Tummala GK, Joffre T, Lopes VR, Liszka A, Buznyk O, Ferraz N, Persson C, Griffith M, Mihranyan A
ACS Biomater. Sci. Eng. 2 (11) 2072-2079 [2016-11-14; online 2016-10-18]
A nanocellulose-reinforced poly(vinyl alcohol) hydrogel material of exceptionally high water content for ophthalmic applications is presented (>90 wt %), which also features a hitherto unprecedented combination of optical, mechanical, viscoelastic, oxygen permeability, and biocompatibility properties. The hydrogel combines the desired softness with remarkable strain-dependent mechanical strength and thereby demonstrates hyperelastic, rubber-like mechanical properties. The observed unusual mechanical behavior is due to both high water content and the combination of relatively stiff cellulose nanowhiskers entangled in a soft polymer matrix of poly(vinyl alcohol) (PVA), thus mimicking the structural characteristics of the cornea's main constituents, i.e., water and collagen.