[DOWNLOAD] "Terminology for Biorelated Polymers and Applications (IUPAC Recommendations 2012) (Report)" by Pure and Applied Chemistry # Book PDF Kindle ePub Free
eBook details
- Title: Terminology for Biorelated Polymers and Applications (IUPAC Recommendations 2012) (Report)
- Author : Pure and Applied Chemistry
- Release Date : January 01, 2012
- Genre: Chemistry,Books,Science & Nature,
- Pages : * pages
- Size : 244 KB
Description
INTRODUCTION For thousands of years, humans have been using available substances for applications as materials, i.e., as substances of practical interest to achieve specific functions. As soon as they became industrially available, man-made polymers (as opposed to natural polymers) have been tested to serve in therapy, several having found clinical and commercial applications, thanks to the development of medical grades. Examples of such compounds are ultra-high-molar-mass polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), poly(methyl methacrylate) (PMMA), and other acrylics and methacrylics, silicones, polyurethanes, etc., that are successfully used for applications such as total hip prosthesis (UHMWPE), vascular grafts (PTFE, silicones), intraocular lenses [PMMA and poly(2-hydroxyethyl methacrylate) (PHEMA) and silicones], dentistry (PMMA and other methacrylics), etc. Among these applications, some require a therapeutic aid for a limited period of time, namely, the healing period. Ideally, the temporary therapeutic aid must disappear from the body after healing in order to avoid storage of unnecessary foreign material. Indeed, skin, mucosa, and various endothelia are semi-permeable barriers that are closed to macromolecular compounds with molar mass higher than ca. [10.sup.3] g x [mol.sup.-1]. Accordingly, high-molar-mass molecules introduced in the gastrointestinal (GI or enteral compartment) tract cannot be absorbed by the intestinal mucosa, whereas those introduced in parenteral (between skin and mucosa) compartments of animal or human bodies are entrapped. There are only two exits available. The first is the kidneys via complex filtration, but molecules have to be soluble in blood. The second is the lungs, but molecules have to be metabolized and converted to water and carbon dioxide. Exceptionally, cyst formation can lead to expulsion through the skin. Therefore, any high-molar-mass macromolecule or polymer that is to be used parenterally for a limited period of time has to be first degraded, in terms of molar mass decrease, and turned into soluble low-molar-mass compounds to be excretable, unless degradation byproducts can be biochemically processed and transformed into carbon dioxide, water, and biomass. The demand of surgical life-respecting polymers was progressively extended to domains like pharmacology (drug delivery systems, bioactive macromolecules) and dentistry (bone augmentation, periodontal membranes). The most recent research is oriented toward tissue engineering and medicated temporary prostheses, i.e., temporary prostheses that are associated with drugs or other bioactive substances, including macromolecules (DNA, genes, proteins, and peptides). Therefore, biology is also implicated.