Synthetic polymers Systems therapeutic

Numerous microfabrication techniques have been used to produce a wide range of implantable and oral drug delivery systems using materials ranging from silicon, glass, silicone elastomer, and plastics. Fabrication techniques have rapidly evolved to produce nanoscale objects and therapeutic systems using polymeric materials as the substrate due to their biodegradable nature. There are a number of different synthetic polymer systems that have been developed for this type of application, and the most common ones are listed below ... 

The unique power of synthesis is the ability to create new molecules and materials with valuable properties. This capacity can be used to interact with the natural world, as in the treatment of disease or the production of food, but it can also produce compounds and materials beyond the capacity of living systems. Our present world uses vast amounts of synthetic polymers, mainly derived from petroleum by synthesis. The development of nanotechnology, which envisions the application of properties at the molecular level to catalysis, energy transfer, and information management has focused attention on multimolecular arrays and systems capable of self-assembly. We can expect that in the future synthesis will bring into existence new substances with unique properties that will have impacts as profound as those resulting from syntheses of therapeutics and polymeric materials. 

Bruck, S.D. Mueller, E.P. Materials and biological aspects of synthetic polymers in controlled drug release systems problems and challenges. Critical Reviews in Therapeutic Drug Carrier Systems 1988, 5 (3), 171-187. 

Polymer nanoparticles including nanospheres and nanocapsules (Fig. 1) can be prepared according to numerous methods that have been developed over the last 30 years. The development of these methods occurred in several steps. Historically, the first nanoparticles proposed as carriers for therapeutic applications were made of gelatin and cross-linked albumin. Then, to avoid the use of proteins that may stimulate the immune system and to limit the toxicity of the cross-linking agents, nanoparticles made from synthetic polymers were developed. At first, the nanoparticles were made by emulsion polymerization of acrylamide and by dispersion polymerization of methylmethacry-late.f These nanoparticles were proposed as adjuvants for vaccines. However, since they were made of non-biodegradable polymers, these nanoparticles were rapidly substituted by particles made of biodegradable... 

Before the middle of the 1970s, a few synthetic polymers found applications in the pharmaceutical industry, such as polyvinyl pyrrolidone and polyvinyl alcohol for oral formulations, polyethylene glycol and polyethylene (PE) for ointments, and polyacrylic acid for poultice. Nowadays, following the development of the drug delivery system (DDS), more varied synthetic polymers are applied in formulation studies. Because DDS concentrates on increasing the therapeutic effectiveness of... 

For a polymer to be effective in a therapeutic encapsulation system, it must meet two criteria (1) the polymer must be hydrolytically or enzymatically labile, and (2) the resulting hydrolysis by-products must be biocompatible. Many natural polymers are excellent choices for encapsulation polymers, especially the natural polysaccharides discussed in Chapter 8. Synthetic polymers having an all-carbon backbone are generally not hydrolytically labile and are generally not employed as encapsulating polymers, although one does encounter the use of some methacrylate and silicone-based polymers in delivery systems. 

---