A facile method to construct ZIF-8 MOFs on contact lens for high antibiotics loading and self-defensive release

Eye trauma, ophthalmic surgery and contact lens (CL) wearing cause corneal infection and bacterial biofilms formation, which further lead to corneal ulcer and perforation. In view of the low bioavailability of antibiotic eye drops and the clinical problems that cause bacterial resistance, we used pH sensitive zeolitic imidazolate framework-8 metal–organic frameworks (ZIF-8 MOFs) to load broad-spectrum antibacterial drugs levofloxacin (LEVO). After the surface modification by hyaluronic acid (HA), the nanomaterial surface was negatively charged. A simple amination treatment was used to endow CL surface with amino groups to combine the negatively charged nano drug loading system through electrostatic forces. The bacteriostatic ring of ZIF-8@LEVO@HA-PEI modified CL (ZLHP-CL) was 34 mm, which could be owing to the high drug loading capacity of ZIF-8 (0.65 mg/cm2). The bactericidal function was further confirmed by shake flask method and live/dead bacterial staining assay against S. aureus, S. epidermidis and E. coli. It is worth mentioning that ZLHP-CL showed significant pH sensitivity to the bacterial infection, which released drug rapidly at pH 5.5 and hardly released drug at pH 7.4. In the bacterial biofilm's formation experiment, it was found that ZLHP-CL obviously inhibited bacterial adhesion and biofilms formation. Furthermore, it was proved in infectious keratitis animal that ZLHP-CL could kill the bacteria and reduce the inflammation reaction, which showed advantages in corneal tissue repair and light transmittance maintenance. In this work, based on nanotechnology, a facile CL drug loading technology is developed, which can be used to sustained release of various drugs for ophthalmic diseases treatment.