Non-invasive ocular siRNA delivery induces effective gene silencing in corneal epithelium

Guildford, UK

2 October 2020

SiSaf ltd announces Journal of Controlled Release publication of proof of concept data demonstrating a significant advance in the ability to treat corneal diseases with patient friendly non-invasive topical gene therapies using their unique Bio-Courier® technology.

Topical siRNA delivery to the cornea and anterior eye by hybrid silicon-lipid nanoparticles. Journal of Controlled Release Volume 326, 10 October 2020, Pages 192-202

SiSaf Ltd, the creator of Bio-Courier® technology that leverages the unique properties of fully bio-absorbable silicon (14Si) to overcome the limitations of conventional drug delivery technologies. Today announced the publication of its in vitro and in vivo proof of concept data demonstrating:

  • Bio-Courier technology enables efficient encapsulation of siRNA
  • ProSilic Bio-Courier nanoparticles can facilitate intracellular delivery of oligonucleotides
  • Topically administered siRNA-loaded nanoparticles penetrate across all cornea layers
  • Non-invasive ocular siRNA delivery induces effective gene silencing in corneal epithelium

“This data represents a significant step forward in addressing the major unmet need for safe and effective non-invasive delivery of siRNA to the cornea and in overcoming many of the concerns of regular intraocular injections,” said Suzanne Saffie-Siebert, PhD, Chief Executive Officer of SiSaf. “The versatility of our technology allows us to tailor it to other gene therapy agents and targets advancing SiSaf’s mission to unlock the full power of precision medicine to improve patient care and access.”

“It’s really difficult to deliver large complex molecules to the front of the eye without injection,” said Tara Moore, PhD, Professor of Personalized Medicine at Ulster University. “In my lifetime as a researcher this is the first time my research team are getting close to achieving that. In our evaluation, SiSaf’s Bio-Courier technology was the only option to deliver siRNA successfully and safely to all layers of the cornea using eyedrop application and produce a significant enough reduction in gene expression for it to be of therapeutic value.

SiSaf would like to acknowledge Innovate UK Knowledge Transfer Partnership award (KTP 010283) grant funding support for the early developmental work on nucleic acid formulations carried out in Ulster University. The project final report was awarded an ‘Outstanding’ grade for the developmental work.

About SiSaf

SiSaf are pioneers of silicon-based Bio-courier technology that leverages the unique properties of elemental silicon (14Si) to overcome the limitations of current drug technologies. Built upon a decade of research and patented technological innovation, SiSaf’s platform is changing the way therapeutic molecules target disease helping to make tomorrow’s precision medicines a reality. SiSaf is a commercial stage biopharmaceutical company headquartered in Guilford, UK, with fully integrated state-of-the-art research labs, manufacturing and bio-analytical facilities to fast track development. To learn more, please visit

About Bio-Courier® Technology

SiSaf’s first-to-market Bio-Courier platform technology leverages the unique properties of bioabsorbable silicon, lipids and amino acids to address the significant challenges of stability, solubility, targeting and controlled release of complex therapeutic molecules.
Its customizable design and fabrication provide unparalleled flexibility with respect to therapeutic molecule type and target cell location. Bio-Couriers degrade to the bioavailable form of silicon, eliminating the accumulation of potentially toxic or immune-activating material and supporting cell health. Cost-effective, scaled manufacturing provides unequalled capacity to address both rare diseases and large patient populations.