In vivo experimental study on bone regeneration in critical bone defects using an injectable biodegradable PLA/PGA copolymer.
OBJECTIVE
An assessment was done of the bone-healing rate after implantation of a polylactide/polyglycolide copolymer (PLA-PGA) 50/50 dispersed in aqueous solution of PGA and dextran, used as bone substitutes in an animal model.


METHODS
Two groups of 5 rabbits each were used. In both the femoral condyles, a critical size defect of 6x10 mm was made. On the right side PLA/PGA was inserted; the left side remained empty. Thirty and 90 days after surgery the animals were killed.


RESULTS
Defects left unfilled showed no spontaneous healing after 30 and 90 days. Sites filled with experimental materials showed new bone ranging between 11.46% and 76.82% after 30 days, and 75.98% and 95.34% after 90 days. Histomorphometry showed an increase in bone maturation between day 30 and 90 in experimental sites. At day 90, no statistical difference was seen as compared to normal bone.


CONCLUSIONS
PLA/PGA copolymer dispersed in hydrosoluble matrix seems to be suitable as osteoconductive material in critical size defects.
Rimondini
Lia
L
Research Institute Codivilla-Putti, Bologna, Italy.
Nicoli-Aldini
Nicolò
N
Fini
Milena
M
Guzzardella
Gaetano
G
Tschon
Matilde
M
Giardino
Roberto
R
D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D001847:Bone Diseases / Q000473:pathology / Q000601:surgery*; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D003911:Dextrans; D004195:Disease Models, Animal; D004337:Drug Carriers; D005269:Femur / Q000601:surgery* / Q000648:ultrastructure; D019344:Lactic Acid / Q000627:therapeutic use*; D008297:Male; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000187:drug effects; D011092:Polyethylene Glycols; D011098:Polyglactin 910; D011100:Polyglycolic Acid / Q000627:therapeutic use*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000627:therapeutic use*; D011817:Rabbits; D012997:Solvents; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects
D001672:Biocompatible Materials; D018786:Bone Substitutes; D003911:Dextrans; D004337:Drug Carriers; D011108:Polymers; D012997:Solvents; C102418:poly(lactic-glycolic acid)-poly(ethyleneglycol) copolymer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011098:Polyglactin 910; D011092:Polyethylene Glycols