Droplette: A Platform Technology to Directly Deliver Nucleic Acid Therapeutics and Other Molecules into Cells and Deep into Tissue Without Transfection Reagents

Abstract

Droplette (US 9,700,686 B2 and PCT/US2016/035695) is the first portable and contact-free transdermal technology comprising the unique combination of a piezoelectric transducer and a pneumatic diaphragm pump to deliver large biomolecules including nucleic acid therapeutics (NATs) deep into cells, and into skin and soft tissue for effective delivery over short timescales. The droplets that come out of the device are 10–50× smaller upon impact than what is created through other commercial atomizers, such as the piezoelectric transducer alone. This device has been tested extensively in vitro, in vivo and in IRB approved human studies. The Droplette device delivers metered doses using a water droplet dispersal technology already commonly used in humidifier devices, by utilizing a piezoelectric material. Three key innovations make this device technically novel and tailored specifically for both field and lab use: (1) The combination of the piezo and pump to generate sub-micron drug-loaded droplets that penetrate cells, skin, and soft tissue to effectively deliver a range of large molecules, proteins, and nucleic acids. (2) Their assembly in a modular manner which enables portability, safe sterilization, and ejection without direct device-surface contact or significant force, allowing for improved safety and ease of use in both research and clinical settings. (3) The integration of a single-use, sterile cartridge that contains a therapeutic formulation and allows easy integration of a large number of molecules. The platform has broad applications across multiple fields, such as delivery of drugs for inflammatory skin diseases, antibiotics for skin infections, and gene delivery for gene therapy and biomedical research. In this chapter, we briefly introduce the Droplette delivery technology, instructions for building your own setup (note that fully built devices are available for purchase from Droplette, Inc), and provide protocols for directly transfecting adherent cell cultures and for direct in vivo transfection using the Droplette system without the need for traditional transfection reagents or methods.

1 Electronics Supplementary Material

Video 1

Direct transfection of DNA into adherent cell cultures via Droplette. 1 mL of a 50 μg/mL solution of pKL490, an mVenus-expressing DNA plasmid, was loaded into the Droplette device for transfection into a 35 mm plate of HEK293FT cells. This video demonstrates the Droplette delivery step; aspiration of cell culture medium prior to Droplette delivery and addition of DMEM with additives post-Droplette delivery not shown (DOCX 25999 kb)