title: Insulin particles as building blocks for controlled insulin release multilayer nano-films.
abstract: Insulin nanoparticles (NPs) were prepared by pH-shift precipitation and a newly developed disassembly method at room temperature. Then, an electrostatic interaction-based, layer-by-layer (LbL) multilayer film incorporating insulin NPs was fabricated with poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH), which is described herein as Si/(PAH/PAA)5(PAH/PAA-insulin NPs)n. The positively charged insulin NPs were introduced into the LbL film in the form of biocompatible PAA-insulin NP aggregates at a pH of 4.5 and were released in phosphate-buffered saline (pH7.4), triggered by changes in the charges of the insulin molecules. In addition, the insulin-incorporated multilayer was swollen because of the different ionic environment, leading also to insulin release. Eighty percent of the insulin was released from the LBL film in the first stage of 3h, and sustained release could be maintained in the second stage for up to 7 days in vitro, which is very critical for specific diabetic patients. These striking findings could offer novel directions to researchers in establishing insulin delivery systems for diabetic therapy and fabricating other protein nanoparticles applied to various biomedical platforms.
authors.affiliation: School of Chemical Engineering & Material Science, Chung-Ang University, 47 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
authors.forename: Xiangde
authors.initials: X
authors.lastname: Lin
authors.affiliation: School of Chemical Engineering & Material Science, Chung-Ang University, 47 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
authors.forename: Daheui
authors.initials: D
authors.lastname: Choi
authors.affiliation: School of Chemical Engineering & Material Science, Chung-Ang University, 47 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea. Electronic address: jkhong@cau.ac.kr.
authors.forename: Jinkee
authors.initials: J
authors.lastname: Hong
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D003692:Delayed-Action Preparations; D065546:Drug Liberation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D053758:Nanoparticles / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D055672:Static Electricity
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D007328:Insulin; D011073:Polyamines; D011108:Polymers; C063994:polyallylamine; C006903:carbopol 940
keywords: Diabetic therapy; Insulin delivery; Insulin nanoparticles; Layer-by-layer assembly; Long-acting release