Modified gold nanoparticle vectors: A biocompatible intracellular delivery system for pancreatic islet cell transplantation

Vega, Rafael A.; Wang, Yong; Harvat, Tricia A.; Wang, Shusen; Qi, Meirigeng; Adewola, Adeola F.; Lee, Dongyoung; Benedetti, Enrico; Oberholzer, José

doi:10.1016/j.surg.2010.07.036

Cited by 12 publications

(8 citation statements)

References 25 publications

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“…47 Future strategies for increasing the infection efficiency could include dissociation of islets, infection and expansion, then re-aggregation before transplantation, or the use of an alternative, non-viral DNA delivery system, such as gold nanoparticles, that infect the whole islets rather than merely the mantle. 48,49 One concern with this approach is the uncontrolled expression of cell cycle genes, leading to the formation of tumors. While this is a consideration for long-term culture of permanently mutated cells, the use of a transient non-incorporating adenovirus lessens these concerns in the experiments shown here.…”

Section: Discussionmentioning

confidence: 99%

Overexpression ofE2F3promotes proliferation of functional human β cells without induction of apoptosis

et al. 2013

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The mechanisms that control proliferation, or lack thereof, in adult human β cells are poorly understood. Controlled induction of proliferation could dramatically expand the clinical application of islet cell transplantation and represents an important component of regenerative approaches to a functional cure of diabetes. Adult human β cells are particularly resistant to common proliferative targets and often dedifferentiate during proliferation. Here we show that expression of the transcription factor E2F3 has a role in regulating β-cell quiescence and proliferation. We found human islets have virtually no expression of the pro-proliferative G 1/S transcription factors E2F1-3, but an abundance of inhibitory E2Fs 4-6. In proliferative human insulinomas, inhibitory E2Fs were absent, while E2F3 is expressed. Using this pattern as a "roadmap" for proliferation, we demonstrated that ectopic expression of nuclear E2F3 induced significant expansion of insulin-positive cells in both rat and human islets. These cells did not undergo apoptosis and retained their glucose-responsive insulin secretion, showing the ability to reverse diabetes in mice. Our results suggest that E2F4-6 may help maintain quiescence in human β cells and identify E2F3 as a novel target to induce proliferation of functional β cells. Refinement of this approach may increase the islets available for cell-based therapies and research and could provide important cues for understanding in vivo proliferation of β cells.

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Section: Discussionmentioning

confidence: 99%

Overexpression ofE2F3promotes proliferation of functional human β cells without induction of apoptosis

et al. 2013

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“…Finally, using the HEAT-on-a-chip protocol, we expressed a fluorescent protein throughout islets and achieved ~75% efficiency of beta-cell Please do not adjust margins Please do not adjust margins expression, including cells located in the tissue core. Other groups have previously explored methods to transgenically modify ex vivo islets, either virally [37][38][39][40] , or with DNAfunctionalized nanoparticles 41,42 . A major disadvantage of these methods is the long vector transduction and incubation time (between 24 and 48 hours) required for efficient gene expression.…”

Section: Discussionmentioning

confidence: 99%

Highly efficient adenoviral transduction of pancreatic islets using a microfluidic device

et al. 2016

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Tissues are challenging to genetically manipulate due to limited penetration of viral particles resulting in low transduction efficiency. We are particularly interested in expressing genetically-encoded sensors in ex vivo pancreatic islets to measure glucose-stimulated metabolism, however poor viral penetration biases these measurements to only a subset of cells at the periphery. To increase mass transfer of viral particles, we designed a microfluidic device that holds islets in parallel hydrodynamic traps connected by an expanding by-pass channel. We modeled viral particle flow into the tissue using fluorescently-labelled gold nanoparticles of varying sizes and showed a penetration threshold of only ∼5 nm. To increase this threshold, we used EDTA to transiently reduce cell-cell adhesion and expand intercellular space. Ultimately, a combination of media flow and ETDA treatment significantly increased adenoviral transduction to the core of the islet. As proof-of-principle, we used this protocol to transduce an ER-targeted redox sensitive sensor (eroGFP), and revealed significantly greater ER redox capacity at core islet cells. Overall, these data demonstrate a robust method to enhance transduction efficiency of islets, and potentially other tissues, by using a combination of microfluidic flow and transient tissue expansion.

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“…Recently, two research groups have demonstrated that polyvalent gold nanoparticles densely functionalized with covalently immobilized DNA oligonucleotides (AuNP-DNA) have a high penetrative capacity for islet cells which can reach the islet cores of both mouse and human islets with no evidence of toxicity; demonstrating that islet function is preserved well both in vitro and in vivo as compared to control. One study showed that AuNP-treated islets have normal mitochondrial response kinetics when stimulated by glucose, in conjunction with preserved calcium influx and insulin secretion when compared to control [109]. The other study indicated that AuNP-DNA conjugated with antisense eGFP reduced eGFP expression in MIP-eGFP islets (mouse insulin promoter controlled eGFP) [110].…”

Section: Mitochondria and Mitoprotection In Islet Isolation And Cumentioning

confidence: 99%

Implication of Mitochondrial Cytoprotection in Human Islet Isolation and Transplantation

Wang

Mendoza-Elias

et al. 2012

Biochemistry Research International

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Islet transplantation is a promising therapy for type 1 diabetes mellitus; however, success rates in achieving both short- and long-term insulin independence are not consistent, due in part to inconsistent islet quality and quantity caused by the complex nature and multistep process of islet isolation and transplantation. Since the introduction of the Edmonton Protocol in 2000, more attention has been placed on preserving mitochondrial function as increasing evidences suggest that impaired mitochondrial integrity can adversely affect clinical outcomes. Some recent studies have demonstrated that it is possible to achieve islet cytoprotection by maintaining mitochondrial function and subsequently to improve islet transplantation outcomes. However, the benefits of mitoprotection in many cases are controversial and the underlying mechanisms are unclear. This article summarizes the recent progress associated with mitochondrial cytoprotection in each step of the islet isolation and transplantation process, as well as islet potency and viability assays based on the measurement of mitochondrial integrity. In addition, we briefly discuss immunosuppression side effects on islet graft function and how transplant site selection affects islet engraftment and clinical outcomes.

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Modified gold nanoparticle vectors: A biocompatible intracellular delivery system for pancreatic islet cell transplantation

Cited by 12 publications

References 25 publications

Overexpression ofE2F3promotes proliferation of functional human β cells without induction of apoptosis

Overexpression ofE2F3promotes proliferation of functional human β cells without induction of apoptosis

Highly efficient adenoviral transduction of pancreatic islets using a microfluidic device

Implication of Mitochondrial Cytoprotection in Human Islet Isolation and Transplantation

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