Delivery systems for ocular surface and cornea disease treatments

This work demonstrates how the potential for overcoming the limitations of conventional treatments for ocular surface and corneal diseases may be achieved through the advancement offered by biomedical nanotechnology with the drug delivery systems. The opening section of the thesis presents an analysis of an etiological strand relating to ocular disorders. This is followed by an examination of the methodologies of loading and controlled release of protein molecules, with a view to restoring the loss of tear film homeostasis that occurs during certain ocular diseases. Conventional drug/substance administration to the ocular surface involves repeated drops of active ingredients and frequent, non-resolving pharmacological treatments. The present study explores the potential of a device constituted by two copolymers, loaded with lysozyme and lactoferrin, two proteins present in the tears of healthy patients, as a delivery system in a conjunctival application. First, the copolymers were synthesised and characterised from a molecular, thermal, structural and mechanical point of view. The characterisation included an analysis of the molecular structure, thermal properties, physical state and mechanical properties. The surface wettability was also evaluated. Subsequently, predetermined quantities of the active substance were loaded by melt-mixing, and the release kinetics from the polymeric matrices were studied. The results demonstrated that these materials allowed us to obtain a delivery system suitable for conjunctival tissue applications. In vitro cytotoxicity assays showed that both biomaterials supported growth of for 24h. Release analysis showed a gradual release over time of model proteins which kept their structure intact during the analyses. These properties make these materials promising candidates for ocular delivery treatments, especially for eye diseases that need frequent targeted administrations.