title: Nanofibrous poly(lactide-co-glycolide) membranes loaded with diamond nanoparticles as promising substrates for bone tissue engineering.
abstract: BACKGROUND
  Nanofibrous scaffolds loaded with bioactive nanoparticles are promising materials for bone tissue engineering.
  
  
  METHODS
  In this study, composite nanofibrous membranes containing a copolymer of L-lactide and glycolide (PLGA) and diamond nanoparticles were fabricated by an electrospinning technique. PLGA was dissolved in a mixture of methylene chloride and dimethyl formamide (2:3) at a concentration of 2.3 wt%, and nanodiamond (ND) powder was added at a concentration of 0.7 wt% (about 23 wt% in dry PLGA).
  
  
  RESULTS
  In the composite scaffolds, the ND particles were either arranged like beads in the central part of the fibers or formed clusters protruding from the fibers. In the PLGA-ND membranes, the fibers were thicker (diameter 270 ± 9 nm) than in pure PLGA meshes (diameter 218 ± 4 nm), but the areas of pores among these fibers were smaller than in pure PLGA samples (0.46 ± 0.02 μm(2) versus 1.28 ± 0.09 μm(2) in pure PLGA samples). The PLGA-ND membranes showed higher mechanical resistance, as demonstrated by rupture tests of load and deflection of rupture probe at failure. Both types of membranes enabled the attachment, spreading, and subsequent proliferation of human osteoblast-like MG-63 cells to a similar extent, although these values were usually lower than on polystyrene dishes. Nevertheless, the cells on both types of membranes were polygonal or spindle-like in shape, and were distributed homogeneously on the samples. From days 1-7 after seeding, their number rose continuously, and at the end of the experiment, these cells were able to create a confluent layer. At the same time, the cell viability, evaluated by a LIVE/DEAD viability/cytotoxicity kit, ranged from 92% to 97% on both types of membranes. In addition, on PLGA-ND membranes, the cells formed well developed talin-containing focal adhesion plaques. As estimated by the determination of tumor necrosis factor-alpha levels in the culture medium and concentration of intercellular adhesion molecule-1, MG-63 cells, and RAW 264.7 macrophages on these membranes did not show considerable inflammatory activity.
  
  
  CONCLUSIONS
  This study shows that nanofibrous PLGA membranes loaded with diamond nanoparticles have interesting potential for use in bone tissue engineering.
authors.affiliation: Department of Biomaterials and Tissue Engineering, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Parizek
authors.forename: Timothy E L
authors.initials: TE
authors.lastname: Douglas
authors.forename: Katarina
authors.initials: K
authors.lastname: Novotna
authors.forename: Alexander
authors.initials: A
authors.lastname: Kromka
authors.forename: Mariea A
authors.initials: MA
authors.lastname: Brady
authors.forename: Andrea
authors.initials: A
authors.lastname: Renzing
authors.forename: Eske
authors.initials: E
authors.lastname: Voss
authors.forename: Marketa
authors.initials: M
authors.lastname: Jarosova
authors.forename: Lukas
authors.initials: L
authors.lastname: Palatinus
authors.forename: Pavel
authors.initials: P
authors.lastname: Tesarek
authors.forename: Pavla
authors.initials: P
authors.lastname: Ryparova
authors.forename: Věra
authors.initials: V
authors.lastname: Lisa
authors.forename: Ana M
authors.initials: AM
authors.lastname: dos Santos
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Warnke
authors.forename: Lucie
authors.initials: L
authors.lastname: Bacakova
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D002448:Cell Adhesion; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival; D018130:Diamond / Q000737:chemistry*; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D050997:Nanomedicine; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology / Q000276:immunology / Q000502:physiology; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D018786:Bone Substitutes; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D018130:Diamond