Engineering bone regeneration with bioabsorbable scaffolds with novel microarchitecture.
Critical-sized defects (CSDs) were introduced into rat calvaria to test the hypothesis that absorption of surrounding blood, marrow, and fluid from the osseous wound into a bioabsorbable polymer matrix with unique microarchitecture can induce bone formation via hematoma stabilization. Scaffolds with 90% porosity, specific surface areas of approximately 10 m2/g, and median pore sizes of 16 and 32 microm, respectively, were fabricated using an emulsion freeze-drying process. Contact radiography and radiomorphometry revealed the size of the initial defects (50 mm2) were reduced to 27 +/- 11 mm2 and 34 +/- 17 mm2 for CSDs treated with poly(D,L-lactide-co-glycolide). Histology and histomorphometry revealed scaffolds filled with significantly more de novo bone than negative controls (p < 0. 007), more osteoid than both the negative and autograft controls (p < 0.002), and small masses of mineralized tissue (< 15 mm in diameter) observed within the scaffolds. Based on these findings, we propose a change in the current paradigm regarding the microarchitecture of scaffolds for in vivo bone regeneration to include mechanisms based on hematoma stabilization.
Whang
K
K
Division of Biological Materials, Northwestern University Medical School, Chicago, IL 60611-3008, USA.
Healy
K E
KE
Elenz
D R
DR
Nam
E K
EK
Tsai
D C
DC
Thomas
C H
CH
Nuber
G W
GW
Glorieux
F H
FH
Travers
R
R
Sprague
S M
SM
D020341:Absorbable Implants; D000818:Animals; D001698:Biomedical Engineering / Q000379:methods*; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes; D001842:Bone and Bones / Q000293:injuries* / Q000601:surgery; D006406:Hematoma; D019344:Lactic Acid; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D051381:Rats; D017207:Rats, Sprague-Dawley; D012886:Skull
D018786:Bone Substitutes; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid