Poly(2-hydroxyethyl methacrylate-co-methacrylated hyaluronan-β-cyclodextrin) hydrogel: A potential contact lens material with high hydrophilicity, good mechanical properties and sustained drug delivery

A novel poly(2-hydroxyethyl methacrylate-co-methacrylated hyaluronan-β-cyclodextrin) [p(HEMA-co-mHA-β-CD)] hydrogel was developed as a potential contact lens for ophthalmic disease. The hydrogel was synthesized from the copolymerization of 2-hydroxyethyl methacrylate (HEMA) monomer and mHA-β-CD as a hydrophilic macromolecular crosslinker. By adjusting the methacrylate substitution degree in hyaluronan (20-29 %) and the mHA-β-CD content (5-11 %), transparent p(HEMA-co-mHA-β-CD) hydrogels were achieved. p(HEMA-co-m₂₀HA-β-CD) hydrogels exhibited an enhanced tensile modulus (from 0.35 to 0.88 MPa) with a decreased elongation at break (from 255 % to 108 %), meanwhile they showed increased hydrophilicity with a decreased water contact angle (from 83.4° to 48.6°) and an increased equilibrium water content (from 38.2 % to 46.4 %). Increasing the mHA-β-CD content resulted in a higher encapsulation and cumulative release of hydrophilic levofloxacin hydrochloride or hydrophobic puerarin, due to the improved hydrophilicity and the formation of β-CD/drug inclusion complexes. Compared with pHEMA hydrogel, p(HEMA-co-m₂₀HA-β-CD) hydrogels better inhibited the deposition of lysozyme and bovine serum albumin, and the bacterial adhesion against S. aureus and E. coli. The hydrogels were stable at physiological conditions and non-toxic to immortalized human keratinocytes. With good mechanical properties, tear protein deposition resistance, antibacterial activity, and sustained drug delivery capabilities, p(HEMA-co-m₂₀HA-β-CD) hydrogels were identified as a promising contact lens material for eye diseases.