title: Electrically stimulated osteogenesis on Ti-PPy/PLGA constructs prepared by laser-assisted processes.
abstract: This work describes a versatile laser-based protocol for fabricating micro-patterned, electrically conductive titanium-polypyrrole/poly(lactic-co-glycolic)acid (Ti-PPy/PLGA) constructs for electrically stimulated (ES) osteogenesis. Ti supports were patterned using fs laser ablation in order to create high spatial resolution microstructures meant to provide mechanical resistance and physical cues for cell growth. Matrix Assisted Pulsed Laser Evaporation (MAPLE) was used to coat the patterned Ti supports with PPy/PLGA layers acting as biocompatible surfaces having chemical and electrical properties suitable for cell differentiation and mineralization. In vitro biological assays on osteoblast-like MG63 cells showed that the constructs maintained cell viability without cytotoxicity. At 24 h after cell seeding, electrical stimulation with currents of 200 μA was applied for 4 h. This treatment was shown to promote earlier onset of osteogenesis. More specifically, the alkaline phosphatase activity of the stimulated cultures reached the maximum before that of the non-stimulated ones, i.e. controls, indicating faster cell differentiation. Moreover, mineralization was found to occur at an earlier stage in the stimulated cultures, as compared to the controls, starting with Day 6 of cell culture. At later stages, calcium levels in the stimulated cultures were higher than those in control samples by about 70%, with Ca/P ratios similar to those of natural bone. In all, the laser-based protocol emerges as an efficient alternative to existing fabrication technologies.
authors.affiliation: Faculty of Applied Sciences, University Politehnica of Bucharest, RO-060042, Romania; National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest RO-077125, Romania. Electronic address: irina.paun@physics.pub.ro.
authors.forename: Irina Alexandra
authors.initials: IA
authors.lastname: Paun
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest RO-077125, Romania.
authors.forename: Flavian
authors.initials: F
authors.lastname: Stokker-Cheregi
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest RO-077125, Romania. Electronic address: catalin.luculescu@inflpr.ro.
authors.forename: Catalin Romeo
authors.initials: CR
authors.lastname: Luculescu
authors.affiliation: Horia Hulubei National Institute for Physics and Nuclear Engineering IFIN-HH, Magurele, Bucharest RO-077125, Romania.
authors.forename: Adriana Maria
authors.initials: AM
authors.lastname: Acasandrei
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest RO-077125, Romania.
authors.forename: Valentin
authors.initials: V
authors.lastname: Ion
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest RO-077125, Romania.
authors.forename: Marian
authors.initials: M
authors.lastname: Zamfirescu
authors.affiliation: Horia Hulubei National Institute for Physics and Nuclear Engineering IFIN-HH, Magurele, Bucharest RO-077125, Romania.
authors.forename: Cosmin Catalin
authors.initials: CC
authors.lastname: Mustaciosu
authors.affiliation: Faculty of Applied Sciences, University Politehnica of Bucharest, RO-060042, Romania.
authors.forename: Mona
authors.initials: M
authors.lastname: Mihailescu
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest RO-077125, Romania. Electronic address: dinescum@nipne.ro.
authors.forename: Maria
authors.initials: M
authors.lastname: Dinescu
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D001842:Bone and Bones / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004558:Electric Stimulation / Q000379:methods; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry* / Q000494:pharmacology*; D053685:Laser Therapy / Q000379:methods; D010006:Osteoblasts / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects*; D011100:Polyglycolic Acid / Q000737:chemistry* / Q000494:pharmacology*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology*; D011758:Pyrroles / Q000737:chemistry* / Q000494:pharmacology*; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D011758:Pyrroles; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; C067635:polypyrrole; D019344:Lactic Acid; D014025:Titanium
keywords: Conductive polymer; Electrical stimulation; Laser ablation; MAPLE; Osteogenesis