Table 1.

Benefits and limitations of cell and growth factor therapy for tendon injury

Delivery factor	Carrier/control	Group	Tendon treated	Result	Limitation
BMSCs	Fibrin sealant	Chong et al.35	Rabbit Achilles tendon	Improved modulus and cell alignment along fiber direction at 3 weeks after treatmenta	No difference in outcome at 12 weeksa
ADSCs	Platelet-rich plasma	Uysal et al.36	Rabbit Achilles tendon	Increased the tensile strength of the repaired tendon, collagen type I deposition, and levels of FGF and VEGFa Decreased levels of TGF-β1, -β2, and -β3	Tendon adhesions were not evaluated Benefit of platelet-rich plasma delivery mechanism is not conclusive
PDGF	Heparin-based delivery system	Thomopoulos et al.41	Canine flexor tendon	Increased cell proliferation and range of motiona	No improvement in tensile propertiesa Ineffective in improving collagen I deposition
bFGF	Heparin-based delivery system	Thomopoulos et al.42	Canine flexor tendon	Increased vascular response, population of inflammatory cells, and cell proliferation at high concentrations of growth factor (1000 ng bFGF)	Matrix production at the repair site was primarily scar tissue Did not show significant improvement in tendon strengtha
IGF-1	4% methylcellulose gel Carrageenan (inflammation analysis)	Kurtz et al.43	Rat Achilles tendon	Lower functional deficit and time for functional recovery when compared to controls for both the surgical repair group and the nontreated carrageenan group	No significant effect of IGF-1 in increasing the failure loadsa
BMP-12	β-Galactosidase recombinant adenovirus	Lou et al.44	Chicken flexor profundus tendon	30% increase of newly synthesized type I collagen Ultimate load and stiffness were 2× that of controls (4 weeks) No evidence of bone formation in 2 or 4 weeks	Adhesions were observed around the callus in all groups Range of motion as a measure of adhesion formation was not studied
CDMP-1 CDMP-2 CDMP-3	50-μL acetate buffer	Forslund et al.52	Rat Achilles tendon	No difference in mechanics between CDMP (1, 2, 3) treatment Force and stiffness were increased at higher dosage (10 μg)a Structural improvements were noted after 4 weeks, with most fibers oriented in the longitudinal direction in all casesa CDMP-2 was the least osteogenic	For 10-μg dose, all CDMPs groups showed some cartilage or bone formation in some specimens Mechanical properties of injured tissue were significantly lower than native

^aCompared to untreated controls.