title: The potential of using biodegradable microspheres in retinal diseases and other intraocular pathologies.
abstract: Pathologies affecting the posterior segment of the eye are one of the major causes of blindness in developed countries and are becoming more prevalent due to the increase in society longevity. Successful therapy of diseases affecting the back of the eye requires effective concentrations of the active substance maintained during a long period of time in the intraocular target site. Treatment of vitreoretinal diseases often include repeated intravitreous injections that are associated with adverse effects. Local administration of biodegradable microspheres offers an excellent alternative to multiple administrations, as they are able to deliver the therapeutic molecule in a controlled fashion. Furthermore, injection of microparticles is performed without the need for surgical procedures. As most of the retinal diseases are multifactorial, microspheres result especially promising because they can be loaded with more than one active substance and complemented with the inclusion of additives with pharmacological properties. Personalized therapy can be easily achieved by changing the amount of administered microspheres. Contrary to non-biodegradable devices, biodegradable PLA and PLGA microspheres disappear from the site of administration after delivering the drug. Furthermore, microspheres prepared from these mentioned biomaterials are well tolerated after periocular and intravitreal injections in animals and humans. After injection, PLA and PLGA microspheres suffer aggregation behaving like an implant. Biodegradable microspheres are potential tools in regenerative medicine for retinal repair. According to the reported results, presumably a variety of microparticulate formulations for different ophthalmic therapeutic uses will be available in the clinical practice in the near future.
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; 1-Pharmaceutical Innovation in Ophthalmology (Innovación Farmacéutica en Oftalmología), Instituto de Investigación Sanitaria, Hospital Clínico San Carlos (IdISSC), Calle Profesor Martín Lagos, s/n, 28040 Madrid, Spain. Electronic address: rociohv@ucm.es.
authors.forename: Rocío
authors.initials: R
authors.lastname: Herrero-Vanrell
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; 1-Pharmaceutical Innovation in Ophthalmology (Innovación Farmacéutica en Oftalmología), Instituto de Investigación Sanitaria, Hospital Clínico San Carlos (IdISSC), Calle Profesor Martín Lagos, s/n, 28040 Madrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Bravo-Osuna
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; 1-Pharmaceutical Innovation in Ophthalmology (Innovación Farmacéutica en Oftalmología), Instituto de Investigación Sanitaria, Hospital Clínico San Carlos (IdISSC), Calle Profesor Martín Lagos, s/n, 28040 Madrid, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Andrés-Guerrero
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; 1-Pharmaceutical Innovation in Ophthalmology (Innovación Farmacéutica en Oftalmología), Instituto de Investigación Sanitaria, Hospital Clínico San Carlos (IdISSC), Calle Profesor Martín Lagos, s/n, 28040 Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Vicario-de-la-Torre
authors.affiliation: Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Complutense University of Madrid, Plaza Ramón y Cajal, s/n, 28040 Madrid, Spain; 1-Pharmaceutical Innovation in Ophthalmology (Innovación Farmacéutica en Oftalmología), Instituto de Investigación Sanitaria, Hospital Clínico San Carlos (IdISSC), Calle Profesor Martín Lagos, s/n, 28040 Madrid, Spain.
authors.forename: Irene Teresa
authors.initials: IT
authors.lastname: Molina-Martínez
mesh_terms: D020341:Absorbable Implants; D003692:Delayed-Action Preparations / Q000008:administration & dosage; D016503:Drug Delivery Systems / Q000379:methods*; D005128:Eye Diseases / Q000188:drug therapy*; D006801:Humans; D056965:Injections, Intraocular / Q000379:methods; D008863:Microspheres; D011108:Polymers / Q000008:administration & dosage; D057285:Precision Medicine / Q000379:methods; D012164:Retinal Diseases / Q000188:drug therapy
chemical_list: D003692:Delayed-Action Preparations; D011108:Polymers
keywords: Controlled release; Microspheres; Ocular drug delivery; PLGA; Retina