Objective      To evaluate the effect of thermosensitive poly(lactic acid)-polyethylene glycol- poly(lactic acid) block polymer (PLEL) hydrogel containing recombinant human stromal cell-derived factor-1α (rhSDF-1α) on preventing intrauterine adhesion and promoting the regeneration of endometrium.       Methods      Twenty-four adult female New Zealand rabbits (48 uteruses) were randomly divided to 4 groups: spontaneous regeneration group (n=12) which was treated by cutting the uterus lengthwise

removing the endometrium with scissors

and then suturing the incision after hemostasis

PLEL treatment group (n=12) which was treated by injecting PLEL hydrogel after suturing the incision

PLEL-rhSDF-1α treatment group (n=12) which was treated by injecting PLEL hydrogel containing rhSDF-1α after suturing the incision

and sham operation group (n=12) which just exposed the uterus via an abdominal midline incision. All the rabbits underwent euthanasia on postoperative 7 and 28 d to get the uterus samples. The expression levels of CD44 and CD90 were determined by immunofluorescence staining

and the regenerative endometrium was observed by immunohistochemical staining.       Results      Epithelial tissue was not regenerated nearly in the spontaneous regeneration group. There were more MSCs homing to the regenerative endometrium in the PLEL-rhSDF-1α treatment group than in the PLEL treatment group (P0.05)

and the ratio of epithelial layer length to basal layer length was larger (P0.05). But the sham operation group was better than all of them (P0.05).       Conclusion       Thermosensitive PLEL hydrogel containing rhSDF-1α is effective on preventing intrauterine adhesion and promoting the regeneration of endometrium.