Circulating progenitor cells home to and engraft to sites of ischemia, mediated in part by the adhesion molecule L-selectin; however, accumulation in tissues such as the heart is low. In this study, an acellular collagen-based matrix containing sialyl Lewis^X (sLe^X), which binds L-selectin, was developed in order to enhance the endogenous progenitor cell therapeutic response. Its effect on progenitor cells and angiogenesis were assessed in vitro and using a hindlimb ischemia model with rats. In culture, the sLe^X-collagen matrix recruited more CD133⁺CD34⁺L-selectin⁺ cells than collagen-only matrix, with adhesion mediated by L-selectin binding. Increased angiogenic/chemotactic cytokine production and improved resistance to apoptosis appeared in cells cultured on sLe^X-collagen matrix. In vivo, mobilization of endogenous circulating progenitor cells was increased, and greater recruitment of these and systemically injected human peripheral blood CXCR4⁺L-selectin⁺ cells to sLe^X-collagen treated limbs was observed compared to collagen-only. This condition was associated with differences in angiogenic/chemotactic cytokine levels, with greater arteriole density and increased perfusion in sLe^X-collagen treated hindlimbs. With these factors taken together, we demonstrated that an acellular matrix-bound ligand approach can enhance the mobilization, recruitment, and therapeutic effects of endogenous and/or transplanted progenitor cells, possibly through paracrine and antiapoptotic mechanisms, and could be used to improve cell-based regenerative therapies.—Suuronen, E. J., Zhang, P., Kuraitis, D., Cao, X., Melhuish, A., McKee, D., Li, F., Mesana, T. G., Veinot, J. P., Ruel, M. An acellular matrix-bound ligand enhances the mobilization, recruitment and therapeutic effects of circulating progenitor cells in a hindlimb ischemia model.