Injectable GelMA Hydrogel Microspheres with Sustained Release of Platelet‐Rich Plasma for the Treatment of Thin Endometrium

Platelet-rich plasma (PRP) intrauterine infusion has been demonstrated to be effective in treating thin endometrium and achieving pregnancy. However, the rapid release of growth factors limits its effectiveness in clinical applications, and thus, multiple intrauterine infusions are often required to achieve therapeutic efficacy. In this study, a GelMA hydrogel microsphere biomaterial is developed using droplet microfluidics to modify the delivery mode of PRP and thus prolong its duration of action. Its biocompatibility is confirmed through both in vivo and in vitro studies. Cell experiments show that PRP-loaded microspheres significantly enhance cell proliferation, migration, and angiogenesis. In vivo experiments show that the effects of PRP-loaded microspheres on repairing the endometrium and restoring fertility in mice could achieve the impact of triple PRP intrauterine infusions. Further mechanistic investigations reveal that PRP could facilitate endometrial repair by regulating the expression of E2Fs, a group of transcription factors. This study demonstrates that hydrogel microspheres could modify the delivery of PRP and prolong its duration of action, enabling endometrial repair and functional reconstruction. This design avoids repeated intrauterine injections of PRP in the clinic, reduces the number of patient visits, and provides a new avenue for clinical treatment of thin endometrium.