A biomimetic approach has been exercised to design novel contact lenses, to tackle the unmet need for the controlled loading and release of ocular H1-anithistamines, for the treatment of allergenic conjunctivitis. These novel contact lenses incorporate a technique known as configurational biomimetic imprinting, where in the formation of a pre-polymerization complex the template molecule (i.e. ketotifen fumarate) and the functional monomers are involved in non-covalent chemistry resembling that of histamine and its complementary ligand binding pocket. Through this approach, it becomes possible to enhance drug loading within hydrogels for the extended release of antihistamines on the surface of the conjunctiva. Problems occurring on the surface of the eye (i.e. allergenic conjunctivas) are the result of an allergen causing IL-4 and TH2 secretions, which prompt IgE secretions that cause mast cell and esinophil degranulation and the release inflammatory mediators such as H1-receptor binding histamine.

Treatment options for allergenic conjunctivitis primarily consist of oral antihistamines and topical treatments. Since ocular bioavailability of topical drugs is very poor (typically less than 7% is absorbed by the eye), a high dosage is needed which prohibits contact lens use. Controlling and tailoring the release of anti-histamines via novel recognitive contact lenses with significantly enhanced loading can solve these problems with increased bioavailability, less irritation to ocular tissue, and reduced ocular and systemic side effects.

Gels of multiple binding points with varying functionalities outperformed gels formed with fewer types of functionality and showed the greatest loading potential (i.e., up to 6 times more than control lenses) with comparable mechanical and optical properties as conventional lenses. Dynamic drug release profiles under in vitro physiological conditions demonstrated that release rates can be tailored via type and amount of functionality. Viable therapeutic concentrations of drug can be delivered at a constant rate for extended periods from 16 hours to 20 days depending on formulation. The template molecule poses constraints on the polymer chain motion and hence is related to the propagation of the polymer chains. Kinetic studies showed that configurational biomimetic imprinting is reflected at the molecular level due to rates of polymerization decreasing by the increasing mole percentage of template or the introduction of multiple functional monomers while holding the mole percentage of functional monomer constant. Developing networks based on these configurational biomimetic imprinting techniques can enhance the therapeutic range and biological function of polymer gels.