title: In vivo evaluation of a novel electrically conductive polypyrrole/poly(D,L-lactide) composite and polypyrrole-coated poly(D,L-lactide-co-glycolide) membranes.
abstract: This study evaluated the in vivo biocompatibility and biodegradation behavior of a novel polypyrrole (PPy)/poly(D,L-lactide) (PDLLA) composite and PPy-coated poly(D,L-lactide-co-glycolide) membranes. Test membranes were implanted subcutaneously in rats for 3-120 days. The biocompatibility was assessed by quantifying the alkaline and acid phosphatase secretion, the immunohistochemical staining of the ED-2-positive macrophages, and the histology at the tissue/material interface. The degradation was investigated using scanning electron microscopy. Pure PDLLA and poly(D,L-lactide-co-glycolide) membranes were used as references, whereas expanded polytetrafluoroethylene and a commercial styrene-butadiene rubber were used as controls. The enzyme activity of the PPy-containing specimens was shown to be similar to that of the references. The histological findings were consistent with the enzymatic results, showing a mild-to-moderate acute inflammation followed by a resolution of the inflammatory response with a decrease in inflammatory cells for each biodegradable membrane. The tissue reactions to the PPy, which was either in the form of nanoparticles or surface coating, were comparable to the response to the neighboring biodegradable materials. Elevated ED-2-positive macrophage populations appeared as early as day 3 in the loose connective tissue surrounding the implants. The density of these populations was related to the degree of inflammation. Scanning electron microscopy showed that the degradation of the PPy/PDLLA composite was not affected by the presence of PPy.
authors.affiliation: Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, QC, Canada.
authors.forename: Zhaoxu
authors.initials: Z
authors.lastname: Wang
authors.forename: Christophe
authors.initials: C
authors.lastname: Roberge
authors.forename: Lê H
authors.initials: LH
authors.lastname: Dao
authors.forename: Ying
authors.initials: Y
authors.lastname: Wan
authors.forename: Guixin
authors.initials: G
authors.lastname: Shi
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Rouabhia
authors.forename: Robert
authors.initials: R
authors.lastname: Guidoin
authors.forename: Ze
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D001673:Biodegradation, Environmental; D003094:Collagen / Q000378:metabolism; D004553:Electric Conductivity; D005337:Fibrin / Q000378:metabolism; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D019344:Lactic Acid / Q000737:chemistry / Q000494:pharmacology*; D008264:Macrophages / Q000502:physiology; D008297:Male; D008422:Materials Testing; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D011100:Polyglycolic Acid / Q000737:chemistry / Q000494:pharmacology*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D011138:Polytetrafluoroethylene; D019736:Prostheses and Implants; D011758:Pyrroles / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013242:Sterilization; D016707:Tissue Fixation
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011108:Polymers; D011758:Pyrroles; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; C067635:polypyrrole; D019344:Lactic Acid; D005337:Fibrin; D011138:Polytetrafluoroethylene; D003094:Collagen; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase