Fetal vs adult mesenchymal stem cells achieve greater gene expression, but less osteoinduction

Table 1 Bone morphogenic protein 2 expression from adenoviral-transduced mesenchymal stem cells

Medium	O.D. (Mean ± SD)	Corrected O.D.	BMP2 (pg/cell-day)	Total BMP2 injected (ng/day)
fMSC	0.043 ± 0.004	-	-	-
aMSC	0.031 ± 0.002	-	-	-
Ad-BMP2-fMSC	2.99 ± 0.33	2.95	0.02	32.8b
Ad-BMP2-aMSC	1.69 ± 0.27	1.66	0.01	18.5

^bP < 0.01 Ad-BMP2-fMSC vs Ad-BMP2-aMSC. BMP2: Bone morphogenic protein 2; MSCs: Mesenchymal stem cells; Ad-GFP: E1-A-deleted-green fluorescent protein; fMSCs: Fetal mesenchymal stem cells; aMSCs: Adult mesenchymal stem cells.

Table 2 Summary data of the analysis of the microradiographs

Treatment group	Total thighs(n)	Thighs with new bone[n (%) of total]	Mean ossiclearea (mm2)	Mean extent ofperiosteal new bone	Mean midshaftdiameter (mm ± SD)
Saline	4	0	0	0	1.24 ± 0.07
Ad-BMP2-aMSC	6	5 (83)a	0.78	1	1.57 ± 0.35c
aMSC	4	0	0	0	1.26 ± 0.09
Ad-BMP2-fMSC	6	1 (17)	0.45	0	1.27 ± 0.08
fMSC	4	0	0	0	1.23 ± 0.07

^aP < 0.05 Ad-BMP2-aMSC vs Ad-BMP2-fMSC;

^cP < 0.05 intergroup comparison. BMP2: Bone morphogenic protein 2; MSCs: Mesenchymal stem cells; Ad-GFP: E1-A-deleted-green fluorescent protein; fMSCs: Fetal mesenchymal stem cells; aMSCs: Adult mesenchymal stem cells.

Table 3 Association between ossicle formation and E1-A-deleted-bone morphogenic protein 2-mesenchymal stem cell treatment

Treatment group	No.of thighs (n)	Ossicles (n)	Mean ossicle area(mm2± SD; range)
Ad-BMP2-aMSC
No ossicle	4
Ossicle	2	6	0.78 ± 1.23 (0.03-3.20)
Ad-BMP2-fMSC
No ossicle	5
Ossicle	1	3	0.45 ± 0.12 (0.32-0.47)

BMP2: Bone morphogenic protein 2; MSCs: Mesenchymal stem cells; Ad-GFP: E1-A-deleted-green fluorescent protein; fMSCs: Fetal mesenchymal stem cells; aMSCs: Adult mesenchymal stem cells.

Table 4 Extent of periosteal new bone in E1-A-deleted-bone morphogenic protein 2-adult mesenchymal stem cell treatment group

Extent of periosteal new bone	Thighs (n)	Midshaft diameter (mm)
0	3	1.27
1	2	1.76
4	1	2.10