title: Chitosan/alginate based multilayers to control drug release from ophthalmic lens.
abstract: In this study we investigated the possibility of using layer-by-layer deposition, based in natural polymers (chitosan and alginate), to control the release of different ophthalmic drugs from three types of lens materials: a silicone-based hydrogel recently proposed by our group as drug releasing soft contact lens (SCL) material and two commercially available materials: CI26Y for intraocular lens (IOLs) and Definitive 50 for SCLs. The optimised coating, consisting in one double layer of (alginate - CaCl2)/(chitosan+glyoxal) topped with a final alginate-CaCl2 layer to avoid chitosan degradation by tear fluid proteins, proved to have excellent features to control the release of the anti-inflammatory, diclofenac, while keeping or improving the physical properties of the lenses. The coating leads to a controlled release of diclofenac from SCL and IOL materials for, at least, one week. Due to its high hydrophilicity (water contact angle≈0) and biocompatibility, it should avoid the use of further surface treatments to enhance the useŕs comfort. However, the barrier effect of this coating is specific for diclofenac, giving evidence to the need of optimizing the chemical composition of the layers in view of the desired drug.
authors: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors: Diana
authors: D
authors: Silva
authors: Altakitin S.A., Rua José Gomes Ferreira, Arm. D, 2660-360 São Julião do Tojal, Lisboa, Portugal; CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal.
authors: Luís F V
authors: LFV
authors: Pinto
authors: PhysIOL sa/nv, Liège Science Park, Allée des Noisetiers 4, 4031 Liège, Belgium.
authors: Dimitriya
authors: D
authors: Bozukova
authors: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
authors: Luís F
authors: LF
authors: Santos
authors: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; CIIEM, Instituto Superior de Ciências da Saúde Egas Moniz, Campus Universitário, Quinta da Granja, Monte de Caparica, 2829-511 Caparica, Portugal.
authors: Ana Paula
authors: AP
authors: Serro
authors: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. Electronic address: b.saramago@tecnico.ulisboa.pt.
authors: Benilde
authors: B
authors: Saramago
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D003263:Contact Lenses, Hydrophilic; D065546:Drug Liberation; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D007910:Lenses, Intraocular; D012828:Silicones / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D006603:Hexuronic Acids; D012828:Silicones; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid; D048271:Chitosan
keywords: Alginate; Chitosan; Controlled drug release; Layer-by-layer coatings; Ophthalmic lens