@article{yu_zhang_ye_disanto_sun_ranson_ligler_buse_gu_2015, title={Microneedle-array patches loaded with hypoxia-sensitive vesicles provide fast glucose-responsive insulin delivery}, volume={112}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.1505405112}, abstractNote={Significance For exploiting synthetic glucose-responsive insulin delivery systems, challenges remain to demonstrate a strategy that would combine (i) fast responsiveness, (ii) ease of administration, and (iii) excellent biocompatibility. We have developed a novel glucose-responsive insulin delivery device using a painless microneedle-array patch containing hypoxia-sensitive hyaluronic acid-based vesicles. The vesicles quickly dissociate and release encapsulated insulin under the local hypoxic environment, caused by the enzymatic oxidation of glucose in the hyperglycemic state. This “smart insulin patch” with a new enzyme-based glucose-responsive mechanism can regulate the blood glucose of type 1 diabetic mice to achieve normal levels, with faster responsiveness compared with the commonly used pH-sensitive formulations, and can avoid the risk of hypoglycemia. A glucose-responsive “closed-loop” insulin delivery system mimicking the function of pancreatic cells has tremendous potential to improve quality of life and health in diabetics. Here, we report a novel glucose-responsive insulin delivery device using a painless microneedle-array patch (“smart insulin patch”) containing glucose-responsive vesicles (GRVs; with an average diameter of 118 nm), which are loaded with insulin and glucose oxidase (GOx) enzyme. The GRVs are self-assembled from hypoxia-sensitive hyaluronic acid (HS-HA) conjugated with 2-nitroimidazole (NI), a hydrophobic component that can be converted to hydrophilic 2-aminoimidazoles through bioreduction under hypoxic conditions. The local hypoxic microenvironment caused by the enzymatic oxidation of glucose in the hyperglycemic state promotes the reduction of HS-HA, which rapidly triggers the dissociation of vesicles and subsequent release of insulin. The smart insulin patch effectively regulated the blood glucose in a mouse model of chemically induced type 1 diabetes. The described work is the first demonstration, to our knowledge, of a synthetic glucose-responsive device using a hypoxia trigger for regulation of insulin release. The faster responsiveness of this approach holds promise in avoiding hyperglycemia and hypoglycemia if translated for human therapy.}, number={27}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Yu, Jicheng and Zhang, Yuqi and Ye, Yanqi and DiSanto, Rocco and Sun, Wujin and Ranson, Davis and Ligler, Frances S. and Buse, John B. and Gu, Zhen}, year={2015}, month={Jul}, pages={8260–8265} }
 @misc{disanto_subramanian_gu_2015, title={Recent advances in nanotechnology for diabetes treatment}, volume={7}, ISSN={["1939-0041"]}, DOI={10.1002/wnan.1329}, abstractNote={Nanotechnology in diabetes research has facilitated the development of novel glucose measurement and insulin delivery modalities which hold the potential to dramatically improve quality of life for diabetics. Recent progress in the field of diabetes research at its interface with nanotechnology is our focus. In particular, we examine glucose sensors with nanoscale components including metal nanoparticles and carbon nanostructures. The addition of nanoscale components commonly increases glucose sensor sensitivity, temporal response, and can lead to sensors which facilitate continuous in vivo glucose monitoring. Additionally, we survey nanoscale approaches to 'closed-loop' insulin delivery strategies which automatically release insulin in response to fluctuating blood glucose levels (BGLs). 'Closing the loop' between BGL measurements and insulin administration by removing the requirement of patient action holds the potential to dramatically improve the health and quality of life of diabetics. Advantages and limitations of current strategies, as well as future opportunities and challenges are also discussed.}, number={4}, journal={WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY}, author={DiSanto, Rocco Michael and Subramanian, Vinayak and Gu, Zhen}, year={2015}, pages={548–564} }
 @article{mo_jiang_disanto_tai_gu_2014, title={ATP-triggered anticancer drug delivery}, volume={5}, ISSN={["2041-1723"]}, DOI={10.1038/ncomms4364}, abstractNote={Stimuli-triggered drug delivery systems have been increasingly used to promote physiological specificity and on-demand therapeutic efficacy of anticancer drugs. Here we utilize adenosine-5'-triphosphate (ATP) as a trigger for the controlled release of anticancer drugs. We demonstrate that polymeric nanocarriers functionalized with an ATP-binding aptamer-incorporated DNA motif can selectively release the intercalating doxorubicin via a conformational switch when in an ATP-rich environment. The half-maximal inhibitory concentration of ATP-responsive nanovehicles is 0.24 μM in MDA-MB-231 cells, a 3.6-fold increase in the cytotoxicity compared with that of non-ATP-responsive nanovehicles. Equipped with an outer shell crosslinked by hyaluronic acid, a specific tumour-targeting ligand, the ATP-responsive nanocarriers present an improvement in the chemotherapeutic inhibition of tumour growth using xenograft MDA-MB-231 tumour-bearing mice. This ATP-triggered drug release system provides a more sophisticated drug delivery system, which can differentiate ATP levels to facilitate the selective release of drugs.}, journal={NATURE COMMUNICATIONS}, author={Mo, Ran and Jiang, Tianyue and DiSanto, Rocco and Tai, Wanyi and Gu, Zhen}, year={2014}, month={Mar} }