In vitro and in vivo degradation of poly(L: -lactide-co-glycolide) films and scaffolds.
Poly(L: -lactide-co-glycolide) (PLGA) was synthesized using a biocompatible initiator, zirconium acetylacetonate. In vitro and in vivo degradation properties of PLGA films (produced by solvent casting, 180 microm thick) and PLGA scaffolds (produced by an innovated solvent casting and particulate leaching, 3 mm thick) were evaluated. The samples were either submitted for degradation in phosphate buffered saline (PBS) at 37 degrees C for 30 weeks, or implanted into rat skeletal muscles for 1, 4, 12, 22 and 30 weeks. The degradation was monitored by scanning electron microscopy, atomic force microscopy, weight loss, and molecular weight changes (in vitro), and by microscopic observations of the materials' morphology after histological staining with May-Grunwald-Giemsa (in vivo). The results show that the films in both conditions degraded much faster than the scaffolds. The scaffolds were dimensionally stable for 23 weeks, while the films lost their integrity after 7 weeks in vitro. The films' degradation was heterogenous--degradation in their central parts was faster than in the surface and subsurface regions due to the increased concentration of the acidic degradation products inside. In the scaffolds, having much thinner pore walls, heterogenous degradation due to the autocatalytic effect was not observed.
Pamula
Elzbieta
E
Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al. Mickiewicza 30, Krakow 30-059, Poland. epamula@agh.edu.pl
Menaszek
Elzbieta
E
D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002384:Catalysis; D007249:Inflammation; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008752:Methylene Chloride / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D013499:Surface Properties; D013997:Time Factors; D023822:Tissue Engineering
D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D008752:Methylene Chloride