writer：Guohua Jiang,* Bin Xu, Jiangying Zhu, Yang Zhang, Tianqi Liu, Cong Cao
keywords：microneedles; diabetes; glucose-sensitive; transdermal delivery; hypoglycemic
source：期刊
specific source：Biomedical Physics & Engineering Express
Issue time：2019年

Abstract: The traditional subcutaneous or intravenous injection of insulin can not effectively control the release of insulin, resulting in an unregulated the blood glucose levels on diabetic patients. It is urgently to develop a self-controllable insulin delivery system with high sensitivity to the change of blood glucose levels in vivo. In this work, polymer microneedles (MNs) integrated with glucose-responsive mesoporous bioactive glass nanoparticles (BGNs) for transdermal delivery of insulin had been developed for the self-regulate and painless transdermal administration. The hypoglycaemic drug (insulin) was loaded in the mesoporous BGNs that surface premodification by a composite enzyme layer (CEL). The CEL was consisted of polyethyleneimine (PEI), glucose oxidase (GOx) and catalase (CAT). The formed CEL could be used as the glucose-sensitive layer and “gatekeeper” for the release of encapsulated insulin from mesoporous of BGNs. The glucose in CEL that diffused and penetrated from body fluids could be catalyzed to gluconic acid by GOx/CAT which caused the pH decrease in the CEL, resulting the structure destruction of CEL and leading to release of preloaded insulin from the BGNs. After the treatment of the as-prepared MNs on diabetic rats, a highly hypoglycemic effect and lower risk of hypoglycemia could be obtained. This study demonstrated that as-designed glucose-sensitive and pH-triggered transdermal delivery system was a promising strategy for the treatment of the diabetes.