Octopus-like flexible vector for noninvasive intraocular delivery of short interfering nucleic acids.

Abstract

Gene therapy is promising for chronic posterior ocular diseases, which are causal factors for severe vision impairment and even blindness worldwide. However, inherent absorption barriers of the eye restrict intraocular delivery of therapeutic nucleic acids via topical instillation. Safe and efficient non-viral vectors for ocular gene therapy are still unmet clinical desires. Herein, an octopus-like flexible multivalent penetratin (MVP) was designed to facilitate therapeutic nucleic acids condensation and delivery using multi-arm polyethylene glycol (PEG) as a core and conjugating penetratin at each end of the PEG arms as outspread tentacles. Among the MVPs, 8-valent penetratin (8VP) stably compacted nucleic acids into positively charged polyplexes smaller than 100 nm, promoting cellular uptake efficiency (approaching 100%) and transfection rate (over 75%). After instilled into the conjunctival sac, 8VP enabled rapid (< 10 min) and prolonged (> 6 h) distribution of nucleic acids in the retina via a non-corneal pathway. In a retinoblastoma-bearing mice model, topical instillation of 8VP/siRNA efficiently inhibited the protein expression of intraocular tumor without toxicity. MVP is advantageous over the commercial transfection reagent in safety and efficiency, therefore provides a promising vector for noninvasive intraocular gene delivery.