title: Ectopic bone formation by gel-derived bioactive glass-poly-L-lactide-co-glycolide composites in a rabbit muscle model.
abstract: In this study we aimed to assess the in vivo osteoinductive properties of two composite scaffolds made of PLGA (poly-L-lactide-co-glycolide) and two types of gel-derived bioactive glasses, namely a high silica S2 bioactive glass (S2-PLGA composites) or high lime A2 bioactive glass (A2-PLGA composites). To achieve that, the potential of the composites to induce ectopic bone formation in a rabbit muscle has been examined along with the control PLGA scaffold. Cylinder-like scaffolds of 7  ×  3 mm (width  ×  height) were implanted into pouches created in the latissimus dorsi muscle of 18 New Zealand rabbits. The tissue sections were obtained at 6, 12 or 24 weeks post-surgery (six rabbits per each time point) and stained with hematoxylin-eosin. The process of wound healing, the formation of collagen-rich connective tissue and its transition to cartilage were examined by Sirius red and Alcian blue histological stainings. We also performed immunohistochemical verification of the presence of osteoblast- and osteoclast- like cells in the vicinity of the scaffolds. A typical foreign body reaction and wound healing process was observed for all implanted scaffolds. Osteoblast- and osteoclast-like cells were observed in the vicinity of the scaffolds as determined by the immunohistochemical staining for Osteocalcin, BMP-2 and Cathepsin K. Compared to plain PLGA scaffolds, numerous osteoblast-like cells were observed 12 weeks post implantation near the composites and the scaffolds gradually degraded as bone formation proceeded. S2-PLGA and A2-PLGA composites display osteoinductive properties in vivo. Furthermore, they are more effective at inducing ectopic bone formation in a rabbit muscle compared to plain PLGA. Thus these SBG-PLGA composite scaffolds have potential for clinical applications in dental and/or orthopedic-bone tissue engineering.
authors.affiliation: Department of Cell Biology & Imaging, Faculty of Biology & Earth Sciences, Jagiellonian University, 9 Gronostajowa Str., 30-387 Kraków, Poland. Chair of Anatomy, Faculty of Medicine, Jagiellonian University Medical College, 12 Kopernika Str., 31-034 Kraków, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Filipowska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Cholewa-Kowalska
authors.forename: Jarosław
authors.initials: J
authors.lastname: Wieczorek
authors.forename: Danuta
authors.initials: D
authors.lastname: Semik
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Dąbrowski
authors.forename: Maria
authors.initials: M
authors.lastname: Łączka
authors.forename: Anna M
authors.initials: AM
authors.lastname: Osyczka
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D018786:Bone Substitutes / Q000737:chemistry*; D056657:Cathepsin K / Q000378:metabolism; D005898:Glass / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000166:cytology* / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D055396:Bone Morphogenetic Protein 2; D018786:Bone Substitutes; D015675:Osteocalcin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D056657:Cathepsin K