Wear effects on microscopic morphology and hyaluronan uptake in siloxane-hydrogel contact lenses

• Published in: Journal of biomedical materials research. Part B, Applied biomaterials Vol. 103; no. 5; pp. 1092 - 1098
• Main Authors: Tavazzi, Silvia, Tonveronachi, Martina, Fagnola, Matteo, Cozza, Federica, Ferraro, Lorenzo, Borghesi, Alessandro, Ascagni, Miriam, Farris, Stefano
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.07.2015; Wiley Subscription Services, Inc
• Subjects: Biomedical materials; contact lens; Contact Lenses, Hydrophilic; Freeze drying; Humans; hyaluronan; Hyaluronic Acid - chemistry; Hydrogels - chemistry; Materials research; Materials science; Materials Testing; scanning electron microscopy; siloxane-hydrogel; Siloxanes - chemistry; Surface Properties; scanning electron microscopy; freeze-drying; siloxane-hydrogel; hyaluronan; contact lens
• ISSN: 1552-4973; 1552-4981; 1552-4981
• DOI: 10.1002/jbm.b.33278

The purpose of this study was a comparison between new and worn siloxane‐hydrogel contact lenses in terms of microscopic structure, surface morphology, and loading of hyaluronan. The analyses were performed by scanning electron microscopy, with the support of the freeze‐drying technique, and by fluorescence confocal microscopy. Along the depth profile of new lenses, a thin porous top layer was observed, which corresponds to the region of hyaluronan penetration inside well‐defined channels. The time evolution was followed from one day to two weeks of daily wear, when a completely different scenario was found. Clear experimental evidence of a buggy surface was observed with several crests and regions of swelling, which could be filled by the hyaluronan solution. The modifications are attributed to the progressive relaxation of the structure of the polymeric network. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1092–1098, 2015.