Title
Protein Nanogels with Temperature-Induced Reversible Structures and Redox Responsiveness
Author
Yue Zhang, Jiamin Zhang, Cheng Xing, Mingming Zhang, Lianyong Wang, Hanying Zhao
Year
2016
Journal
Biomaterials Science & Engineering
Abstract
There are many natural examples of smart structures that are able to change conformations and functionalities responding to the external stimuli. The responsiveness is directly related to their unique structures. In the design of new materials it is crucial to endow these materials with the capabilities to change structures and functionalities under the external stimuli. In this research, virus-mimicking protein nanogels with temperature-induced reversible structures and redox responsiveness are synthesized by crosslinking a thermally responsive polymer poly(di(ethyleneglycol) methyl ether methacrylate-co-2-(2-pyridyldisulfide) ethylmethacrylate) with reduced bovine serum albumin (BSA) molecules through thiol-disulfide exchange reaction. The lower critical solution temperature (LCST) and sizes of the nanogels can be controlled by controlling the reaction conditions. The nanogels are able to change their structures responding to the temperature change. Below the LCST, BSA molecules are embedded inside the nanogels and protected by the polymer chains. Above the LCST, polymer chains collapse forming the cores and BSA moves to the shells to stabilize the nanogels. The disulfide-crosslinked nanogels are dissociated in the presence of glutathione. In vitro cytotoxicity assays and cell uptake assays demonstrate that the nanogels show low toxicity towards 3T3, 293T and MCF-7 cells and can be internalized into the MCF-7 cells. The nanogels will find applications in protein delivery.
Instrument
J-715
Keywords
Circular dichroism, Secondary structure, Polymers, Nanostructures, Materials, Biochemistry