Acceleration of skin regeneration in full-thickness burns by incorporation of bFGF-loaded alginate microspheres into a CMCS-PVA hydrogel.

Two important issues in skin tissue engineering are the vascularization and regeneration of the dermis. Basic fibroblast growth factor (bFGF) is known to promote angiogenesis and accelerate wound healing. Direct delivery of bFGF to the wound area, however, would lead to a loss of bioactivity. To this end, bFGF-loaded alginate microspheres (Ms) were fabricated and incorporated into carboxymethyl chitosan (CMCS)-poly(vinyl alcohol) (PVA) to form a composite hydrogel. Scanning electron microscopy (SEM) results indicated that the incorporation of Ms does not significantly affect the inner structure of CMCS-PVA. In an in vitro study, the release of bFGF from Ms-CMCS-PVA in a sustained manner retained higher bioactivity over a 2-week period. Full-thickness burn wounds were created in the dorsal area of rats for in vivo evaluation of skin regeneration treated with CMCS-PVA hydrogel, with and without bFGF. Compared with the control, CMCS-PVA and bFGF-CMCS-PVA groups, the bFGF/Ms-CMCS-PVA group revealed significantly faster wound recovery rates, with re-epithelialization and regeneration of the dermis. Moreover, the bFGF/Ms-CMCS-PVA group had the highest density of newly formed and mature blood vessels during the 2 mweek treatment period. The ability of the bFGF/Ms-CMCS-PVA hydrogel to accelerate wound healing in a full-thickness burn model suggests its potential for use in dermal tissue regeneration.