Simplified procedure for encapsulating cytochrome c in silica aerogel nanoarchitectures while retaining gas-phase bioactivity.


Cytochrome c (cyt. c) has been encapsulated in silica sol-gels and processed to form bioaerogels with gas-phase activity for nitric oxide through a simplified synthetic procedure. Previous reports demonstrated a need to adsorb cyt. c to metal nanoparticles prior to silica sol-gel encapsulation and processing to form aerogels. We report that cyt. c can be encapsulated in aerogels without added nanoparticles and retain structural stability and gas-phase activity for nitric oxide. While the UV-visible Soret absorbance and nitric oxide response indicate that cyt. c encapsulated with nanoparticles in aerogels remains slightly more stable and functional than cyt. c encapsulated alone, these properties are not very different in the two types of aerogels. From UV-visible and Soret circular dichroism results, we infer that cyt. c encapsulated alone self-organizes to reduce contact with the silica gel in a way that may bear at least some resemblance to the way cyt. c self-organizes into superstructures of protein within aerogels when nanoparticles are present. Both the buffer concentration and the cyt. c concentration of solutions used to synthesize the bioaerogels affect the structural integrity of the protein encapsulated alone within the dried aerogels. Optimized bioaerogels are formed when cyt. c is encapsulated from 40 mM phosphate buffered solutions, and when the loaded cyt. c concentration in the aerogel is in the range of 5 to 15 μM. Increased viability of cyt. c in aerogels is also observed when supercritical fluid used to produce aerogels is vented over relatively long times.

DOI: 10.1021/la3011025

Cite this paper

@article{HarperLeatherman2012SimplifiedPF, title={Simplified procedure for encapsulating cytochrome c in silica aerogel nanoarchitectures while retaining gas-phase bioactivity.}, author={Amanda S. Harper-Leatherman and Mariam Iftikhar and Adela Ndoi and Steven J Scappaticci and George P. Lisi and Kaitlyn L Buzard and Elizabeth M Garvey}, journal={Langmuir : the ACS journal of surfaces and colloids}, year={2012}, volume={28 41}, pages={14756-65} }