Creation of a prevascularized site for cell transplantation in rats.
BACKGROUND
Transplanted cells, especially islet cells, are likely to become apoptotic due to local hypoxia leading to graft dysfunction. Isolated pancreatic islet cells depend on the diffusion of oxygen from the surrounding tissue; therefore, access to sufficient oxygen supply is beneficial, particularly when microcapsules are used for immunoisolation in xenotransplantation. The aim of this study was to create a prevascularized site for cell transplantation in rats and test its effectiveness with microencapsulated HEK293 cells.


METHODS
The combination of implantation of a foam dressing, vacuum-assisted wound closure (foam+VAC) and hyperbaric oxygenation (HBO) was used in 40 Sprague-Dawley rats. Blood flow and vascular endothelial growth factor (VEGF) levels were determined. Sodium cellulose sulphate (SCS)-microencapsulated HEK293 cells were xenotransplanted into the foam dressing in rats pre-treated with HBO, and angiogenesis and apoptosis were assessed.


RESULTS
Vessel ingrowth and VEGF levels increased depending on the duration of HBO treatment. The area containing the foam was perfused significantly better in the experimental groups when compared to controls. Only a small amount of apoptosis occurs in SCS-microencapsulated HEK293 cells after xenotransplantation.


CONCLUSIONS
As ischemia-damaged cells are likely to undergo cell death or loose functionality due to hypoxia, therefore leading to graft dysfunction, the combination foam+VAC and HBO might be a promising method to create a prevascularized site to achieve better results in xenogeneic cell transplantation.
Department of Surgery, Division of Transplantation Surgery, Medical University Graz, Graz, Austria. philipp.stiegler@meduni-graz.at
Philipp
P
Stiegler
Veronika
V
Matzi
Eve
E
Pierer
Oliver
O
Hauser
Silvia
S
Schaffellner
Heiko
H
Renner
Joachim
J
Greilberger
Reingard
R
Aigner
Alfred
A
Maier
Carolin
C
Lackner
Florian
F
Iberer
Freyja-Maria
FM
Smolle-Jüttner
Karlheinz
K
Tscheliessnigg
Vanessa
V
Stadlbauer
D000818:Animals; D017690:Cell Transplantation / Q000379:methods*; D004339:Drug Compounding / Q000379:methods; D057809:HEK293 Cells; D006801:Humans; D020007:Implants, Experimental; D018919:Neovascularization, Physiologic; D051381:Rats; D017207:Rats, Sprague-Dawley; D014183:Transplantation, Heterologous / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D042461:Vascular Endothelial Growth Factor A