Understanding Nanomedicine:  An Introductory Textbook
By Rob Burgess, PhD
Copyright 2011. Pan Stanford Publishing.  All Rights Reserved.

Chapter 7 Review Question Answers

Following are selected answers to the review questions at the end of Chapter 7 in Understanding Nanomedicine:  An Introductory Textbook by Rob Burgess.

1. Active targeted drug delivery most often occurs as a result of tight binding between receptors present on the surface of a target cell and a targeting agent that is often the actual naturally-occurring ligand (a molecule that binds to a receptor) specific for the target receptor or has been designed to mimic ligand binding effects. Active targeted drug delivery can thus be defined as the delivery of a drug to a particular tissue or cell type through specific and precise binding of the drug to the target tissues or cells. Passive targeted drug delivery is a mechanism and process by which certain sizes of molecules tend to preferentially accumulate in tumor tissues and is also known as the enhanced permeability retention (EPR) effect. It is based upon the considerable blood supply requirements of tumors. As tumors grow and tumor cells divide new vasculature is generated locally to support this growth. Newly formed blood vessels are usually abnormal in form and architecture, with poor alignment of endothelial cells resulting in wide fenestrations lacking a smooth muscle layer. In addition, lymphatic drainage is usually hindered proximal to tumor tissues. These factors all contribute to fluid transport dynamics that promote the preferential uptake of macromolecules of a certain size by tumor tissues.



4. i) Drug incorporation and release; ii) Nanoparticle/drug complex formulation stability and shelf-life; iii) Biocompatibility; iv) Biodistribution and targeting efficiency; v) Functionality



7. Polylactides are biocompatible and can be custom synthesized to meet both size and conformational requirements that allow for the encapsulation of a variety of drugs. PLA degradation allows for drug release and its rate can be controlled by the polymer's molecular weight, conformation and overall composition.



10. For the attachment of targeting moieties as well as side-chains to promote the aqueous solubility of therapeutic agents.


13. By Hirsh-Bingel chemistry (use of malonate derivatives to introduce side chains onto fullerenes) and assessed their potential as gene delivery vehicles. Engel noted that most C60 derivatives are only slightly soluble in an aqueous environment and the use of solvents in their manufacture could contribute to observed cytotoxicity. The Hirsch-Bingel reaction is one of the simplest and highest yielding C60 functionalization methods known. It involves the attack of C60 by a nucleophilic anion followed by elimination of a negatively charged ion to yield the final derivatized products which may be positively charged, negatively charged or neutral, with charge considerably affecting water solubility.



16. EE = (The amount of 5FU in the nanoparticles/The total amount of 5fU) *100%


LC = (The amount of 5FU in the nanoparticles/The total amount of nanoparticle wt) *100%