Abstract
Purpose :
Surface modification of contact lenses to improve comfort or deliver ophthalmic drugs has been explored extensively. However, current approaches are not satisfactory due to unstable lens surfaces (due to polymer chain rearrangement) and/or poor lens quality (such as low transparency) after modification. The goal of this study is to develop a simple and effective method to modify contact lenses using fluorous chemistry, which overcomes the above limitations.
Methods :
The presence/absence of fluorine in the formulation of several commercial contact lenses was determined by x-ray photoelectron spectroscopy (XPS). A model fluorinated fluorescent compound (F-FITC) was tested for incorporation/release by commercial lenses by fluorescence detection. The un-modified compound FITC and contact lenses without fluorine in their formulation were also tested as controls (n=3). Ciprofloxacin was used as a model drug and modified with various fluorinated carbon chain lengths. The antimicrobial activity of four different chain lengths of fluorinated ciprofloxacin (F-Cip) as well as F-Cip loaded comfilcon A lenses was tested against Pseudomonoas aeruginosa (PA) strain ATCC 19660 using a bacterial inhibition assay (n≥3).
Results :
XPS analysis showed the presence of fluorine in comfilcon A lenses, but not in narafilcon A, delefilcon A, or ocufilcon D lenses. The fluorinated fluorescent compound F-FITC showed a 17 fold increase in incorporation into comfilcon A lenses compared to the control molecule FITC. Furthermore, comfilcon A lenses incorporated 2.3-7.4 fold more F-FITC molecules compared to non fluorine-containing lenses. The release of F-FITC from comfilcon A lenses showed sustained release over a period of 8 h, while FITC exhibited a typical burst release pattern. Two of the four F-Cips tested in solution inhibited the growth of PA19660 with IC50 values of 0.69 ± 0.62 and 0.85 ± 0.45 μM. These two F-Cips as well as Cip were loaded onto Comfilcon A lenses, which exhibited 84%, 99%, and 33% killing of PA19660.
Conclusions :
Fluorous chemistry facilitated the incorporation of fluorinated materials into fluorine-containing contact lenses. In contrast to the burst release of drug commonly found with other incorporation methods, this approach resulted in a sustained release profile, which permits longer therapeutic effects.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.