Tissue-engineered Reconstructable Uterus-Derived Materials For Uterus Recovery Toward Efficient Live Births

Background:The uterus has many biological functions and provides a critical microenvironment for mammalian reproduction,and the endometrium is essential for the implantation and growth of embryos.Thus,severe endometrial injuries,such as iatrogenic injury,intrauterine infection and drug-induced injury,often causes intrauterine adhesion(IUA)and further infertility,which has become an increasing public health issue.Several strategies,including hysteroscopic transcervical resection of adhesion(TCRA),physical barriers(contraceptive device,intrauterine balloon device,Foley balloon,etc.)and hormone drugs,have been developed to improve endometrial injury in clinic.However,these strategies cannot efficiently recover the structure and function of the endometrium,leading to intrauterine readhesion and subsequent infertility.In recent years,with the rapid development of stem cell engineering,recent advances have demonstrated the ptential of MSCs for the treatment of injured endometrium in rats and monkeys.Owing to the rapid secretion and turnover of endometrial mucus,directly injected MSCs are easily removed.MSC-mediated treatments of endometrial injury have substantial challenges due to the poor survival and retention rates of MSCs in the endometrium.Currently,no scaffolds suitable for the clinical treatment that can be loaded with MSCs are available.Moreover,despite major advances,the potential of the repaired endometrium for live births is often ignored to futher comprehensively investigate.Therefore,new efficient solutions to regenerate the structure and function of the injured endometrium and restore the fertility of rats with severe uterine injury.Object:Focusing on the current problems faced by MSCs in clinical applications,we are trying to find new ways to solve the obstacles of stem cells in the clinical treatment of uterine injuries,which could effectively treat uterine injuries in rats,and restore the fertility of rats with severe uterine injury.Methods:In this study,we used enzymatic digestion to isolate MSCs from human placental chorion.And then we developed the protocol system and the standardized identification system for efficiently extracting decellularized extracellular matrix hydrogels from pig uterus.It is proved that the hydrogel had good biological tissue compatibility with the uterus,and it could act as a physical barrier to prevent IUA.Reconstructed uterine-derived materials(RUMs)were formed by combining uterine-derived extracellular matrix hydrogels and villus-derived mesenchymal stem cells,and cultured into injectable RUMs and RUMs patches by adjusting the modulus and cell density,etc.Finally,a severe rat uterine injury model was used to verify the therapeutic effect of RUMs and explore the mechanism of action.Results:MSCs have great biological tissue compatibility with uterine hydrogel,and could be cultured in the hydrogel.By adjusting the modulus and cell density,it could be made into injectable RUMs and RUMs patches.Injectable RUMs could be used as a mobile barrier to effectively prevent intrauterine adhesions by promoting angiogenesis,endometrial regeneration and muscle collagen reconstruction,and RUMs adhered to the uterine wall could prevent CV-MSCs from leaking,preventing wounds and abdominal tissues adhere and accelerate wound healing.The injured uterus was regenerated within 15 days after organ transplantation and effectively supported the development of the fetus to full term and live birth.Conclusions:We have constructed a tissue-engineered uterine regeneration system by synergistically combining injectable RUMs and RUMs patches to achieve efficient live births in rats with severe uterine injuries.These results provide convincing evidence that opens up new possibilities for the clinical treatment of uterine injury.