title: Effects of unidirectional permeability in asymmetric poly(DL-lactic acid-co-glycolic acid) conduits on peripheral nerve regeneration: an in vitro and in vivo study.
abstract: The high outflow permeability of the nerve conduit used to emit the drained waste generated from the traumatized host nerve stump is critical in peripheral nerve regeneration. Our earlier studies have established that asymmetric conduits fulfill the basic requirements for use as nerve guide conduits. In this study, the inflow characteristics of optimal nerve conduits were further examined using in vivo and in vitro trials. Various asymmetric poly(DL-lactic acid-co-glycolic acid) (PLGA) conduits were controlled by modifying precipitation baths using 0, 20, and 95% isopropyl alcohol, with high-porosity (permeability), medium-porosity (high outflow and low inflow), and low-porosity (permeability), respectively. In the in vitro trial, the Schwann cells and fibroblasts were seeded on either side of the asymmetric PLGA films in a newly designed coculture system that simulated the repaired nerve conduit environment. The results of the directional permeable films indicated the statistically significant proliferation of Schwann cells and the inhibition of the division of fibroblasts in lactate dehydrogenase release and inhibition of 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) reduction, compared with the other films. In the in vivo trial, the PLGA conduits seeded with Schwann cells were implanted into 10 mm right sciatic nerve defects in rats. After 6 weeks, implanted conduits were harvested. Histological examination verified that directional permeable conduits had markedly more A-type and B-type myelin fibers in the midconduit and distal nerve. In this work, the directional transport characteristics were established as an extremely important factor to the design and development of optimal nerve guide conduits in peripheral nerve regeneration.
authors.affiliation: Department of Radiological Technology, Central Taiwan University of Science and Technology, Taichung, Taiwan.
authors.forename: Chen-Jung
authors.initials: CJ
authors.lastname: Chang
authors.forename: Shan-Hui
authors.initials: SH
authors.lastname: Hsu
authors.forename: Hung-Jen
authors.initials: HJ
authors.lastname: Yen
authors.forename: Han
authors.initials: H
authors.lastname: Chang
authors.forename: Shih-Kuang
authors.initials: SK
authors.lastname: Hsu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D002478:Cells, Cultured; D018920:Coculture Techniques; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D048091:Guided Tissue Regeneration / Q000295:instrumentation / Q000379:methods; D020007:Implants, Experimental; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008422:Materials Testing; D009416:Nerve Regeneration / Q000502:physiology*; D010525:Peripheral Nerves / Q000033:anatomy & histology / Q000473:pathology / Q000502:physiology*; D010539:Permeability; D011100:Polyglycolic Acid / Q000737:chemistry / Q000378:metabolism*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012583:Schwann Cells / Q000166:cytology / Q000502:physiology
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid