Clickable and Degradable Polycarbonate Vehicles for mRNA Delivery

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Gene Therapy Delivery

Background:

• Effective and safe delivery of nucleic acid therapies remains a significant challenge.
• Current synthetic and viral vectors often face limitations regarding safety and biodegradability.
• Synthetic vehicles offer modularity for optimizing performance and safety.

Purpose of the Study:

• To introduce a novel biodegradable polycarbonate (PC) system as an alternative to nondegradable gene therapy vectors.
• To evaluate the performance and safety of PC-based vehicles with varying pendant groups for mRNA delivery.
• To demonstrate the modularity and degradability of the novel PC scaffold.

Main Methods:

• Synthesis of polycarbonate polymers via ring-opening polymerization of cyclic carbonate, yielding polymers with pendant allyl groups.
• Post-polymerization modification using thiol-ene click chemistry to introduce different pendant groups (cationic DMA, hydrophilic OH, COOH, PEG).
• Characterization of polymer-mRNA complexes (polyplexes) using dynamic light scattering and gel electrophoresis.
• In vitro evaluation of cytotoxicity and mRNA delivery efficiency in HEK293T and A549 cells, comparing with JetPEI.

Main Results:

• Formation of stable polymer-mRNA complexes (polyplexes) was confirmed.
• The novel polycarbonate system exhibited minimal cytotoxicity and statistically significant cell viability improvement compared to the polymer control.
• In vitro delivery efficiency of enhanced green fluorescent protein (EGFP)-encoding mRNA was comparable to JetPEI across most tested formulations.
• The polycarbonate system demonstrated degradability via hydrolysis.

Conclusions:

• The modular polycarbonate scaffold offers a promising biodegradable alternative for nucleic acid and mRNA delivery.
• This system achieves comparable delivery performance to established nondegradable vectors while enhancing cell viability.
• The inherent degradability and modularity of the polycarbonate system provide significant advantages for future gene therapy applications.