MRI tracking of human Wharton's jelly stem cells seeded onto acellular dermal matrix labeled with superparamagnetic iron oxide nanoparticles in burn wounds.

Background: In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based therapies. This study investigated tracking of human Wharton's jelly stem cells (hWJSCs) seeded onto an acellular dermal matrix (ADM) and labeled with superparamagnetic iron oxide nanoparticles (SPIONs) by magnetic resonance imaging (MRI) in burn injury. Method: The hWJSCs were characterized and assessed for growth kinetics. A total of 30 rats were enrolled in three equal groups. Group 1 underwent scald burn injury left without treatment, the group 2 was treated by an ADM that was prepared from cosmetic surgery skin samples and the group 3 received hWJSCs labeled with SPIONs seeded onto an ADM. Tensile strength was evaluated before and after interventions, real time PCR assessed apoptosis, and Prussian blue staining, scanning electron microscopy (SEM) and MRI were used for the tracking of labeled cells. Results: The hWJSCs exhibited mesenchymal stem cell properties. Population doubling time was 40.1 hours. SPIONs did not show any toxic effect. The hWJSCs seeded onto an ADM decreased Bax and increased Bcl-2 gene expression. Internalization of SPIONs within hWJSCs was confirmed by Prussian blue staining, SEM and MRI until day 21. There was a significant difference between the Young's moduli of normal skin and the group receiving hWJSCs seeded onto an ADM. Histological observations and SEM imaging confirmed that MRI is an accurate method to track SPION-labeled hWJSCs in vivo. Conclusions: This study showed that SPION labeling coupled with MRI can be used to further understand the fate of stem cells after transplantation in a burn model.

The effect of allogenic human Wharton's jelly stem cells seeded onto acellular dermal matrix in healing of rat burn wounds.

BACKGROUND: Various methods were introduced to overcome the autograft shortage in burn wound care, including cell transplantation and tissue engineering. AIMS: To evaluate the healing effect of allogenic human Wharton's jelly stem cells (hWJSCs) seeded onto acellular dermal matrix (ADM) in rat burn injuries. PATIENTS AND METHODS: Human Wharton's jelly stem cells provided from umbilical cord tissue were characterized before transplantation, and the growth kinetic was determined. Skin samples from cosmetic surgeries were used for preparation of ADM. Forty male Sprague Dawley rats were randomly divided into 4 equal groups. Third-degree burn was induced for all animals by exposing to hot water using a 2 cm ring for 10 seconds. Group 1 was burned rats that did not receive any treatment. After burn injury, the second group received silver sulfadiazine (SSD), the third group was treated just by using ADM, and the fourth group received 2 × 106 hWJSCs seeded onto ADM. The animals were euthanized for histologic evaluation after 7, 14, and 21 days. RESULTS: Human Wharton's jelly stem cells were characterized to be spindle shape and positive for osteogenic and adipogenic induction and for mesenchymal markers but lacked hematopoietic markers. Population doubling time (PDT) was 40.1 hours with an increasing growth trend until day 6th. Macro- and microscopically, the healing was mild in ADM group and moderate in ADM + hWJSCs group after 21 days. CONCLUSION: Allogenic hWJSCs seeded onto ADM improved the healing process in burn wounds denoting to their therapeutic and anti-inflammatory effects in burn wounds that can be added to the literature.