Stromal-derived factor-1 delivered via hydrogel drug-delivery vehicle accelerates wound healing in vivo

Topical treatment of superficial wounds has many advantages including decreased cost and increased ease of application compared with systemic treatments. Many of the advantages, however, are lost when it is necessary for repeated doses of topical medications to be given over an extended period of time. Therefore, a drug-delivery vehicle that delivers biologically appropriate doses in a sustained fashion would prove valuable. In this study, an alginate hydrogel scaffold impregnated with the angiogenic chemokine stromal-derived factor-1 was used to provide targeted, though short-term, delivery directly into the wound bed. Wounds were created on the dorsum of mice, and either a stromal-derived factor-1-impregnated or a saline-impregnated scaffold was applied. Wounds were explanted after 1, 3, 7 days, wound area was measured, and histology and immunohistochemistry for endothelial markers were performed. The remaining wound area in stromal-derived factor-1-treated wounds vs. controls was not significant 1 day after wounding (96.7 +/- 0.1 vs. 97.5 +/- 1.1%, p=0.317), but was significant after 3 days postwounding (46.7 +/- 0.1 vs. 82.3 +/- 2.4%, p=0.046) and 7 days postwounding (2.3 +/- 1.3 vs. 32.0 +/- 4.0%, p=0.049). Immunohistochemistry revealed a greater degree of endothelial cell invasion into the wound bed infiltration compared with controls. The results of this study suggest significant clinical promise for our hydrogel-delivery vehicle in the treatment of wounds.