Drug delivery systems engineering

Polyphosphazenes can be considered as biomaterials in several different ways, depending on the type of utilization one can predict for these substrates. In this regard, we will consider three different topics concerning water-soluble POPs and their hydrogels, bioerodible POPs for drug delivery systems and for tissue engineering, and the surface implications of POP films. 

Skeletal Biocompatibility. Two Substituent Groups Attached to the Same Phosphazene Skeleton. Hydrolytical Instability 0 II — NH- CH2— C- OC2H5 Glycine or Lower Alkyl Aminoacid Esters Hydrolytically Unstable Polymers. Bioerodible Materials. Drug Delivery Systems. Tissue Engineering... 

Recently, biodegradable polymers have been used to fabricate macro- and nanometer scale self-assembled systems such as microspheres (MSs), nanospheres (NSs), polymer micelles, nanogels, and polymersomes (Fig. 1). These have attracted growing interest because of their potential utility for drug delivery systems (DDS), tissue engineering, and other applications. To construct these self-assembled systems... 

Kim, S. W., Temperature Sensitive Polymers for Delivery of Macromolecular Drugs, in Advanced Biomaterials in Biomedical Engineering and Drug Delivery Systems (N. Ogata, et al., Eds.), pp. 125-133. Springer, Tokyo (1996). 

Yih TC, Al-Eandi M (2006) Engineered nanoparticles as precise drug delivery systems. J Cell Biochem 97 1184-1190... 

Michael J. Groves, a pharmacist with a doctorate in chemical engineering, has spent much of his career working in industry and academe. Now retired, his scientific interests include dispersed drug delivery systems and quality control issues for parenteral drug products. Editor or joint editor of a number of books, he has published 400 research papers, patents, reviews, and book reviews. He is a Fellow of the Royal Pharmaceutical Society of Great Britain, the Institute of Biology, and the American Association of Pharmaceutical Scientists. 

These environmentally sensitive gels are being extensively studied and applied to a variety of fields in medical science, engineering, ecology, food science, drug delivery systems, chemo-mechanical and electro-mechanical actuators, switching devices, molecular sieves, chemical re-collecting retainers, and so on. These aspects are not covered in this issue. The reader may consult some of the references [1,8]. 

The field of metal-catalyzed copolymerization of oxetanes and C02 will continue to flourish, due not only to the versatility of the reaction but also to the aliphatic polycarbonate products being important components of thermoplastic elastomers that, in turn, have huge potential in medical applications such as sutures, drug-delivery systems, body, and dental implants, and tissue engineering. The exploration of other oxetane monomers (Figure 8.17) such as 3,3-dimethyloxetane and 3-methoxymethyl-3-methyloxetane, will surely provide a multitude of applications... 

The regulation of drug input into the body is the core tenet of controlled release drug delivery systems. With advances in engineering and material sciences, controlled release delivery systems are able to mimic multiple kinetic types of input, ranging from instantaneous to complex kinetic order. In this section three of the most common input functions found in controlled release drug delivery systems will be discussed— instantaneous, zero order, and first order. 

J. Kopecek. Smart and genetically engineered biomaterials and drug delivery systems. Eun. J. Phanm. Sci. 20 1-16, 2003. 

Boden, N., Aggeli, A., Ingham, E., and Kirkham, J. Supramolecular Networks Made by Beta-Sheet Self-Assembly of Rationally Designed Peptides, and Their Uses as Industrial Fluids, Personal Care Products, Tissue Engineering Scaffolds and Drug Delivery Systems, 2003-GB3016 WO 2004007532 (2004). 

Historically, polyanhydrides were synthesized for engineering materials. Because of their hydrolytical instability, these polyanhydrides have never been commercialized for engineering purposes. This instability has a beneficial aspect in drug delivery systems since the implant incorporated with an active drug does not need to be retrieved. The anhydride has a labile bond in the main chain of the polymer. This labile bond then breaks down into two carboxylic acid groups. 

---