Antigen toxic

The attachment of PEG to bioactive macromolecules is called PEGylation and provides various benefits [312]. These include better water solubility, enhanced resistance to proteolysis, decrease of immimogenicity, antigenicity, toxicity of drugs and slower rate of kidney clearance [313]. PEG has been approved for use in drugs, food and cosmetics [314]. The monodispersity of todays available PEGs eliminates former risks that were related to impurities foimd during chemical synthesis of PEG. 

The cell surface contains antigens, which are referred to as CD, which stands for cluster of differentiation. The antibodies are produced against a specific antigen. When administered, usually by an intravenous injection, the antibody binds to the antigen, which may trigger the immune system to result in cell death through complement-mediated cellular toxicity, or the antigen-antibody cell complex may be internalized to the cancer cell, which results in cell death. Monoclonal antibodies also may carry radioactivity, sometimes referred to as hot antibodies, and may be referred to as radioimmunotherapy, so the radioactivity is delivered to the cancer cell. Antibodies that contain no radioactivity are referred to as cold antibodies. 

The important attributes of liposomes as a drug carrier are (a) they are biologically inert and completely biodegradable (b) they pose no concerns of toxicity, antigenicity, or pyrogenicity, because phospholipids are natural components of all cell membranes (c) they can be prepared in various sizes, compositions, surface charges, and so forth, depending on the requirements of... 

The answer is b. (Hardman, pp 1268-1269J Asparaginase is an enzyme that catalyzes the hydrolysis of serum asparagine to aspartic acid and ammonia. Major toxicities are related to antigenicity and pancreatitis. In addition, more than 50% of those treated present biochemical evidence of hepatic dysfunction. 

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