Studies Of Pre-clinic Application Of The Umbilical Cord Mesenchymal Stem Cells

Objective Human umbilical cord mesenchymal stem cellswere cultured and then their biological safety was analyzed, providing abasis for clinical application.Methods Blood vessels were stripped fromfresh umbilical cord and cells taken from Wharton’s jelly were cultured bytissue adherent method. Different generations(P1~P9) were identified bymorphology, surface marker, differentiation and proliferation ability. Inorder to clarify the security of mesenchymal stem cells, cells fromP3~P6were researched by etiology, karyotype, acute or chronic toxicity,allergy and tumorigenicity.Results In vitro, Human umbilical cordmesenchymal stem cells presented with long spindle-shaped adherentgrowth and cell expansion was in steady state. Proliferation curve ofcultured MSCs was “S” shape. Then cultured cells were tested by flowcytometer, expression levels of cell surface positive markers such as CD90,CD44, CD73were all above90%. Furthermore, expression levels ofnegative markers were very low at P3to P6. Cell cultures coulddifferentiate into adipocytes, osteoblasts and chondroblasts. Bacteria,fungi and other pathogenic microorganisms were not detected. Cells fromP3to P6were used to analyze karyotype by G-banding method, andchromosomal aberrations were not found in passaging process. The safetyof umbilical cord mesenchymal stem cells was also studied in animalexperiment. After mesenchymal stem cells infusion, acute toxicity was notfound, chronic toxicity experiments showed no pathological change inall tissues，tumorigenicity experiments indicated no tumor cells around theinjection site, and neither local nor systemic anaphylaxis was detected.Conclusion Mesenchymal stem cells isolated from human umbilical cordcould be amplified steadily in vitro. Additionally, with good biological safety, the umbilical cord mesenchymal stem cells can become a candidatefor future clinical treatment. Objective We explored the feasibility of intranasaldelivering different types of stem cells to cure rats with cerebral whitematter injury.Methods Rat oligodendrocyte precursor cells, bone marrowmesenchymal stem cells and human umbilical cord mesenchymal stem cellswere cultured. Animal models of cerebral white matter lesions wereprepared on day7after the birth of40SD rats.Then these rats wererandomly divided into four groups (n=10in each group):ratoligodendrocyte precursor cells transplantation group, human umbilicalcord mesenchymal stem cells were cultured and then their biological safety was analyzed, providing a basis for clinical application. rat bone marrowmesenchymal stem cells transplantation group, human umbilical cordmesenchymal stem cells transplantation group, and PBS control group. Thehyaluronidase(200U) was dripped into nasal cavity in30min beforetransplantation, and then different types of cells (5×105cells suspendedin20μl physiological saline)were intranasally transplanted into ratmodels at age of10days. Rats were sacrificed respectively at24h,48h,72h and7d after transplantation, and brain tissues were removed, fixed anddehydrated for preparation of frozen tissue slices, then cell migration wasobserved.Results Three types of cultured cells grew well and theexpression of MBP was reduced significantly at the injured sides ofcerebral white matter injury groups. Both labelled rat oligodendrocyteprecursor cells and rat bone marrow mesenchymal stem cells could befound at the injured part after intranasal transplantation, and the number ofcells migrating to the injured site was increased gradually over time.However, human umbilical cord mesenchymal stem cell could not bedetected in the injured part after transplantation.Conclusion Ratoligodendrocyte precursor cells and rat bone marrow mesenchymal stemcells had the ability of migrating to injured part of brain. Thus it is asimple, non-invasive, feasible method to cure cerebral white matterinjury though intranasal cell transplantation.