Sequestration mechanism

Preisinger E, Jordan BM, Kazantsev A, Housman D. Evidence for a recruitment and sequestration mechanism in Huntington s disease. Philos Trans R Soc Lond Ser B Biol Sci 1999 354 1029-34. 

Specific sequestration mechanisms from media and the capability to establish protection and recognition structures for microbial organisms. 

Bioaccumulation results when uptake of chemicals by dietary and nondietary pathways exceeds metabolism and excretion. Rates at which substances are absorbed, altered, and then excreted are relatively important. Bioaccumulation may involve sequestration mechanisms, such as the deposition of polychlorinated biphenyls (PCBs) in fat, or the incorporation of lead in the mineral portion of bone. Incorporation into fat is dependent on the lipophilicity of the compound. The most commonly performed test of lipophilicity involves experimental determination of the equilibrium partitioning of a test compound between octanol, a nonmiscible organic solvent, and water, often expressed as the log10 of the ratio or the octanol/ water partition coefficient (log K ). Organic compounds in which the log Kow value is less than 3.5 do not appreciably accumulate in the lipids of mammals [5], Because energetic compounds have relatively low log Kow values (Table 10.1), bioaccumulation cannot be explained solely by lipophilicity. 

However, recent results did not support the chemical protection of C bound to iron and aluminium complexes [38]. Some studies have suggested that it is the surface area of the mineral particles that can explain the slow C mineralization [39 2]. In previous studies one has shown that the carbon and nitrogen content is also related to the specific surface area [11, 17]. High specific surface areas will increase the possible adsorption sites for chemical species and certainly participate in the sequestration mechanism but the peculiar (fractal) structure of the allophane aggregate should play a role in the sequestration process. The mesopore protection hypothesis proposes that carbon is trapped in the tortuous porosity of the soils because the organic matter is protected from enzymatic degradation by sequestration within the mineral mesopores (2-50 nm diameter) [40, 42-44]. 

Pluronic-coated carbon nanotubes The applicability of carbon nanotubes for neural tissue engineering was further proved by Bardi et al. (2009), wherein the carbon nanotubes when coated with Pluronic F127 (PF127), a PPO-PEO-PPO block copolymer, showed more distinctive biocompatibility properties than the individual components. The researchers proposed that PF127 stabilized and solubilized the CNTs due to its surfactant action, whereas CNTs circumvented the PF127-induced apoptosis by the so-called surfactant sequestration mechanism (Bardi et al., 2009). 

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