TY  - JOUR
A1  - Charan, Himanshu
A1  - Glebe, Ulrich
A1  - Anand, Deepak
A1  - Kinzel, Julia
A1  - Zhu, Leilei
A1  - Bocola, Marco
A1  - Garakani, Tayebeh Mirzaei
A1  - Schwaneberg, Ulrich
A1  - Böker, Alexander
T1  - Nano-thin walled micro-compartments from transmembrane protein-polymer conjugates
JF  - Soft matter
N2  - The high interfacial activity of protein-polymer conjugates has inspired their use as stabilizers for Pickering emulsions, resulting in many interesting applications such as synthesis of templated micro-compartments and protocells or vehicles for drug and gene delivery. In this study we report, for the first time, the stabilization of Pickering emulsions with conjugates of a genetically modified transmembrane protein, ferric hydroxamate uptake protein component A (FhuA). The lysine residues of FhuA with open pore (FhuA Delta CVFtev) were modified to attach an initiator and consequently controlled radical polymerization (CRP) carried out via the grafting-from technique. The resulting conjugates of FhuA Delta CVFtev with poly(N-isopropylacrylamide) (PNIPAAm) and poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA), the so-called building blocks based on transmembrane proteins (BBTP), have been shown to engender larger structures. The properties such as pH-responsivity, temperature-responsivity and interfacial activity of the BBTP were analyzed using UV-Vis spectrophotometry and pendant drop tensiometry. The BBTP were then utilized for the synthesis of highly stable Pickering emulsions, which could remain non-coalesced for well over a month. A new UV-crosslinkable monomer was synthesized and copolymerized with NIPAAm from the protein. The emulsion droplets, upon crosslinking of polymer chains, yielded micro-compartments. Fluorescence microscopy proved that these compartments are of micrometer scale, while cryo-scanning electron microscopy and scanning force microscopy analysis yielded a thickness in the range of 11.1 +/- 0.6 to 38.0 +/- 18.2 nm for the stabilizing layer of the conjugates. Such micro-compartments would prove to be beneficial in drug delivery applications, owing to the possibility of using the channel of the transmembrane protein as a gate and the smart polymer chains as trigger switches to tune the behavior of the capsules.
Y1  - 2017
U6  - https://doi.org/10.1039/c6sm02520j
SN  - 1744-683X
SN  - 1744-6848
VL  - 13
SP  - 2866
EP  - 2875
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -