Influence of flap prefabrication on seeding of subcutaneously injected mesenchymal stem cells in microvascular beds in rats.

BACKGROUND

In this article, the authors investigated whether the prefabrication of an autologous pedicled flap by isolation from the surrounding with artificial skin substitutes would increase mesenchymal stem cell (MSC) seeding.

METHODS

Mesenchymal stem cells were isolated from human umbilical cords and were cultured and characterized by fluorescence-activated cell sorting. Oxacarbocyanine and its green fluorescence emission were used to label the MSCs population.Sixteen adult Wistar rats were randomized in 4 groups (n = 4 animals per group). In group 1, a prefabricated groin flap (GF) with skin substitutes was harvested without cell injection; in group 2, 1 million MSCs were injected subcutaneously in the area corresponding to the GF without flap harvesting; in Group 3, a prefabricated GF with skin substitutes was harvested and 1 million MSCs were injected subcutaneously; and in Group 4, a prefabricated GF with skin substitutes was harvested and 2 million MSCs were injected subcutaneously. All procedures were performed bilaterally in each animal. Animals were sacrificed 2 weeks after the surgery. Flap viability was then assessed by clinical inspection and histology, and seeding of MSCs was observed.

RESULTS

All flaps survived 2 weeks after the surgery. Oxacarbocyanine-labeled cells were found in all prefabricated flaps injected (Groups 3 and 4) in higher number in comparison with the group where subcutaneous injection without flap harvesting was performed (Group 2). This difference was statistically significant (P < 0.05).

CONCLUSIONS

Prefabricated skin flaps with skin substitutes may provide a useful vehicle for the implantation of MSCs to serve as an autologous microvascular bioscaffold.