A pH-sensitive multifunctional gene carrier assembled via layer-by-layer technique for efficient gene delivery

Area of Science:

• Biotechnology
• Nanotechnology
• Gene Therapy

Background:

• Gene therapy requires vectors overcoming biological barriers like cell and nuclear membranes.
• Polyethylene glycol (PEG) can inhibit tumor cellular uptake, necessitating alternative strategies.
• The layer-by-layer technique offers an efficient method for assembling multifunctional gene carriers.

Purpose of the Study:

• To develop a pH-sensitive multifunctional gene vector for enhanced gene delivery.
• To overcome limitations of PEGylated vectors in tumor cellular uptake.
• To create a novel gene carrier with long circulation properties and tumor-specific targeting.

Main Methods:

• Constructed a multifunctional vector (CMCS-CLDPD) using layer-by-layer assembly with DNA, protamine, cationic liposomes, and o-carboxymethyl-chitosan (CMCS).
• Condensed DNA with protamine to form a cationic core template.
• Evaluated in vitro cytotoxicity and transfection in HepG2 cells, and in vivo transfection efficiency in tumor-bearing mice.

Main Results:

• CMCS-CLDPD exhibited an ellipsoidal, core-shell structure, providing stability in serum and protection against nuclease degradation.
• The vector demonstrated pH-sensitivity, with the outer CMCS layer detaching in tumor tissue.
• This detachment enhanced gene transfection efficiency by preventing serum interactions and facilitating cellular uptake.

Conclusions:

• The multifunctional CMCS-CLDPD vector shows pH-sensitivity, offering a promising new strategy for antitumor gene delivery.
• The layer-by-layer assembly approach is effective for creating complex, functional gene carriers.
• The pH-triggered release mechanism enhances therapeutic potential in tumor environments.