Metal-organic framework tethering PNIPAM for ON-OFF controlled release in solution

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) are versatile porous materials with applications in drug delivery.
• Controlled release systems are crucial for optimizing therapeutic efficacy and reducing side effects.
• Thermoresponsive polymers offer tunable properties based on temperature variations.

Purpose of the Study:

• To engineer a smart MOF with temperature-triggered controlled release functionality.
• To investigate the surface-selective modification of MOFs with thermoresponsive polymers.
• To demonstrate the controlled release of guest molecules from the modified MOF system.

Main Methods:

• Surface-selective post-synthetic modification of MOFs with poly(N-isopropylacrylamide) (PNIPAM).
• Characterization of the polymer-modified MOF structure and properties.
• In vitro release studies of guest molecules (resorufin, caffeine, procainamide) at different temperatures.

Main Results:

• Successful grafting of PNIPAM onto the MOF surface, creating a smart material.
• Temperature-dependent conformational changes of PNIPAM controlled the MOF's pore accessibility.
• Demonstrated "on-off" switching of guest molecule release by simple temperature modulation.

Conclusions:

• The developed thermoresponsive polymer-modified MOF exhibits smart, controlled release behavior.
• This approach offers a promising strategy for developing advanced drug delivery systems.
• Temperature-responsive MOFs represent a new frontier in smart materials for biomedical applications.