Combined angiogenic therapies may be superior to single angiogenic therapy for treatment of hindlimb ischemia. Therefore, we first investigated whether the angiogenic efficacy of basic fibroblast growth factor (bFGF) administration and bone marrow mon ...

Combined angiogenic therapies may be superior to single angiogenic therapy for treatment of hindlimb ischemia. Therefore, we first investigated whether the angiogenic efficacy of basic fibroblast growth factor (bFGF) administration and bone marrow mononuclear cell (BMMNC) transplantation can be enhanced by sustained delivery of bFGF and BMMNC transplantation using a matrix, respectively, in mouse ischemic limbs. Next, we investigated whether the angiogenic efficacy of long-term delivery of bFGF is superior to short-term delivery of bFGF. Finally, we investigated whether the angiogenic efficacy of combination of two angiogenic strategies is superior to either strategy alone. One day after surgical induction of hindlimb ischemia, mice were randomized to receive either no treatment, daily injection of bFGF, sustained delivery of bFGF, granulocyte colony-stimulating factor (G-CSF) injection, BMMNC transplantation using culture medium, BMMNC transplantation using fibrin matrix, or combination of any two of these strategies. The sustained delivery of bFGF significantly increased the microvessel density, compared with daily injection of bFGF, and the long-term delivery of bFGF further increased the capillary density and BrdU-positive capillary density, as compared to short-term delivery. BMMNC transplantation using fibrin matrix significantly increased the microvessel density, compared with BMMNC transplantation using culture medium. Importantly, combination of bFGF sustained release with BMMNC transplantation using fibrin matrix or EPC mobilization by G-CSF further increased the densities of microvessels and arterioles, compared to either strategy alone. The densities of capillaries and arterioles were the highest in combination of bFGF sustained delivery and BMMNC transplantation using fibrin matrix. The sustained delivery methods of protein and cell transplantation using matrix potentiate the angiogenic efficacy of bFGF and BMMNC transplantation, respectively, for limb ischemia.

The release rate of bFGF can be controlled by heparin and concentration of thrombin and fibrinogen. Basic FGF-incorporated fibrin gels retained its biological activity and sustained the bFGF release. The bFGF delivery system showed the therapeutic pot ...

The release rate of bFGF can be controlled by heparin and concentration of thrombin and fibrinogen. Basic FGF-incorporated fibrin gels retained its biological activity and sustained the bFGF release. The bFGF delivery system showed the therapeutic potential of angiogenesis in mouse ischemic limb. The fibrin gel drug delivery system could be a valuable modality in angiogenesis.
Delivery system of HCPNs in fibrin gel can sustain bFGF release for more than one month at nearly zero-order, and that the release rate can be controlled with the fibrinogen concentration. The basic FGF released by the delivery system retained its biological activity. The bFGF delivery system showed therapeutic potential for angiogenesis in a mouse ischemic limb model. The local, sustained, and controllable delivery system for bFGF developed in this study may provide a powerful modality for a variety of therapeutic interventions, such as cardiac ischemia, limb ischemia, wound healing, and bone regeneration. This delivery system could also be applied to deliver dual or multiple angiogenic factors that have affinities for heparin, such as vascular endothelial cell growth factor, hepatocyte growth factor, epidermal growth factor, and bone morphogenetic protein, which could synergistically enhance angiogenesis.
To the best of our knowledge, this is the first report that the combination therapy of sustained release of bFGF and transplantation of BMMNCs synergistically enhances angiogenesis in mouse ischemic limbs compared to each separate therapy. The combination therapy could be utilized to enhance neovascularization in myocardial and peripheral ischemia. Further studies such as optimization of release rate and duration of bFGF and determination of in vivo bFGF release kinetics are required to maximize the angiogenic efficacy. Type and number of bone marrow-derived stem cells for implantation should also be optimized in order to enhance the angiogenic efficacy.
This is the first report that the combination therapy of angiogenic factor sustained release and EPCs mobilization synergistically enhances angiogenesis in mouse ischemic limbs compared to either single therapy alone. The combination therapy could be utilized to enhance neovascularization in myocardial and peripheral ischemia. Further studies, such as optimization of release rate and duration of bFGF, determination of in vivo bFGF release kinetics, optimization of dose and treatment period of G-CSF, and investigation of the mechanisms of bFGF and G-CSF action concerning neovascularization and vessel maturation, are required to maximize the angiogenic efficacy.
This is the first report that the combination therapy of EPC mobilization and BMMNC transplantation additively enhances angiogenesis in mouse ischemic limbs, as compared to each therapy separately. This combination therapy could be utilized to enhance neovascularization in myocardial and peripheral ischemia. Further studies, such as investigations of the optimization of the dose and treatment period of G-CSF, are required to maximize the angiogenic efficacy. The type and number of bone marrow-derived stem cells for transplantation should also be optimized in order to enhance the treatment efficacy.