title: Experimental composite guidance conduits for peripheral nerve repair: an evaluation of ion release.
abstract: Poly (lactide-co-glycolide) (PLGA) - Pluronic F127 - glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si(4+), Ca(2+), Na(+), Zn(2+), and Ce(4+) from experimental composite nerve guidance conduits (CNGC) comprising PLGA (at 12.5, and 20 wt.%), F127 (at 0, 2.5 and 5 wt.%) and various loadings of Si-Ca-Na-Zn-Ce glass (at 20 and 40 wt.%) for incubation periods of up to 28 days. The concentration of each ion, at various time points, was determined using Inductively Coupled Plasma-Atomic Emission Spectrometry (Perkin Elmer Optima 3000). It was observed that the Si(4+), Na(+), Ca(2+), Zn(2+) release from CNGCs in this study ranged from 0.22 to 6.477 ppm, 2.307 to 3.277 ppm, 40 to 119 ppm, and 45 to 51 ppm, respectively. The Ce(4+) concentrations were under the minimum detection limits for the ICP instrument utilized. The results indicate that the ion release levels may be appropriate to mediate therapeutic effects with respect to peripheral nerve regeneration. The data generated in this paper provides requisite evidence to optimize composition for pre-clinical evaluation of the experimental composite.
authors.affiliation: Department of Biological Sciences and Medical Engineering Design and Innovation Centre, Cork Institute of Technology, Cork, Ireland.
authors.forename: X F
authors.initials: XF
authors.lastname: Zhang
authors.affiliation: Inamori School of Engineering, Alfred University, Alfred, NY. 14802, USA.
authors.forename: A
authors.initials: A
authors.lastname: Coughlan
authors.affiliation: Department of Biological Sciences and Medical Engineering Design and Innovation Centre, Cork Institute of Technology, Cork, Ireland.
authors.forename: H
authors.initials: H
authors.lastname: O'Shea
authors.affiliation: Inamori School of Engineering, Alfred University, Alfred, NY. 14802, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Towler
authors.affiliation: Department of Applied Oral Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2; School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada B3H 4R2.
authors.forename: S
authors.initials: S
authors.lastname: Kehoe
authors.affiliation: Department of Applied Oral Sciences, Dalhousie University, Halifax, NS, Canada B3H 4R2; School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada B3H 4R2.
authors.forename: D
authors.initials: D
authors.lastname: Boyd
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology*; D005898:Glass / Q000737:chemistry; D007477:Ions / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry / Q000494:pharmacology; D008422:Materials Testing / Q000379:methods; D009416:Nerve Regeneration / Q000187:drug effects*; D059348:Peripheral Nerve Injuries / Q000628:therapy*; D020442:Poloxamer / Q000737:chemistry / Q000494:pharmacology; D011100:Polyglycolic Acid / Q000737:chemistry / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
chemical_list: D001672:Biocompatible Materials; D007477:Ions; D020442:Poloxamer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid