title: Macrophage-mediated biodegradation of poly(DL-lactide-co-glycolide) in vitro.
abstract: Biodegradation of poly-DL-lactide-co-glycolide (PLGA) both in vitro and in vivo has been well documented. However, the roles that macrophages and their fused multinucleated giant cells (MNGCs) play in this biodegradation are still unclear. The current study aimed to investigate macrophage-mediated biodegradation of PLGA thin films and of PLGA composites with hydroxyapatite (HA) and tricalcium phosphate (TCP) ceramic powders in vitro using a murine macrophage cell line (RAW 264.7). The interactions were analyzed by using cell viability assays, scanning electron microscopy, and focused ion beam microscopy. The results showed that RAW 264.7 cells effectively attached and proliferated on the PLGA films and PLGA-HA, PLGA-TCP composites. The RAW 264.7 cells were observed to aggregate and fuse to form MNGCs. The cell processes on the membrane, or pseudopodia, penetrated into the PLGA films and evidently eroded the surface. We conclude that macrophages and fused MNGCs actively respond to PLGA films as substratum and degrade the surface of this polymer.
authors.affiliation: Nuffield Department of Orthopaedic Surgery, The Botnar Research Centre, Institute of Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Zhidao
authors.initials: Z
authors.lastname: Xia
authors.forename: Yizhong
authors.initials: Y
authors.lastname: Huang
authors.forename: Iannis E
authors.initials: IE
authors.lastname: Adamopoulos
authors.forename: Andrew
authors.initials: A
authors.lastname: Walpole
authors.forename: James T
authors.initials: JT
authors.lastname: Triffitt
authors.forename: Zhanfeng
authors.initials: Z
authors.lastname: Cui
mesh_terms: D000818:Animals; D002130:Calcium Phosphates / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019344:Lactic Acid / Q000378:metabolism* / Q000633:toxicity; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011100:Polyglycolic Acid / Q000378:metabolism* / Q000633:toxicity; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000378:metabolism* / Q000633:toxicity; D012997:Solvents
chemical_list: D002130:Calcium Phosphates; D011108:Polymers; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C018392:tricalcium phosphate