Thermosensitive hydrogel-containing polymersomes for controlled drug delivery.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Polymersomes (Ps) are self-assembled vesicles with potential in drug delivery.
• Incorporating stimuli-responsive polymers like poly(N-isopropylacrylamide) (PNIPAAm) can enhance Ps functionality.
• PNIPAAm exhibits a lower critical solution temperature (LCST), enabling thermoresponsive behavior.

Purpose of the Study:

• To synthesize and characterize PNIPAAm-containing polymersomes (N/Ps) as drug delivery vehicles.
• To investigate the incorporation and behavior of PNIPAAm within polymersomes.
• To evaluate the drug release profile of these novel hydrosomes.

Main Methods:

• Preparation of N/Ps via self-assembly from mPEG-PDLLA and PNIPAAm.
• Characterization using Dynamic Light Scattering (DLS), Confocal Laser Scanning Microscopy (CLSM), Fluorescence Correlation Spectroscopy (FCS), and Fluorescence Anisotropy (FA).
• Drug release studies using fluorescein isothiocyanate tagged dextran (FD).

Main Results:

• Hydrogel-containing Ps (Hs) with an average diameter of 127 nm were successfully prepared.
• Dual fluorescence microscopy confirmed the co-localization of PNIPAAm within the polymersomes.
• Micron-sized giant Ps were formed, exhibiting phase separation of PNIPAAm above its LCST.
• Hs demonstrated sustained release of FD over 30 days with a reduced initial burst effect compared to bare Ps.

Conclusions:

• PNIPAAm-containing polymersomes (hydrosomes) are effective carriers for controlled substance delivery.
• The thermoresponsive PNIPAAm hydrogel component enhances drug release profiles, providing sustained release.
• These hydrosomes represent a promising platform for advanced drug and protein delivery systems.