Photodegradable neutral-cationic brush block copolymers for nonviral gene delivery

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Gene Delivery Systems

Background:

• Developing efficient and controllable gene delivery vectors is crucial for gene therapy.
• Photodegradable materials offer spatiotemporal control over drug/gene release.
• Neutral-cationic brush block copolymers present a promising platform for gene delivery.

Purpose of the Study:

• To fabricate a novel photodegradable gene-delivery vector based on PEO-b-P(GMA-g-PDMAEMA) neutral-cationic brush block copolymers.
• To investigate the DNA complexation, UV-triggered release, and in vitro gene transfection efficiency of the developed vector.

Main Methods:

• Synthesis of PEO-b-P(GMA-g-PDMAEMA) copolymers using reversible addition-fragmentation transfer (RAFT) polymerization and postmodification.
• Complexation of plasmid DNA (pDNA) with the copolymer to form nanoparticles.
• Evaluation of pDNA release upon UV irradiation.
• In vitro gene transfection assays in cells.

Main Results:

• The synthesized neutral-cationic brush block copolymer effectively complexed pDNA into nanoparticles at an N/P ratio of 4.
• UV irradiation induced the release of pDNA due to the cleavage of PDMAEMA side chains and nitrobenzyl ester linkages.
• The polyplexes showed effective cellular internalization and good gene transfection efficiency.
• UV irradiation significantly enhanced the gene transfection efficiency.

Conclusions:

• PEO-b-P(GMA-g-PDMAEMA) neutral-cationic brush block copolymers serve as effective photodegradable gene-delivery vectors.
• The vector enables UV-triggered DNA release and enhanced gene transfection.
• This system holds potential for advanced gene therapy applications requiring controlled release.