Engineering bone-like tissue in vitro using human bone marrow stem cells and silk scaffolds.
Porous biodegradable silk scaffolds and human bone marrow derived mesenchymal stem cells (hMSCs) were used to engineer bone-like tissue in vitro. Two different scaffolds with the same microstructure were studied: collagen (to assess the effects of fast degradation) and silk with covalently bound RGD sequences (to assess the effects of enhanced cell attachment and slow degradation). The hMSCs were isolated, expanded in culture, characterized with respect to the expression of surface markers and ability for chondrogenic and osteogenic differentiation, seeded on scaffolds, and cultured for up to 4 weeks. Histological analysis and microcomputer tomography showed the development of up to 1.2-mm-long interconnected and organized bonelike trabeculae with cuboid cells on the silk-RGD scaffolds, features still present but to a lesser extent on silk scaffolds and absent on the collagen scaffolds. The X-ray diffraction pattern of the deposited bone corresponded to hydroxyapatite present in the native bone. Biochemical analysis showed increased mineralization on silk-RGD scaffolds compared with either silk or collagen scaffolds after 4 weeks. Expression of bone sialoprotein, osteopontin, and bone morphogenetic protein 2 was significantly higher for hMSCs cultured in osteogenic than control medium both after 2 and 4 weeks in culture. The results suggest that RGD-silk scaffolds are particularly suitable for autologous bone tissue engineering, presumably because of their stable macroporous structure, tailorable mechanical properties matching those of native bone, and slow degradation.
Division of Health Sciences and Technology, Massachusetts Institute of Technology, E25-330, 45 Carleton Street, Cambridge, Massachusetts 02139, USA.
Lorenz
L
Meinel
Vassilis
V
Karageorgiou
Sandra
S
Hofmann
Robert
R
Fajardo
Brian
B
Snyder
Chunmei
C
Li
Ludwig
L
Zichner
Robert
R
Langer
Gordana
G
Vunjak-Novakovic
David L
DL
Kaplan
D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000378:metabolism; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry / Q000378:metabolism; D058574:Integrin-Binding Sialoprotein; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D053495:Osteopontin; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism; D047011:Silk / Q000737:chemistry; D023822:Tissue Engineering / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
C525718:BMP2 protein, human; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D006882:Hydroxyapatites; C546871:IBSP protein, human; D058574:Integrin-Binding Sialoprotein; D010455:Peptides; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D047011:Silk; D016212:Transforming Growth Factor beta; D053495:Osteopontin