Human Umbilical Cord Mesenchymal Stem Cells Treatment in Sepsis

The primary objective: To evaluate the efficacy of intravenous infusion of universal UC-MSCs and CD83+MSCs subpopulation injection in the treatment of sepsis by using the 28-day survival rate of the subjects as the primary efficacy criterion.The secondary objectives: 1. To systematically evaluate the safety of universal UC-MSCs and CD83+MSCs subpopulation in the treatment of sepsis; 2. To provide theoretical basis and clinical research data for establishing a safe, effective and feasible clinical treatment plan for sepsis using stem cells.