A simplified method for manufacturing RNAi therapeutics for local administration.

Area of Science:

• Biotechnology
• Nanomedicine
• Cancer Therapeutics

Background:

• RNA interference (RNAi) holds promise for cancer treatment but requires efficient, scalable delivery systems.
• Lipoplexes are a key delivery vehicle for RNAi therapeutics.
• Current manufacturing methods can be complex and difficult to scale for clinical use.

Purpose of the Study:

• To develop a simple, industrially viable method for manufacturing lipoplexes for RNAi cancer therapy.
• To evaluate the physicochemical properties and efficacy of freeze-dried lipoplexes (FD-lipoplexes).
• To assess the potential of FD-lipoplexes for clinical application in peritoneal disseminated cancer.

Main Methods:

• A novel freeze-drying technique was employed to produce lipoplexes containing thymidylate synthase short hairpin RNA (TS shRNA).
• TS shRNA was mixed with cationic liposome precursors or lipids, lyophilized, and then activated by hydration.
• Physicochemical properties, stability in ascites fluid, and *in vivo* therapeutic efficacy in a gastric cancer mouse model were evaluated.

Main Results:

• The freeze-drying method successfully produced FD-lipoplexes (FD-lipoplex-1 and FD-lipoplex-2) with properties comparable to conventional lipoplexes.
• FD-lipoplexes demonstrated stability in the presence of tumor ascites fluid, retaining TS shRNA.
• Intraperitoneal administration of FD-lipoplexes showed therapeutic efficacy comparable to conventional lipoplexes in a peritoneal disseminated gastric cancer mouse model.

Conclusions:

• Freeze-drying offers a simple, scalable, and industrially applicable method for preparing RNAi therapeutics.
• FD-lipoplexes are stable and therapeutically effective, presenting a viable option for clinical treatment of peritoneal disseminated cancers.
• This approach could facilitate the translation of RNAi therapeutics into clinical practice.