Polyethylenimine-grafted polycarbonates as biodegradable polycations for gene delivery

Area of Science:

• Biomaterials Science
• Gene Therapy
• Polymer Chemistry

Background:

• Non-viral vectors are crucial for gene delivery, with polycations gaining attention.
• Polyethylenimine (PEI) is a common non-viral vector, but its cytotoxicity is a concern.

Purpose of the Study:

• To synthesize and characterize novel biodegradable polycations, PMAC-g-PEIx, for gene delivery.
• To evaluate the gene delivery efficiency and cytotoxicity of these novel vectors compared to existing ones.

Main Methods:

• Synthesis of poly(5-methyl-5-allyloxycarbonyl-trimethylene carbonate) (PMAC) using immobilized porcine pancreas lipase (IPPL).
• Modification of PMAC with low molecular weight polyethylenimine (PEIx) to form PMAC-g-PEIx.
• Characterization of PMAC-g-PEIx using GPC-MALLS, and evaluation of polyplex formation, buffer capacity, cytotoxicity, and transfection efficiency in 293T cells.

Main Results:

• Synthesized PMAC-g-PEIx with controlled molecular weights (81,900–200,600 g/mol) and low polydispersities.
• PMAC-g-PEIx formed nano-sized polyplexes (30-90 nm) with pDNA, exhibiting good buffer capacity.
• Demonstrated significantly lower cytotoxicity and enhanced transfection efficiency compared to PEI25K in 293T cells.

Conclusions:

• PMAC-g-PEIx are promising biodegradable polycations for gene delivery.
• The biodegradability of PMAC-g-PEIx aids in efficient pDNA release and reduced cytotoxicity.
• These novel vectors represent an advancement in developing safer and more effective gene delivery systems.