Fig. 9: The effects of PRG4 and IGF-1 on promotion of regenerative wound healing in rats.

a Morphological comparison of the healing process of rat dorsal full-thickness wounds between different treatments. b Quantitative evaluation of wound closure during healing (n = 3). Note: application of IGF-1 and/or IGF-1 + PRG4 promoted the rate of wound healing rate compared to the control. The best treatments was that of IGF-1 + PRG4. c Skin sections from the excision wounds on POD 28 with Masson’ trichrome staining. Note that HF/SG-like structures were clearly seen at the margin and middle of the wounds in IGF-1 or IGF-1 + PRG4 group, while no appendages were observed in the wound bed of the control group. d, e Quantification of neogenic HFs and SGs. Note that numbers of regenerated HFs and SGs in the IGF-1 and IGF-1 + PRG4 treatment group were significantly higher than those in the control group. Data is shown as the mean ± SEMs (n = 3) with six fields randomly chosen from three replicates of each tissue section for statistical analysis. f IHC staining of CD31 on POD 10. Note that a large number of neogenic vessels were seen on the wound bed after IGF-1 + PRG4 treatment. g Quantification of neogenic vessels. Note that the number of the vessels in IGF-1 + PRG4 group was significantly higher than the other groups, and there was no significant difference between the IGF-1 and the control group. Data is shown as the mean ± SEMs (n = 3) with six fields randomly chosen from three replicates of each tissue section for statistical analysis. h, i Tube structure on Matrigel could be observed 4 h after seeding HUVECs. j–m Quantification of the branch number and the total branch length. Data is shown as the mean ± SEMs (n = 3) with six fields randomly chosen from three replicates for statistical analysis.