Examination of nanoC60 aggregates through dialysis membranes as surrogates for cell membrane diffusion
EMSL Project ID
33208
Abstract
AbstractOnce the production of Fullerenes became prevalent in the 1990s, Fullerene Chemistry was able to discover multiple properties about buckyballs. Every carbon atom develops a bond to three other adjacent atoms through hybridization to form the soccer ball shaped cage. Two types of bonds form in the structure. Pentagons form single bonds and Hexagons form double bonds. The electrons of the C60 molecule form a delocalized pi double bond system over the hexagons forming a relatively stable low energy structure. Although the C60 is relatively stable and inert, the entire structure is not considered aromatic because the pentagon electrons do not delocalize. But, the sp2-hybridized carbons atoms are bent to form the sphere and therefore show slight angle strain. As a result, C60 can be considered slightly electrophilic and in water will become ionic to form loose metallic bonding with the electrons from the oxygen in water.
In 2005, environmental studies confirmed the natural formation of C60 buckyball aggregates as singular C60 buckyballs come into contact with water in the environment. Formation of organic aggregates in a water based environment was unexpected, but it is now known that the higher surface energy and electrophilic properties make C60 nanoparticles interact strongly with each other to form aggregates. The nano-C60 aggregates contain a negative surface charge and behave as a stable nanoparticle suspension.
Varying opinions were formed about the toxicological effects of singular buckyballs and C60 aggregates (nano-C60). Microbial response to nano-C60 was monitored and a slight response was observed. Cell membrane damage was shown to occur by lipid peroxidation of the phospholipid bilayer. Recently, singular C60 was shown to readily jump into the membrane and can cross a lipid bilayer. Other studies show that water soluble fullerenes do not penetrate into the hydrocarbon tails of a supported bilayer because they absorb to the lipid head groups.
In 2005, the C60 aggregation rate, structure and morphology were determined to help assess the ecological risk associated with the exposure. Other studies on the cellular toxicity of carbon based nanomaterials have shown that the form, size, and surface charge have a strong influence on toxicity and all should be included in future studies.
Since there has been conflicting opinions about the interactions of the C60 aggregates with the phospholipid bilayer and therefore its toxicological effects, I would like to simplify the study by observation of the interactions of the aggregates based on pore size alone. I would do this by using dialysis cells as surrogates for cell membrane and allowing diffusion the process for entering the cell. The movement across the cellular membrane is passive so the filtering capacity of the cell pores in membranes is an important aspect to study. Different size pore membranes would be used to determine when the aggregates start to filter through the cellular membrane without adding in the complexity of the different chemical reactions of the phospholipid bilayer. The impact of this work is to illustrate and clarify the impact nanoparticles can have on cells after exposure to environmental conditions. EMSL is necessary for this work because the instrumentation to measure at the nanoscale is limited at the University level and the joint benefit of discovering information pertaining to the impact of environmental toxicological affects and partnering with local Universities for educational purposes will be seen.
Project Details
Project type
Exploratory Research
Start Date
2009-04-08
End Date
2010-04-11
Status
Closed
Released Data Link
Team
Principal Investigator