Biomedical Devices Improve Islet Transplants for Diabetics

Over 590 Oklahoma Auctions End Tomorrow 05/12 - Bid Now
Over 450 Total Lots Up For Auction at Two Locations - CA 05/14, NJ 05/24

生物医学的设备改进小岛移植为糖尿病患者

Lynn Shapiro, Writer | January 21, 2009
Islet Transplants
Improvements in biomedical devices have increased the overall success rates of islet transplantation for diabetics, as noted in the January issue of Cell Transplantation (Vol. 17 No.9).

A review by Dr. Cherie Stabler and colleagues from the Diabetes Research Institute and the Department of Biomedical Engineering at the University of Miami, evaluated the engineering of bio-hybrid devices and encapsulation technologies that may aid in the success of islet transplants.

"A recent focus has been to redesign bio-hybrid devices that promote vascularization and effective nutrient delivery to prevent islet cell necrosis and at the same time minimize device volumes," said Stabler.

Servicing GE/Siemens Nuclear Medicine equipment with OEM trained engineers

Numed, a well established company in business since 1975 provides a wide range of service options including time & material service, PM only contracts, full service contracts, labor only contracts & system relocation. Call 800 96 Numed for more info.

According to Stabler, one bio-hybrid design has been fabricated for pre-vascularization to afford maximum nutrient delivery and minimal exposure to inflammatory agents. At the same time, macrodevices, such as hollow fibers, have also been used for cell loading.

"The combination of these two treatments increased vascularization and blood flow around a bioartificial pancreas when compared to control implants," noted Stabler.

Encapsulation is also a technique for minimizing both immune response and the need for high dose immunosuppressive protocols. By coating the surface of the cell with semi-permeable biomaterial, the ability of host cells to recognize surface antigens on implanted cells is impaired and provides a barrier between the host and transplanted cells. Masking immune recognition also opens the possibility for xenotransplantation.

"Biomaterials used for encapsulation should be well-characterized, pharmaceutical grade and verified as pyrogen and endotoxin-free," explained Stabler. "It is critical to establish guidelines for generating capsules optimized for biocompatibility, immunoprotection and islet function."

Researchers supported the use of the portal vein as a site for islet transplantation, but noted that there are issues with injecting encapsulated cells into the liver. Finally, the research team suggested decreasing capsule size to nano-scale and combining PEGylation coating of capsules with a layer of poly(ethylene) glycol molecules with low-dose immunosuppression to improve engraftment and long-term function.