Drug delivery protein-based

FIGURE 52.7 A diagram representing the mechanism of action of the specific adhesion of K99 fimbriae from E. coli to cell receptors. The carrier system consists of a polyacrylic acid matrix containing the fim-brial protein for adhesion. (Reprinted from Eur. J. Pharm. ScL, 3(5), Bernkop-Schniirch, A., Gabor, R, Szostak, M.R, and Lubitz, W., An adhesive drug delivery system based on K99-fimbriae, 293-299. Copyright 1995, with permission from Elsevier.)... 

Ciofani et al. (2008) studied the preparation and properties of a drug delivery system based on calcium alginate microgels. For the experiments were used gels in three different forms (spheres, films, and libers) obtained from 100 pL of a 1 %w/ w sodium alginate solution containing the tested protein. Spheres were prepared by... 

Starch 1. Slow release drug delivery system based on amylose-rich starch has been marketed under the trade name Contramid . 2. Starch microspheres have been investigated as a bioadhesive drug delivery system for the nasal delivery of proteins. Khanlari and Dube (2013), Nair and Laurencin (2006), and Marques et al. (2002)... 

This section of the chapter addresses our input into the development of drug-delivery prototypes based on chitosan, antioxidants and common therapeutic agents, as well as development of protein-based drug-delivery systems. It presents three in-vitro approaches based on chitosan and antioxidants, as synergistic defense mechanisms towards uncontrolled free radicals, with a particular focus on understanding and preventing oral mucositis and cancer at the molecular level (Figure 11.4). 

Although oral administration is considered the most convenient and comfortable method for drug delivery, protein- and peptide-based drugs still have to be administered by injection, which is costly and has very low patient acceptability. 

Alternatively, one interesting drug delivery technique exploits the active transport of certain naturally-occurring and relatively small biomacromolecules across the cellular membrane. For instance, the nuclear transcription activator protein (Tat) from HIV type 1 (HlV-1) is a 101-amino acid protein that must interact with a 59-base RNA stem-loop structure, called the traus-activation region (Tar) at the 5 end of all nascent HlV-1 mRNA molecules, in order for the vims to replicate. HIV-Tat is actively transported across the cell membrane, and localizes to the nucleus [28]. It has been found that the arginine-rich Tar-binding region of the Tat protein, residues 49-57 (Tat+9 57), is primarily responsible for this translocation activity [29]. 

DW Urry, CM Harris, CX Luan, CH Luan, C Gowda, TM Parker, SQ Peng, J Xu. Transductional protein-based polymers as new controlled-release vehicles. In K Park, ed. Controlled Drug Delivery Challenges and Strategies. Washington, DC ACS, 1997, pp 405-437. 

Prokop, A., Kozlov, E., Carlesso, G. and Davidsen, ]. M. Hydrogel-Based Colloidal Polymeric System for Protein and Drug Delivery Physical and Chemical Characterization, Permeability Control and Applications. Vol. 160, pp. 119-174. 

Lastly, pharmacogenomics could provide new tools for the design of more specific and active CNS pharmaceuticals. The efficacy of a broad spectrum of neuro-pharmaceutical drugs is often complicated by their inability to reach their site of action because of the BBB. One way to overcome this is to use carrier-mediated transport at the luminal and/or abluminal membranes of the endothelial cells of the BBB. This will provide a physiologically based drug delivery strategy for the brain by designing new chemical entities or fused proteins that can cross the BBB via these transporters. 

The copolymer-based systems possessing the core-shell structure in solutions are known and studied rather well (see, e.g., [14-16]). These copolymers in aqueous media tend to form polymeric micelles, which are often considered as promising drug delivery nano-vehicles [ 17,18], i.e., these macromolecular systems are not only of scientific, but also of considerable applied significance. Among such systems there are interesting examples, whose properties are very similar to the properties that should be inherent in the protein-like copolymers. All of these macromolecules possess the primary structure of... 

Silicones are frequently used in transdermal drug delivery. Recently, the use of loosely cross-linked silicone elastomer blends for this application was surveyed.537 The mechanisms of controlled drug release in the silicone-based systems have been studied,538 as silicones are evaluated for relatively new protein drug-delivery systems.5... 

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