In Vivo Safety and Regeneration of Long-Term Transported Amniotic Fluid Stem Cells for Renal Regeneration

BACKGROUND: Despite major progress in stem cell therapy, our knowledge of the characteristics and tissue regeneration potency of long-term transported cells is insufficient. In a previous in vitro study, we established the optimal cell transport conditions for amniotic fluid stem cells (AFSCs). In the present study, the target tissue regeneration of long-term transported cells was validated in vivo. METHODS: For renal regeneration, transported AFSCs were seeded on a poly(lactide-co-glycolide) scaffold and implanted in a partially resected kidney. The target tissue regeneration of the transported cells was compared with that of freshly harvested cells in terms of morphological reconstruction, histological microstructure reformation, immune cell infiltration, presence of induced cells, migration into remote organs, expression of inflammation/fibrosis/renal differentiation-related factors, and functional recovery. RESULTS: The kidney implanted with transported cells showed recovery of total kidney volume, regeneration of glomerular/renal tubules, low CD4/CD8 infiltration, and no occurrence of cancer during 40 weeks of observation. The AFSCs gradually disappeared and did not migrate into the liver, lung, or spleen. We observed low expression levels of proinflammatory cytokines and fibrotic factors; enhanced expression of the genes Wnt4, Pax2, Wt1, and Emx2; and significantly reduced blood urea nitrogen and creatinine values. There were no statistical differences between the performance of freshly harvested cells and that of the transported cells. CONCLUSION: This study demonstrates that long-term transported cells under optimized conditions can be used for cell therapy without adverse effects on stem cell characteristics, in vivo safety, and tissue regeneration potency.

Optimal Stem Cell Transporting Conditions to Maintain Cell Viability and Characteristics

BACKGROUND: The preservation of stem cell viability and characteristics during cell transport from the bench to patients can significantly affect the success of cell therapy. Factors such as suspending medium, time, temperature, cell density, and container type could be considered for transport conditions. METHODS: To establish optimal conditions, human amniotic fluid stem cells' (AFSCs) viabilities were analyzed under different media {DMEM(H), DMEM/F-12, K-SFM, RPMI 1640, α-MEM, DMEM(L), PBS or saline}, temperature (4, 22 or 37 ℃), cell density (1 × 10⁷ cells were suspended in 0.1, 0.5, 1.0 or 2.0 mL of medium) and container type (plastic syringe or glass bottle). After establishing the transport conditions, stem cell characteristics of AFSCs were compared to freshly prepared cells. RESULTS: Cells transported in DMEM(H) showed relatively higher viability than other media. The optimized transport temperature was 4 ℃, and available transport time was within 12 h. A lower cell density was associated with a better survival rate, and a syringe was selected as a transport container because of its clinical convenience. In compare of stem cell characteristics, the transported cells with established conditions showed similar potency as the freshly prepared cells. CONCLUSION: Our findings can provide a foundation to optimization of conditions for stem cell transport.

Use of Stem Cell in Fetal Therapy: Current Status and Future Perspectives

During the past decades, there has been a great evolution in the field of fetal therapy for congenital defects. Prenatal screening or diagnostic methods including non-invasive and invasive methods and fetal ultrasound have led to earlier and more accurate diagnosis of congenital anomalies. Recent advances in several therapeutic techniques including ultrasound-guided needle therapy, laser therapy or fetal endoscopy, have allowed some fetuses at risk with anatomical defects, to be corrected in utero but still, its clinical indications remain limited. Over the last 30 years, many researchers found usefulness of pluripotent stem cells from amniotic fluid and placenta because they are sources of diverse progenitor cell populations called mesenchymal stem cells. In some human conditions like severe combined immunodeficiency syndrome and chronic granulomatous disease, fetal therapy using stem cell replacement showed some promising results in researches but more studies are required to apply in clinical settings. The aim of this article is to summarize a current status and future perspective of stem cell therapy for treatment of congenital fetal anomalies.