Critically sized skin flaps used to treat skin defects
often suffer
from necrosis due to insufficient blood supply. Hence there is an
urgent need to improve the survival rate of skin flaps by promoting
local angiogenesis. The delivery of growth factor loaded microcarriers
have shown promise in enhancing defect repair, however, their rapid
clearance from the defect site limits their regenerative potential.
Thus, it is critical to develop microcarriers which can promote the
sustained release of bioactive factors to effectively stimulate tissue
repair. This study aimed to develop a stromal cell-derived factor
1 (SDF-1) loaded microcarrier coated with Matrigel (MC@SDF-1@Mat)
to promote skin flap repair. SEM imaging showed that the surface of
the microcarrier was coated by a porous Matrigel film. The drug release
experiment showed that the Matrigel-coated microcarriers enhanced
the sustained release of the model drug methylene blue when compared
to uncoated group. MC@SDF-1@Mat significantly promoted the proliferation,
migration, and angiogenesis of HUVECs via CCK-8, wound healing assay,
and tube formation assay, respectively. Moreover, the murine random
skin flap model was further established and treated. It was found
that the flap necrosis area in the MC@SDF-1@Mat treated group was
significantly reduced. H&E and Masson staining showed the histological
structure and collagen organization exhibited a normal phenotype in
the MC@SDF-1@Mat treated group. Additionally, CD31 immunohistochemical
analysis showed that the MC@SDF-1@Mat treated group exhibited the
greatest degree of neovascularization. In conclusion, our SDF-1 functionalized
gelatin-based hydrogel microcarrier has potential clinical applications
in promoting skin flap repair and drug delivery.