Star-shaped poly(2-aminoethyl methacrylate)s as non-viral gene carriers: Exploring structure-function relationship

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Gene Therapy Vectors

Background:

• Gene therapy holds significant potential for treating diseases, but effective gene vector design remains a challenge.
• Non-viral polymer-based gene carriers require optimized structure-function relationships for safety and efficiency.
• Cationic poly(2-aminoethyl methacrylate) (PAEM) with primary amino groups is a candidate for gene delivery.

Purpose of the Study:

• To synthesize and characterize four PAEM-based polycations with defined molecular weights and architectures.
• To evaluate the DNA condensation, stability, cytotoxicity, and transfection efficiency of these polycations.
• To investigate the impact of molecular weight and architecture on gene delivery performance.

Main Methods:

• Synthesis of three cyclodextrin (CD)-cored star-shaped PAEM (s-PAEM) and one linear PAEM (l-PAEM) via atom transfer radical polymerization (ATRP) techniques.
• Formation and characterization of plasmid DNA (pDNA) polyplexes, assessing size and stability.
• In vitro evaluation of polycation and polyplex cytotoxicity and gene transfection efficiency in different cell lines (MCF-7 and COS-7).

Main Results:

• All synthesized PAEM polycations successfully condensed pDNA into small (<200 nm) spherical polyplexes with good stability.
• Polycation cytotoxicity was dose- and cell-type dependent, but polyplexes exhibited low cytotoxicity across all types.
• Transfection efficiency varied significantly with molecular weight, architecture (star vs. linear), and cell type, with high-molecular-weight s-PAEM generally showing the best performance.
• s-PAEM demonstrated higher transfection efficiency in MCF-7 cells compared to COS-7 cells, unlike l-PAEM.

Conclusions:

• PAEM-based polycations, particularly high-molecular-weight star-shaped architectures, are effective non-viral gene carriers.
• Molecular weight and architecture significantly influence gene delivery efficiency and cell-type specificity.
• Star-shaped PAEM polycations show promise for future gene therapy applications due to their favorable gene delivery characteristics.