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Multilayered polyelectrolyte microcapsules: interaction with the enzyme cytochrome C oxidase.

Pastorino L, Dellacasa E, Noor MR, Soulimane T, Bianchini P, D'Autilia F, Antipov A, Diaspro A, Tofail SA, Ruggiero C - PLoS ONE (2014)

Bottom Line: Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time.We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components.This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

View Article: PubMed Central - PubMed

Affiliation: Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, Genova, Italy.

ABSTRACT
Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time. The interaction of polyelectrolyte microcapsules, fabricated by electrostatic layer-by-layer assembly, with cytochrome c oxidase molecules was investigated. We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components. This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

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(CHI/PEC)4/CytcO NPCs sequence of images before (Panel A) and after addition of dye (B–D).The dashed line indicates the border of one (CHI/PEC)4/CytcO NPCs which upon addition of the dye swells and finally explodes. Scale bar is 5 µm.
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pone-0112192-g005: (CHI/PEC)4/CytcO NPCs sequence of images before (Panel A) and after addition of dye (B–D).The dashed line indicates the border of one (CHI/PEC)4/CytcO NPCs which upon addition of the dye swells and finally explodes. Scale bar is 5 µm.

Mentions: In another experiment, NPCs were prepared using two weak polyelectrolytes. The cationic chitosan and anionic pectin were used for this. Specifically, we used a form of pectin with a high degree of methylation (70–75%), which is inversely proportional to the pectin charge density. Charge density plays a pivotal role in determining the stability of the multilayer [39]. The formation of stable films is not possible below a minimum charge density. Therefore, we can postulate that in the chitosan/pectin multilayer, there is an excess of positive charge and thus multilayer results in a more unstable and loose structure. Taking into consideration that the pKa of chitosan and pectin are ca. 6.8 and 3.6, respectively, the NPCs were assembled at pH 5 to achieve a good degree of ionization for both polysaccharides, and then functionalized with CytcO. The NPCs morphology was checked by optical microscopy during all the preparation steps. It was observed that after CytcO functionalization and related washing steps, the majority of the capsules were destroyed or deformed. The functionalized capsules were then imaged by CLSM. It was observed that when the surrounding environment was perturbated by the addition of dye, the capsules suddenly “exploded” (Figure 5). On the bases of these observations, it can be hypothesized that CytcO molecules strongly interact with the multilayer and that different interaction types are involved, such as hydrophobic ones This inteaction leads to the formation of defects, which determine an increased permeability, for strongly bound multilayers (PSS/PAH), and to a loose and instable structure for weakly bound multilayers (chitosan/pectin).


Multilayered polyelectrolyte microcapsules: interaction with the enzyme cytochrome C oxidase.

Pastorino L, Dellacasa E, Noor MR, Soulimane T, Bianchini P, D'Autilia F, Antipov A, Diaspro A, Tofail SA, Ruggiero C - PLoS ONE (2014)

(CHI/PEC)4/CytcO NPCs sequence of images before (Panel A) and after addition of dye (B–D).The dashed line indicates the border of one (CHI/PEC)4/CytcO NPCs which upon addition of the dye swells and finally explodes. Scale bar is 5 µm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221607&req=5

pone-0112192-g005: (CHI/PEC)4/CytcO NPCs sequence of images before (Panel A) and after addition of dye (B–D).The dashed line indicates the border of one (CHI/PEC)4/CytcO NPCs which upon addition of the dye swells and finally explodes. Scale bar is 5 µm.
Mentions: In another experiment, NPCs were prepared using two weak polyelectrolytes. The cationic chitosan and anionic pectin were used for this. Specifically, we used a form of pectin with a high degree of methylation (70–75%), which is inversely proportional to the pectin charge density. Charge density plays a pivotal role in determining the stability of the multilayer [39]. The formation of stable films is not possible below a minimum charge density. Therefore, we can postulate that in the chitosan/pectin multilayer, there is an excess of positive charge and thus multilayer results in a more unstable and loose structure. Taking into consideration that the pKa of chitosan and pectin are ca. 6.8 and 3.6, respectively, the NPCs were assembled at pH 5 to achieve a good degree of ionization for both polysaccharides, and then functionalized with CytcO. The NPCs morphology was checked by optical microscopy during all the preparation steps. It was observed that after CytcO functionalization and related washing steps, the majority of the capsules were destroyed or deformed. The functionalized capsules were then imaged by CLSM. It was observed that when the surrounding environment was perturbated by the addition of dye, the capsules suddenly “exploded” (Figure 5). On the bases of these observations, it can be hypothesized that CytcO molecules strongly interact with the multilayer and that different interaction types are involved, such as hydrophobic ones This inteaction leads to the formation of defects, which determine an increased permeability, for strongly bound multilayers (PSS/PAH), and to a loose and instable structure for weakly bound multilayers (chitosan/pectin).

Bottom Line: Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time.We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components.This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

View Article: PubMed Central - PubMed

Affiliation: Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, Genova, Italy.

ABSTRACT
Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time. The interaction of polyelectrolyte microcapsules, fabricated by electrostatic layer-by-layer assembly, with cytochrome c oxidase molecules was investigated. We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components. This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

Show MeSH