title: Processing and size range separation of pristine and magnetic poly(l-lactic acid) based microspheres for biomedical applications.
abstract: Biodegradable poly(l-lactic acid) (PLLA) and PLLA/CoFe2O4 magnetic microspheres with average sizes ranging between 0.16-3.9μm and 0.8-2.2μm, respectively, were obtained by an oil-in-water emulsion method using poly(vinyl alcohol) (PVA) solution as the emulsifier agent. The separation of the microspheres in different size ranges was then performed by centrifugation and the colloidal stability assessed at different pH values. Neat PLLA spheres are more stable in alkaline environments when compared to magnetic microspheres, both types being stable for pHs higher than 4, resulting in a colloidal suspension. On the other hand, in acidic environments the microspheres tend to form aggregates. The neat PLLA microspheres show a degree of crystallinity of 40% whereas the composite ones are nearly amorphous (17%). Finally, the biocompatibility was assessed by cell viability studies with MC3T3-E1 pre-osteoblast cells.
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal; Centro/Departamento de Química, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: D M
authors.initials: DM
authors.lastname: Correia
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal; School of Mechanical, Materials and Mechatronics Engineering, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: V
authors.initials: V
authors.lastname: Sencadas
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal; CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal. Electronic address: cribeiro@fisica.uminho.pt.
authors.forename: C
authors.initials: C
authors.lastname: Ribeiro
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: P M
authors.initials: PM
authors.lastname: Martins
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Martins
authors.affiliation: CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: F M
authors.initials: FM
authors.lastname: Gama
authors.affiliation: Centro/Departamento de Química, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: G
authors.initials: G
authors.lastname: Botelho
authors.affiliation: Centro/Departamento de Física, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal; BCMaterials, Parque Científico y Tecnológico de Bizkaia, 48160 Derio, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Lanceros-Méndez
mesh_terms: D000818:Animals; D020811:Biomedical Technology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D060328:Magnetic Phenomena; D008863:Microspheres; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D013499:Surface Properties
chemical_list: D011091:Polyesters; C033616:poly(lactide)
keywords: Biocompatibility; Cell viability; Magnetic nanocomposites; Oil in water emulsion technique; Poly(l-lactic acid) microspheres