Controlled Release of rAAV Vectors from APMA-Functionalized Contact Lenses for Corneal Gene Therapy

Abstract

As an alternative to eye drops and ocular injections for gene therapy, the aim of this work was to design for the first time hydrogel contact lenses that can act as platforms for the controlled delivery of viral vectors (recombinant adeno-associated virus, rAAV) to the eye in an effective way with improved patient compliance. Hydrogels of hydroxyethyl methacrylate (HEMA) with aminopropyl methacrylamide (APMA) (H1: 40, and H2: 80 mM) or without (Hc: 0 mM) were synthesized, sterilized by steam heat (121 °C, 20 min), and then tested for gene therapy using rAAV vectors to deliver the genes to the cornea. The hydrogels showed adequate light transparency, oxygen permeability, and swelling for use as contact lenses. Loading of viral vectors (rAAV-lacZ, rAAV-RFP, or rAAV-hIGF-I) was carried out at 4 °C to maintain viral vector titer. Release in culture medium was monitored by fluorescence with Cy3-rAAV-lacZ and AAV Titration ELISA. Transduction efficacy was tested through reporter genes lacZ and RFP in human bone marrow derived mesenchymal stem cells (hMSCs). lacZ was detected with X-Gal staining and quantified with Beta-Glo®, and RFP was monitored by fluorescence. The ability of rAAV-hIGF-I-loaded hydrogels to trigger cell proliferation in hMSCs was evaluated by immunohistochemistry. Finally, the ability of rAAV-lacZ-loaded hydrogels to transduce bovine cornea was confirmed through detection with X-Gal staining of β-galactosidase expressed within the tissue.

Materials promoting viral gene delivery

“…This transparent hydrogel network allowed high vector loading and controlled, long-term gene expression over a period of 14 days while being able to correct refractive errors. 291 Microgels from vinyl ether acrylate-functionalized poly(vinyl alcohol) (PVA-VEA) and thiolated PVA-VEA were fabricated by a microfluidic technology and Michael-type cross-linking reaction to yield pH-degradable injectable spheres for efficient Ad delivery to tumor sites. The antitumor treatment could be reinforced by the addition of the bromodomain inhibitor JQ1.…”

Topical Administration of SLN-Based Gene Therapy for the Treatment of Corneal Inflammation by De Novo IL-10 Production

“…However, the induction of the immune response and inflammation limits the application of viral vectors to inflammatory diseases, including cornea inflammation, even considering its relative immune privilege [ 1 ]. Moreover, they have been frequently administered by invasive methods such as intrastromal, intralimbal, intracameral, or after removing the corneal epithelium [ 30 , 31 , 32 ]. Non-viral gene therapy has proven to be a feasible alternative for corneal gene therapy even after topical administration [ 33 , 34 , 35 , 36 ].…”

Contact Lenses as Ophthalmic Drug Delivery Systems: A Review

“…To date, the soaking method is the common strategy employed to load active compounds mainly into hydrogel-based contact lenses [ 44 , 45 , 46 , 47 , 48 , 49 , 50 ], and to a lesser extent, into polymeric films [ 38 , 39 ]. The soaking method consists in immersing the lens/support in a solution/suspension/emulsion containing the drug to be loaded [ 74 ].…”