Promotion of skin regeneration in diabetic rats by electrospun core-sheath fibers loaded with basic fibroblast growth factor

Diabetic skin ulcer is difficult to heal due to the lack of cellular and molecular signals required for normal wound repair. Emulsion electrospinning was adopted to imbed basic fibroblast growth factor (bFGF) into ultrafine fibers with a core-sheath structure to promote the wound healing process. An initially burst release as low as 14.0 ± 2.2% was achieved, followed by gradual release for around 4 wk. In vitro investigations on mouse embryo fibroblasts indicated that bFGF-loaded fibrous mats enhanced cell adhesion, proliferation, and secretion of extracellular matrix (ECM). Skin wounds were created in the dorsal area of diabetic rats for in vivo evaluation of skin regeneration after covered with bFGF-loaded fibrous mats. Compared with fibrous mats infiltrated with free bFGF, bFGF-loaded scaffolds revealed significantly higher wound recovery rate with complete re-epithelialization and regeneration of skin appendages. Higher density and mature capillary vessels were generated during 2 wk after treatment with bFGF-loaded fibers, and there was no fiber fragment observed in the histological sections at week 4 after operation. The gradual release of bFGF from fibrous mats enhanced collagen deposition and ECM remodeling, and the arrangement and component of collagen fibers were similar to normal tissues. The above results demonstrate the potential use of bFGF-loaded electrospun fibrous mats to rapidly restore the structural and functional properties of wounded skin for patients with diabetic mellitus.