Luminescence or Temperature...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Amphiphilic block copolymers (BCPs) offer versatile platforms for self-assembly and drug delivery.
• Upconversion nanoparticles (UCNPs) can convert near-infrared (NIR) light into UV or visible light, enabling remote triggering.
• Controlled drug release systems are crucial for targeted and efficient therapeutic interventions.

Purpose of the Study:

• To synthesize a novel photo- and thermo-responsive amphiphilic block copolymer (BCP).
• To develop a core/shell upconversion nanoparticle (UCNP) and encapsulate it within BCP micelles.
• To investigate the controlled release of a model drug (Nile red) from the hybrid UCNP@BCP nanoparticles using dual stimuli.

Main Methods:

• Atom transfer radical polymerization (ATRP) for BCP synthesis.
• Sol-gel or co-precipitation methods for UCNP synthesis (LiYF4:Yb3+, Tm3+@LiYF4:Yb3+).
• Encapsulation of UCNPs within BCP micelles and incorporation of Nile red (NR) as a model drug.

Main Results:

• NIR light irradiation disrupted the polymer micelles, leading to decreased Nile red fluorescence intensity.
• Increased temperature also caused NR release due to BCP micelle contraction, further decreasing fluorescence.
• The hybrid UCNP@BCP nanoparticles demonstrated dual-stimuli responsive drug release.

Conclusions:

• The synthesized hybrid UCNP@BCP nanoparticles exhibit effective dual-stimuli (NIR light and temperature) responsive drug release.
• This system holds potential for advanced drug delivery applications requiring precise spatiotemporal control.
• The combination of photo- and thermo-responsive polymers with UCNPs offers a promising strategy for smart nanomedicine.