ELPIS Human Cord derived MSC (SNC Stemcell Engineering)

Primary objectives: To evaluate the safety and tolerability of single administration of different doses of ELPIS human umbilical cord mesenchymal stem cells; To evaluate the safety and tolerability of multiple administrations of different doses of ELPIS human umbilical cord mesenchymal stem cells; To determine the recommended dose (RP2D) of Phase II clinical trial of ELPIS human umbilical cord mesenchymal stem cell therapy. Secondary objectives: To evaluate the preliminary efficacy of ELPIS human umbilical cord mesenchymal stem cells in the treatment of moderate to severe chronic plaque psoriasis; To preliminarily explore the pharmacokinetic characteristics of patients treated with injectable mesenchymal stem cells (umbilical cord); To investigate the changes in lymphocyte subsets and cytokines before and after treatment with ELPIS human umbilical cord mesenchymal stem cells; To evaluate the immunogenicity of ELPIS human umbilical cord mesenchymal stem cell therapy.