Maintenance of aerobic metabolism increases immunoisolated islet survival

Stagner, John I.; Seelan, Ratnam S.; Parthasarathy, R.

doi:10.4161/isl.3.3.15404

Cited by 8 publications

(2 citation statements)

References 22 publications

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“…It is this last approach which greatly interfaces with materials scientists. Immunoisolation attempts have utilized either microencapsulation of small numbers of islets or macroencapsulation of multiple islets in chambers, hollow fibers, sheets, or sponges with or without vascularization …”

Section: Current Surgical Needs—the Tip Of a Large Icebergmentioning

confidence: 99%

What would surgeons like from materials scientists?

Grundfest‐Broniatowski

2013

WIREs Nanomed Nanobiotechnol

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Surgery involves the repair, resection, replacement, or improvement of body parts and functions and in numerous ways, surgery should be considered human engineering. There are many areas in which surgical materials could be improved, but surgeons are generally unaware of materials available for use, while materials scientists do not know what surgeons require. This article will review some of the areas where surgeons and materials scientists have interacted in the past and will discuss some of the most pressing problems which remain to be solved. These include better implant materials for hernia repair, breast reconstruction, the treatment of diabetes, vascular stenting and reconstruction, and electrical pacing devices. The combination of tissue engineering and nanomaterials has great potential for application to nearly every aspect of surgery. Tissue engineering will allow cells or artificial organs to be grown for specific uses while nanotechnology will help to ensure maximal biocompatibility. Biosensors will be combined with improved electrodes and pacing devices to control impaired neurological functions.

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Section: Current Surgical Needs—the Tip Of a Large Icebergmentioning

confidence: 99%

What would surgeons like from materials scientists?

Grundfest‐Broniatowski

2013

WIREs Nanomed Nanobiotechnol

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“…Increasing the oxygen tension in the islet graft has been shown to improve islet survival [157][158][159][160][161][162][163] and monitoring the graft oxygen tension is desirable [164][165][166]. Strategies to increase local oxygen tension include: incorporation of hemoglobin [167][168][169], calcium peroxide-based oxygen generating particles [170], [171], perfluorocarbons [172], or a nearby gas phase oxygen reservoir [59], [173].…”

Section: Provision Of Oxygen During the Engraftment Period To Reduce mentioning

confidence: 99%

Tissue Engineering Sites for Pancreatic Islet Transplantation

Bowers¹

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Pancreatic islet transplantation, a curative treatment for Type 1 Diabetes, is restricted from broad application due to hypoxia as well as innate and specific immunity. Encapsulation technology offers the ability to exclude cellular immunity, however clinical success has not yet been achieved. This thesis aims to prepare a transplantation site for islets using a novel encapsulation device through three approaches. Firstly, Aim 1 was to investigate the pre-seeding of accessory cells to the biomimetic nanofibers and evaluate the dimensional stability of these fibers. Cell pre-seeding did not have a significant effect on nanofiber implant volume however porcine decellularized dermis was much more dimensionally stable. Secondly, Aim 2 sought to equip the encapsulation device with boron dye based hypoxia sensors. Using a novel polymer conjugated form of the dye, nanofibers were electrospun that displayed reduced signal decay in a hydrated environment for 3 weeks. Hypoxia, due to a 5X cell density increase in vitro (13.9 vs 6.7 PPM) and after islets are infused in vivo, is evident with spatiotemporal resolution. Thirdly, Aim 3 is to evaluate the ability of the device to precondition a space for islet transplant by neovascularization and immunomodulation. Vessel length density in dorsal skinfold window chambers is increased by FTY720 loaded fibers over the unloaded fibers in healthy mice and moderately diabetic animals (Day 0-3.37%, Day 7-4.22%, p<0.05). Local release of FTY720 decreases the proportion of inflammatory macrophages in surrounding subcutaneous tissue (ratio of inflammatory to non-inflammatory: 14:1 vs 8:1). The nanofiber morphology and local release of FTY720 has been shown to improve islet health in vitro. Using the dimensionally stable ECM from Aim 1 an in vivo void is maintained (confirmed by ultrasound) in order to ensure that the 2 nd procedure to deliver islets can be done without disturbing the tissue implant interface. Therefore, a FTY720 releasing nanofiber membrane could address both innate and specific immunity while also increasing vasculature even in the diabetic environment. These findings improve major challenges, including the need to monitor oxygenation, facing islet transplant as well as other tissue engineering applications.

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