title: Effect of electrospun fiber diameter and alignment on macrophage activation and secretion of proinflammatory cytokines and chemokines.
abstract: Macrophage activation can be modulated by biomaterial topography according to the biological scale (micrometric and nanometric range). In this study, we investigated the effect of fiber diameter and fiber alignment of electrospun poly(L-lactic) (PLLA) scaffolds on macrophage RAW 264.7 activation and secretion of proinflammatory cytokines and chemokines at 24 h and 7 days. Macrophages were cultured on four different types of fibrous PLLA scaffold (aligned microfibers, aligned nanofibers, random microfibers, and random nanofibers) and on PLLA film (used as a reference). Substrate topography was found to influence the immune response activated by macrophages, especially in the early inflammation stage. Secretion of proinflammatory molecules by macrophage cells was chiefly dependent on fiber diameter. In particular, nanofibrous PLLA scaffolds minimized the inflammatory response when compared with films and microfibrous scaffolds. The histological evaluation demonstrated a higher number of foreign body giant cells on the PLLA film than on the micro- and nanofibrous scaffolds. In summary, our results indicate that the diameter of electrospun PLLA fibers, rather than fiber alignment, plays a relevant role in influencing in vitro macrophage activation and secretion of proinflammatory molecules.
authors.affiliation: Department of Biochemistry, University of Pavia, Pavia, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Saino
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Focarete
authors.forename: Chiara
authors.initials: C
authors.lastname: Gualandi
authors.forename: Enzo
authors.initials: E
authors.lastname: Emanuele
authors.forename: Antonia I
authors.initials: AI
authors.lastname: Cornaglia
authors.forename: Marcello
authors.initials: M
authors.lastname: Imbriani
authors.forename: Livia
authors.initials: L
authors.lastname: Visai
mesh_terms: D000818:Animals; D002460:Cell Line; D018925:Chemokines / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism*; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008855:Microscopy, Electron, Scanning
chemical_list: D018925:Chemokines; D016207:Cytokines; D018836:Inflammation Mediators