Activation of the epidermal growth factor receptor by hydrogels in artificial tears

Abstract

Most formulations of artificial tears include high-molecular weight hydrophilic polymers (hydrogels) that are usually thought to serve to enhance viscosity and to act as demulcents. A few reports have indicated that application of some of the polymers accelerates healing of wounds in epithelia. Since activation of the epidermal growth factor (EGF) receptor is critical for spontaneous corneal epithelial wound healing, we tested commonly used hydrogels for their ability to activate the EGF receptor and enhance closure of wounds. Five structurally unrelated hydrogels used in artificial tears were found to activate the EGF receptor. Importantly, two of the hydrogels enhanced wound healing in an organ culture model. We propose that the efficacy of hydrogels in treating dry eye may be related to their ability to activate the EGF receptor, and that hydrogels are inexpensive, safe agents to promote healing of wounds in the cornea and possibly in other tissues.

Assessment of ocular surface toxicity after topical instillation of nitric oxide donors

“…In addition, topical application may allow the use of locally high concentrations of active principles, with minor or non-significant side effects (33) . The HPMC used for the topical instillations of aqueous SNAC and GSNO solutions in this work is a non-toxic hydrophilic mucoadhesive polymer with film forming properties, commonly used in intraocular sur gery, topical administrations, artificial tears and drug vehicle (34,35) . It is known that tear drainage and blinking action may result in low drug absorption following topical ocular application.…”

Brief treatment with heparin-binding EGF-like growth factor, but not with EGF, is sufficient to accelerate epithelial wound healing

“…Poorly-healing wounds and chronic ulcers are often difficult to treat and significant efforts are directed to develop improved therapies. One approach is to use growth factors to stimulate healing, and many reports have described the successful use of EGF (for references see Lozano et al [10]). However, in epithelia that are covered with fluids, such as the corneal epithelium, one major difficulty is that EGF is rapidly washed out.…”

Biodegradable hybrid polymeric membranes for ocular drug delivery

“…It has been used as a component of some ocular preparations as a viscosity-inducing polymer in eye drops [25], and artificial tear substitutes [17]. It has also been used in ocular hydrogels [26,27] and for the preparation of ophthalmic viscosurgical devices [24]. The presence of hydroxyl and carboxyl groups in carboxymethylcellulose makes it attractive for chemical modification.…”