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The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system, thus protecting the brain from harmful or unwanted substances in the blood. [1]
In chemistry, a nucleophilic substitution (S N) is a class of chemical reactions in which an electron-rich chemical species (known as a nucleophile) replaces a functional group within another electron-deficient molecule (known as the electrophile). The molecule that contains the electrophile and the leaving functional group is called the ...
Drug delivery to the brain is the process of passing therapeutically active molecules across the blood–brain barrier into the brain.This is a complex process that must take into account the complex anatomy of the brain as well as the restrictions imposed by the special junctions of the blood–brain barrier.
A hydroxide ion acting as a nucleophile in an S N 2 reaction, converting a haloalkane into an alcohol. In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they ...
A brain tumor (sometimes referred more commonly as brain cancer) occurs when a group of cells within the brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors : malignant (cancerous) tumors and benign (non-cancerous) tumors. [ 2 ]
The blood–brain barrier (BBB) is protected by a network of blood vessels and tissue that shields it from harmful substances. This protection also stops anti-cancer drugs from getting to the brain. To treat brain tumours and other brain related diseases, [ 2 ] [ 3 ] blood–brain barrier disruption is needed for the anti-cancer drugs to be ...
This reaction is similar to nucleophilic aliphatic substitution where the reactant is a nucleophile rather than an electrophile. The four possible electrophilic aliphatic substitution reaction mechanisms are S E 1, S E 2(front), S E 2(back) and S E i (Substitution Electrophilic), which are also similar to the nucleophile counterparts S N 1 and ...
For example, in the S N 2 mechanism, a nucleophile attacks an organic compound containing the nucleofuge (the bromo group) which simultaneously breaks the bond with the nucleofuge. SN2 reaction of bromoethane with hydroxide ion