title: Prostaglandin D2-loaded microspheres effectively activate macrophage effector functions.
abstract: Biodegradable lactic-co-glycolic acid (PLGA) microspheres (MS) improve the stability of biomolecules stability and allow enable their sustained release. Lipid mediators represent a strategy for improving host defense; however, most of these mediators, such as prostaglandin D2 (PGD2), have low water solubility and are unstable. The present study aimed to develop and characterize MS loaded with PGD2 (PGD2-MS) to obtain an innovative tool to activate macrophages. PGD2-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process, and the size, zeta potential, surface morphology and encapsulation efficiency were determined. It was also evaluated in vitro the phagocytic index, NF-κB activation, as well as nitric oxide and cytokine production by alveolar macrophages (AMs) in response to PGD2-MS. PGD2-MS were spherical with a diameter of 5.0±3.3 μm and regular surface, zeta potential of -13.4±5.6 mV, and 36% of encapsulation efficiency, with 16-26% release of entrapped PGD2 at 4 and 48 h, respectively. PGD2-MS were more efficiently internalized by AMs than unloaded-MS, and activated NF-κB more than free PGD2. Moreover, PGD2-MS stimulated the production of nitric oxide, TNF-α, IL-1β, and TGF-β, more than free PGD2, indicating that microencapsulation increased the activating effect of PGD2 on cells. In LPS-pre-treated AMs, PGD2-MS decreased the release of IL-6 but increased the production of nitric oxide and IL-1β. These results show that the morphological characteristics of PGD2-MS facilitated interaction with, and activation of phagocytic cells; moreover, PGD2-MS retained the biological activities of PGD2 to trigger effector mechanisms in AMs. It is suggested that PGD2-MS represent a strategy for therapeutic intervention in the lungs of immunocompromised subjects.
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-903, Brazil.
authors.forename: Priscilla Aparecida Tartari
authors.initials: PA
authors.lastname: Pereira
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-903, Brazil.
authors.forename: Claudia da Silva
authors.initials: Cda S
authors.lastname: Bitencourt
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-903, Brazil.
authors.forename: Daiane Fernanda
authors.initials: DF
authors.lastname: dos Santos
authors.affiliation: Fundação Oswaldo Cruz (Fiocruz Rondônia), Rua da Beira, 7671, Porto Velho, RO 76812-245, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Nicolete
authors.affiliation: Laboratório de Tecnologia de Medicamentos, Alimentos e Cosméticos (LTMAC), Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
authors.forename: Guilherme Martins
authors.initials: GM
authors.lastname: Gelfuso
authors.affiliation: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-903, Brazil. Electronic address: faccioli@fcfrp.usp.br.
authors.forename: Lúcia Helena
authors.initials: LH
authors.lastname: Faccioli
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D065546:Drug Liberation; D004655:Emulsions; D053583:Interleukin-1beta / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry; D008070:Lipopolysaccharides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008863:Microspheres; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010316:Particle Size; D010587:Phagocytosis; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D015230:Prostaglandin D2 / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D017208:Rats, Wistar; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D004655:Emulsions; C000594089:IL1B protein, rat; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D016328:NF-kappa B; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D009569:Nitric Oxide; D019344:Lactic Acid; D015230:Prostaglandin D2
keywords: Alveolar macrophages; Cytokines; Drug delivery; Microspheres; PGD(2); Phagocytosis