An initial investigation of photocurable three-dimensional lactic acid based scaffolds in a critical-sized cranial defect.
Degradable polymer networks formed by the photoinitiated polymerization of multifunctional monomers have great potential as in situ forming materials, especially for bone tissue engineering. In this study, one specific chemistry was analyzed with respect to bone formation in a critical-sized defect model with and without adsorbed osteoinductive growth factors present. The scaffolds degraded in approximately 8 months and possessed an elastic modulus similar to that of trabecular bone. A porous scaffold fabricated with approximately 80% porosity and pore diameters ranging from 45 to 150 mm was implanted in a critical-sized cranial defect in rats. When implanted alone, the scaffolds were filled primarily with fibrous tissue after 9 weeks with only mild inflammation at the defect site. When the scaffolds released osteoinductive growth factors, statistically more bone filled the scaffold. For instance, 65.8+/-9.4% (n=5) of the defects were filled with radiopaque tissue in the osteoinductive releasing scaffolds, whereas only 24.2+/-7.4% (n=5) of the defects were filled in the untreated defects 9 weeks after implantation. These results illustrate not only the benefits of delivering osteoinductive factors when developing synthetic bone grafts, but the potential of these materials for supporting the infiltration and development of bone in large defects.
Burdick
Jason A
JA
Department of Chemical Engineering, University of Colorado, Campus Box 424, Engineering Center, ECCH 111, Boulder, CO 80309-0424, USA.
Frankel
Daniel
D
Dernell
William S
WS
Anseth
Kristi S
KS
D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D004548:Elasticity; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D011091:Polyesters; D011108:Polymers / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000002:abnormalities* / Q000187:drug effects; D013718:Tensile Strength
D018786:Bone Substitutes; D006133:Growth Substances; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)