Biodegradable polyphosphoester micelles for gene delivery

Area of Science:

• Biomaterials Science
• Gene Therapy
• Polymer Chemistry

Background:

• Gene delivery systems are crucial for genetic therapies but often face challenges with toxicity and efficiency.
• Developing safe and effective non-viral vectors remains a significant goal in molecular biology and medicine.

Purpose of the Study:

• To synthesize and characterize a new biodegradable polyphosphoester, PCEP, for gene delivery applications.
• To evaluate the physicochemical properties, DNA binding capacity, cytotoxicity, and transfection efficiency of PCEP in vitro and in vivo.

Main Methods:

• Synthesis of poly[[(cholesteryl oxocarbonylamido ethyl) methyl bis(ethylene) ammonium iodide] ethyl phosphate] (PCEP).
• Characterization of PCEP micelle formation, DNA binding, and protection from nuclease digestion.
• Cytotoxicity assessment using WST-1 assay and cell proliferation assays.
• In vitro transfection studies in HEK293, Caco-2, and HeLa cell lines.
• In vivo gene expression studies in muscle tissue.

Main Results:

• PCEP self-assembles into 60-100 nm micelles and effectively binds and protects plasmid DNA.
• PCEP exhibits significantly lower cytotoxicity compared to poly-L-lysine and Lipofectamine (IC50: 69.8 µg/mL).
• Efficient DNA delivery was achieved in multiple cell lines, with optimal transfection at a +/- charge ratio of 1.5-2 in Opti-MEM.
• Transfection efficiency was enhanced 10- to 50-fold with chloroquine co-administration.
• In vivo studies demonstrated luciferase expression in muscle over 3 months, though at lower levels than naked DNA.

Conclusions:

• PCEP is a promising biodegradable and low-toxicity material for gene delivery.
• The structural versatility of PCEP allows for optimization of transfection efficiency through modifications in charge density and lipophilicity.
• Further development of PCEP holds potential for advancing non-viral gene therapy strategies.