title: Development of an injectable PHBV microparticles-GG hydrogel hybrid system for regenerative medicine.
abstract: Uncontrollable displacements that greatly affect the concentration of active agents at the target tissues are among a major limitation of the use of microparticulate drug delivery systems (DDS). Under this context a biphasic injectable DDS combining poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) microparticles (MPs) and a gellan gum (GG) injectable hydrogel is herein proposed for the localized delivery and long-term retention of MPs carrying hydrophilic and hydrophobic model active agents. A double emulsion-solvent evaporation method was adopted to develop the PHBV MPs, carrying bovine serum albumin (BSA) or dexamethasone (Dex) as hydrophilic and hydrophobic active agents' models, respectively. Moreover, this method was modified, together with the properties of the hydrogel to tailor the delivery profile of the active agents. Variations of the composition of the organic phase during the process allowed tuning surface topography, particle size distribution and core porosity of the PHBV MPs and, thus, the in vitro release profile of Dex but not of BSA. Besides, after embedding hydrogels of higher GG concentration led to a slower and more sustained release of both active agents, independently of the processing conditions of the microparticulate system.
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; Laboratory of Pharmaceutical Technology/Centre of Research in Pharmaceutical Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal.
authors.forename: Daniela P
authors.initials: DP
authors.lastname: Pacheco
authors.affiliation: Laboratory of Pharmaceutical Technology/Centre of Research in Pharmaceutical Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal.
authors.forename: Maria H
authors.initials: MH
authors.lastname: Amaral
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
authors.forename: Rui L
authors.initials: RL
authors.lastname: Reis
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal.
authors.forename: Alexandra P
authors.initials: AP
authors.lastname: Marques
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal. Electronic address: vitorcorrelo@dep.uminho.pt.
authors.forename: Vítor M
authors.initials: VM
authors.lastname: Correlo
mesh_terms: D003907:Dexamethasone / Q000737:chemistry; D016503:Drug Delivery Systems; D065546:Drug Liberation; D020100:Hydrogels / Q000737:chemistry*; D007267:Injections; D011091:Polyesters / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D044968:Regenerative Medicine; D012710:Serum Albumin, Bovine / Q000737:chemistry; D000094122:Polyhydroxybutyrates
chemical_list: D003907:Dexamethasone; D020100:Hydrogels; D011091:Polyesters; D011135:Polysaccharides, Bacterial; D012710:Serum Albumin, Bovine; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C048288:gellan gum
keywords: Gellan gum; Injectable hydrogel; Microparticulate systems; Polyhydroxybutyrate-co-hydroxyvalerate; Regenerative medicine