ATLANTA, GA USA (PRESS RELEASE) - May 19, 2012 -
Novel bioprinter, organ printing and cell seeding approaches for regenerative medicine tested
Three studies examining new techniques in regenerative medicine and organ engineering will be presented at the 107th Annual Scientific Meeting of the American Urological Association (AUA). Led by Dr. Anthony Atala, Director, Institute for Regenerative Medicine, Wake Forest Baptist Medical Center, Winston Salem, NC, the studies will be presented to reporters during a special press conference at the Georgia World Congress Center, Atlanta, GA on Sunday, May 20 at 10:30 a.m.
In Situ Bioprinting of Skin for Reconstruction (#20): A novel skin bioprinter has been shown to successfully deliver two different types of skin cells and biomaterials directly to target locations in order to cover skin defects, according to Dr. Atala and researchers from Wake Forest Baptist Medical Center. The research team investigated whether the new printer could be used for the repair of large full thickness wounds in a porcine model. Skin fibroblasts and keratinocytes were isolated from porcine skin, suspended in fibrinogen/ collagen solution and used to cover four 10x10 cm full-thickness wounds.
Animals receiving autologous cells (cells originating from own body) demonstrated faster wound healing, as compared to other treatment groups. These animals showed approximately 90% reduction in wound size, 80% re-epithelialization and a 40% contracture of original wound size within the first 3 weeks of the study. Animals treated with allogeneic cells showed comparable wound size, re-epithelialization and wound contracture as compared to the controls, which received only fibrinogen/collagen gel without cells.
“Results show that delivery of autologous cells facilitates wound healing and repair of skin defects,” said Atala, who also serves as a member of the AUA Public Media Committee and is a recognized world leader in the area of regenerative medicine. “This suggests that the use of a skin bioprinter may be a preferred approach for use in extensive reconstructive procedures.”
Integrated Organ Printer for Reconstruction (#1223): Dr. Atala and researchers from Wake Forest Baptist Medical Center have successfully designed and constructed an integrated organ printing system that can print a 3-D organ structure with precision, according to a new study. Because current bioprinting technology utilizes hydrogels, which present limitations in maintaining structural integrity, the research team set out to investigate the feasibility of using a printing system that integrates solid freeform fabrication to deliver viable cells while fabricating durable synthetic scaffolds simultaneously to create durable tissue structures.
An inverted microscope confirmed the presence of cells within the synthetic polymers one day after printing. The cells appeared morphologically normal and showed evidence of proliferation. The printed cells were viable on day 0 and day 3 as evidenced by the viability assay, while the percentage of live cells increased as time progressed. Two different cell types were confirmed within a single printed structure. Further, the researchers concluded that the new system is able to process cells, gel biomaterials and synthetic polymers simultaneously to yield a durable structure, providing a major leap in the advancement of organ printing technology.
Re-Endothelialization of Acellular Kidney Scaffolds for Whole Organ Engineering (#2278): The shortage of donor kidneys for transplantation has prompted researchers to work toward engineering kidneys in the laboratory. One strategy under development is to remove all cells from animal organs with the goal of replacing them with a human patient’s own cells. This decellularization technique holds great promise due to the maintenance of structural integrity. However, in order maintain blood circulation and induce renal function, these structures will require an endothelial cell lining to avoid blood clotting and thrombus formation when transplanted into a living recipient.
In this study, researchers at Wake Forest Baptist Medical Center describe an endothelial cell seeding method that permits effective endothelial cell coating on the vascular walls of the decellularized porcine kidney scaffolds. The researchers found that a combination method that involved perfusion and static introduction of cells facilitated well-organized endothelium on the decellularized blood vessels. Organized endothelial cells were shown on the artery, vein, and smaller blood vessels without apparent clogging of cells at the capillary structures in the cortex. Vascular tree imaging demonstrated that the endothelium on the arterial system of the kidney is well preserved and covered with viable endothelial cells. The combination seeding method proved to be a viable method for endothelial cells seeding. Future work will be aimed at improving cell adhesion as well as increasing cell numbers.
About the American Urological Association: Founded in 1902 and headquartered near Baltimore, Maryland, the American Urological Association is a leading advocate for the specialty of urology, and has more than 18,000 members throughout the world. The AUA is a premier urologic association, providing invaluable support to the urologic community as it pursues its mission of fostering the highest standards of urologic care through education, research and the formulation of health policy.