Structure-guided PEGylated fibroblast growth factor 2 variants
accelerate wound healing with improved stability
Abstract
Background and Purpose Fibroblast growth factor 2 (FGF2) plays an
important role in multiple physiological functions such as tissue
repair. However, it has a short half-life in vivo, thus limiting its
clinical application. Experimental Approach Based on the crystal
structure of FGF2, surface-exposed sites near the receptor and heparin
binding region or separated from both binding regions, were selected and
PEGylated to investigate the effects of these sites on protein stability
and bioactivity. The efficacy of FGF2 conjugates for wound healing in
vitro was screened by cell proliferation, migration of human dermal
fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs).
Angiogenesis activity was assessed by tube forming and aortic ring
assays. The stability was confirmed in plasma and wound fluid. The in
vivo wound healing of FGF2 conjugates were further evaluated on a
cutaneous wound model using H&E, IHC, IF, and collagen staining. Key
Results Compared with native FGF2, all PEG-FGF2 conjugates exhibited
significantly improved stability in plasma and wound fluid. Compound 6
more effectively promoted proliferation and migration in HDFs and HUVECs
than FGF2, and exhibited excellent angiogenesis and wound healing
activity in vivo. However, conjugates with the PEGylated sites near the
receptor and heparin binding regions showed some reduction in
bioactivity, with a greater loss of bioactivity for protein with site
near the heparin binding domain. Conclusion and Implications Heparin
binding domain may be a key contribution region to activity of FGF2.
Compound 6 is a potential therapeutic candidate for wound healing,
deserving further investigation.